+ version 1.0 of listings package

docs/packages/listings/listings.dtx

@@ -1,7111 +1,15103 @@
-% \iffalse
-%
-% NOTE: This file contains very long lines (upto approx 270 characters).
-%       I haven't wrapped them since I won't do that by hand and haven't
-%       written any program doing the work.
-%
-%       If you want to read this .dtx file, you might get in trouble with
-%       such long lines!
-%
-%
-%  S O F T W A R E   L I C E N S E
-% =================================
-%
-% The files  listings.dtx  and  listings.ins  and all files generated
-% from only these two files are referred as 'the listings package' or
-% simply 'the package'. A driver file is any file generated mainly from
-% lstdrvrs.dtx.
-%
-% Copyright.
-%	The listings package is copyright 1996--1998 Carsten Heinz.
-%	The driver files are copyright 1997, 1998 or 1997--1998 any
-%	individual author listed in these files.
-%
-% Distribution.
-%	The listings package as well as lstdrvrs.dtx and all driver files
-%	are distributed freely. You are not allowed to take money for the
-%	distribution, except for a nominal charge for copying etc..
-%
-% Use of the package.
-%	The listings package is free for any non-commercial use. Commercial
-%	use needs (i) explicit permission of the author of this package and
-%	(ii) the payment of a license fee. This fee is to be determined in
-%	each instance by the commercial user and the package author and is
-%	to be payed as donation to the LaTeX3 project.
-%
-% No warranty.
-%	The listings package as well as lstdrvrs.dtx and all driver files
-%	are distributed without any warranty, express or implied, as to
-%	merchantability or fitness for any particular purpose.
-%
-% Modification advice.
-%	Permission is granted to change the listings package as well as
-%	lstdrvrs.dtx. You are not allowed to distribute any changed version
-%	of the package or any changed version of lstdrvrs.dtx, neither under
-%	the same name nor under a different one. Tell the author of the
-%	package about your local changes: other users will welcome removed
-%	bugs, new features and additional programming languages.
-%
-% Contacts.
-%	Send comments and ideas on the package, error reports and additional
-%	programming languages to
-%
-%		Carsten Heinz
-%		Tellweg 6
-%		42275 Wuppertal
-%		Germany
-%
-%	or preferably to 
-%
-%		[email protected]
-%
-% Trademarks
-%	appear throughout this documentation without any trademark symbol,
-%	so you can't assume that a name is free. There is no intention of
-%	infringement; the usage is to the benefit of the trademark owner.
-%
-% end of software license
-%
-%<*driver>
-\documentclass{ltxdoc}
-
-\usepackage[doc]{listings}[1998/11/09]
-\newif\iffancyvrb
-\IfFileExists{fancyvrb.sty}
-    {\fancyvrbtrue \usepackage{fancyvrb}}
-    {\fancyvrbfalse}
-
-\EnableCrossrefs         
-\CodelineIndex
-\OldMakeindex
-\OnlyDescription
-
-\begin{document}
-    \DocInput{listings.dtx}
-\end{document}
-%</driver>
-% \fi ^^A balance the \iffancyvrb! :-)
-% \fi
-%
-%
-% \makeatletter
-%^^A
-%^^A A modified `environment' environment
-%^^A
-%\def\aspect{^^A
-%    \def\SpecialMainEnvIndex##1{^^A
-%        \@bsphack ^^A
-%        \index{aspects:\levelchar{\protect\ttfamily##1}\encapchar main}^^A
-%        \@esphack}^^A
-%    \begingroup \catcode`\\12 \MakePrivateLetters ^^A
-%    \m@cro@ \iffalse}
-%\let\endaspect\endmacro
-%
-%^^A
-%^^A We define a sample environment. All material between
-%^^A \begin{lstsample} and \end{lstsample} is executed
-%^^A 'on the left side' and typeset verbatim on the right.
-%^^A
-%^^A The environment is *not* designed for purposes other than
-%^^A this documentation.
-% \lst@Environment{lstsample}[1]\is
-%    {\gdef\lst@sample{#1}^^A
-%     \lst@BeginWriteFile{listings.tmp}^^A
-%     \def\lst@BOLGobble##1{}}^^A to gobble each first %
-%    {\lst@EndWriteFile ^^A
-%^^A We execute the code resp. typset it verbatim (= empty language
-%^^A with \ttfamily).
-%     \begin{center}
-%     \small ^^A \lstCC@Let{`\^^M}\space ^^A
-%     \begin{minipage}{0.45\linewidth}^^A
-%       \MakePercentComment\lst@sample
-%       \input{listings.tmp}\MakePercentIgnore^^A
-%     \end{minipage}
-%     \qquad
-%     \begin{minipage}{0.45\linewidth}
-%       \lstset{language={},style={},basicstyle=\ttfamily,baseem=0.51}^^A
-%       \hbox to \linewidth{\lstbox\lstinputlisting{listings.tmp}\hss}
-%     \end{minipage}
-%     \end{center}}
-%
-%^^A
-%^^A We redefine the appearance of part, section, ...
-%^^A
-%\def\@part[#1]#2{\addcontentsline{toc}{part}{#1}%
-%    {\parindent\z@ \raggedright \interlinepenalty\@M
-%     \normalfont \huge \bfseries #2\markboth{}{}\par}%
-%    \nobreak\vskip 3ex\@afterheading}
-%\renewcommand*\l@section[2]{%
-%  \ifnum \c@tocdepth >\z@
-%    \addpenalty\@secpenalty
-%    \addvspace{.25em \@plus\p@}%
-%    \setlength\@tempdima{1.5em}%
-%    \begingroup
-%      \parindent \z@ \rightskip \@pnumwidth
-%      \parfillskip -\@pnumwidth
-%      \leavevmode ^^A \bfseries
-%      \advance\leftskip\@tempdima
-%      \hskip -\leftskip
-%      #1\nobreak\hfil \nobreak\hb@xt@\@pnumwidth{\hss #2}\par
-%    \endgroup
-%  \fi}
-%\renewcommand*\l@subsection{\@dottedtocline{2}{1.5em}{2.3em}}
-%\renewcommand*\l@subsubsection{\@dottedtocline{3}{3.8em}{3.2em}}
-%\renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
-%                                    {1.25ex \@plus1ex \@minus.2ex}%
-%                                    {-1em}%
-%                                    {\normalfont\normalsize\bfseries}}
-%
-%^^A
-%^^A Suppress warning
-%^^A
-% \let\lstenv@DroppedWarning\relax
-% \makeatother
-%
-%^^A
-%^^A The following definitions come in handy soon.
-%^^A There will be more in future.
-%^^A
-% \newcommand\lsthelper[4]{#1\ifx\empty#2\empty\typeout{^^JWarning: #1 has unknown email^^J}\else\space\texttt{<#2>}{}\fi}
-% \newcommand\lstthanks[2]{#1\ifx\empty#2\empty\typeout{^^JWarning: #1 has unknown email^^J}\fi}
-% \newcommand\lst{\texttt{lst}}
-% \lstdefinelanguage[doc]{Pascal}{^^A
-%  keywords={alfa,and,array,begin,boolean,byte,case,char,const,div,^^A
-%      do,downto,else,end,false,file,for,function,get,goto,if,in,^^A
-%      integer,label,maxint,mod,new,not,of,or,pack,packed,page,program,^^A
-%      procedure,put,read,readln,real,record,repeat,reset,rewrite,set,^^A
-%      text,then,to,true,type,unpack,until,var,while,with,write,writeln},^^A
-%  sensitive=false,^^A
-%  doublecomment={(*}{*)}{\{}{\}},^^A
-%  stringizer=[d]{'}}^^A
-% \lstset{defaultdialect=[doc]Pascal}
-% \lstset{language=Pascal}
-%
-%
-%^^A
-%^^A The long awaited beginning of documentation
-%^^A
-% \newbox\abstractbox
-% \setbox\abstractbox=\vbox{
-%	\begin{abstract}
-%	Listings.dtx is a source code printer for \LaTeX\ --- which always means \LaTeXe\ in this documentation.
-%	You can typeset stand alone files as well as enter listings using an environment similar to \texttt{verbatim} as well as you can print fragments using a command similar to |\verb|.
-%^^A	Since listings.dtx is a package and not a cross compiler, all listings are up to date without maintaining differences between (changed) source files and cross compiled files.
-%	The package supports a wide spectrum of programming languages --- some come already with \texttt{lstdrvrs.dtx}.
-%	Finally: Many parameters control the output.
-%	\end{abstract}}
-%
-% \title{{Listings.dtx} Version {0.19}}
-% \author{Copyright 1996--1998 Carsten Heinz}
-% \date{\box\abstractbox}
-%
-% \makeatletter\@twocolumntrue\makeatother
-% \maketitle
-% {\makeatletter\@starttoc{toc}}
-%\iftrue
-% \vfill
-% \noindent \textbf{Again incompatibilities!}
-% And there are certainly teething troubles since the complete kernel has been rewritten.
-% So read this manual with care.
-%\fi
-% \onecolumn
-%
-%
-% \part{User's guide}
-%
-%
-% \section{Preface}
-%
-% The files \texttt{listings.dtx} and \texttt{listings.ins} and all files generated from only these two files are referred as 'the \textsf{listings} package' or simply 'the package'.
-% A driver file is any file generated mainly from \texttt{lstdrvrs.dtx}.
-%
-% \paragraph{Alternatives.}
-% The \textsf{listings} package is certainly not the final utility for typesetting source code listings.
-% Other programs do their jobs very well if you are not satiesfied with \textsf{listings}.
-% I should mention \textsf{a2ps} and the \textsf{LGrind} package.
-% Let me know if you're using none of these solutions; I'd like to extend my suggestions.
-%
-% \paragraph{Reading this manual.}
-% In any case you should read section ''\emph{\ref{uGettingStarted}. Getting started}'' step by step.
-% You either start from the scratch there or you get in touch with the new user interface and other changes.
-% That section is an introduction and doesn't cover all of the \textsf{listings} package, but the most common.
-% After reading it you are prepared for the main reference if you need more details, more control or more features.
-%
-% \paragraph{Sorry!}
-% On 1998/11/02 I decided to make major changes to the user interface, which were planned for version 0.2.
-% But it's better to get the interface stable as soon as possible.
-% In particular I must say sorry to all people I posted a pre-version of \textsf{listings} 0.19.
-%
-% \paragraph{Thanks.}
-% There are many people I have to thank for fruitful communication, posting their ideas, giving error reports (first bug finder is listed), adding programming languages to \texttt{lstdrvrs.dtx}, etc..
-% If you want to know that in detail, search for the names in the implementation part.
-%^^A
-%^^A Thanks for error reports (first bug finder only), new programming languages, etc.
-%^^A Special thanks for communication which lead to kernel extensions.
-%^^A 
-% Special thanks go to (alphabetical order)
-% \begin{quote}
-% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth\relax
-%	\lstthanks{Andreas~Bartelt}{[email protected]},
-%	\lstthanks{Jan~Braun}{[email protected]},
-%	\lstthanks{Denis~Girou}{[email protected]},
-%	\lstthanks{Arne~John~Glenstrup}{[email protected]},
-%	\lstthanks{Rolf~Niepraschk}{[email protected]},
-%	\lstthanks{Rui~Oliveira}{[email protected]} and
-%	\lstthanks{Boris~Veytsman}{[email protected]}.
-% \end{quote}
-% Moreover I wish to thank
-% \begin{quote}
-% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth\relax
-%	\lstthanks{Bj{\o}rn~{\AA}dlandsvik}{[email protected]},
-%	\lstthanks{Gaurav~Aggarwal}{[email protected]},
-%	\lstthanks{Kai~Below}{[email protected]},
-%	\lstthanks{Detlev~Dr\"oge}{[email protected]},
-%	\lstthanks{Anders~Edenbrandt}{[email protected]},
-%	\lstthanks{Harald~Harders}{[email protected]},
-%	\lstthanks{Christian~Haul}{[email protected]},
-%	\lstthanks{J\"urgen~Heim}{[email protected]},
-%	\lstthanks{Dr.~Jobst~Hoffmann}{[email protected]},
-%	\lstthanks{Knut~M\"uller}{[email protected]},
-%	\lstthanks{Zvezdan~V.~Petkovic}{[email protected]},
-%	\lstthanks{Michael~Piotrowski}{[email protected]},
-%	\lstthanks{Ralf~Quast}{[email protected]},
-%	\lstthanks{Aslak~Raanes}{[email protected]},
-%	\lstthanks{Detlef~Reimers}{[email protected]},
-%	\lstthanks{Magne~Rudshaug}{[email protected]},
-%	\lstthanks{Andreas~Stephan}{[email protected]},
-%	\lstthanks{Dominique~de~Waleffe}{[email protected]},
-%	\lstthanks{Herbert~Weinhandl}{[email protected]},
-%	\lstthanks{J\"orn~Wilms}{[email protected]} and
-%	\lstthanks{Kai~Wollenweber}{[email protected]}.
-% \end{quote}
-%
-%^^A \lsthelper{Andreas Bartelt}{[email protected]}{1997/09/11}{single line comes out using \inputlisting inside \fbox}
-%^^A \lsthelper{Michael Piotrowski}{[email protected]}{1997/11/04}{! Use of \lstdrv@perl@TestCommentCut doesn't match its definition^^J\lst@line ->I^^JRF::LangID -- Statistical identification of language for IRF/1^^J^^J(POD ist Zeile '=irgendwas' bis Zeile '=cut')}
-%^^A \lsthelper{Bj{\o}rn {\AA}dlandsvik}{[email protected]}{1997/10/27}{listings.sty is incompatible to inputenc.sty}
-%
-%
-% \section{Software license}
-%
-% \paragraph{Copyright.}
-%	The \textsf{listings} package is copyright 1996--1998 Carsten Heinz.
-%	The driver files are copyright 1997, 1998 or 1997--1998 any individual author listed in these files.
-%
-% \paragraph{Distribution.}
-%	The \textsf{listings} package as well as \texttt{lstdrvrs.dtx} and all driver files are distributed freely.
-%	You are not allowed to take money for the distribution, except for a nominal charge for copying etc..
-%
-% \paragraph{Use of the package.}
-%	The \textsf{listings} package is free for any non-commercial use.
-%	Commercial use needs (i) explicit permission of the author of this package and (ii) the payment of a license fee.
-%	This fee is to be determined in each instance by the commercial user and the package author and is to be payed as donation to the \LaTeX3 project.
-%
-% \paragraph{No warranty.}
-%	The \textsf{listings} package as well as \texttt{lstdrvrs.dtx} and all driver files are distributed without any warranty, express or implied, as to merchantability or fitness for any particular purpose.
-%
-% \paragraph{Modification advice.}
-%	Permission is granted to change the \textsf{listings} package as well as \texttt{lstdrvrs.dtx}.
-%	You are not allowed to distribute any changed version of the package or any changed version of \texttt{lstdrvrs.dtx}, neither under the same name nor under a different one.
-%	Tell the author of the package about your local changes: other users will welcome removed bugs, new features and additional programming languages.
-%
-% \paragraph{Contacts.}
-%	Send comments and ideas on the package, error reports and additional programming languages to \emph{Carsten Heinz, Tellweg 6, 42275 Wuppertal, Germany} or preferably to \texttt{[email protected]}.
-%
-% \paragraph{Trademarks}
-%	appear throughout this documentation without any trademark symbol, so you can't assume that a name is free.
-%	There is no intention of infringement; the usage is to the benefit of the trademark owner.
-%
-%
-% \section{Getting started}\label{uGettingStarted}
-% 
-%
-% \iffalse
-% \subsection{Installation}
-%
-% \begin{enumerate}
-% \item	You need \texttt{listings.dtx} and \texttt{listings.ins} to install the \textsf{listings} package.
-%	\texttt{lstdrvrs.dtx} contains some language drivers.
-%	Move \texttt{.dtx} and \texttt{.ins} files into a separate folder if you want to.
-% \item	Remove all \texttt{lst???.sty} files if you update from an earlier version.
-% \item	Run \texttt{listings.ins} through \TeX.
-%	This creates the kernel \texttt{listings.sty} and two interface files \texttt{lst017.sty} and \texttt{lstfvrb.sty}.
-%	If you have \texttt{lstdrvrs.dtx}, a configuration file \texttt{listings.cfg} and a couple of driver files are also generated.
-% \item	Copy all created \texttt{.sty} and \texttt{.cfg} files to a directory searched by \TeX.
-% \end{enumerate}
-% \fi
-%
-%
-% \subsection{Package loading}
-%
-% As usual in \LaTeX\ the package is loaded by |\usepackage[|\meta{options}|]{listings}|, where |[|\meta{options}|]| is optional.
-% Note that \textsf{listings} 0.19 needs more save stack size than any previous version.
-% The following options are available:
-% \begin{description}
-% \item[\texttt{0.17}]
-%	Use this option to compile documents created with version 0.17 of the \textsf{listings} package.
-%	Note that you can't use old driver files and that the option does not guarantee full compatibility.
-%	If you want to polish up an old document, use this option together with new commands and keys.
-%	There shouldn't be many problems, but I haven't made deep tests.
-% \item[\normalfont\texttt{index} and \texttt{procnames}] define the 'index' respectively 'procnames' aspect, whatever that means.
-% \item[\normalfont\texttt{ndkeywords} and \texttt{rdkeywords}] define second respectively third order keywords.
-% \end{description}
-% Note: Each option slows down the package, so it becomes quite slow if you use all options, for example.
-% Note also that you can't activate any optional feature after package loading --- except you're a hacker and read the implementation part.
-%
-% Here is some kind of minimal file.
-% \begin{verbatim}
-%    \documentclass{article}
-%
-%    \usepackage{listings}
-%    %\usepackage[ndkeywords,index]{listings}% with some options
-%
-%    \begin{document}
-%
-%    \lstset{language=Pascal}
-%    % Any example may be inserted here.
-%
-%    \end{document}\end{verbatim}
-% \label{uMinimalFile}It loads the \textsf{listings} package without any option, but shows how the package is loaded with index option and second order keywords.
-% Moreover we select Pascal as programming language.
-%
-% If you need more than one programming language in your document, I recommend the preamble command |\lstloadlanguages|, which loads the given programming languages only, e.g.\ |\lstloadlanguages{Pascal,Fortran,C++}|.
-% You find more details in section \ref{uLanguagesAndStyles}.
-%
-%
-% \subsection{Typesetting listings}
-%
-% You can print (a) stand alone files, (b) source code from \texttt{.tex} files or (c) code fragments within a paragraph.
-% The difference between (b) and (c) is something like between display and text formulas (|$$| and |$|).
-%
-% We begin with code fragments.
-% If you want '\lstinline!var i:integer;!', you can simply write '|\lstinline!var i:integer;!|'.
-% The exclamation marks delimit the code fragment.
-% They could be replaced by any character not in the code fragment, i.e.\ '|\lstinline$var i:integer;$|' would produce the same output.
-%
-% The \texttt{lstlisting} environment typesets the source code in between.
-% It has one parameter, which we leave empty for the moment.
-% \begin{lstsample}{}
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% Like most examples this shows the \LaTeX\ source code on the right and the result on the left.
-% If you insert the \LaTeX\ code in the minimal file and run it through \TeX, the listing uses the whole text width.
-%
-% Finally examples for stand alone files:
-% \begin{lstsample}{\lstset{baseem=0.5}}
-%\lstinputlisting{listings.tmp}
-% \end{lstsample}
-% \noindent
-% Do you wonder about the left hand side?
-% Well, the file \texttt{listings.tmp} contains the current example.
-% This is exactly the line you see on the right.
-% If you want this line to be typeset in Pascal mode, you get what you've got.
-% If you want the lines $3,4,\ldots,10$ of \texttt{testfile.pas}, write
-% \begin{verbatim}
-%    \lstinputlisting[first=3,last=10]{testfile.pas}\end{verbatim}
-% But be sure that the first line does exist, or you will get a ''runaway argument'' error.
-%
-% Problems could arise if you (try to) put a listing in a box, tabular environment or something similar.
-% The |\lstbox| command in section \ref{uTypesettingListings} might solve this.
-% If you use an extended character table in your listings, you must use the |extendedchars| key, see section \ref{uSomeSpecialKeys}.
-%
-%
-% \subsection{The ''key=value'' interface}
-%
-% The \textsf{listings} package uses \textsf{keyval.sty} from the \textsf{graphics} bundle by David Carlisle.
-% Each 'aspect' or 'parameter' you can control has an associated key.
-% To select a programming language, for example, you need the key |language|, the sign |=| and the name of the language as value.
-% The command |\lstset| gets this construction as argument.
-% You have seen this in the minimal file on page \pageref{uMinimalFile}.
-% You can set more than one parameter with a single |\lstset| if you separate two or more ''key=value'' constructions by commas:
-% \begin{verbatim}
-%    \lstset{language=Pascal,keywordstyle=\bfseries}\end{verbatim}
-% If the value itself contains a comma, you must enclose the value in braces:
-% \begin{verbatim}
-%    \lstset{keywords={one,two,three}}\end{verbatim}
-% |\lstset{keywords=one,two,three}| would set the one and only keyword |one| and gives an error message since the parameters |two| and |three| do not exist.
-%
-% Two final notes:
-% (1) Some keys has default values, e.g.\ |flexiblecolumns=true| turns flexible columns on, but |flexiblecolumns| without any |=true| would do the same since the value true is default for that key.
-% But you must use the value |false| if you want to turn them off.
-% (2) |\lstset| sets the values local to the current group.
-% Just forget it if you don't know what that means.
-% The command |\lstinputlisting| (as seen above) and the environment (as you see below) both have optional arguments.
-% If you use a key=value list as optional argument, these selections are valid for the particular listing only and the previous values are restored afterwards.
-% For example, if the current language is Pascal, but you want \texttt{testfile.f95} from line 3 on, write
-% \begin{verbatim}
-%    \lstinputlisting[first=3,language=Fortran]{testfile.f95}\end{verbatim}
-% Afterwards Pascal is still the current language.
-% Note that |\lstinline| has no optional parameter.
-%
-%
-% \subsection{Figure out the appearance}
-%
-% Keywords are typeset bold, comments in italic shape and spaces in strings appear as '\textvisiblespace' (without the two quotes).
-% You can change that default behaviour:
-% \begin{verbatim}
-%\lstset{
-%    basicstyle=\small,              % print whole listing small
-%    keywordstyle=\bfseries\underbar,% 'underlined' bold keywords
-%    nonkeywordstyle={},             % nothing happens to other identifiers
-%    commentstyle=\itshape,          % default
-%    stringstyle=\ttfamily,          % typewriter font for strings
-%    blankstring=true}               % blank spaces are blank in strings\end{verbatim}
-% We typeset a previous example with these styles again.
-%\lstset{basicstyle=\small,
-%    keywordstyle=\bfseries\underbar,nonkeywordstyle={},
-%    commentstyle=\itshape,stringstyle=\ttfamily,blankstring=true}
-% \begin{lstsample}{}
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% The style definitions above use two kind of commands; on the one hand |\ttfamily| or |\bfseries| taking no arguments and on the other |\underline|, which gets exactly one argument.
-% The \emph{very last} token of |keywordstyle|, |nonkeywordstyle| and |labelstyle| (see below) \emph{may} be a macro getting exactly one argument, namely the (non)keyword or label.
-% All other tokens \emph{must not} take any arguments --- or you will get deep in trouble.
-% \lstset{style={},blankstring=false}
-%
-% \textbf{Warning:}
-% You shouldn't use striking styles too often, but 'too often' depends on how many keywords the source code contains, for example.
-% Your eyes would concentrate on the framed, bold red printed keywords only, and your brain must compensate this.
-% Reading such source code could be very exhausting.
-% If it were longer, the last example would be quite good in this sense.
-% Believe me.
-%
-%
-% \subsection{Line numbers}
-%
-% You want tiny line numbers each second line?
-% Here you are:
-% \begin{lstsample}{}
-%\lstset{labelstyle=\tiny,%   <===
-%        labelstep=2}%        <===
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% |labelstep=0| turns line numbering off.
-% In the sequel we use |labelstyle=\tiny| and |labelstep=2|, even if it doesn't appear in the verbatim part.
-% And now we try to interrupt (continue) a listing.
-% For this purpose we use |{ }| as argument to the environment.
-% \begin{lstsample}{\lstset{labelstyle=\tiny,labelstep=2}}
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%
-%\end{lstlisting}
-%
-%And we continue the listing:
-%
-%\begin{lstlisting}{ }%       <===
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% Note that the empty line at the end of the first part is not printed, but it is responsible for correct line numbering.
-% |{ }| continued the previous '|{}|'-listing.
-% In general the argument is the name of the listing.
-% An empty (= |{}|) named listing always starts with line number one, no matter whether line numbers are printed or not.
-% A space (= |{ }|) named listing continues the last empty or space named one.
-% That's easy.
-% And this mechanism becomes easier if you use real names for your listings.
-% In that case all listings with the same name use a common line counter: the second (same named) listing continues automatically the first.
-% Even if there are other listings in between.
-% \begin{lstsample}{\lstset{labelstyle=\tiny,labelstep=2}}
-%\begin{lstlisting}{Test}%    <===
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%
-%\end{lstlisting}
-%
-%And we continue the listing:
-%
-%\begin{lstlisting}{Test}%    <===
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% The next |Test| listing goes on with line number {\makeatletter\lstno@Test}.
-% Note that listing names are case sensitive.
-%
-%
-% \subsection{Tabulators and form feeds}
-%
-% You might get some unexpected output if your source code contains a tabulator or form feed.
-% The package assumes tabulator stops at columns 9,17,25,33,\ldots, and a form feed prints an empty line.
-% This is predefined via
-% \begin{verbatim}
-%    \lstset{tabsize=8,formfeed=\bigbreak}\end{verbatim}
-% If you change the eight to the number $n$, you will get tabulator stops at columns $n+1,\allowbreak 2n+1,\allowbreak 3n+1,$ and so on.
-% If you want a new page every form feed, use |formfeed=\newpage|.
-% \lstset{tabsize=4}
-% \begin{lstsample}{}
-%\lstset{tabsize=4}
-%\begin{lstlisting}{}
-%123456789
-%	{ one tabulator }
-%		{ two tabs }
-%123		{ 123 and two tabs }
-%\end{lstlisting}
-% \end{lstsample}
-% \lstset{tabsize=8}\noindent
-% Unfortunately both sides are typeset with |tabsize=4|.
-%
-%
-% \subsection{Indent the listing}
-%
-% The examples are typeset with centered \texttt{minipage}s.
-% That's the reason why you can't see that line numbers are printed in the margin (default).
-% Now we separate the 'minipage margin' and the minipage by a vertical rule:
-% \begin{lstsample}{\lstset{frame=l,frametextsep=0pt,labelstyle=\tiny,labelstep=2}}
-%Some text before
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% The listing is lined up with the normal text.
-% You can change this if you want.
-% The parameter |indent| 'moves' the listing to the right (or left if the skip is negative).
-% \begin{lstsample}{\lstset{frame=l,frametextsep=0pt,labelstyle=\tiny,labelstep=2}}
-%Some text before
-%\lstset{indent=2em}%         <===
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%\end{lstlisting}
-%
-%\begin{lstlisting}{ }
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% Note that |\lstset{indent=2em}| also changes the indent for the second listings.
-% If you want to indent a single listing only, use the argument of |\lstset| as optional argument to the listing environment:
-% \begin{lstsample}{\lstset{frame=l,frametextsep=0pt,labelstyle=\tiny,labelstep=2}}
-%\begin{lstlisting}[indent=2em]{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%\end{lstlisting}
-%
-%\begin{lstlisting}{ }
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-% \end{lstsample}
-% \noindent
-% Such local changes apply to all supported parameters.
-%
-% If you use environments like \texttt{itemize} or \texttt{enumerate}, there is 'natural' indention coming from these environments.
-% By default the \textsf{listings} package respects this.
-% But you might use |wholeline=true| (or |false|) to make your own decision.
-% \begin{lstsample}{\lstset{frame=l,frametextsep=0pt,labelstyle=\tiny,labelstep=2}}
-%\begin{itemize}
-%\item First item:
-%
-%\begin{lstlisting}{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%\end{lstlisting}
-%
-%\item Second item:
-%\lstset{wholeline=true}%     <===
-%\begin{lstlisting}{ }
-%Write('Keywords are case ');
-%WritE('insensitive here.');
-%\end{lstlisting}
-%\end{itemize}
-% \end{lstsample}
-% \noindent
-% You can use |wholeline| together with |indent|, of course.
-% Refer section \ref{uListingAlignment} for a description of |spread|.
-%
-%
-% \subsection{Fixed and flexible columns}
-%
-% The first thing a reader notices is --- except different styles for keywords etc. --- the column alignment of a listing.
-% The problem: I don't like listings in typewriter fonts and other fonts need not to have a fixed width.
-% But we don't want
-% \begin{itemize}\item[]\begin{tabular}{@{}l}
-%	if\ x=y\ then\ write('alignment')\\
-%	\ \ \ \ \ \ \ else\ print('alignment');
-% \end{tabular}\end{itemize}
-% only because spaces are not wide enough.
-% There is a simple trick to avoid such things.
-% We make boxes of the same width and put one character in each box:
-% \def\docharfbox#1#2{\fbox{\hbox to#1em{\hss\vphantom{fy}#2\hss}}}
-% \def\docharbox#1#2{\hbox to#1em{\hss#2\hss}}
-% \begin{itemize}\item[]
-%     \def\makeboxes#1{\docharfbox1#1\ifx#1\relax\else\expandafter\makeboxes\fi}
-%     \makeboxes if\ x=y\ then\ write\relax\space\ldots\\
-%     \makeboxes \ \ \ \ \ \ \ else \ print\relax\space\ldots
-% \end{itemize}
-% Going this way the alignment of columns can't be disturbed.
-%	\def\makeboxes#1{\docharbox{0.45}#1\ifx#1\relax\else\expandafter\makeboxes\fi}
-% But if the boxes are not wide enough, we get '\makeboxes if\ x=y\ then\relax\ldots', and choosing the width so that the widest character fits in leads to
-%	\def\makeboxes#1{\docharbox{1}#1\ifx#1\relax\else\expandafter\makeboxes\fi}
-% '\makeboxes if\ x=y\ then\ write\relax\ldots'.
-% Both are not acceptable.
-% Since all input will be cut up in units, we can put each unit in a box, which width is multiplied by the number of characters we put in, of course.
-% The result is
-%	\def\makeboxes#1#2{\docharfbox{#1}{#2}\ifx#2\relax\else\expandafter\makeboxes\fi}
-%	\makeboxes{1.4}{i\hss f}{.7}{\ }{.7}{x}{.7}{=}{.7}{y}{.7}{\ }{2.8}{t\hss h\hss e\hss n}{.7}{\ }{3.5}{w\hss r\hss i\hss t\hss e}{.7}\relax\space.
-% Since we put wide and thin characters in the same box, the width of a single character box need not to be the width of the widest character.
-% The empirical value {\makeatletter\lst@baseemfixed}em (which is called 'base em' later) is a compromise between overlapping characters and the number of boxes not exceeding the text width, i.e.\ how many characters fit a line without getting an overfull |\hbox|.
-%
-% \begingroup
-% But overlapping characters are a problem if you use many upper case letters, e.g.\ \docharbox{3}{W\hss O\hss M\hss E\hss N} --- blame me and not the women, in fact \docharbox{1.8}{M\hss E\hss N} doesn't look better.
-% To go around this problem the \textsf{listings} package supports more 'flexible columns' in contrast to the fixed columns above.
-% Arne John Glenstrup (whose idea the format is) pointed out that he had good experience with flexible columns and assembler listings.
-% The differences can be summed up as follows: The fixed column format ruins the nice spacing intended by the font designer, and the flexible format ruins the column alignment (possibly) intended by the programmer.
-% We illustrate that:
-%	\lstset{style={},language={}}
-%	\def\sample{\begin{lstlisting}{}^^J\ WOMEN\ \ are^^J \ \ \ \ \ \ \ MEN^^J WOMEN are^^J better MEN^^J \end{lstlisting}}
-%	\begin{center}\begin{tabular}{c@{\qquad\quad}c@{\qquad\quad}c}
-%	verbatim&fixed columns&flexible columns\\
-%		&with {\makeatletter\lst@baseemfixed}em&with {\makeatletter\lst@baseemflexible}em\\ \noalign{\medskip}
-%	\setkeys{lst}{basicstyle=\ttfamily,baseem=0.51}\lstbox\sample&\lstset{flexiblecolumns=false}\lstbox\sample&\lstset{flexiblecolumns=true}\lstbox\sample\lstset{flexiblecolumns=false}
-%	\end{tabular}\end{center}
-% Hope this helps.
-% Note the varying numbers of spaces between 'WOMEN' and 'are' and look at the different outputs.
-% The flexible column format typesets all characters at their natural width.
-% In particular characters never overlap.
-% If a word needs more space than reserved ('WOMEN'), the rest of the line moves to the right.
-% Sometimes a following word needs less space than reserved, or there are spaces following each other.
-% Such 'surplus' space is used to fix the column alignment:
-% The blank space in the third line have been printed properly, but the two blanks in the first line have been printed as one blank space.
-% We can show all this more drastic if we reduce the width of a single character box:
-%	\begin{center}\lstset{baseem={0.3,0.0}}\begin{tabular}{c@{\qquad\quad}c@{\qquad\quad}c}
-%		&{\makeatletter\lst@baseemfixed}em&{\makeatletter\lst@baseemflexible}em\\ \noalign{\medskip}
-%	\setkeys{lst}{basicstyle=\ttfamily,baseem=0.51}\lstbox\sample&\lstset{flexiblecolumns=false}\lstbox\sample&\lstset{flexiblecolumns=true}\lstbox\sample\lstset{flexiblecolumns=false}
-%	\end{tabular}\end{center}
-% In flexible column mode the first 'MEN' moves to the left since the blanks before are $7\cdot 0.0$em$=0$em wide.
-% Even in flexible mode you shouldn't reduce 'base em' to less than 0.33333em ($\approx$ width of a single space).
-% \endgroup
-%
-% You want to know how to select the flexible column format and how to reset to fixed columns?
-% Try |flexiblecolumns=true| and |flexiblecolumns=false|.
-%
-%
-% \subsection{Selecting other languages}\label{uSelectingOtherLanguages}
-%
-% You already know that |language=|\meta{language name} selects programming languages --- at least Pascal and Fortran.
-% But that's not the whole truth.
-% Both languages know different dialects (= version or implementation), for example Fortran 77 and Fortran 90.
-% You can choose such special versions with the optional argument of |language|.
-% Write
-% \begin{verbatim}
-%    \lstset{language=[77]Fortran}% Fortran 77
-%    \lstset{language=[XSC]Pascal}% Pascal XSC\end{verbatim}
-% to select Fortran 77 and Pascal XSC, respectively.
-%
-% We give a list of all languages and dialects supported by \texttt{lstdrvrs.dtx}.
-% Use the given names as (optional) values to |language|.
-% An 'empty' language is also defined: |\lstset{language={}}| detects no keywords, no comments, no strings, \ldots
-% \begin{center}
-% \begin{tabular}{ll}
-% Ada & Lisp \\
-% Algol (|68|,|60|) & Logo \\
-% C (|ANSI|,|Objective|)& Matlab \\
-% Cobol (|1985|,|1974|,|ibm|) & Mercury \\
-% Comal 80 & Modula-2 \\
-% C++ (|ANSI|,|Visual|) & Oberon-2 \\
-% csh & Pascal (|Standard|,|XSC|,|Borland6|) \\
-% Delphi & Perl \\
-% Eiffel & PL/I \\
-% Elan & Prolog \\
-% Euphoria & Simula (|67|,|CII|,|DEC|,|IBM|) \\
-% Fortran (|95|,|90|,|77|) & SQL \\
-% IDL & TeX (|plain|,|primitive|,|LaTeX|,|alLaTeX|) \\
-% HTML & VHDL \\
-% Java
-% \end{tabular}
-% \end{center}
-% The configuration file \texttt{listings.cfg} defines each first dialect as default dialect, i.e.\ |\lstset{language=C}| selects ANSI C.
-% After
-% \begin{verbatim}
-%    \lstset{defaultdialect=[Objective]C}\end{verbatim}
-% Objective-C becomes default dialect for C, but the language is \emph{not} selected with that command.
-%
-% \medskip
-% Remark: The driver files define the languages with |\lstdefinelanguage|.
-% The languages have all 'bugs' coming from the language commands, e.g.\ in Ada and Matlab it is still possible that the package assumes a string where none exists.
-% See \texttt{lstdrvrs.dtx} for more remarks on special programming languages.
-%
-%
-% \section{Main reference}
-%
-% \newcommand\UTODO[1]{}
-% \newenvironment{TODO}{\begin{quote}\footnotesize To do:}{\end{quote}}
-% \newenvironment{macrosyntax}
-%	{\list{}{\itemindent-\leftmargin\labelsep=0pt\relax %
-%		\def\makelabel##1{\lstmklab##1,\relax}}}
-%	{\endlist}
-% \def\lstmklab#1,#2\relax{%
-%	\ifx\empty#2\empty %
-%		\lstmklabb#1,,\relax %
-%	\else
-%		\lstmklabb#1,#2\relax %
-%	\fi}
-% \def\lstmklabb#1,#2,\relax{%
-%	\llap{\scriptsize\itshape#2}%
-%	\rlap{\hskip-\itemindent\hskip\labelwidth\hskip\linewidth#1}}
-%
-% In this section we list all user environments, commands and keys together with their parameters and possible values.
-% Sometimes there are examples or more detailed information at the end of the subsections.
-% All user macros have the prefix \lst.
-% This avoids naming conflicts with other packages or document classes.
-%
-% In the sequel the label \emph{changed} indicates any change in behaviour or syntax of a command, environment or key, so read these items carefully.
-% Keys strongly related to special programming languages have the label \emph{lang.spec.}.
-% Usually they are available only if you have loaded the corresponding programming language.
-% All other labels should be clear.
-% The numbers in the right margin give the version number of introduction (either as internal or as user macro/key).
-%
-% Note that commands, environments and keys can be distinguished easily:
-% A command begins with a backslash and a key is presented in ''|key=|\meta{value}'' fashion.
-% All the rest are environments, which is in fact a single one.
-%
-%
-% \subsection{Typesetting listings}\label{uTypesettingListings}
-%
-% \begin{macrosyntax}
-% \item[0.1,changed] |\lstinputlisting[|\meta{key=value list}|]{|\meta{file name}|}|
-%
-%		typesets the source code file using the active language and style (locally modified by the key=value list).
-%		Empty lines at the end of listing are dropped.
-%
-%		The keys |first| and |last| determines the printed line range.
-%		Default is \emph{always} 1--9999999, where 'always' means that you can't set |first| and |last| globally.
-%		If you don't want a whole file, you must specify the line range.
-%		The example |\lstinputlisting[first=3,last=10]{testfile.pas}| would print lines 3,4,\ldots,10 of \texttt{testfile.pas} if file and lines are present.
-%
-%		The boolean key |print| controls whether or not |\lstinputlisting| typesets a listing:
-%		|print=false| speed up things for draft versions of your document and |print=true| typesets the stand alone files.
-%
-%		Note: The keys |first|, |last| and |print| only apply to |\lstinputlisting|.
-%^^A
-%^^A TODO: That's not true.
-%^^A       The key |first| also applies to lstlisting.
-%^^A       It sets the line number of the first line.
-%^^A
-%
-% \item[0.15,changed] |lstlisting[|\meta{key=value list}|]{|\meta{name}|}|
-%
-%		typesets source code between |\begin{lstlisting}{|\meta{name}|}| (+ line break) and |\end{lstlisting}|, but empty lines at the end of listing are dropped.
-%		Characters on the same line as the end of environment are \emph{not} dropped, i.e.\ source code right before and \LaTeX\ code after the end of environment is typeset respectively executed.
-%		If \meta{name} is not empty and the listing is not continued, the name appears in the list of listings.\\
-%		Same named listings have common line counter, i.e.\ the second (same named) listing continues the first, the third continues the second, and so on.
-%		There are two exceptions: An empty named listing always starts with line number 1 and is continued with listings named |{ }| (single blank space).
-%
-%		The key |resetlineno| (given without any value) sets the line number of the first line to 1.
-%		You can also specify a number, e.g.\ |resetlineno=10|.
-%		|advancelineno=|\meta{number} advances the number of the first line by \meta{number}.
-%		These two keys take also effect on |{}| and |{ }| named listings.
-%
-%		Note: The keys |resetlineno| and |advancelineno| only apply to the environment and must be used in the optional key=value list.
-%
-% \item[0.18,new] |\lstinline|
-%
-%		works like |\verb|, but uses the active language and style, of course.
-%		You can write '|\lstinline!var i:integer;!|' and get '\lstinline!var i:integer;!'.
-%		Note that these listings always use flexible columns and that |\lstinline| has no optional key=value list.
-%\UTODO{implement optional key=value list}
-%
-% \item[0.18,new] |\lstbox[|\meta{b$\vert$c$\vert$t}|]|
-%
-%		is used right before |\lstinputlisting| or a listing environment.
-%		Without |\lstbox| the listing uses  a new paragraph and the complete line width, even if the listing is one character wide.
-%		|\lstbox| returns the listing as a |\hbox|, which has the necessary width only (line numbers possibly not included).
-%		Use this command within explicit |\hbox|es, |$$|\ldots|$$|, etc..
-%		The optional argument gives the vertical position of the listing: bottom, center (default) or top.
-% \end{macrosyntax}
-%
-%
-% \subsection{List of listings}
-%
-% \begin{macrosyntax}
-% \item[0.16] |\listoflistings|
-%
-%		prints a list of listings.
-%		The names are the file names or names of the listings.
-%
-% \item[0.16] |\listlistingsname|
-%
-%		contains the header name, which is 'Listings' by default.
-%		You may adjust it via |\renewcommand\listlistingsname{whatever}|.
-%
-% \item[0.19,new] |\lstname|
-%
-%		contains the name of the current (last) listing in \emph{printable} form.
-%		After |pre=\subsubsection{\lstname}| each listing begins a new subsubsection, which name is the listing name.
-%		The key |pre| is described in section \ref{uSomeSpecialKeys}.
-%		You can also use it to index all listings, but then you must expand the content first.
-%		Simply write |\expandafter\index\expandafter{\lstname}| (as value to |pre| if you want).
-%
-% \item[0.19,new] |\lstintname|
-%
-%		contains the name of the current (last) listing possibly in nonprintable form.
-%		Use this macro inside |\label| and |\ref| for example.
-%		But be aware that a reference counter must be defined --- or the label is the current section, subsection, and so on.
-%		You might use it like this:
-% \begin{verbatim}
-%    \lstset{pre=\caption{\lstname}\label{lst\lstintname}}
-%
-%    \begin{figure}
-%    \begin{lstlisting}{Empty}
-%    \end{lstlisting}
-%    \end{figure}
-%
-%    Figure \ref{lstEmpty} shows an empty listing.\end{verbatim}
-%		Here \emph{all} listings get a caption and a label (unless |pre| is redefined).
-% \end{macrosyntax}
-%
-%
-% \subsection{Basic style keys}\label{uBasicStyleKeys}
-%
-% \begin{macrosyntax}
-% \item[0.18,new] |basicstyle=|\meta{basic style and size}
-% \item[0.11] |keywordstyle=|\meta{style for keywords}
-% \item[0.19,new,optional] |ndkeywordstyle=|\meta{style for second keywords}
-% \item[0.19,new,optional] |rdkeywordstyle=|\meta{style for third keywords}
-% \item[0.18,new] |nonkeywordstyle=|\meta{style}
-% \item[0.11] |commentstyle=|\meta{style}
-% \item[0.12] |stringstyle=|\meta{style}
-% \item[0.16] |labelstyle=|\meta{style}
-%
-%		Each value of these keys determines the font and size (or more general style) in which special parts of a listing appear.
-%		The \emph{last} token of the (non,nd,rd) keyword and label style might be an one-parameter command like |\textbf| or |\underline|.
-%
-% \item[0.16,bug] |labelstep=|\meta{step}
-%
-%		No line numbers are printed if \meta{step} is zero.
-%		Otherwise all lines with ''line number $\equiv 0$ modulo \meta{step}'' get a label, which appearance is controlled by the label style.
-%
-%		Bug: If a comment (or string) goes over several lines, the line numbers (if on) also have comment (string) style.
-%		The easiest work-around is possibly the use of |\normalfont| in |\lstlabelstyle|.
-%
-% \item[0.12] |blankstring=|\meta{true$\vert$false}
-%
-%		let blank spaces in strings appear as blank spaces respectively as \textvisiblespace.
-%		The latter is predefined.
-%
-% \item[0.12] |tabsize=|\meta{number}
-%
-%		sets tabulator stops at columns $n+1$, $2n+1$, $3n+1$, etc. if $n=$\meta{number}.
-%		Each tabulator in a listing moves the current column to the next tabulator stop.
-%		It is initialized with |tabsize=8|.
-%
-% \item[0.19,new] |formfeed=|\meta{token sequence}
-%
-%		Whenever a listing contains a form feed \meta{token sequence} is executed.
-%		It is initialized with |formfeed=\bigbreak|.
-% \end{macrosyntax}
-%
-%
-% \subsection{Fixed and flexible columns}
-%
-% \begin{macrosyntax}
-% \item[0.18,new] |flexiblecolumns=|\meta{true$\vert$false}
-%
-%		selects the flexible respectively the fixed column format.
-%
-% \item[0.16,addon] |baseem=|\meta{width in units of em}\quad or\quad|baseem={|\meta{fixed}|,|\meta{flexible mode}|}|
-%
-%		sets the width of a single character box for fixed and flexible mode (both to the same value or individually).
-%		It's pre-defined via |baseem={|{\makeatletter\lst@baseemfixed}|,|{\makeatletter\lst@baseemflexible}|}|.
-% \end{macrosyntax}
-%
-%
-% \subsection{Listing alignment}\label{uListingAlignment}
-%
-% \begin{macrosyntax}
-% \item[0.19,new] |indent=|\meta{dimension}
-%
-%		indents each listing by \meta{dimension}, which is initialized with 0pt.
-%		This command is the best way to move line numbers (and the listing) to the right.
-%
-% \item[0.19,new] |wholeline=|\meta{true$\vert$false}
-%
-%		prevents or lets the package use indention from list environments like \texttt{enumerate} or \texttt{itemize}.
-%
-% \item[0.16,bug,addon] |spread=|\meta{dimension}\quad or\quad|spread={|\meta{inner}|,|\meta{outer}|}|
-%
-%		defines \emph{additional} line width for listings, which may avoid overfull |\hbox|es if a listing has long lines.
-%		The inner and outer spread is given explicitly or is equally shared.
-%		It is initialized via |spread=0pt|.
-%		For one sided documents 'inner' and 'outer' have the effect of 'left' and 'right'.
-%		Note that |\lstbox| doesn't use this spread but |indent| (which is always 'left').
-%
-%		Bug (two sided documents):
-%		At top of page it's possible that the package uses inner instead of outer spread or vice versa.
-%		This happens when \TeX\ finally moves one or two source code lines to the next page, but hasn't decided it when the \textsf{listings} package processes them.
-%		Work-around: interrupt the listing and/or use an explicit |\newpage|.
-%
-% \item[0.17] |lineskip=|\meta{additional space between lines}
-%
-%		specifies the additional space between lines in listings.
-%		You may write |lineskip=-1pt plus 1pt minus 0.5pt| for example, but 0pt is the default.
-%
-% \item[0.19,new] |outputpos=|\meta{c$\vert$l$\vert$r}
-%
-%		controls horizontal orientation of smallest output units (keywords, identifiers, etc.).
-%		The arguments work as follows, where vertical bars visualize the effect:
-%			$\vert$\hbox to 4.2em{\hss l\hss i\hss s\hss t\hss i\hss n\hss g\hss }$\vert$,
-%			$\vert$\hbox to 4.2em{l\hss i\hss s\hss t\hss i\hss n\hss g\hss }$\vert$ and
-%			$\vert$\hbox to 4.2em{\hss l\hss i\hss s\hss t\hss i\hss n\hss g}$\vert$
-%		in fixed column mode resp.\ 
-%			$\vert$\hbox to 3.15em{\hss listing\hss}$\vert$,
-%			$\vert$\hbox to 3.15em{listing\hss}$\vert$ and
-%			$\vert$\hbox to 3.15em{\hss listing}$\vert$
-%		with flexible columns (using pre-defined |baseem|).
-%		By default the output is centered.
-%		To make all things clear: You may write |outputpos=c|, |outputpos=l| or |outputpos=r|.
-% \end{macrosyntax}
-%
-%
-% \subsection{Escaping to \LaTeX}
-%
-% \textbf{Note:} {\itshape Any escape to \LaTeX\ may disturb the column alignment since the package can't control the spacing there.}
-% \begin{macrosyntax}
-% \item[0.18,new] |texcl=|\meta{true$\vert$false}
-%
-%		activates or deactivates \LaTeX\ comment lines, see the example below.
-%
-% \item[0.19,new] |mathescape=|\meta{true$\vert$false}
-%
-%		activates or deactivates special behaviour of the dollar sign.
-%		If activated, a dollar sign acts as \TeX's text math shift (not display style!).
-%
-% \item[0.19,new] |escapechar=|\meta{single character} (or empty)
-%
-%		The given character escapes the user to \LaTeX:
-%		All code between two such characters is interpreted as \LaTeX\ code.
-%		Note that \TeX's special characters must be entered with a preceding backslash, e.g.\ |escapechar=\%|.
-% \end{macrosyntax}
-% Some examples clarify these commands.
-% Since |texcl| only makes sense with comment lines, we will use C++ comment lines here (without saying how to define them).
-% Note that only the first example runs through a C++ compiler if the source code is placed in a separate file.
-% All \LaTeX\ escapes are local here, but you can also use |\lstset|.
-% \lstset{commentline=//}
-% \begin{lstsample}{}
-%\begin{lstlisting}[texcl]{}
-%// calculate $a_{ij}$
-%  A[i][j] = A[j][j]/A[i][j];
-%\end{lstlisting}
-% \end{lstsample}
-%
-% \begin{lstsample}{}
-%\begin{lstlisting}[mathescape]{}
-%// calculate $a_{ij}$
-%  $a_{ij} = a_{jj}/a_{ij}$;
-%\end{lstlisting}
-% \end{lstsample}
-%
-% \begin{lstsample}{}
-%\lstset{escapechar=\%}
-%\begin{lstlisting}{}
-%// calc%ulate $a_{ij}$%
-%  %$a_{ij} = a_{jj}/a_{ij}$%;
-%\end{lstlisting}
-% \end{lstsample}
-% \lstset{commentline={}}
-% \noindent
-% In the first example the whole comment line is typset in '\LaTeX\ mode' --- except the comment line indicators |//|.
-% Note that |texcl| uses comment style.
-% In the second example the comment line upto $a_{ij}$ have been typeset in comment style and by the \textsf{listings} package.
-% The '$a_{ij}$' itself is typeset in '\TeX\ math mode' without comment style.
-% About the half comment line of the third example have been typeset by this package.
-% The rest is in '\LaTeX\ mode' without comment style.
-%
-% To avoid problems with the current and future version of this package:
-% \begin{enumerate}
-% \item Don't use any command of the \textsf{listings} package when you have escaped to \LaTeX.
-% \item Any environment must start and end inside the same escape.
-% \item You might use |\def|, |\edef|, etc., but do not assume that the definitions are present later --- except they are |\global|.
-% \item |\if \else \fi|, groups, math shifts |$| and |$$|, \ldots\ must be balanced each escape.
-% \item \ldots
-% \end{enumerate}
-% Expand that list yourself and mail me about new items.
-%
-%
-% \subsection{Some special keys}\label{uSomeSpecialKeys}
-%
-% \begin{macrosyntax}
-% \item[0.18,new] |extendedchars=|\meta{true$\vert$false}
-%
-%		allows or prohibits extended characters in listings, i.e.\ characters with codes 128--255.
-%		If you use extended characters, you should load the \texttt{inputenc} or \texttt{fontenc} package!
-%
-% \item[0.19,new,lang.spec.]|printpod=|\meta{true$\vert$false}
-%
-%		prints or drops PODs in Perl.
-%
-% \item[0.12,addon] |pre=[|\meta{continue}|]{|\meta{commands to execute}|}|
-% \item[0.12,addon] |post=[|\meta{continue}|]{|\meta{commands to execute}|}|
-%
-%		The given control sequences are executed before and after typesetting resp.\ when continuing a listing, but in all cases inside a group.
-%		The commands are not executed if you use |\lstbox| or |\lstinline| (since the user given pre and post commands are assumed to be unsave inside |\hbox|).
-%		By default \meta{continue} is empty.
-%		The other arguments are pre-set empty.
-% \end{macrosyntax}
-%
-% \begin{lstsample}{}
-%\lstset{flexiblecolumns}
-%\lstset{pre=[%
-%    We continue the listing.
-%  ]A simple prelisting example.}
-%\begin{lstlisting}{}
-%{ Get listings.dtx. Now! }
-%\end{lstlisting}
-%
-%\begin{lstlisting}{ }
-%{ You have it already? Good. }
-%\end{lstlisting}
-%
-%\begin{lstlisting}{ }
-%{ Tell your friends about it. }
-%\end{lstlisting}
-% \end{lstsample}
-%\lstset{style={}}
-%
-%
-% \subsection{Languages and styles}\label{uLanguagesAndStyles}
-%
-% \begin{macrosyntax}
-% \item[0.17,changed] |language=[|\meta{dialect}|]|\meta{language name}
-%
-%		activates a (dialect of a) programming language.
-%		All arguments are case \emph{insensitive} here.
-%
-% \item[0.19,new] |\lstloadlanguages{|\meta{list of languages}|}|
-%
-%		can only be used in the preamble.
-%		It loads all specified languages, where each language is given in the form |[|\meta{dialect}|]|\meta{language}.
-%		List of languages means a comma separated list.
-%
-% \item[0.18,new]	|style=|\meta{style name}
-%
-%		activates a style.
-%		The arguments is case \emph{insensitive}.
-%
-% \item[0.19,new] |\lstdefinestyle{|\meta{style name}|}{|\meta{key=value list}|}|
-%
-%		stores the key=value list: You can select the style via |style| using te style name as argument.
-% \end{macrosyntax}
-% After package loading a 'standard' style and an 'empty' language are active.
-% The style is defined as follows.
-% \begin{verbatim}
-%    \lstdefinestyle{}
-%    {basicstyle={},
-%     keywordstyle=\bfseries,nonkeywordstyle={},
-%     commentstyle=\itshape,
-%     stringstyle={},
-%     labelstyle={},labelstep=0
-%    }\end{verbatim}
-%
-%
-% \subsection{Language definitions}
-%
-% \begin{macrosyntax}
-% \item[0.19,new] |\lstdefinelanguage[|\meta{dialect}|]{|\meta{language}|}{|\meta{key=value list}|}|
-%
-%		defines a programming language.
-%		Use any 'language' key=value list and the definition is yours.
-%
-% \item[0.19,new] |\lstdefinedrvlanguage[|\meta{dialect}|]{|\meta{language}|}{|\meta{key=value list}|}|
-%
-%		defines a programming language only if the user has requested the language.
-%		Thus this command can only be used in driver files.
-%
-% \item[0.19,new] |defaultdialect=[|\meta{dialect}|]|\meta{language}
-%
-%		defines a default dialect for a language, that means a dialect which is selected whenever you leave out the optional dialect.
-%		If you have defined a default dialect other than empty, for example |defaultdialect=[iama]fool|, you can't select the 'empty' dialect, even not with |language=[]fool|.
-%
-%		Note that a configuration file possibly defines some default dialects.
-%
-% \item[0.18,new] |\lstalias{|\meta{alias}|}{|\meta{language}|}|
-%
-%		defines an alias for a programming language.
-%		Any dialect of \meta{alias} selects in fact the same dialect of \meta{language}.
-%		It's also possible to define an alias for one dialect: |\lstalias[|\meta{dialect alias}|]{|\meta{alias}|}[|\meta{dialect}|]{|\meta{language}|}|.
-%		Here all four parameters are \emph{non}optional.
-%		An alias with empty \meta{dialect} will select the default dialect.
-%		Note that aliases can't be nested: The two aliases |\lstalias{foo1}{foo2}| and |\lstalias{foo2}{foo3}| redirect |foo1| not to |foo3|.
-%
-%		Note that a configuration file possibly defines some aliases.
-%
-% \item[0.18,new] |\lststorekeywords|\meta{macro}|{|\meta{keywords}|}|
-%
-%		stores \meta{keywords} in \meta{macro} for use with keyword keys.
-%		This command can't be used in a language definition since it is a command and not a key.
-% \end{macrosyntax}
-%
-% Now come all the language keys, which might be used in the key=value list of |\lstdefinelanguage|.
-% Note: {\itshape If you want to enter {\upshape|\|, |{|, |}|, |%|, |#|} or {\upshape|&|} inside or as an argument here, you must do it with a preceding backslash!}
-%
-% \begin{macrosyntax}
-% \item[0.11] |keywords={|\meta{keywords}|}|
-% \item[0.11] |morekeywords={|\meta{additional keywords}|}|
-% \item[0.18,new] |deletekeywords={|\meta{keywords to remove}|}|
-%
-% \item[0.19,new,optional] |ndkeywords={|\meta{second keywords}|}|
-% \item[0.19,new,optional] |morendkeywords={|\meta{additional second keywords}|}|
-% \item[0.19,new,optional] |deletendkeywords={|\meta{second keywords to remove}|}|
-%
-% \item[0.19,new,optional] |rdkeywords={|\meta{third keywords}|}|
-% \item[0.19,new,optional] |morerdkeywords={|\meta{additional third keywords}|}|
-% \item[0.19,new,optional] |deleterdkeywords={|\meta{third keywords to remove}|}|
-%
-%		Each 'keyword' argument (here and below) is a list of keywords separated by commas.
-%		You might use macros defined with |\lststorekeywords| as elements (i.e.\ also separated by commas).
-%		|keywords={save,Test,test}| defines three keywords (if keywords are case sensitive).
-%		If you want to remove them all, simply write |keywords={}| --- in |\lstset|'s argument, in an optional argument or in a language definition.
-%		The characters |\|, |{|, and |}| (entered as |\\|, |\{| and |\}|) are \emph{not} allowed within a keyword.
-%		You might use each of
-%^^A
-%^^A We need some definitions here.
-%^^A
-%\makeatletter ^^A
-%\def\lstspec#1{^^A
-%    \ifx\relax#1\else ^^A
-%        {\lstset{keywords=#1}\setbox\@tempboxa\hbox{\lstinline a#1a}}^^A
-%        \lst@ifspec\lstinline a#1a\fi ^^A
-%        \expandafter\lstspec ^^A
-%    \fi}^^A
-%\lst@AddToHook{Output}{\lstspectest}^^A
-%\gdef\lstspecfalse{\global\let\lst@ifspec\iffalse}^^A
-%\gdef\lstspectest{^^A
-%    \global\let\lst@ifspec=\iftrue ^^A
-%	 \ifx\lst@thestyle\lst@keywordstyle\else ^^A
-%        \lstspecfalse ^^A
-%	 \fi}^^A
-%\makeatother ^^A
-%	{\lstset{language={}}^^A
-%    \lstspec !"\#$\%\&'()*+-./:;<=>?[]^`\relax.}
-%^^A
-%^^A a comma also works!
-%^^A
-%^^A End of test.
-%^^A
-%		But note that you must enter |\#|, |\%| and |\&| instead of |#|, |%| and |&|.
-%
-% \item[0.14] |sensitive=|\meta{true$\vert$false}
-%
-%		makes the keywords (first, second and third) case sensitive resp.\ insensitive.
-%^^A	It would be nice to have |\lst|\meta{\texttt{nd}$\vert$\texttt{rd}}|sensitive|\meta{\texttt{true}\textbar\texttt{false}}?
-%		This key affect the keywords only in the phase of typesetting.
-%		In all other situations keywords are case sensitive, i.e.\ |deletekeywords={save,Test}| removes 'save' and 'Test', but neither 'SavE' nor 'test'.
-%
-% \item[0.19,new] |alsoletters={|\meta{character sequence}|}|
-% \item[0.19,new] |alsodigits={|\meta{character sequence}|}|
-% \item[0.19,new] |alsoother={|\meta{character sequence}|}|
-%
-%		These keys support the 'special character' auto-detection of the keyword commands.
-%		For our purpose here, identifiers are out of letters (|A|--|Z|,|a|--|z|,|_|,|@|,|$|) and digits (|0|--|9|), but an identifier must begin with a letter.
-%		If you write |keywords={one-two,\#include}|, the minus becomes necessarily a digit and the sharp a letter since the keywords can't be detected otherwise.
-%		The three keys overwrite such default behaviour.
-%		Each character of the sequence becomes a letter, digit and other, respectively.
-%		Note that the auto-detection might fail if you remove keywords and always fails if you use special characters not listed above.
-%^^A
-%^^A TODO: This is mainly due to improper \lst@ReplaceIn inside ..MakeKeywordArg..
-%^^A
-%
-% \item[0.19,new] |stringtest=|\meta{true$\vert$false}
-%
-%		enables or disables string tests:
-%		If activated, line exceeding strings issue warnings and the package exits string mode.
-%
-% \item[0.12,addon] |stringizer=[|\meta{b$\vert$d$\vert$m$\vert$bd}|]{|\meta{character sequence}|}|
-%
-%		Each character might start a string or character literal.
-%		'Stringizers' match each other, i.e.\ starting and ending delimiters are the same.
-%		The optional argument controls how the stringzier(s) itself is/are represented in a string or character literal:
-%		It is preceded by a |b|ackslash, |d|oubled (or both is allowed via |bd|) or it is |m|atlabed.
-%		The latter one is a special type for Ada and Matlab and possibly more languages, where the stringizers are also used for other purposes.
-%		In general the stringizer is also doubled, but a string does not start after a letter or a right parenthesis.
-%
-% \item[0.19,new,lang.spec.] |texcs={|\meta{list of control sequences \textup(without backslashes\textup)}|}|
-%
-%		defines control sequences for \TeX\ and \LaTeX.
-%
-% \item[0.18,new,lang.spec.] |cdirectives={|\meta{list of compiler directives}|}|
-%
-%		defines compiler directives in C, C++ and Objective-C.
-% \end{macrosyntax}
-% If you have already defined any of the following comments and you want to remove it, let all arguments to the comment key empty.
-% \begin{macrosyntax}
-% \item[0.13,changed] |commentline=|\meta{1or2 chars}
-%
-%		The characters (\emph{in the given order}) start a comment line, which in general starts with the comment separator and ends at end of line.
-%		If the character sequence |//| starts a comment line (like in C++, Comal 80 or Java), |commentline=//| is the correct declaration.
-%		For Matlab it would be |commentline=\%| --- note the preceding backslash.
-%
-% \item[0.18,new] |fixedcommentline=[|\meta{n=preceding columns}|]{|\meta{character sequence}|}|
-%
-%		Each given character becomes a 'fixed comment line' separator: It starts a comment line if and only if it is in column $n+1$.
-%		Fortran 77 declares its comments via |fixedcommentline={*Cc}| ($n=0$ is default).
-%
-% \item[0.13,changed] |singlecomment={|\meta{1or2 chars}|}{|\meta{1or2 chars}|}|
-% \item[0.13,changed] |doublecomment={|\meta{1or2 chars}|}{|\meta{1or2 chars}|}{|\meta{1or2 chars}|}{|\meta{1or2 chars}|}|
-%
-%		Here we have two or four comment separators.
-%		The first starts and the second ends a comment, and similarly the third and fourth separator for double comments.
-%		If you need three such comments use |singlecomment| and |doublecomment| at the same time.
-%		C, Java, PL/I, Prolog and SQL all define single comments via |singlecomment={/*}{*/}|, and Algol does it with |singlecomment={\#}{\#}|, which means that the sharp delimits both beginning and end of a single comment.
-%
-% \item[0.13,changed] |nestedcomment={|\meta{1or2 chars}|}{|\meta{1or2 chars}|}|
-%
-%		is similar to |singlecomment|, but comments can be nested.
-%		Identical arguments are not allowed --- think a while about it!
-%		Modula-2 and Oberon-2 use |nestedcomment={(*}{*)}|.
-%
-% \item[0.17,lang.spec.] |keywordcomment={|\meta{keywords}|}|
-% \item[0.17,lang.spec.] |doublekeywordcommentsemicolon={|\meta{keywords}|}{|\meta{keywords}|}{|\meta{keywords}|}|
-%
-%		A (paired) keyword comment begins with a keyword and ends with the same keyword.
-%		Consider |keywordcomment={comment,co}|.
-%		Then '\textbf{comment}\allowbreak\ldots\textbf{comment}' and '\textbf{co}\ldots\textbf{co}' are comments.\\
-%^^A
-%		Defining a double keyword comment (semicolon) needs three keyword lists, e.g.\ |{end}{else,end}{comment}|.
-%		A semicolon always ends such a comment.
-%		Any keyword of the first argument begins a comment and any keyword of the second argument ends it (and a semicolon also); a comment starting with any keyword of the third argument is terminated with the next semicolon only.
-%		In the example all possible comments are '\textbf{end}\ldots\textbf{else}', '\textbf{end}\ldots\textbf{end}' (does not start a comment again) and '\textbf{comment}\ldots;' and '\textbf{end}\ldots;'.
-%		Maybe a curious definition, but Algol and Simula use such comments.\\
-%^^A
-%		Note: The keywords here need not to be a subset of the defined keywords.
-%		They won't appear in keyword style if they aren't.
-% \end{macrosyntax}
-%
-%
-% \section{Experimental features}
-%
-% This section describes the more or less unestablished parts of the \textsf{listings} package.
-% It's unlikely that they are removed, but they are liable to (heavy) changes and maybe improvements.
-%
-%
-% \subsection{Interface to \textsf{fancyvrb}}
-%
-% The \textsf{fancyvrb} package --- fancy verbatims --- from Timothy van Zandt provides macros for reading, writing and typesetting verbatim code.
-% It has some remarkable features the \textsf{listings} package doesn't have --- some are also possible with \textsf{listings}, but you must find somebody who implements them ; -- ).
-% The \textsf{fancyvrb} package is available from \texttt{CTAN: macros/latex/contrib/supported/fancyvrb}.
-%
-% \begin{macrosyntax}
-% \item	[0.19,new]|fancyvrb=|\meta{true$\vert$false}
-%
-%		activates or deactivates the interface.
-%		This defines an appropiate version of |\FancyVerbFormatLine| to make the two packages work together.
-%		If active, the verbatim code read by the \textsf{fancyvrb} package is typeset by the \textsf{listings} package, i.e.\ with emphasized keywords, strings, comments, and so on.
-%		--- You should know that |\FancyVerbFormatLine| is responsible for the typesetting a single code line.
-%
-%		If \textsf{fancyvrb} and \textsf{listings} provide similar functionality, use \textsf{fancyvrb}'s.
-%
-%		Note that this is the first interface.
-%		It works only with |Verbatim|, neither with |BVerbatim| nor |LVerbatim|.
-%		And you shouldn't use \textsf{defineactive}. (As I can see it doesn't matter since it does nothing at all.)
-%		I hope to remove some restrictions in future.
-% \end{macrosyntax}
-%
-% \iffancyvrb
-% \begin{lstsample}{}
-%\lstset{commentline=\ }% :-)
-%
-%\begin{Verbatim}[commandchars=\\\{\}]
-%First verbatim line.
-%\fbox{Second} verbatim line.
-%\end{Verbatim}
-%
-%\lstset{fancyvrb}
-%\begin{Verbatim}[commandchars=\\\{\}]
-%First verbatim line.
-%\fbox{Second} verbatim line.
-%\end{Verbatim}
-%\lstset{fancyvrb=false}
-% \end{lstsample}
-% \noindent
-% The last two lines are wider than the first two since |baseem| equals not the width of a single typewriter character.
-% \else
-% \begin{center}
-% \textsf{fancyvrb} seems to be unavailable on your platform, thus the example couldn't be printed here.
-% \end{center}
-% \fi
-%
-%
-% \subsection{Listings inside arguments}\label{uListingsInsideArguments}
-%
-% There are some things to consider if you want to use |\lstinline| or the listing environment inside arguments.
-% Since \TeX\ reads the argument before the '\lst-macro' is executed, this package can't do anything to preserve the input:
-% Spaces shrink to one space, the tabulator and the end of line are converted to spaces, the comment character is not printable, and so on.
-% Hence, you must work a little bit more.
-% You have to put a backslash in front of each of the following four characters: |\{}%|.
-% Moreover you must protect spaces in the same manner if: (i) there are two or more spaces following each other or (ii) the space is the first character in the line.
-% That's not enough: Each line must be terminated with a 'line feed' |^^J|.
-% Finally you can't escape to \LaTeX\ inside such listings.
-%
-% The easiest examples are with |\lstinline| since we need no line feed.
-% \begin{verbatim}
-%\footnote{\lstinline!var i:integer;! and
-%          \lstinline!protected\ \ spaces! and
-%          \fbox{\lstinline!\\\{\}\%!}}\end{verbatim}
-% yields\lstset{language=Pascal}\footnote{\lstinline!var i:integer;! and \lstinline!protected\ \ spaces! and \fbox{\lstinline!\\\{\}\%!}} if the current language is Pascal.
-% The environment possibly needs a preceding |\lstbox|, as the following examples show.
-%
-%{\let\smallbreak\relax\lstset{language={}}
-% \begin{lstsample}{}
-%\fbox{\lstbox
-%\begin{lstlisting}{}^^J
-%\ !"#$\%&'()*+,-./^^J
-%0123456789:;<=>?^^J
-%@ABCDEFGHIJKLMNO^^J
-%PQRSTUVWXYZ[\\]^_^^J
-%`abcdefghijklmno^^J
-%pqrstuvwxyz\{|\}~^^J
-%\end{lstlisting}}
-% \end{lstsample}
-%
-% \lstset{language={}}
-% \begin{lstsample}{}
-%\fbox{\lstbox
-%\begin{lstlisting}{}^^J
-%We need no protection here,^^J
-%\ but\ \ in\ \ this\ \ line.^^J
-%\end{lstlisting}}
-% \end{lstsample}
-%}
-%
-%
-% \subsection{Frames}
-%
-% \begin{macrosyntax}
-% \item	[0.19,new] |frame=|\meta{any subset of \textup{\texttt{tlrbTLRB}}}
-%
-%		The characters |tlrbTLRB| are attached to lines at the |t|op of a listing, on the |l|eft, |r|ight and at the |b|ottom.
-%		There are two lines if you use upper case letters.
-%		If you want a single frame around a listing, write |frame=tlrb| or |frame=bltr| for example (but as optional argument or argument to |\lstset|, of course).
-%		If you want double lines at the top and on the left and no other lines, write |frame=TL|.
-%		Note that frames reside outside the listing's space.
-%		Use |spread| if you want to shrink frames (to |\linewidth| for example) and use |indent| if you want to move line number inside frames.
-%
-% \item	[0.19,new] |framerulewidth=|\meta{dimension}
-% \item	[0.19,new] |framerulesep=|\meta{dimension}
-%
-%		These keys control the width of the rules and the space between double rules.
-%		The predefined values are {\makeatletter\lst@framewidth} width and {\makeatletter\lst@framesep} separation.
-%
-%\iffalse
-% \item	[0.19,new] |frametextsep=|\meta{dimension}
-%
-%		controls the space between frame and listing, but currently only between the listing and vertical frame lines.
-%		The predefined value is {\makeatletter\lst@frametextsep}.
-%\fi
-% \end{macrosyntax}
-% |frame| does not work with |\lstbox| or |fancyvrb=true|!
-% And there are certainly more problems with other commands.
-% Take the time to report in.
-%
-% \begin{lstsample}{}
-%\begin{lstlisting}[frame=tLBr]{}
-%for i:=maxint to 0 do
-%begin
-%    { do nothing }
-%end;
-%\end{lstlisting}
-% \end{lstsample}
-%
-%
-% \subsection{Export of identifiers}
-%
-%^^A \lsthelper{Aslak Raanes}{[email protected]}{1997/11/24}{export function names}
-% It would be nice to export function or procedure names, for example to index them automatically or to use them in |\listoflistings| instead of a listing name.
-% In general that's a dream so far.
-% The problem is that programming languages use various syntaxes for function and procedure declaration or definition.
-% A general interface is completely out of the scope of this package --- that's the work of a compiler and not of a pretty printing tool.
-% However, it is possible for particular languages: in Pascal each function or procedure definition and variable declaration is preceded by a particular keyword.
-% \begin{macrosyntax}
-% \item	[0.19,new,optional] |index={|\meta{identifiers}|}|
-%
-%		\meta{identifiers} is a comma-separated list of identifiers.
-%		Each appearance of such an identifier is indexed.
-%
-% \item	[0.19,new,optional] |indexmacro=|\meta{'one parameter' macro}
-%
-%		The specified macro gets exactly one parameter, namely the identifier, and must do the indexing.
-%		It is predefined as |indexmacro=\lstindexmacro|, which definition is
-% \begin{verbatim}
-%    \newcommand\lstindexmacro[1]{\index{{\ttfamily#1}}}\end{verbatim}
-% \item[0.19,new,optional] |prockeywords={|\meta{keywords}|}|
-%
-%		\meta{keywords} is a comma-separated list of keywords, which indicate a function or procedure definition.
-%		Any identifier following such a keyword appears in 'procname' style.
-%		For Pascal you might use
-% \begin{verbatim}
-%    prockeywords={program,procedure,function}\end{verbatim}
-%
-% \item[0.19,new,optional] |procnamestyle=|\meta{style for procedure names}
-%
-%		defines the style in which procedure and function names appear.
-%
-% \item[0.19,new,optional] |indexprocnames=|\meta{true$\vert$false}
-%
-%		If activated, procedure and function names are also indexed (if used with |index| option).
-% \end{macrosyntax}
-%
-%
-% \section{Troubleshooting}
-%
-% The known bugs have already been described.
-% This section deals with problems concerning not only the \textsf{listings} package.
-%
-%
-% \subsection{Problems with \texttt{.fd} files}
-%
-% You probably get the following error message with a different font definition file:
-% \begin{verbatim}
-%! LaTeX Error: Command textparagraph unavailable in encoding T1.
-%
-%See the LaTeX manual or LaTeX Companion for explanation.
-%Type  H <return>  for immediate help.
-% ...
-%
-%l.68 \P
-%       rovidesFile{omscmr.fd}
-%?\end{verbatim}
-% So, what happened?
-% (a) The \textsf{listings} package redefines the character table to print listings.
-% (b) \LaTeX\ loads the font definition files on demand.
-% (a) plus (b) gives the error: \LaTeX\ loads the \texttt{.fd} files with modified character table.
-% And that goes wrong.
-% The work-around is quite easy: Input the \texttt{.fd} file before typesetting the listing.
-%
-%
-% \subsection{Language definitions}
-%
-% Language definitions and also some style definitions tend to have long definition parts.
-% This is why we tend to forget commas between the key=value elements.
-% If you select a language and get a |Missing = inserted for \ifnum| error, this is surely due to a missing comma after |keywords=|value.
-% If you encounter unexspected characters after selecting a language (or style), you have either forgotten a comma or you have given to many arguments to a key, for example |commentline={--}{!}|.
-%
-%
-% \section{Forthcoming}
-%
-% \begin{itemize}
-% \item I'd like to support more languages, for example Maple, Mathematica, PostScript, Reduce and so on.
-%		Fortunately my lifetime is limited, so other people may do that work.
-%		Write a language definition and (e-)mail it to me (with a proposal in which file to place the definition).
-%
-% \item There will possibly a boolean |blanklisting=|\meta{true$\vert$false} or a $*$-version of the environment.
-%
-% \item 'procnames' is already interesting, but marks (and indexes) only the function definitions so far.
-%		It would be quite easy to mark also the following function calls:
-%		Write another 'keyword class' which is empty at the very beginning (and can be reset with a key); each function definition appends a 'keyword' which will appear in 'procnamestyle'.
-%		But this would be another 'keyword test' within an inner loop.
-% \item I plan to put all language definitions in a single file.
-% \end{itemize}
-%
-%
-% \StopEventually{}
-%
-%
-% \part{Implementation}
-%
-% \CheckSum{5520}
-% \DoNotIndex{\[,\{,\},\],\1,\2,\3,\4,\5,\6,\7,\8,\9,\0}
-% \DoNotIndex{\`,\,,\!,\#,\$,\&,\',\(,\),\+,\.,\:,\;,\<,\=,\>,\?,\_}
-% \DoNotIndex{\@@end,\@@par,\@currenvir,\@depth,\@dottedtocline,\@ehc}
-% \DoNotIndex{\@empty,\@firstoftwo,\@gobble,\@gobbletwo,\@gobblefour,\@height}
-% \DoNotIndex{\@ifnextchar,\@ifundefined,\@namedef,\@ne,\@secondoftwo}
-% \DoNotIndex{\@spaces,\@starttoc,\@undefined,\@whilenum,\@width}
-% \DoNotIndex{\A,\active,\addtocontents,\advance,\aftergroup,\batchmode}
-% \DoNotIndex{\begin,\begingroup,\bfseries,\bgroup,\box,\bigbreak,\bullet}
-% \DoNotIndex{\c@page,\catcode,\contentsname,\csname,\def,\divide,\do,\dp}
-% \DoNotIndex{\edef,\egroup,\else,\end,\endcsname,\endgroup,\endinput}
-% \DoNotIndex{\endlinechar,\escapechar,\everypar,\expandafter,\f@family}
-% \DoNotIndex{\fi,\footnotesize,\gdef,\global,\hbox,\hss,\ht}
-% \DoNotIndex{\if,\ifdim,\iffalse,\ifnum,\ifodd,\iftrue,\ifx}
-% \DoNotIndex{\ignorespaces,\index,\input,\itshape,\kern}
-% \DoNotIndex{\lccode,\l@ngrel@x,\leftskip,\let,\linewidth,\llap}
-% \DoNotIndex{\long,\lowercase,\m@ne,\makeatletter,\mathchardef}
-% \DoNotIndex{\message,\multiply,\NeedsTeXFormat,\newbox,\new@command}
-% \DoNotIndex{\newcommand,\newcount,\newdimen,\newtoks,\noexpand}
-% \DoNotIndex{\noindent,\normalbaselines,\normalbaselineskip}
-% \DoNotIndex{\offinterlineskip,\par,\parfillskip,\parshape}
-% \DoNotIndex{\parskip,\ProcessOptions,\protect,\ProvidesPackage}
-% \DoNotIndex{\read,\relax,\removelastskip,\rightskip,\rlap,\setbox}
-% \DoNotIndex{\smallbreak,\smash,\space,\string,\strut,\strutbox}
-% \DoNotIndex{\the,\thepage,\ttdefault,\ttfamily,\tw@,\typeout,\uppercase}
-% \DoNotIndex{\vbox,\vcenter,\vrule,\vtop,\wd,\xdef,\z@,\zap@space}
-% \DoNotIndex{\char,\closeout,\immediate,\newwrite,\openout,\write}
-% \DoNotIndex{\vskip}
-%
-% \DoNotIndex{\define@key,\setkeys}
-%
-% \DoNotIndex{\textasciicircum,\textasciitilde,\textasteriskcentered}
-% \DoNotIndex{\textbackslash,\textbar,\textbraceleft,\textbraceright}
-% \DoNotIndex{\textdollar,\textendash,\textgreater,\textless}
-% \DoNotIndex{\textunderscore,\textvisiblespace}
-%
-% \DoNotIndex{\filename@area,\filename@base,\filename@ext}
-% \DoNotIndex{\filename@parse,\IfFileExists,\InputIfFileExists}
-% \DoNotIndex{\DeclareOption,\MessageBreak}
-% \DoNotIndex{\GenericError,\GenericInfo,\GenericWarning}
-%
-% \DoNotIndex{\blankstringfalse,\blankstringtrue,\commentstyle}
-% \DoNotIndex{\DeclareCommentLine,\DeclareDoubleComment}
-% \DoNotIndex{\DeclareNestedComment,\DeclarePairedComment}
-% \DoNotIndex{\DeclareSingleComment,\inputlisting,\inputlisting@,\keywords}
-% \DoNotIndex{\keywordstyle,\labelstyle,\listingfalse,\listingtrue}
-% \DoNotIndex{\morekeywords,\normallisting,\postlisting,\prelisting}
-% \DoNotIndex{\selectlisting,\sensitivefalse,\sensitivetrue}
-% \DoNotIndex{\spreadlisting,\stringizer,\stringstyle,\tablength}
-%
-% \DoNotIndex{\lst@AddToHook@,\lst@Aspect@,\is,\lst@AspectGobble}
-% \DoNotIndex{\lst@DeleteKeysIn@,\lst@Environment@}
-% \DoNotIndex{\lst@IfNextChars@,\lst@IfNextChars@@,\lst@KCOutput@}
-% \DoNotIndex{\lst@MakeActive@,\lst@MSkipUptoFirst@,\lst@ReplaceIn@}
-% \DoNotIndex{\lst@LocateLanguage@,\lst@SKS@,\lstalias@,\lstalias@@}
-% \DoNotIndex{\lstbaseem@,\lstbox@,\lstCC@ECUse@,\lstCC@Escape@}
-% \DoNotIndex{\lstCC@CBC@,\lstCC@CBC@@,\lstCC@CommentLine@}
-% \DoNotIndex{\lstCC@EndKeywordComment@,\lstCC@FixedCL@}
-% \DoNotIndex{\lstCC@ProcessEndPOD@,\lstCC@SpecialUseAfter@}
-% \DoNotIndex{\lstCC@Stringizer@,\lstdrvlanguage@,\lstenv@AddArg@}
-% \DoNotIndex{\lstenv@Process@,\lstenv@ProcessJ@,\lstinputlisting@}
-% \DoNotIndex{\lstoutputpos@,\lstresetlineno@,\lstresetlineno@@}
-% \DoNotIndex{\lstspread@}
-% \DoNotIndex{\lstnestedcomment@,\lstpost@,\lstpre@,\lststringizer@}
-%
-%
-% \section{Overture}
-%
-% The version 0.19 kernel needs 1 token register, 6 counters and 5 dimensions.
-% The macros, boxes and counters |\@temp?a| and |\@temp?b| and the dimension |\@tempdima| are also used, see the index.
-% And I shouldn't forget |\@gtempa|.
-% Furthermore, the required \textsf{keyval} package allocates one token register.
-% The \textsf{fancyvrb} interface needs one box.
-%
-% Before considering the implementation, here some conventions I used:
-% \begin{itemize}
-% \item All public macros have lower case letters and the prefix \lst.
-% \item The name of all private macros and variables use the prefixes (possibly not up to date):
-%	\begin{itemize}
-%	\item |lst@| for a general macro or variable,
-%	\item |lstenv@| if it is defined for the listing |env|ironment,
-%	\item |lstCC@| for |c|haracter |c|lass macros,
-%	\item |lsts@| for |s|aved character meanings,
-%	\item |lstf@| for frame declaration,
-%	\item |\lsthk@|\meta{name of hook} holds hook material,
-%	\item a language may define (|Pre| for prepare, |SCT| for select char table)
-%		\begin{itemize}
-%		\item[] |\lstPre@|\meta{language}
-%		\item[] |\lstPre@|\meta{language}|@|\meta{dialect}
-%		\item[] |\lstSCT@|\meta{language}
-%		\item[] |\lstSCT@|\meta{language}|@|\meta{dialect}
-%		\end{itemize}
-%		where the first two are executed (if they exist) one time each listing (before selecting character table, but after executing the hook Before\-Select\-Char\-Table).
-%		The other two macros are called possibly more than once, namely whenever the package selects the character table.
-%		The specialized \meta{dialect} versions are called after the more general \meta{language} macros.
-%	\item |lstk@| is reserved for keyword tests,
-%
-%	\item |\lstlang@|\meta{language}|@|\meta{dialect} contains a language definition,
-%	\item |\lststy@|\meta{the style} contains style definition,
-%
-%	\item |\lstloc@|\meta{language} keeps location (= file name without extension) of a language definition if it's not |lst|\meta{language},
-%	\item |\lsta@|\meta{language}|@|\meta{dialect} contains alias,
-%	\item |\lstaa@|\meta{language} contains alias for all dialects of a language,
-%	\item |\lstdd@|\meta{language} contains default dialect of a language (if present).
-%	\end{itemize}
-% \item If a submacro does the main work, e.g.\ |\lstinputlisting@| does it for |\lstinputlisting|, we use the suffix |@|.
-% \item To distinguish procedure-like macros from macros holding data, the name of procedure macros use upper case letters with each beginning word, e.g.\ |\lst@AddTo|.
-% \end{itemize}
-%
-% The kernel starts with identification and option declaration and processing.
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-\NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{listings}[1998/11/09 v0.19 by Carsten Heinz]
-\RequirePackage{keyval}
-%    \end{macrocode}
-%    \begin{macrocode}
-\DeclareOption{0.17}{\@namedef{[email protected]}{}}
-\DeclareOption{index}{\@namedef{lst@index}{}}
-\DeclareOption{procnames}{\@namedef{lst@prockeywords}{}}
-\DeclareOption{ndkeywords}{\@namedef{lst@ndkeywords}{}}
-\DeclareOption{rdkeywords}{\@namedef{lst@rdkeywords}{}}
-\DeclareOption{doc}{\@namedef{lst@doc}{}}
-\ProcessOptions
-%</kernel>
-%    \end{macrocode}
-% Note that |doc| option is designed for this documentation only.
-% \endgroup
-%
-% \begingroup
-%    \begin{macrocode}
-%<*info>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@InfoInfo}
-% \begin{macro}{\lst@InfoWarning}
-% \begin{macro}{\lst@InfoError}
-% Each macro gets one argument, which is printed (\texttt{.log} and/or screen) as info, warning or error.
-%    \begin{macrocode}
-\def\lst@InfoInfo#1{%
-    \GenericInfo %
-    {(Listings) \@spaces\@spaces\space\space}%
-    {Listings Info: #1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@InfoWarning#1{%
-    \GenericWarning %
-    {(Listings) \@spaces\@spaces\@spaces\space}%
-    {Listings Warning: #1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@InfoError#1{%
-    \GenericError %
-    {(Listings) \@spaces\@spaces\@spaces\space}%
-    {Listings Error: #1}%
-    {See the package documentation for explanation.}%
-    {You're using a debug version of listings.sty.^^J%
-     Contact your system administrator to install nondebug one.}}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</info>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{General problems and \TeX{}niques}
-%
-%
-% \subsection{Quick 'if parameter empty'}
-%
-% There are many situations where you have to look whether or not a macro parameter is empty.
-% Let's say, we want to test |#1|.
-% The \emph{natural} way would be something like
-% \begin{verbatim}
-%     \def\test{#1}%
-%     \ifx \test\empty %
-%             % #1 is empty
-%     \else %
-%             % #1 is not empty
-%     \fi %\end{verbatim}
-% where |\empty| is defined by |\def\empty{}|, of course.
-% And now the \emph{mad} way:
-% \begin{verbatim}
-%     \ifx \empty#1\empty %
-%             % #1 is empty
-%     \else %
-%             % #1 is not empty
-%     \fi %\end{verbatim}
-% If the parameter is empty, the |\empty| left from |#1| is compared with the |\empty| on the right.
-% All is fine since they are the same.
-% If the parameter is not empty, the |\empty| on the left is compared with the first token of the parameter.
-% Assuming this token is not equivalent to |\empty| the |\else| section is executed, as desired.
-%
-% The mad way works if and only if the first token of the parameter is not equivalent to |\empty|.
-% You must check if this meets your purpose.
-% The two |\empty|s might be replaced by any other macro, which is not equivalent to the first token of the parameter.
-% But the definition of that macro shouldn't be too complex since this would slow down the |\ifx|.
-% In the examples above the mad version needs about $45\%$ of the natural's time.
-% Note that this \TeX{}nique lost its importance from version 0.18 on.
-%
-%
-% \subsection{Replacing characters}\label{iReplacingCharacters}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% In this section we define the macro
-% \begin{macrosyntax}
-% \item	|\lst@ReplaceIn|\meta{macro}|{|\meta{replacement list $c_1m_1$\ldots$c_nm_n$}|}|
-% \end{macrosyntax}
-% Each character $c_i$ inside the given macro is replaced by the macro $m_i$.
-% In fact, $c_i$ may be a character sequence (enclosed in braces and possibly containing macros), but $m_i$ must be a single macro which is not equivalent to |\empty| --- use |\relax| instead.
-% |\lst@ReplaceIn\lst@arg{_\textunderscore {--}\textendash}| is allowed but not |\lst@ReplaceIn\lst@arg{\textunderscore_\textendash{--}}|.
-% These restrictions can be dropped, see the TODO part below.
-%
-% We derive the main macro from \LaTeX's |\zap@space|:
-% \begin{verbatim}
-%     \def\zap@space#1 #2{%
-%       #1%
-%       \ifx#2\@empty\else\expandafter\zap@space\fi
-%       #2}\end{verbatim}
-% It is called like this:
-% \begin{verbatim}
-%     \zap@space Some characters with(out) sense and \@empty
-%     \expandafter\zap@space\lst@arg{} \@empty
-%     \edef\lst@arg{\expandafter\zap@space\lst@arg{} \@empty}\end{verbatim}
-% Note that |{}|\textvisiblespace\ produces a space holding up the syntax of |\zap@space|: it's defined with a space between the two parameters.
-% If we want to replace a space by a visible space, we could use
-% \begin{verbatim}
-%     \def\lst@temp#1 #2{%
-%       #1%
-%       \ifx#2\@empty\else %
-%           \noexpand\textvisiblespace %
-%           \expandafter\lst@temp %
-%       \fi #2}\end{verbatim}
-% The additional |\noexpand\textvisiblespace| inserts visible spaces where spaces have been.
-% We want to replace several characters and thus have to save our intermediate results.
-% So we will follow the third '|\edef|' example.
-% But there is some danger: After replacing the first character, the macro $m_1$ will expand inside the next |\edef|.
-% Knowing that letters don't expand, we simply say that $m_1$ is a letter.
-% Such changes must be local, so \ldots
-%
-% \begin{macro}{\lst@ReplaceIn}
-% we open a group, store the original macro contents in |\@gtempa| and start a loop.
-% Afterwards we close the group and assign the modified character string to our given macro.
-%    \begin{macrocode}
-\def\lst@ReplaceIn#1#2{%
-    \bgroup \global\let\@gtempa#1%
-    \lst@ReplaceIn@#2\@empty\@empty %
-    \egroup \let#1\@gtempa}
-%    \end{macrocode}
-% If we haven't reached the end of the list (the two |\@empty|s), we let the macro $m_i$ be a letter and define an appropiate macro to replace the character (sequence) |#2| by the macro |#3|.
-%    \begin{macrocode}
-\def\lst@ReplaceIn@#1#2{%
-    \ifx\@empty#2\else %
-        \let#2=a%
-        \def\lst@temp##1#1##2{##1%
-            \ifx\@empty##2\else %
-                #2\expandafter\lst@temp %
-            \fi ##2}%
-%    \end{macrocode}
-% Now we call that macro using |\xdef| (since the changes in |\@gtempa| must exist after closing a group).
-% Finally we continue the loop.
-%    \begin{macrocode}
-        \xdef\@gtempa{\expandafter\lst@temp\@gtempa#1\@empty}%
-        \expandafter\lst@ReplaceIn@ %
-    \fi}
-%    \end{macrocode}
-% \begin{TODO}
-% This |\lst@ReplaceIn| is currently sufficient.
-% If we need to replace character sequences by character sequences (instead of single macros), we have to make some minor changes.
-% The main difference is that we build the new contents inside |\lst@temp| instead of using |\edef|.
-% Note that the improved version is much slower than the macros above.\vspace*{-\baselineskip}
-% \begin{verbatim}
-%\def\lst@ReplaceIn#1#2{\lst@ReplaceIn@#1#2\@empty\@empty}
-%\def\lst@ReplaceIn@#1#2#3{%
-%    \ifx\@empty#3\else %
-%        \def\lst@temp##1#2##2{%
-%            \ifx\@empty##2%
-%                \lst@lAddTo#1{##1}%
-%            \else %
-%                \lst@lAddTo#1{##1#3}%
-%                \expandafter\lst@temp %
-%            \fi ##2}%
-%        \let\@tempa#1\let#1\@empty %
-%        \expandafter\lst@temp\@tempa#2\@empty %
-%        \expandafter\lst@ReplaceIn@\expandafter#1%
-%    \fi}\end{verbatim}
-% \removelastskip
-% Even here you will have a problem replacing a single brace, if it has the meaning of opening or closing a group:
-% You can't enter it as an argument!
-% \end{TODO}
-% \end{macro}
-%
-% \begin{macro}{\lst@DeleteKeysIn}
-% We define another macro, which looks quite similar to |\lst@ReplaceIn|.
-% The arguments are two macros containing a comma separated keyword list.
-% All keywords in the second list are removed from the first.
-%    \begin{macrocode}
-\def\lst@DeleteKeysIn#1#2{%
-    \bgroup \global\let\@gtempa#1%
-    \let\lst@dollar=A\let\lst@minus=B\let\lst@underscore=C%
-    \expandafter\lst@DeleteKeysIn@#2,\relax,%
-    \egroup \let#1\@gtempa}
-%    \end{macrocode}
-% To terminate the loop we remove the very last |\lst@DeleteKeysIn@| with |\@gobble|.
-%    \begin{macrocode}
-\def\lst@DeleteKeysIn@#1,{%
-    \ifx\relax#1\@empty %
-        \expandafter\@gobble %
-    \else %
-        \ifx\@empty#1\@empty\else %
-            \def\lst@temp##1,#1##2{##1\ifx\@empty##2\else %
-                \ifx,##2\else #1\fi \expandafter\lst@temp\fi ##2}%
-            \xdef\@gtempa{%
-                \expandafter\lst@temp\expandafter,\@gtempa,#1\@empty}%
-        \fi %
-    \fi %
-    \lst@DeleteKeysIn@}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Looking ahead for character sequences}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@IfNextChars}
-% The macro |\@ifnextchar|\meta{single character}|{|\meta{then part}|}{|\meta{else part}|}| from the \LaTeX{} kernel is well known:
-% Whether or not the character behind the three arguments --- usually a character from the 'user input stream' --- equals the given single character the 'then' or 'else' part is executed.
-% We define a macro which looks for an arbitrary character sequence stored in a macro:{}
-% \begin{macrosyntax}
-% \item |\lst@IfNextChars|\meta{macro}|{|\meta{then part}|}{|\meta{else part}|}|
-% \end{macrosyntax}
-% Note an important difference:
-% \LaTeX's |\@ifnextchar| doesn't remove the character behind the arguments, but we remove the characters until it is possible to decide whether the 'then' or 'else' part must be executed.
-% However, we save these characters in a macro called |\lst@eaten|, so they can be inserted if necessary.
-%
-% We save the arguments and call the macro which does the comparisons.
-%    \begin{macrocode}
-\def\lst@IfNextChars#1#2#3{%
-    \let\lst@tofind#1\def\@tempa{#2}\def\@tempb{#3}%
-    \let\lst@eaten\@empty \lst@IfNextChars@}
-%    \end{macrocode}
-% This macro reads the next character from the input and compares it with the next character from |\lst@tofind|.
-% We append |#1| to the eaten characters and get the character we are looking for (via |\lst@IfNextChars@@|).
-%    \begin{macrocode}
-\def\lst@IfNextChars@#1{%
-    \lst@lAddTo\lst@eaten{#1}%
-    \expandafter\lst@IfNextChars@@\lst@tofind\relax %
-    \ifx #1\lst@temp %
-%    \end{macrocode}
-% If the characters are the same, we either execute |\@tempa| or continue the test.
-%    \begin{macrocode}
-        \ifx\lst@tofind\@empty %
-            \let\lst@next\@tempa %
-        \else %
-            \let\lst@next\lst@IfNextChars@ %
-        \fi %
-        \expandafter\lst@next %
-    \else %
-%    \end{macrocode}
-% If the characters are different, we have to call |\@tempb|.
-%    \begin{macrocode}
-        \expandafter\@tempb %
-    \fi}
-%    \end{macrocode}
-% Finally comes the subsubmacro |\lst@IfNextChars@@| used above, which assigns the next character to |\lst@temp| and the rest upto |\relax| to |\lst@tofind|.
-% If the implementation is not clear, read the last sentence again.
-%    \begin{macrocode}
-\def\lst@IfNextChars@@#1#2\relax{\let\lst@temp#1\def\lst@tofind{#2}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@IfNextCharsArg}
-% The difference between |\lst@IfNextChars| and the macro here is that the first parameter is a character sequence and not a macro.
-% Moreover, the character sequence is made active here.
-%    \begin{macrocode}
-\def\lst@IfNextCharsArg#1#2#3{%
-    \lst@MakeActive{#1}\let\lst@tofind\lst@arg %
-    \def\@tempa{#2}\def\@tempb{#3}%
-    \let\lst@eaten\@empty \lst@IfNextChars@}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Catcode changes of characters already read}\label{iCatcodeChangesOfCharactersAlreadyRead}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% Here we define two important macros:
-% \begin{macrosyntax}
-% \item	|\lst@MakeActive{|\meta{character sequence}|}|
-%
-%	stores the character sequence in |\lst@arg|, but all characters become active.
-%	The string must \emph{not} contain a begin group, end group or escape character (|{}\|); it may contain a left brace, right brace or backslash with other meaning (=catcodes).
-%	This command would be quite surplus if \meta{character sequence} is not already read by \TeX{} (since such catcodes can be changed easily).
-%	It is explicitly allowed that the charcaters have been read, e.g.\ in |\def\test{\lst@MakeActive{ABC}}| |\test|!
-%
-%	Note that |\lst@MakeActive| changes |\lccode|s 0--9 without restoring them.
-% \item	|\lst@IfNextCharActive{|\meta{then part}|}{|\meta{else part}|}|
-%
-%	executes 'then' part if next character behind the arguments is active, and the 'else' part otherwise.
-% \end{macrosyntax}
-% \TeX{} knows sixteen different catcodes, which say whether a character is a letter, a space, a math shift character, subscript character, and so on.
-% A character gets its catcode right after reading it and \TeX{} has no primitive command to change a catcode of characters already read.
-% Consider for example |\def\mathmode#1{$#1$}|.
-% After that definition there is no chance to say: ''\emph{Print} the two dollar signs and the argument between instead of entering math mode''.
-% And if we write |\mathmode{a_i}| and have just entered the macro |\mathmode|, the argument |a_i| is read and it's too late to change the meaning of the subscript character to a printable underbar, for example.
-% But that's not the whole truth: We can change character-catcodes of an argument.
-% In fact, we replace the characters by characters with same ASCII codes but different catcodes.
-% It's not the same but suffices since the result is the same.
-% Here we treat the very special case that all characters become active.
-% A prototype macro would be
-% \begin{verbatim}
-%     \def\MakeActive#1{\lccode`\~=`#1\lowercase{\def\lst@arg{~}}}|\end{verbatim}
-% But this macro handles a single character only:
-% The |\lowercase| changes the ASCII code of |~| to that of |#1| since we have said that |~| is the lower case version of |#1|.
-% Fortunately the |\lowercase| doesn't change the catcode, so we have an active version of |#1|.
-% Note that |~| is usually active.
-%
-% \begin{macro}{\lst@MakeActive}
-% We won't do this character by character.
-% To increase speed we change nine characters at the same time (if nine characters are left).
-% We get the argument, empty |\lst@arg| and begin a loop:
-%    \begin{macrocode}
-\def\lst@MakeActive#1{%
-    \let\lst@arg\@empty \lst@MakeActive@#1%
-    \relax\relax\relax\relax\relax\relax\relax\relax\relax}
-%    \end{macrocode}
-% There are nine |\relax|es since |\lst@MakeActive@| has nine parameters and we don't want any problems in the case that |#1| is empty.
-% We need nine active characters now instead of a single |~|.
-% We make these catcode changes local and define the coming macro |\global|.
-%    \begin{macrocode}
-\begingroup
-\catcode`\^^@=\active \catcode`\^^A=\active \catcode`\^^B=\active %
-\catcode`\^^C=\active \catcode`\^^D=\active \catcode`\^^E=\active %
-\catcode`\^^F=\active \catcode`\^^G=\active \catcode`\^^H=\active %
-%    \end{macrocode}
-% First we |\let| the next operation be |\relax|.
-% This aborts our loop for processing all characters (default and possibly changed later).
-% Then we look if we have at least one character.
-% If this is not the case, the loop terminates and all is done.
-%    \begin{macrocode}
-\gdef\lst@MakeActive@#1#2#3#4#5#6#7#8#9{\let\lst@next\relax %
-    \ifx#1\relax %
-    \else \lccode`\^^@=`#1%
-%    \end{macrocode}
-% Otherwise we say that |^^@|=chr(0) is the lower case version of the first character.
-% Then we test the second character.
-% If there is none, we append the lower case |^^@| to |\lst@arg|.
-% Otherwise we say that |^^A|=chr(1) is the lower case version of the second character and we test the next argument, and so on.
-%    \begin{macrocode}
-    \ifx#2\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@}}%
-    \else \lccode`\^^A=`#2%
-    \ifx#3\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A}}%
-    \else \lccode`\^^B=`#3%
-    \ifx#4\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B}}%
-    \else \lccode`\^^C=`#4%
-    \ifx#5\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B^^C}}%
-    \else \lccode`\^^D=`#5%
-    \ifx#6\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B^^C^^D}}%
-    \else \lccode`\^^E=`#6%
-    \ifx#7\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B^^C^^D^^E}}%
-    \else \lccode`\^^F=`#7%
-    \ifx#8\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B^^C^^D^^E^^F}}%
-    \else \lccode`\^^G=`#8%
-    \ifx#9\relax %
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B^^C^^D^^E^^F^^G}}%
-%    \end{macrocode}
-% If nine characters are present, we append (lower case versions of) nine active characters and call this macro again via redefining |\lst@next|.
-%    \begin{macrocode}
-    \else \lccode`\^^H=`#9%
-        \lowercase{\lst@lAddTo\lst@arg{^^@^^A^^B^^C^^D^^E^^F^^G^^H}}%
-        \let\lst@next\lst@MakeActive@ %
-    \fi \fi \fi \fi \fi \fi \fi \fi \fi %
-    \lst@next}
-\endgroup
-%    \end{macrocode}
-% This |\endgroup| restores the catcodes of chr(0)--chr(8), but not the catcodes of the characters inside |\lst@MakeActive@| since they are already read.
-% \end{macro}
-%
-% \begin{macro}{\lst@IfNextCharActive}
-% The implementation is easy now: We compare the character |#3| with its active version |\lowercase{~}|.
-% Note that the right brace between |\ifx~| and |#3| ends the |\lowercase|.
-% The |\egroup| before restores the |\lccode|.
-%    \begin{macrocode}
-\def\lst@IfNextCharActive#1#2#3{%
-    \bgroup \lccode`\~=`#3\lowercase{\egroup %
-    \ifx~}#3%
-        \def\lst@next{#1#3}%
-    \else %
-        \def\lst@next{#2#3}%
-    \fi \lst@next}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{An application to \ref{iCatcodeChangesOfCharactersAlreadyRead}}\label{iAnApplicationTo}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% We need a brief look on how the listing processing works.
-% Right before processing a listing we redefine all characters, for example to preserve successive spaces or to give the tabulator a different meaning.
-% More precisely, each character becomes active in the sense of \TeX, but that's not so important now.
-% After the listing we switch back to the original meanings and all is fine.
-% If an environment is used inside an argument the listing is already read when the environment is executed and we can do nothing to preserve the characters.
-% However, (under certain circumstances) the environment can be used inside an argument --- that's at least what I've said in the user's guide.
-% And now we have to work for it coming true.
-% We define the macro
-% \begin{macrosyntax}
-% \item	|\lstenv@AddArg{|\meta{\TeX{} material (already read)}|}|
-% \end{macrosyntax}
-% which \emph{appends} a 'verbatim' version of the argument to |\lstenv@arg|, but all appended characters are active.
-% Since it's not a character to character conversion, 'verbatim' needs to be explained.
-% All characters can be typed in as they are, except |\|, |{|, |}| and |%|.
-% If you want one of these, you must write |\\|, |\{|, |\}| or |\%| instead.
-% If two spaces should follow each other, the second (third, fourth, \ldots) space must be entered as |\|\textvisiblespace.
-%
-% \begin{macro}{\lstenv@AddArg}
-% We call a submacro (similar to |\zap@space|) to preserve single spaces.
-%    \begin{macrocode}
-\def\lstenv@AddArg#1{\lstenv@AddArg@#1 \@empty}
-%    \end{macrocode}
-% We will need an active space:
-%    \begin{macrocode}
-\begingroup \lccode`\~=`\ \relax \lowercase{%
-%    \end{macrocode}
-% We make all characters upto the first space (with catcode 10) active and append these (plus an active space) to |\lstenv@arg|.
-% If we haven't found the end |\@empty| of the input, we continue the process.
-%    \begin{macrocode}
-\gdef\lstenv@AddArg@#1 #2{%
-    \lst@MakeActive{#1}%
-    \ifx\@empty#2\expandafter%
-        \lst@lAddTo\expandafter\lstenv@arg\expandafter{\lst@arg}%
-    \else \expandafter%
-        \lst@lAddTo\expandafter\lstenv@arg\expandafter{\lst@arg~}%
-        \expandafter\lstenv@AddArg@ %
-    \fi #2}
-%    \end{macrocode}
-% Finally we end the |\lowercase| and close a group.
-%    \begin{macrocode}
-}\endgroup
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{How to define \lst-aspects}\label{iHowToDefineLstAspects}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% This section contains commands used in defining the style and language aspects.
-% There are two command classes: one extends the internal capabilities, and the other actually defines the aspects.
-% \begin{macrosyntax}
-% \item	|\lst@Aspect{|\meta{aspect name}|}{|\meta{definition}|}|
-%
-%		is the one and only command in the latter class.
-%		It defines the aspect using the \textsf{keyval} package.
-%
-% \item	|\lst@AddToHook||{|\meta{name of hook}|}{|\meta{\TeX{} material}|}|
-%
-% \item	|\lst@AddToHookAtTop||{|\meta{name of hook}|}{|\meta{\TeX{} material}|}|
-%
-%		Both add \TeX{} material at predefined points.
-%		The first command appends the code, whereas the second places it in front of existing hook material.
-% \end{macrosyntax}
-% The following hooks are supported (possibly not up to date):
-% \begin{center}\begin{tabular}{rp{0.6\linewidth}}
-%	name of hook & point/aim of execution\\ \hline
-%	|InitVars| & initializes variables each listing\\
-%	|ExitVars| & deinits variables each listing\\
-%	|OnExit| & executed at the very end of typesetting\\
-%	|EveryLine| & called at the beginning of each line\\
-%	|EOL| & executed after printing a source code line\\
-%	|InitVarsEOL| & prepares variables for the next line\\
-%	|EndGroup| & executed whenever the package closes a group (end of comment or string, e.g.)\\
-%	|Output| & called before a printing unit with letters and digits is typeset\\
-%	|OutputOther| & called before any other printing unit is typeset\\
-%	|BeforeSelectCharTable| & executed before the package changes the character table\\
-%	|SelectCharTable| & executed after the package has selected the standard character table\\
-%	&\\
-%	|SetStyle| & called before |\lststy@|\meta{style}\\
-%	|SetLanguage| & called before |\lstlang@|\meta{language}|@|\meta{dialect}\\
-% \end{tabular}\end{center}
-% For example, the hooks make keywords case insensitive (if necessary) before the package processes a listing and call the keyword style before a keyword is printed.
-%
-% \begin{macro}{\lst@Aspect}
-% The command defines the aspect only if not already present.
-% |\lst@ifnew| becomes true (if and) only if a new aspect is defined.
-%    \begin{macrocode}
-\def\lst@Aspect#1{%
-    \@ifundefined{KV@lst@#1}%
-        {\let\lst@ifnew\iftrue}{\let\lst@ifnew\iffalse}%
-    \lst@ifnew %
-%<info>        \lst@InfoInfo{New aspect `#1'}%
-    \else %
-%<info>        \lst@InfoWarning{Gobble aspect `#1'}%
-        \expandafter\@gobblefour %
-    \fi %
-    \lstdefine@key{lst}{#1}}
-%    \end{macrocode}
-% Now come renamed copies from two \textsf{keyval} macros, but the key definitions are made globally.
-%    \begin{macrocode}
-\def\lstdefine@key#1#2{%
-    \@ifnextchar[{\lstKV@def{#1}{#2}}{\global\@namedef{KV@#1@#2}####1}}
-\def\lstKV@def#1#2[#3]{%
-    \global\@namedef{KV@#1@#2@default\expandafter}\expandafter %
-        {\csname KV@#1@#2\endcsname{#3}}%
-    \global\@namedef{KV@#1@#2}##1}
-%    \end{macrocode}
-%    \begin{macrocode}
-\let\lst@ifnew\iftrue % init
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@AddToHook}
-% \begin{macro}{\lst@AddToHookAtTop}
-% The definitions are mainly in terms of |\lst@AddTo| and |\lst@AddToAtTop|.
-% But we test whether the hook already exists.
-%    \begin{macrocode}
-\def\lst@AddToHook#1{%
-    \lst@ifnew %
-        \@ifundefined{lsthk@#1}{%
-%<info>            \lst@InfoInfo{New hook `#1'}%
-            \expandafter\gdef\csname lsthk@#1\endcsname{}}{}%
-        \def\lst@next{\lst@AddToHook@\lst@AddTo{#1}}%
-        \expandafter\lst@next %
-    \else %
-        \expandafter\@gobble %
-    \fi}
-%    \end{macrocode}
-% The submacro makes it possible to use \texttt{if}s inside the second argument (which is the third here).
-%    \begin{macrocode}
-\long\def\lst@AddToHook@#1#2#3{%
-    \expandafter#1\csname lsthk@#2\endcsname{#3}}
-%    \end{macrocode}
-% \begin{TODO}
-% The usage of |\lst@ifnew| is still unsatisfactory:
-% Defining an aspect and its hooks twice doesn't add the \TeX\ material a second time, but defining hooks and then the aspect would do so.
-% \end{TODO}
-%    \begin{macrocode}
-\def\lst@AddToHookAtTop#1{%
-    \lst@ifnew %
-        \@ifundefined{lsthk@#1}{%
-%<info>            \lst@InfoInfo{New hook `#1'}%
-            \expandafter\gdef\csname lsthk@#1\endcsname{}}{}%
-        \def\lst@next{\lst@AddToHook@\lst@AddToAtTop{#1}}%
-        \expandafter\lst@next %
-    \else %
-        \expandafter\@gobble %
-    \fi}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@AddTo}
-% \begin{macro}{\lst@AddToAtTop}
-% These macros add the second argument to the macro |#1|.
-% But the definition is global!
-%    \begin{macrocode}
-\long\def\lst@AddTo#1#2{%
-    \expandafter\gdef\expandafter#1\expandafter{#1#2}}
-%    \end{macrocode}
-% We need a couple of |\expandafter|s now.
-% Simply note that we have\\
-%	{\small\hspace*{2em}
-%	|\expandafter\gdef\expandafter#1\expandafter{\lst@temp|$\langle$\textit{contents of }|#1|$\rangle$|}|
-%	}\\
-% after the first phase of expansion.
-%    \begin{macrocode}
-\def\lst@AddToAtTop#1#2{\def\lst@temp{#2}%
-    \expandafter\expandafter\expandafter\gdef %
-    \expandafter\expandafter\expandafter#1%
-    \expandafter\expandafter\expandafter{\expandafter\lst@temp#1}}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@lAddTo}
-% A local version of |\lst@AddTo|.
-%    \begin{macrocode}
-\def\lst@lAddTo#1#2{\expandafter\def\expandafter#1\expandafter{#1#2}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begingroup
-% \noindent Since some hooks are unused and never defined by the hook macros above, we define them here:
-%    \begin{macrocode}
-\global\let\lsthk@OutputOther\@empty
-\global\let\lsthk@SetStyle\@empty
-\global\let\lsthk@SetLanguage\@empty
-\global\let\lsthk@PreSet\@empty
-\global\let\lsthk@PostSet\@empty
-%    \end{macrocode}
-% \endgroup
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Interfacing with \textsf{keyval}}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% The \textsf{keyval} package passes the value via the one and only paramater |#1| to the definition part of the aspect macro.
-% The following commands may be used to analyse the value.
-% \begin{macrosyntax}
-% \item |\lstKV@SetIfKey|\meta{macro}|{#1}|
-%
-%		\meta{macro} becomes true (more precisely |\iftrue|) if the first character of |#1| equals |t| or |T|.
-%		It becomes false otherwise.
-%
-% \item |\lstKV@OptArg|\meta{submacro}|[|\meta{default arg.}|]{#1}|
-%
-%	calls \meta{submacro} with |#1| and with inserted |[|\meta{default arg.}|]| if |#1| has no optional argument.
-% \end{macrosyntax}
-%
-% \begin{macro}{\lstKV@SetIfKey}
-% We simply test the first character of |#2|.
-%    \begin{macrocode}
-\def\lstKV@SetIfKey#1#2{\lstKV@SetIfKey@#1#2\relax}
-\def\lstKV@SetIfKey@#1#2#3\relax{\lowercase{%
-    \expandafter\let\expandafter#1%
-        \csname \ifx #2t}iftrue\else iffalse\fi\endcsname}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstKV@OptArg}
-% We read the arguments and insert default if necesary, what else?
-%    \begin{macrocode}
-\def\lstKV@OptArg#1[#2]#3{\lstKV@OptArg@{#1}{#2}#3\@}
-\def\lstKV@OptArg@#1#2{%
-    \@ifnextchar[{\lstKV@OptArg@@{#1}}%
-                 {\lstKV@OptArg@@{#1}[#2]}}
-\def\lstKV@OptArg@@#1[#2]#3\@{#1[#2]{#3}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstset}
-% Finally this main user interface macro:
-%    \begin{macrocode}
-\def\lstset#1{\lsthk@PreSet\setkeys{lst}{#1}\lsthk@PostSet}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Internal modes}\label{iInternalModes}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@mode}
-% \begin{macro}{\lst@EnterMode}
-% \begin{macro}{\lst@LeaveMode}
-% While typesetting a listing we will enter 'modes' to distinguish comments from strings, comment lines from single comments, \TeX\ comment lines from fixed comment lines, and so on.
-% The counter |\lst@mode| keeps the current mode number.
-%    \begin{macrocode}
-\newcount\lst@mode
-%    \end{macrocode}
-% Each mode opens a group level, stores the mode number and execute mode specific tokens.
-% Moreover we keep all these changes in mind (locally).
-%    \begin{macrocode}
-\def\lst@EnterMode#1#2{%
-    \bgroup \lst@mode=#1\relax #2%
-    \lst@lAddTo\lst@entermodes{\lst@EnterMode{#1}{#2}}}
-%    \end{macrocode}
-% Leaving a mode simply closes the group and calls the hook |\lsthk@EndGroup|.
-%    \begin{macrocode}
-\def\lst@LeaveMode{\egroup\lsthk@EndGroup}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVars}{\let\lst@entermodes\@empty}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lst@NewMode}
-% defines a new mode number.
-% We simply use |\mathchardef| and advance the number in |\lst@newmode|, which is a macro --- we don't waste another counter.
-%    \begin{macrocode}
-\def\lst@NewMode#1{%
-    \ifx\@undefined#1%
-        \global\mathchardef#1=\lst@newmode\relax %
-        \lst@mode=\lst@newmode\relax \advance\lst@mode\@ne %
-        \edef\lst@newmode{\the\lst@mode}%
-    \fi}
-%    \end{macrocode}
-% We start with number 0.
-% The negative range is reserved for nested comments.
-%    \begin{macrocode}
-\def\lst@newmode{0}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@nomode}
-% \begin{macro}{\lst@Pmode}
-% The very first mode initializes |\lst@mode| (every listing).
-% The other mode indicates active listing processing.
-%    \begin{macrocode}
-\lst@NewMode\lst@nomode
-\lst@AddToHook{InitVars}{\lst@modefalse \lst@mode\lst@nomode}
-\lst@NewMode\lst@Pmode
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@modetrue}
-% \begin{macro}{\lst@modefalse}
-% If |\lst@ifmode| is true, no mode change is allowed --- except leaving the mode.
-%    \begin{macrocode}
-\def\lst@modetrue{\let\lst@ifmode\iftrue}
-\def\lst@modefalse{\let\lst@ifmode\iffalse}
-%    \end{macrocode}
-% Note: |\lst@ifmode| is \emph{not} obsolete since |\lst@mode|$\neq$|\lst@nomode| does \emph{not} imply |\lst@ifmode|$=$|\iftrue|.
-% And even the other implication is not true.
-% It will happen that we enter a mode without setting |\lst@ifmode| true, and we'll set it true without assigning any mode!
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@InterruptModes}
-% \begin{macro}{\lst@ReenterModes}
-% Since we kept all mode changes in mind, it is possible two interrupt and re-enter the current mode.
-% This is useful for \TeX\ comment lines, for example.
-%    \begin{macrocode}
-\def\lst@InterruptModes{%
-    \ifx\lst@entermodes\@empty\else %
-        \global\let\lst@reenter\lst@entermodes %
-        \lst@LeaveAllModes %
-    \fi}
-%    \end{macrocode}
-% The last |\ifx| is not necessay since empty |\lst@entermodes| implies that we don't leave any mode.
-% But we need the |\ifx| in the following macro since empty |\lst@reenter| doesn't tell us anything about the current mode.
-%    \begin{macrocode}
-\def\lst@ReenterModes{%
-    \ifx\lst@reenter\@empty\else %
-        \lst@LeaveAllModes \lst@reenter %
-        \global\let\lst@reenter\@empty %
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVars}{\global\let\lst@reenter\@empty}
-%    \end{macrocode}
-% Note that these macros can't be nested:
-% If you 'interrupt modes', enter some modes and say 'interrupt modes' again, then two 're-enter modes' will \emph{not} take you back in front of the first 'interrupt modes'.
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@LeaveAllModes}
-% This is some kind of emergency macro.
-% Since any mode is terminated by closing a group, leaving all modes means closing groups until the mode equals |\lst@nomode|.
-% We'll need that macro to end a listing correctly.
-%    \begin{macrocode}
-\def\lst@LeaveAllModes{%
-    \ifnum\lst@mode=\lst@nomode %
-        \expandafter\lsthk@EndGroup %
-    \else %
-        \expandafter\egroup\expandafter\lst@LeaveAllModes %
-    \fi}
-\lst@AddToHook{ExitVars}{\lst@LeaveAllModes}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@egroupmode}
-% We allocate a 'processing mode' and define a general purpose 'egroup' mode: close a group at end of line.
-%    \begin{macrocode}
-\lst@NewMode\lst@egroupmode
-\lst@AddToHook{EOL}
-    {\ifnum\lst@mode=\lst@egroupmode \lst@LeaveMode \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Styles and languages}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@Normalize}
-% normalizes the contents of the macro |#1| by making all characters lower case and stripping off spaces.
-%    \begin{macrocode}
-\def\lst@Normalize#1{%
-    \lowercase\expandafter{\expandafter\edef\expandafter#1%
-    \expandafter{\expandafter\zap@space#1 \@empty}}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstdefinestyle}
-% The internal macro name of a style is |\lststy@|\emph{the style} (normalized).
-% If called, it simply sets the keys to given values.
-%    \begin{macrocode}
-\newcommand\lstdefinestyle[2]{%
-    \def\lst@temp{lststy@#1}\lst@Normalize\lst@temp %
-    \global\@namedef\lst@temp{\setkeys{lst}{#2}}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{style}
-% We give an error message if the necessary macro doesn't exist.
-%    \begin{macrocode}
-\lst@Aspect{style}
-    {\def\lst@temp{lststy@#1}\lst@Normalize\lst@temp %
-     \@ifundefined\lst@temp %
-        {\PackageError{Listings}{Style `#1' undefined}%
-         {You might have misspelt the name here or before.^^J%
-          Type <RETURN> to proceed without changing the style.}}%
-%    \end{macrocode}
-% Otherwise we execute the hook and call the macro.
-%    \begin{macrocode}
-        {\lsthk@SetStyle \csname\lst@temp\endcsname %
-%<info>         \lst@InfoInfo{\expandafter\string %
-%<info>             \csname\lst@temp\endcsname\space called}%
-        }}
-%    \end{macrocode}
-% \begin{TODO}
-% It's easy to crash the listings package with |style| (and also with |language|).
-% Define |\lstdefinestyle{crash}{style=crash}| and write |\lstset{style=crash}|.
-% \TeX's capacity will exceed (parameter stack size), sorry.
-% Only bad girls use such recursive calls, but only good girls use this package.
-% Thus this problem is of minor interest.
-% \end{TODO}
-% \end{aspect}
-%
-% \begin{macro}{\lstdefinelanguage}
-% Nearly |\lstdefinestyle|:
-%    \begin{macrocode}
-\newcommand\lstdefinelanguage[3][]{%
-    \def\@tempa{#2@#1}\lst@Normalize\@tempa %
-    \global\@namedef{lstlang@\@tempa}{\lstset{#3}}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstdefinedrvlanguage}
-% The driver file \texttt{lstpascal.sty} contains a couple of Pascal dialects.
-% It is unnecessary to hold all these dialects in memory if the user selects Standard Pascal only.
-% There are different scopes:
-% \begin{itemize}
-% \item[--]	All code outside any (style or language) definition is executed.
-%		Definitions should be |\global| since a driver file is input inside a group.
-%		Note also that |@| is a letter and |"| has catcode 12 (other).
-% \item[--]	All languages declared with |\lstdefinelanguage| are defined.
-% \item[--] A language declared with |\lstdefinedrvlanguage| is defined if and only if the user has requested that language.
-% \end{itemize}
-% We either do the definition or drop it:
-%    \begin{macrocode}
-\newcommand\lstdefinedrvlanguage[3][]{%
-    \def\@tempa{lstlang@#2@#1}\lst@Normalize\@tempa %
-    \ifx\@tempa\lst@requested %
-        \global\@namedef{\@tempa}{\lstset{#3}}%
-    \fi}
-%    \end{macrocode}
-% \begin{TODO}
-% The command syntax is liable to changes.
-% I conjecture that it will be something like the following.
-% \begin{macrosyntax}
-% \item[0.2] |\lstdefinedrvlanguage|[|[|\meta{dialect}|]|]|{|\meta{language}|}|\\
-%		\qquad[|[|\meta{base dialect}|]|]|{|\meta{base language (e.g.\ empty)}|}|\\
-%		\qquad|{|\meta{key=value list}|}|\\
-%		\qquad[|[|\meta{list of extras (keywordcomments,texcs,etc.)}|]|]
-% \end{macrosyntax}
-% To make 'extras' user assessible (without loading a language) a command |\lstloadextras| would be nice.
-% In any case such a macro is needed to load the extras for the supported languages.
-% All in all there should be the following files in future: The kernel |listings.sty|, the language definitions in |lstdrvrs.sty| (or |lstdef.sty|?) and extras in a file |lstextra.sty|.
-% \end{TODO}
-% \end{macro}
-%
-% \begin{macro}{\lstloadlanguages}
-% We iterate through the list and locate and load each language.
-%    \begin{macrocode}
-\def\lstloadlanguages#1{\lstloadlanguages@#1,\relax,}
-\def\lstloadlanguages@#1,{%
-    \ifx\relax#1\@empty \else %
-        \lstKV@OptArg\lstloadlanguages@@[]{#1}%
-        \expandafter\lstloadlanguages@ %
-    \fi}
-\def\lstloadlanguages@@[#1]#2{%
-    \lst@LocateLanguage[#1]{#2}%
-    \@ifundefined{\lst@requested}%
-        {{\catcode`\^^M=9\catcode`\"=12\makeatletter %
-          \input{\[email protected]}}}%
-        {}}
-\@onlypreamble\lstloadlanguages
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{language}
-% If the language macro |\lstlang@|\emph{language}|@|\emph{dialect} doesn't exist, we must load the driver file.
-% In that case the character |@| becomes a letter and we change the catcode of the double quote for compatibility with \texttt{german.sty}.
-% Moreover we make the EOL character being ignored (which removes unwanted spaces if we've forgotten |%| at end of line).
-%    \begin{macrocode}
-\lst@Aspect{language}{\lstKV@OptArg\lstlanguage@[]{#1}}
-\def\lstlanguage@[#1]#2{%
-    \lst@LocateLanguage[#1]{#2}%
-    \@ifundefined{\lst@requested}%
-        {{\catcode`\^^M=9\catcode`\"=12\makeatletter %
-          \input{\[email protected]}}}{}%
-%    \end{macrocode}
-% We give an error message, if the language/dialect is undefined now.
-%    \begin{macrocode}
-    \@ifundefined{\lst@requested}%
-        {\PackageError{Listings}%
-         {\ifx\@empty\lst@dialect@\else \lst@dialect@\space of \fi %
-          \lst@language@\space undefined}{The driver file is not
-          loadable or doesn't support the language.^^J%
-         Type <RETURN> to proceed without changing the language.}}%
-%    \end{macrocode}
-% Otherwise we execute the hook and select the language.
-%    \begin{macrocode}
-        {\lsthk@SetLanguage %
-%<info>         \lst@InfoInfo{\expandafter\string %
-%<info>             \csname\lst@requested\endcsname\space called}%
-         \csname\lst@requested\endcsname %
-         \def\lst@language{#1}\lst@Normalize\lst@language %
-         \def\lst@dialect{#2}\lst@Normalize\lst@dialect}}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{aspect}{defaultdialect}
-% We simply store the dialect.
-%    \begin{macrocode}
-\lst@Aspect{defaultdialect}{\lstKV@OptArg\lstdefaultdialect@[]{#1}}
-\def\lstdefaultdialect@[#1]#2{%
-    \def\lst@temp{#2}\lst@Normalize\lst@temp %
-    \global\@namedef{lstdd@\lst@temp}{#1}}
-%    \end{macrocode}
-% \end{aspect}
-%
-% Languages might have a user name and a different internal name.
-% Moreover we don't always use the standard driver file |lst|\meta{language}|.sty|.
-% If the user writes |language=[fuu]foo|, this could mean that we select (internally) dialect |faa| of language |fee|, which is located in driver file |fii.sty|.
-% We define the following macros:
-% \begin{macrosyntax}
-% \item |\lst@DriverLocation{|\meta{language}|}{|\meta{file name without extension}|}|
-%
-%	Afterwards the package inputs the given driver file to load the language.
-%
-% \item	|\lst@LocateLanguage[|\meta{dialect}|]{|\meta{language}|}|
-%
-%	returns the driver file name in |\lst@driver| and |\lst@requested| contains name of driver macro (i.e.\ with prefix |lstlang@|, without backslash).
-%	The macro automatically chooses aliases.
-% \end{macrosyntax}
-% All language and dialect arguments are standardized, i.e.\ we make them free of spaces and lower case.
-%
-% \begin{macro}{\lstalias}
-% The names are stored in |\lsta@|\emph{language}|@|\emph{dialect} and |\lstaa@|\emph{language}.
-%    \begin{macrocode}
-\newcommand\lstalias{\@ifnextchar[{\lstalias@}{\lstalias@@}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstalias@[#1]#2[#3]#4{%
-    \def\lst@temp{lsta@#2@#1}\lst@Normalize\lst@temp %
-    \global\@namedef{\lst@temp}{#4@#3}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstalias@@#1#2{%
-    \def\lst@temp{lstaa@#1}\lst@Normalize\lst@temp %
-    \global\@namedef{\lst@temp}{#2}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@DriverLocation}
-% We simply define a macro containing the file name.
-%    \begin{macrocode}
-\def\lst@DriverLocation#1#2{%
-    \def\lst@temp{lstloc@#1}\lst@Normalize\lst@temp %
-    \expandafter\gdef\csname\lst@temp\endcsname{#2}%
-    \expandafter\lst@Normalize\csname\lst@temp\endcsname}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@LocateLanguage}
-% First we test for a language alias, \ldots
-%    \begin{macrocode}
-\def\lst@LocateLanguage[#1]#2{%
-    \def\lst@language@{#2}\lst@Normalize\lst@language@ %
-    \@ifundefined{lstaa@\lst@language@}{}%
-        {\edef\lst@language@{\csname lstaa@\lst@language@\endcsname}%
-         \lst@Normalize\lst@language@}%
-%    \end{macrocode}
-% then we set the default dialect if necessary.
-%    \begin{macrocode}
-    \def\lst@dialect@{#1}%
-    \ifx\@empty\lst@dialect@ %
-        \@ifundefined{lstdd@\lst@language@}{}%
-            {\expandafter\let\expandafter\lst@dialect@ %
-             \csname lstdd@\lst@language@\endcsname}%
-    \fi %
-    \lst@Normalize\lst@dialect@ %
-%    \end{macrocode}
-% Now we are ready for an alias for a language dialect.
-%    \begin{macrocode}
-    \edef\lst@requested{\lst@language@ @\lst@dialect@}%
-    \@ifundefined{lsta@\lst@requested}{}%
-        {\expandafter\let\expandafter\lst@requested %
-         \csname lsta@\lst@requested\endcsname %
-         \lst@Normalize\lst@requested}%
-%    \end{macrocode}
-% Finally we get the driver file name and set the default dialect.
-%    \begin{macrocode}
-    \expandafter\lst@LocateLanguage@\lst@requested\relax}
-\def\lst@LocateLanguage@#1@#2\relax{%
-    \edef\lst@driver{\@ifundefined{lstloc@#1}{lst#1}%
-        {\csname lstloc@#1\endcsname}}%
-    \ifx\@empty#2\@empty %
-        \@ifundefined{lstdd@#1}%
-            {\def\lst@dialect@{#2}}%
-            {\expandafter\let\expandafter\lst@dialect@ %
-             \csname lstdd@#1\endcsname}%
-    \fi %
-    \edef\lst@requested{lstlang@#1@\lst@dialect@}%
-    \lst@Normalize\lst@requested}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{Typesetting a listing}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@lineno}
-% This counter keeps the current line number.
-% A register is global if and only if the allocation line shows |% \global|.
-%    \begin{macrocode}
-\newcount\lst@lineno \global\lst@lineno\@ne % \global
-%    \end{macrocode}
-% The counter is initialized and advances every line (which means |\everypar|).
-%    \begin{macrocode}
-\lst@AddToHook{InitVars}
-    {\global\lst@lineno\@ne %
-     \expandafter\everypar\expandafter{\the\everypar %
-         \global\advance\lst@lineno\@ne}}
-%    \end{macrocode}
-% And we (try to) ensure correct line numbers for continued listings.
-%    \begin{macrocode}
-\lst@AddToHook{ExitVars}
-    {\ifx\lst@NewLine\relax\else %
-         \global\advance\lst@lineno-2\relax %
-         \setbox\@tempboxa\vbox{\lst@NewLine}%
-     \fi}
-%    \end{macrocode}
-% \begin{TODO}
-% We only try to.
-% If there is source code before |\end{lstlisting}|, it goes wrong: the line number is one too less.
-% \end{TODO}
-% \end{macro}
-%
-% \begin{macro}{\lst@PrintFileName}
-% makes use of |\lst@ReplaceIn|:
-%    \begin{macrocode}
-\def\lst@PrintFileName#1{%
-    \def\lst@arg{#1}%
-    \lst@ReplaceIn\lst@arg{_\textunderscore $\textdollar -\textendash}%
-    \lst@arg}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@SetName}
-% As proposed by \lsthelper{Boris Veytsman}{[email protected]}{1998/03/22}{listing name accessible for user} the name of a listing (file name or argument to the environment) is user accessible now.
-% It is set using this macro:
-%    \begin{macrocode}
-\def\lst@SetName#1{%
-    \gdef\lst@intname{#1}\global\let\lstintname\lst@intname %
-    \let\lst@arg\lst@intname %
-    \lst@ReplaceIn\lst@arg{_\textunderscore $\textdollar -\textendash}%
-    \global\let\lstname\lst@arg}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{List of listings}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\listoflistings}
-% Instead of imitating |\listoffigures| we make some local adjustments and call |\tableofcontents|.
-% This has the advantage that redefinitions (e.g.\ without any |\MakeUppercase| inside) also take effect on the list of listings.
-%    \begin{macrocode}
-\newcommand\listoflistings{\bgroup %
-    \let\contentsname\listlistingsname %
-    \let\lst@temp\@starttoc \def\@starttoc##1{\lst@temp{lol}}%
-    \tableofcontents \egroup}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\listlistingsname}
-% Simply the header name:
-%    \begin{macrocode}
-\newcommand\listlistingsname{Listings}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@AddToLOL}
-% adds an entry to the list of listings.
-% The first parameter is the name of the listing and the second is unused so far.
-%    \begin{macrocode}
-\newcommand\lst@AddToLOL[2]{%
-    \ifx\@empty#1\@empty \else %
-        \addtocontents{lol}{\protect\lstlolline{#1}{#2}%
-            {\lst@language}{\thepage}}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstlolline}
-% prints one 'lol' line.
-% Using |\lst@PrintFileFile| removes a bug first reported by \lsthelper{Magne Rudshaug}{[email protected]}{1998/01/09}{_ and list of listings}.
-%    \begin{macrocode}
-\newcommand\lstlolline[4]{%
-    \@dottedtocline{1}{1.5em}{2.3em}{\lst@PrintFileName{#1}}{#4}}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Init and EOL}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% We need some macros to initialize registers and variables before typesetting a listing and for the update every line.
-%
-% \begin{macro}{\lst@Init}
-% The argument |#1| (assigned at the end) is either |\relax| or |\lstenv@backslash| since the backslash has a special meaning for the environment.
-% The line number is used as current label (proposed by \lsthelper{Boris Veytsman}{[email protected]}{1998/03/25}{make line numbers referenced via \label and \ref}).
-% The end of line character chr(13)=|^^M| controls the processing, see the definition of |\lst@MProcessListing| below.
-% The vertical space in the macro code is for clarity.
-%    \begin{macrocode}
-\def\lst@Init#1{%
-    \begingroup \normalbaselines \smallbreak %
-    \def\@currentlabel{\the\lst@lineno}%
-    \lst@prelisting %
-%    \end{macrocode}
-%    \begin{macrocode}
-    \lsthk@BeforeSelectCharTable %
-    \normalbaselines \everypar{\lsthk@EveryLine}%
-    \lsthk@InitVars \lsthk@InitVarsEOL %
-%    \end{macrocode}
-%    \begin{macrocode}
-    \csname lstPre@\lst@language\endcsname %
-    \csname lstPre@\lst@language @\lst@dialect\endcsname %
-    \lstCC@Let{"000D}\lst@MProcessListing %
-    \let\lstCC@Backslash#1%
-    \lst@EnterMode{\lst@Pmode}{\lst@SelectCharTable}}
-%    \end{macrocode}
-% Note: From version 0.19 on 'listing processing' is implemented as an internal mode, namely a mode with special character table.
-%    \begin{macrocode}
-\lst@AddToHook{InitVars}
-    {\rightskip\z@ \leftskip\z@ \parfillskip=0pt plus 1fil %
-     \let\par\@@par}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@DeInit}
-% Here we output the remaining characters, update some variables and do some other things.
-%    \begin{macrocode}
-\def\lst@DeInit{%
-    \lst@PrintToken \lst@EOLUpdate \par\removelastskip %
-    \lsthk@ExitVars %
-    \smallbreak\lst@postlisting %
-    \endgroup}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@EOLUpdate}
-% This macro seems to be obsolete since in version 0.19 it degenerates to
-%    \begin{macrocode}
-\def\lst@EOLUpdate{\lsthk@EOL \lsthk@InitVarsEOL}%
-%    \end{macrocode}
-% But in future it might come in handy again.
-% \end{macro}
-%
-% \begin{macro}{\lst@MProcessListing}
-% This is what we have to do at EOL while processing a listing.
-% We output all remaining characters and update the variables.
-% We call |\endinput| if the next line number is greater than the last printing line.
-% Finally we gobble characters to come to beginning of line.
-%    \begin{macrocode}
-\def\lst@MProcessListing{%
-    \lst@PrintToken \lst@EOLUpdate %
-    \ifnum\lst@lastline<\lst@lineno \expandafter\endinput \fi %
-    \lst@BOLGobble}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@BOLGobble}
-% But this is initially |\relax|.
-%    \begin{macrocode}
-\let\lst@BOLGobble\relax
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{The input command}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{TODO}
-% There is a conflict concerning |\lst@firstline|: It contains either the line number of the first code line or line number.
-% This must be clarified before |lstlisting| can use the keys |first| and |last|.
-% \end{TODO}
-%
-% \begin{aspect}{print}
-% \begin{aspect}{first}
-% \begin{aspect}{last}
-% These aspects affect the input command only, not the environment.
-%    \begin{macrocode}
-\lst@Aspect{print}[t]{\lstKV@SetIfKey\lst@ifprint{#1}}
-\lst@Aspect{first}{\def\lst@firstline{#1}}
-\lst@Aspect{last}{\def\lst@lastline{#1}}
-\lstset{print=true}% init
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{macro}{\lstinputlisting}
-% We define the main command.
-% First we take care of the optional paramater and set it to $[1,9999999]$ if none is given.
-%    \begin{macrocode}
-\newcommand\lstinputlisting[2][]{%
-    \begingroup %
-    \def\lst@firstline{1}\def\lst@lastline{9999999}\lstset{#1}%
-    \IfFileExists{#2}{\lst@InputListing{#2}}%
-    {\filename@parse{#2}%
-     \edef\reserved@a{\noexpand\lst@MissingFileError
-         {\filename@area\filename@base}%
-         {\ifx\filename@ext\relax tex\else\filename@ext\fi}}%
-     \reserved@a}%
-    \endgroup %
-    \lsthk@OnExit}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@MissingFileError}
-% is a derivation of \LaTeX's |\@missingfileerror|:
-%    \begin{macrocode}
-\def\lst@MissingFileError#1#2{%
-    \typeout{^^J! Package Listings Error: File `#1.#2' not found.^^J^^J%
-        Type X to quit or <RETURN> to proceed,^^J%
-        or enter new name. (Default extension: #2)^^J}%
-    \message{Enter file name: }%
-    {\endlinechar\m@ne \global\read\m@ne to\@gtempa}%
-%    \end{macrocode}
-% Typing |x| or |X| exits.
-%    \begin{macrocode}
-    \ifx\@gtempa\@empty \else %
-        \def\reserved@a{x}\ifx\reserved@a\@gtempa\batchmode\@@end\fi
-        \def\reserved@a{X}\ifx\reserved@a\@gtempa\batchmode\@@end\fi
-%    \end{macrocode}
-% In all other cases we try the new file name (with default extension).
-%    \begin{macrocode}
-        \filename@parse\@gtempa %
-        \edef\filename@ext{%
-            \ifx\filename@ext\relax#2\else\filename@ext\fi}%
-        \edef\reserved@a{\noexpand\IfFileExists %
-                {\filename@area\filename@base.\filename@ext}%
-            {\noexpand\lst@InputListing %
-                {\filename@area\filename@base.\filename@ext}}%
-            {\noexpand\lst@MissingFileError
-                {\filename@area\filename@base}{\filename@ext}}}%
-        \expandafter\reserved@a %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@InputListing}
-% The one and only argument is the file name.
-% We either add this name to the list of listings or the name plus a bullet to indicate that the listing has been skipped.
-% Note that |\lst@Init| takes |\relax| as an argument.
-%    \begin{macrocode}
-\def\lst@InputListing#1{%
-    \lst@SetName{#1}%
-    \lst@ifprint %
-        \lst@AddToLOL{#1}{}%
-        \lst@Init\relax \lst@SkipUptoFirst \input{#1}\lst@DeInit %
-    \else %
-        \lst@AddToLOL{#1$^\bullet$}{}%
-        \begin{center}%
-        \footnotesize  ---  Listing of #1 has been skipped.  --- 
-        \end{center}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@SkipUptoFirst}
-% The end of line character either processes the listing or is responsible for skipping lines upto first printing line.
-%    \begin{macrocode}
-\def\lst@SkipUptoFirst{%
-    \ifnum\lst@lineno=\lst@firstline\else %
-%    \end{macrocode}
-% To skip input lines we begin a new group level (which makes our changes local) and prohibit mode changes.
-% We redefine the end of line character and all output macros becomes equivalent to |\relax|, i.e.\ nothing is typeset.
-%    \begin{macrocode}
-        \bgroup \lst@modetrue %
-        \let\lst@Output\relax \let\lst@OutputOther\relax %
-        \let\lst@GotoTabStop\relax %
-        \lstCC@Let{"000D}\lst@MSkipUptoFirst %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@MSkipUptoFirst}
-% At the moment we use a fast and not 'everything is looking good' way.
-% When |\lst@MSkipUptoFirst| is executed, one input line has already been skipped.
-% We end the group opened in |\lst@SkipUptoFirst|.
-% This restores the definition of the end of line character chr(13).
-% Then we look whether to skip more lines or not.
-%    \begin{macrocode}
-\def\lst@MSkipUptoFirst{\egroup %
-    \global\advance\lst@lineno\@ne %
-    \ifnum\lst@lineno=\lst@firstline\else %
-        \expandafter\lst@MSkipUptoFirst@ %
-    \fi}
-%    \end{macrocode}
-% The argument of |\lst@MSkipUptoFirst@| ends with the next active chr(13), which means that the next input line is read.
-% Again we look whether to skip more lines or not.
-%    \begin{macrocode}
-\begingroup \lccode`\~=`\^^M%
-\lowercase{\gdef\lst@MSkipUptoFirst@#1~}{%
-    \global\advance\lst@lineno\@ne %
-    \ifnum\lst@lineno=\lst@firstline\else %
-        \expandafter\lst@MSkipUptoFirst@ %
-    \fi}
-\endgroup
-%    \end{macrocode}
-% \begin{TODO}
-% This definition gives rise to a ''runaway argument'' if first line doesn't exist (no |^^M| is found).
-%
-% We could define |\lst@MSkipUptoFirst| exactly as |\lst@MProcessListing|, except that we start the normal line processing if we reach the first printing line.
-% In that case all comments and strings are processed, but not output.
-% Everything looks good, even if the first printing line is in the middle of a comment.
-% We need to do the following things:
-%	\begin{enumerate}
-%	\item Install an \texttt{if} to choose between speed and good looking, which must be noticed in |\lst@SkipUptoFirst|.
-%		There we must (locally) switch to |\lsttexcloff|.
-%	\item Call |\lst@BeginDropOutput{\lst@nomode}| in |\lst@SkipUptoFirst| instead of |\bgroup\lst@modetrue| and assigning |\relax|es.
-%	\item Define |\lst@MSkipUptoFirstExact| by copying |\lst@MProcessListing| and renaming it.
-%		Replace the |\ifnum| by\vspace*{-0.5\baselineskip}
-% \begin{verbatim}
-%\ifnum\lst@lineno=lst@firstline %
-%    \lst@LeaveMode \global\lst@column\z@ \global\lst@pos\z@ %
-%\fi\end{verbatim}
-%	\item Make the fine tuning if necessary.
-%	\end{enumerate}
-% \end{TODO}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{The environment}\label{iTheEnvironment}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@Environment}
-% This is the first attempt to provide a general macro, which defines the \lst-environments.
-% The syntax comes from \LaTeX's |\newenvironment|:
-% \begin{macrosyntax}
-% \item	|\lst@Environment{|\meta{name}|}[|\meta{number of parameters}|][|\meta{opt.~default~arg.}|]\is|\\
-%		|{|\meta{begin code}|}|\\
-%		|{|\meta{end code}|}|
-% \end{macrosyntax}
-% Note the additional |\is|.
-% I should mention that such environments could also be used in command fashion
-% \begin{verbatim}
-%    \lstlisting{my name}
-%    Here comes the listing.
-%    \endlstlisting\end{verbatim}
-% But now the implementation.
-% We define undefined environments only:
-%    \begin{macrocode}
-\def\lst@Environment#1#2\is#3#4{%
-    \@ifundefined{#1}{\lst@Environment@{#1}{#2}{#3}{#4}}%
-    {%
-%<info>         \lst@InfoWarning{Multiple environment `#1'}%
-    }}
-%    \end{macrocode}
-% A lonely 'end environment' produces an error:
-%    \begin{macrocode}
-\def\lst@Environment@#1#2#3#4{%
-    \global\@namedef{end#1}{\lstenv@Error{#1}}%
-%    \end{macrocode}
-% The 'main' environment macro defines the environment name (for later use) and calls a submacro (getting all arguments).
-% We open a group and redefine the (active) EOL character to be |\relax|.
-% This ensures |\@ifnextchar[| not to read characters of the listing --- it reads the active EOL instead.
-%    \begin{macrocode}
-    \global\@namedef{#1}{%
-        \def\lstenv@name{#1}%
-        \begingroup \lstCC@Let{"000D}\relax %
-        \csname#1@\endcsname}%
-%    \end{macrocode}
-% The submacro is defined via |\new@command|.
-% We misuse |\l@ngrel@x| to make the definition |\global|.
-% The submacro defines the first and last line, which are possibly changed by the user's \meta{begin code} |#3|.
-%    \begin{macrocode}
-    \let\l@ngrel@x\global %
-    \expandafter\new@command\csname#1@\endcsname#2%
-        {\def\lst@firstline{1}\def\lst@lastline{9999999}%
-         #3%
-%    \end{macrocode}
-% The definition of the string which terminates the environment (|end{lstlisting}| or |endlstlisting|, for example) needs some care since the braces must not have catcodes 1 and 2 (or |\lst@MakeActive| fails).
-% We enter them as |\{| and |\}| (with preceding |\noexpand|s).
-%    \begin{macrocode}
-         \ifx\@currenvir\lstenv@name %
-             \edef\lst@temp{end\noexpand\{\lstenv@name\noexpand\}}%
-         \else %
-             \edef\lst@temp{end\lstenv@name}%
-         \fi %
-         \expandafter\lst@MakeActive\expandafter{\lst@temp}%
-         \let\lstenv@endstring\lst@arg %
-%    \end{macrocode}
-% We redefine (locally) 'end environment' inside the 'begin environment' macro since ending is legal now.
-% Note that the redefinition also works inside a \TeX\ comment line.
-%    \begin{macrocode}
-         \@namedef{end#1}{\lst@DeInit #4\endgroup \lsthk@OnExit}%
-%    \end{macrocode}
-% Finally the 'begin environment' macro starts the processing.
-%    \begin{macrocode}
-         \lstenv@Process}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@Error}
-% have been used above.
-%    \begin{macrocode}
-\def\lstenv@Error#1{\PackageError{Listings}{Extra \string\end#1}%
-    {I'm ignoring this, since I wasn't doing a \csname#1\endcsname.}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@backslash}
-% We have the problem of finding end of environment, and we've already defined the 'end environment' string.
-% Coming to a backslash we either end the listing or process a backslash and insert the eaten characters again.
-% (Eaten means that these characters have been read (and removed) from the input to test for |\lstenv@endstring|.)
-%    \begin{macrocode}
-\def\lstenv@backslash{%
-    \lst@IfNextChars\lstenv@endstring %
-        {\lstenv@End}%
-        {\lsts@backslash \lst@eaten}}%
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@End}
-% This macro is called by the backslash macro and terminates a listing environment:
-% We call the 'end environment' macro as a command or using |\end|.
-%    \begin{macrocode}
-\def\lstenv@End{%
-    \ifx\@currenvir\lstenv@name %
-        \edef\lst@next{\noexpand\end{\lstenv@name}}%
-    \else %
-        \def\lst@next{\csname end\lstenv@name\endcsname}%
-    \fi %
-    \lst@next}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@Process}
-% First some initialization, then call a submacro.
-%    \begin{macrocode}
-\def\lstenv@Process{%
-    \lst@Init\lstenv@backslash %
-    \global\lst@lineno\lst@firstline\relax %
-    \let\lstenv@ifdropped\iffalse \lstenv@Process@}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstenv@droppedtrue{\let\lstenv@ifdropped\iftrue}
-%    \end{macrocode}
-% We execute either |\lstenv@ProcessM| or |\lstenv@ProcessJ| according to whether we find an active EOL or a nonactive |^^J|.
-%    \begin{macrocode}
-\begingroup \lccode`\~=`\^^M%
-\lowercase{\gdef\lstenv@Process@#1{%
-    \ifx~#1%
-        \expandafter\lstenv@ProcessM %
-    \else\ifx^^J#1%
-        \expandafter\expandafter\expandafter\lstenv@ProcessJ %
-    \else %
-        \lstenv@droppedtrue %
-        \expandafter\expandafter\expandafter\lstenv@Process@ %
-    \fi \fi}
-}\endgroup
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@DroppedWarning}
-% gives a warning if characters have been dropped.
-%    \begin{macrocode}
-\def\lstenv@DroppedWarning{%
-    \lstenv@ifdropped %
-        \PackageWarning{Listings}{Text dropped after begin of listing}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@ProcessM}
-% There is nothing to do if we've found an active EOL, except giving a warning if necessary.
-%    \begin{macrocode}
-\def\lstenv@ProcessM{\lstenv@DroppedWarning \lst@BOLGobble}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@ProcessJ}
-% Now comes the horrible scenario: A listing inside an argument.
-% We've already worked in section \ref{iAnApplicationTo} for this.
-% Here we must get the listing, i.e.\ all characters upto 'end environment'.
-% We must distinguish the cases 'command fashion' and 'environment'.
-%    \begin{macrocode}
-\def\lstenv@ProcessJ{%
-    \lstenv@DroppedWarning %
-    \lst@DontEscapeToLaTeX %
-    \let\lstenv@arg\@empty %
-    \ifx\@currenvir\lstenv@name %
-        \expandafter\lstenv@ProcessJEnv %
-    \else %
-%    \end{macrocode}
-% The first case is pretty simple: The code is terminated by |\end|\meta{name of environment}.
-% Thus we expand that control sequence before defining a temporary macro, which gets all characters upto that control sequence.
-% Inside the temporary macro we assign the argument and call a submacro doing the rest.
-%    \begin{macrocode}
-        \expandafter\def\expandafter\lst@temp\expandafter##1%
-        \csname end\lstenv@name\endcsname{%
-            \lstenv@AddArg{##1}\lstenv@ProcessJ@}%
-%    \end{macrocode}
-% Back to the definition of |\lstenv@ProcessJ| we call the temporary macro.
-%    \begin{macrocode}
-        \expandafter\lst@temp %
-    \fi}
-%    \end{macrocode}
-% We must append an active backslash and the 'end string' to |\lstenv@arg|.
-% So all other processing won't notice that the code has been inside an argument.
-% But the EOL character is chr(10)=|^^J| now and not chr(13).
-% Finally we execute |\lstenv@arg| to typeset the listing.
-% Note that we need |\lccode`\A=`\A| to preserve the argument of |\lstCC@Let| --- but obviously we could also write |\lstCC@Let{10}|\ldots
-%    \begin{macrocode}
-\begingroup \lccode`\~=`\\ \lccode`\A=`\A
-\lowercase{\gdef\lstenv@ProcessJ@{%
-    \expandafter\lst@lAddTo\expandafter\lstenv@arg %
-        \expandafter{\expandafter\ \expandafter~\lstenv@endstring}%
-    \lstCC@Let{"000A}\lst@MProcessListing \def\lst@BOLGobble##1{}%
-    \expandafter\lst@BOLGobble\lstenv@arg}
-}\endgroup
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstenv@ProcessJEnv}
-% Here we get all characters upto an |\end| (and the following argument).
-% If the following argument equals |\lstenv@name|, we have found the end of environment and start typesetting.
-%    \begin{macrocode}
-\def\lstenv@ProcessJEnv#1\end#2{\def\lst@temp{#2}%
-    \ifx\lstenv@name\lst@temp %
-        \lstenv@AddArg{#1}%
-        \expandafter\lstenv@ProcessJ@ %
-    \else %
-%    \end{macrocode}
-% Otherwise we append the characters including the eaten |\end| and the eaten argument to current |\lstenv@arg|.
-% And we look again for the end of environment.
-%    \begin{macrocode}
-        \lstenv@AddArg{#1\\end\{#2\}}%
-        \expandafter\lstenv@ProcessJEnv %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{environment}{lstlisting}
-% The awkward work is done, here we deal with continued line numbering.
-% \lsthelper{Boris Veytsman}{[email protected]}{1998/03/25}{continue line numbering: a.c b.c a.c} proposed to continue line numbers according to listing names.
-% Thus we must save the name and either make a LOL item or define the first line number.
-% Note that the macro |\lstno@| will be undefined or equivalent to |\relax|, so we always start with line number 1 in case of an empty name.
-% Moreover we first test if the user has forgotten the name argument.
-%    \begin{macrocode}
-\lst@Environment{lstlisting}[2][]\is
-    {\lstenv@TestEOLChar{#2}%
-     \expandafter\ifx\csname lstno@\lst@intname\endcsname \relax %
-         \ifx\lst@intname\@empty\else \lst@AddToLOL{#2}{}\fi %
-     \else %
-         \edef\lst@firstline{\csname lstno@\lst@intname\endcsname}%
-         \let\lst@prelisting\lst@@prelisting %
-         \let\lst@postlisting\lst@@postlisting %
-     \fi %
-     \lstset{#1}}
-%    \end{macrocode}
-% At the end of environment we simply save the current line number.
-% If the listing name is empty, we use a space instead of the name.
-% This leaves the macro |\lstno@| undefined.
-%    \begin{macrocode}
-    {\ifx\lst@intname\@empty %
-         \expandafter\xdef\csname lstno@ \endcsname{\the\lst@lineno}%
-     \else %
-         \expandafter\xdef\csname lstno@\lst@intname\endcsname %
-             {\the\lst@lineno}%
-     \fi}
-%    \end{macrocode}
-% \end{environment}
-%
-% \begin{macro}{\lstenv@TestEOLChar}
-% \begin{macro}{\lstenv@EOLCharError}
-% Here we test for the two possible EOL characters.
-%    \begin{macrocode}
-\begingroup \lccode`\~=`\^^M\lowercase{%
-\gdef\lstenv@TestEOLChar#1{%
-    \lst@SetName{}%
-    \ifx~#1\lstenv@EOLCharError \else %
-        \ifx^^J#1\lstenv@EOLCharError \else %
-            \lst@SetName{#1}%
-        \fi %
-    \fi}
-}\endgroup
-%    \end{macrocode}
-% A simple error message.
-%    \begin{macrocode}
-\def\lstenv@EOLCharError{%
-    \PackageError{Listings}
-    {Oops! It seems you've forgotten the argument to\MessageBreak %
-     a listing environment. Assuming empty argument}%
-    {Type <RETURN> to proceed.}}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{aspect}{advancelineno}
-% \begin{aspect}{resetlineno}
-% The last two aspects in this section simply advance/reset the first line.
-%    \begin{macrocode}
-\lst@Aspect{advancelineno}
-    {\global\lst@lineno\lst@firstline\relax %
-     \global\advance\lst@lineno#1\relax %
-     \edef\lst@firstline{\the\lst@lineno}}
-\lst@Aspect{resetlineno}[1]{\def\lst@firstline{#1}}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Inline listings}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lstinline}
-% We redefine some macros here since they are possibly not save inside |\hbox|.
-% Furthermore we use flexible columns and suppress \TeX\ comment lines.
-% After doing initialization we redefine |\everypar| and the new line macro.
-% We don't want them.
-%    \begin{macrocode}
-\def\lstinline{\hbox\bgroup %
-    \let\smallbreak\relax %
-    \let\lst@prelisting\relax \let\lst@postlisting\relax %
-    \let\lst@ifflexible\iftrue \lst@DontEscapeToLaTeX %
-    \def\lst@firstline{1}\def\lst@lastline{1}%
-    \lst@Init\relax \everypar{}\global\let\lst@NewLine\relax %
-    \lst@IfNextCharActive\lst@InlineM\lst@InlineJ}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@InlineM}
-% \begin{macro}{\lst@InlineJ}
-% treat the cases of 'normal' inlines and inline listings inside an argument.
-% In the first case the given character ends the inline listing and EOL (within such a listing) immediately ends it and produces an error message.
-%    \begin{macrocode}
-\def\lst@InlineM#1{%
-    \lstCC@Def{`#1}{\lst@DeInit\egroup}%
-    \lstCC@Def{"000D}{\lst@DeInit\egroup %
-        \PackageError{Listings}{lstinline ended by EOL}\@ehc}}
-%    \end{macrocode}
-% In the other case we get all characters upto |#1| (via temporary macro), make these characters active, execute (typeset) them and end the listing.
-% That's all about it.
-%    \begin{macrocode}
-\def\lst@InlineJ#1{%
-    \def\lst@temp##1#1{%
-        \let\lstenv@arg\@empty \lstenv@AddArg{##1}%
-        \lstenv@arg \lst@DeInit\egroup}%
-    \lst@temp}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{The box command}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lstbox}
-% The macro opens the |\hbox| right at the beginning and indicate its usage.
-% Then we adjust some \lst-parameters:
-% We switch to |\lstlistingtrue| since the command is intend to be used with small listings only;
-% |\smallbreak|s preceding and following each listing are removed by redefining |\smallbreak|.
-%    \begin{macrocode}
-\newcommand\lstbox{%
-    \hbox\bgroup %
-        \let\lst@ifbox\iftrue %
-        \let\smallbreak\relax %
-        \let\lst@prelisting\relax \let\lst@postlisting\relax %
-        \let\lst@@prelisting\relax\let\lst@@postlisting\relax %
-        \lst@outerspread\z@ \lst@innerspread\z@ %
-        \@ifnextchar[{\lstbox@}{\lstbox@[c]}}
-%    \end{macrocode}
-% Here we have to choose the right box --- in fact |\vcenter| isn't a box.
-%    \begin{macrocode}
-\def\lstbox@[#1]{%
-    \hbox to\z@\bgroup %
-        $\if#1t\vtop \else \if#1b\vbox \else \vcenter \fi\fi %
-        \bgroup}%
-%    \end{macrocode}
-% We need to
-%    \begin{macrocode}
-\let\lst@ifbox\iffalse
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@EndBox}
-% And the counterpart: We have to close some groups (and use |\hss| inside the |\hbox| to $0$pt).
-% The outer |\hbox| gets its correct width using a |\vrule|.
-%    \begin{macrocode}
-\def\lst@EndBox{%
-    \egroup $\hss \egroup %
-    \vrule width\lst@maxwidth height\z@ depth\z@ %
-    \egroup}
-%    \end{macrocode}
-% But that macro is called (if and) only if we've begun a |\lstbox| before.
-% Note that we are possibly inside a \lst-environment here, so we have to execute |\lst@EndBox| either now or after closing the environment group.
-%    \begin{macrocode}
-\lst@AddToHook{OnExit}
-    {\lst@ifbox %
-         \global\advance\lst@maxwidth-\lst@innerspread %
-         \global\advance\lst@maxwidth-\lst@outerspread %
-         \ifx\@currenvir\lstenv@name %
-             \expandafter\expandafter\expandafter\aftergroup %
-         \fi %
-         \expandafter\lst@EndBox %
-     \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@maxwidth}
-% is to be allocated:
-%    \begin{macrocode}
-\newdimen\lst@maxwidth % \global
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVars}{\global\lst@maxwidth\z@}
-%    \end{macrocode}
-% Determine width of just printed line and update |\lst@maxwidth|.
-% Here we assume that all characters of the line have been output.
-%    \begin{macrocode}
-\lst@AddToHook{InitVarsEOL}
-    {\@tempdima \lst@column\lst@width %
-     \advance\@tempdima -\lst@pos\lst@width %
-     \ifdim\lst@lostspace<\z@ \advance\@tempdima -\lst@lostspace \fi %
-     \ifdim\@tempdima>\lst@maxwidth \global\lst@maxwidth\@tempdima \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{First \lst-aspects and related macros}
-%
-% In fact we've already defined some aspects, e.g.\ |language| and |style|.
-%
-%
-% \subsection{Keywords}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{TODO}
-% The internal keyword managing should be reorganised, so that is also handles the special characters $<,>,\vert,\sim$.
-% \end{TODO}
-% We have to decide whether or not a given character sequence is a reserved word.
-% For example, if the character sequence is |key|, we define a macro
-% \begin{verbatim}
-%     \def\lst@temp#1,key,#2\relax{...}\end{verbatim}
-% Afterwards we call the macro with the following arguments:
-% \begin{itemize}
-% \item[] |,|all current keywords|,key,\relax|
-% \end{itemize}
-% The additional |,key,\relax| holds up the syntax of |\lst@temp|.
-% When \TeX{} passes the arguments, the second is empty if and only if |key| is not a current keyword.
-% So we know whether or not to select keyword style.
-%
-% Since \TeX{} always passes two arguments to |\lst@temp|, the whole 'input' |\lst@keywords,#1,\relax| is split in two parts.
-% So there is no need to sort the keywords by probability.
-% Alternatively you could do so and make a loop for the keyword tests, which terminates right after finding a keyword.
-% You might think and guess that's faster than the \TeX{}nique used here.
-% If your source code uses the three or four most common keywords only, you are right.
-% In fact the very first versions 0.1 and 0.11 have used something like loops (even something faster), which in general is slower than this here.
-% \begin{TODO}
-% There exists a faster way.
-% For each keyword we make |\lstk@|\emph{the keyword} equivalent to keyword style.
-% |\csname lstk@|\emph{test word}|\endcsname| expands to |\relax| if the control sequence is undefined and to keyword style otherwise.
-% That's the complete keyword test!
-% It works very well, but needs more of \TeX{}'s memory.
-% Therefore we should define also 'memory saving' and/or 'speeding up' option.
-%
-% Note: A keyword or character string in this state might contain |\lst@underscore| and |\lst@minus| (and possibly more macro names), which will expand inside |\csname|\ldots|\endcsname|.
-% Hence the definition of |\lstk@|\emph{the keyword} needs some care.
-% An easy trick: During keyword definition and keyword testing the macros should expand to |_| and |-|, respectively.
-% But the reassignments of |_|, |-|, \ldots\ also need time, so the implemented way is possibly faster \ldots
-% \end{TODO}
-%
-% \begin{macro}{\lst@SetStyleFor}
-% |\relax| terminates the argument here since it is faster than enclosing it in braces.
-% All the rest should be clear from the discussion above.
-%    \begin{macrocode}
-\def\lst@SetStyleFor#1\relax{%
-    \def\lst@temp##1,#1,##2\relax{%
-        \ifx\@empty##2\@empty \let\lst@thestyle\lst@nonkeywordstyle %
-                        \else \let\lst@thestyle\lst@keywordstyle\fi}%
-    \expandafter\lst@temp\expandafter,\lst@keywords,#1,\relax}%
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@SetStyleForNonSensitive}
-% We implement a case insensitive version.
-% Use of two |\uppercase|s normalize the argument.
-%    \begin{macrocode}
-\def\lst@SetStyleForNonSensitive#1\relax{%
-    \uppercase{\def\lst@temp##1,#1},##2\relax{%
-        \ifx\@empty##2\@empty \let\lst@thestyle\lst@nonkeywordstyle %
-                        \else \let\lst@thestyle\lst@keywordstyle\fi}%
-    \uppercase{%
-        \expandafter\lst@temp\expandafter,\lst@keywords,#1},\relax}%
-%    \end{macrocode}
-% Note: This macro and the coming |\lst@IfOneOfNonSensitive| both assume that the keywords in |\lst@keywords| are already upper case!
-% \end{macro}
-%
-% The code above must be activated, of course:
-% We detect keywords if and only if we haven't entered a special mode (comment, string, etc.).
-%    \begin{macrocode}
-\lst@AddToHook{Output}
-    {\lst@ifmode %
-         \let\lst@thestyle\relax %
-     \else %
-         \expandafter\lst@SetStyleFor\the\lst@token\relax %
-     \fi}
-%    \end{macrocode}
-%
-% \begin{macro}{\lst@IfOneOf}
-% \begin{macro}{\lst@IfOneOfNonSensitive}
-% These macros are very familiar with the keyword tests.
-% Roughly speaking the fixed |\lst@keywords| is replaced by an arbitrary macro.
-% The first argument has the same meaning and is terminated by |\relax|, whereas the second must be a macro name.
-% If and only if that macro (= keyword list) contains the first argument, the third parameter is executed (and the fourth otherwise).
-%    \begin{macrocode}
-\def\lst@IfOneOf#1\relax#2{%
-    \def\lst@temp##1,#1,##2\relax{%
-        \ifx \@empty##2\@empty \expandafter\@secondoftwo %
-        \else \expandafter\@firstoftwo \fi}%
-    \expandafter\lst@temp\expandafter,#2,#1,\relax}%
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@IfOneOfNonSensitive#1\relax#2{%
-    \uppercase{\def\lst@temp##1,#1},##2\relax{%
-        \ifx \@empty##2\@empty \expandafter\@secondoftwo %
-        \else \expandafter\@firstoftwo \fi}%
-    \uppercase\expandafter{%
-        \expandafter\lst@temp\expandafter,#2,#1},\relax}%
-%    \end{macrocode}
-% Instead of |\lst@SetStyleFor key\relax|, we could also write
-% \begin{verbatim}
-%     \lst@IfOneOf key\relax \lst@keywords %
-%         {\let\lst@thestyle\lst@keywordstyle}
-%         {\let\lst@thestyle\lst@nonkeywordstyle}\end{verbatim}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lststorekeywords}
-% Note that this command stores the keywords globally.
-%    \begin{macrocode}
-\newcommand\lststorekeywords[2]{\gdef#1{#2}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{sensitive}
-% Announcement and init:
-%    \begin{macrocode}
-\lst@Aspect{sensitive}[t]{\lstKV@SetIfKey\lst@ifsensitive{#1}}
-\lst@AddToHook{SetLanguage}{\let\lst@ifsentitive\iftrue}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \noindent
-% Now we consider the aspects getting keywords from the user.
-% They work up the keywords a little bit, namely using |\lst@Make|\ldots|KeywordArg|.
-%
-% \begin{aspect}{keywords}
-% \lsthelper{Ralf Quast}{[email protected]}{1998/01/08}{name \keywords incompatible with AMS classes} reported a naming conflict with AMS classes.
-% Usage of \textsf{keyval} package removes it.
-% The easy definition:
-%    \begin{macrocode}
-\lst@Aspect{keywords}
-    {\lst@MakeSpecKeywordArg{#1}\let\lst@keywords\lst@arg}
-%    \end{macrocode}
-% We have to delete all current keywords before selecting a new language --- otherwise keywords from the previous language would be present if the user specifies no keywords.
-%    \begin{macrocode}
-\lst@AddToHook{SetLanguage}{\let\lst@keywords\@empty}
-%    \end{macrocode}
-% If the user wants case insensitive keywords, she'll get it:
-% We assign the correct test macros and make all keywords upper case.
-% Note that these changes are local.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifsensitive\else %
-         \let\lst@SetStyleFor\lst@SetStyleForNonSensitive %
-         \let\lst@IfOneOf\lst@IfOneOfNonSensitive %
-         \lst@MakeMacroUppercase\lst@keywords %
-     \fi}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lst@MakeMacroUppercase}
-% This macro makes the contents of a given macro (if present) upper case.
-%    \begin{macrocode}
-\def\lst@MakeMacroUppercase#1{%
-    \ifx#1\@undefined\else \uppercase\expandafter{%
-        \expandafter\def\expandafter#1\expandafter{#1}}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{morekeywords}
-% Add keywords or append control sequence with argument:
-%    \begin{macrocode}
-\lst@Aspect{morekeywords}
-    {\lst@MakeMoreSpecKeywordArg{,#1}%
-     \expandafter\lst@lAddTo\expandafter\lst@keywords %
-         \expandafter{\lst@arg}}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{aspect}{deletekeywords}
-% The 'submacro' |\lst@DeleteKeysIn| has been defined in section \ref{iReplacingCharacters}.
-%    \begin{macrocode}
-\lst@Aspect{deletekeywords}
-    {\lst@MakeKeywordArg{#1}%
-     \lst@DeleteKeysIn\lst@keywords\lst@arg}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lst@MakeKeywordArg}
-% \begin{macro}{\lst@MakeSpecKeywordArg}
-% \begin{macro}{\lst@MakeMoreSpecKeywordArg}
-% The keyword commands don't save their parameters as they are.
-% All spaces are removed and underscores, dollars and minuses are replaced by |\lst@underscore|, |\lst@dollar| and |\lst@minus|.
-% The first thing prepares keyword tests and the second the output.
-% The macro |\lst@arg| holds the parameter free of spaces, underscores and minuses.
-% Use of |\zap@space| was proposed by \lsthelper{Rolf Niepraschk}{[email protected]}{1997/04/24}{use \zap@space}.
-%    \begin{macrocode}
-\def\lst@MakeKeywordArg#1{\edef\lst@arg{\zap@space#1 \@empty}%
-    \lst@ReplaceIn\lst@arg{_\lst@underscore $\lst@dollar -\lst@minus}}
-%    \end{macrocode}
-% The following two macros also scan for special characters like \#, $<$ and $>$.
-%    \begin{macrocode}
-\def\lst@MakeSpecKeywordArg{%
-    \let\lst@ialsodigit\@empty \let\lst@ialsoletter\@empty %
-    \lst@MakeMoreSpecKeywordArg}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@MakeMoreSpecKeywordArg#1{\edef\lst@arg{\zap@space#1 \@empty}%
-    \lstCC@lettertrue %
-    \expandafter\lst@SpecialKeywordScan\lst@arg\relax %
-    \lst@ReplaceIn\lst@arg{_\lst@underscore $\lst@dollar -\lst@minus}}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lst@SpecialKeywordScan}
-% How does this scan work?
-% Whenever we encounter a non-letter or non-digit in a keyword, we call |\lst@SKSAdd| to store that character.
-% If we reach the end of keyword list, we terminate the loop by gobbling one token after the latest |\fi|.
-%    \begin{macrocode}
-\def\lst@SpecialKeywordScan#1{%
-    \ifx\relax#1%
-        \expandafter\@gobble %
-    \else %
-%    \end{macrocode}
-% If the current character is a comma, the next character must be (or become) a letter since it starts a keyword.
-% This switch is turned false after reading the next character.
-%    \begin{macrocode}
-        \ifx,#1%
-            \lstCC@lettertrue %
-        \else %
-            \ifnum`#1<"40\relax %
-                \ifnum`#1<"30\relax \lst@SKSAdd#1\else %
-                \ifnum`#1>"39\relax \lst@SKSAdd#1\else %
-%    \end{macrocode}
-% If we've found a digit, we do a special test to decide whether the digit becomes a letter or not.
-%    \begin{macrocode}
-                    \lst@SKS@#1%
-                \fi \fi %
-            \else %
-                \ifnum`#1<"5B\relax \else %
-                \ifnum`#1="5F\relax \else %
-                \ifnum`#1<"61\relax \lst@SKSAdd#1\else %
-                \ifnum`#1<"7B\relax \else %
-                \ifnum`#1<"80\relax \lst@SKSAdd#1 %
-                \fi \fi \fi \fi \fi %
-            \fi %
-            \lstCC@letterfalse %
-        \fi %
-    \fi \lst@SpecialKeywordScan}
-%    \end{macrocode}
-% The special test for digits: Since any digit is already a digit it needs only to become a letter if necessary.
-%    \begin{macrocode}
-\def\lst@SKS@#1{\lstCC@ifletter \lst@SKSAdd#1\fi}
-%    \end{macrocode}
-% The macros |\lst@ialsoletter| and |\lst@ialsodigit| contain the characters.
-% If not already contained in the appropiate macro, we append the character.
-% Refer |\lst@SelectStyleFor| how we scan for a substring (of length 1).
-%    \begin{macrocode}
-\def\lst@SKSAdd#1{%
-    \lstCC@ifletter %
-        \def\lst@temp##1#1##2\relax{%
-            \ifx\@empty##2\@empty %
-                \lst@lAddTo\lst@ialsoletter{#1}%
-            \fi}%
-        \expandafter\lst@temp\lst@ialsoletter#1\relax %
-    \else %
-        \def\lst@temp##1#1##2\relax{%
-            \ifx\@empty##2\@empty %
-                \lst@lAddTo\lst@ialsodigit{#1}%
-            \fi}%
-        \expandafter\lst@temp\lst@ialsodigit#1\relax %
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\let\lst@ialsoletter\@empty \let\lst@ialsodigit\@empty % init
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{alsoletter}
-% \begin{aspect}{alsodigit}
-% \begin{aspect}{alsoother}
-% For now three easy definitions --- easy since I don't explain the last hook.
-%    \begin{macrocode}
-\lst@Aspect{alsoletter}{\def\lst@alsoletter{#1}}
-\lst@Aspect{alsodigit}{\def\lst@alsodigit{#1}}
-\lst@Aspect{alsoother}{\def\lst@alsoother{#1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{SetLanguage}
-    {\let\lst@alsoletter\@empty %
-     \let\lst@alsodigit\@empty %
-     \let\lst@alsoother\@empty}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{SelectCharTable}
-    {\lstCC@ChangeBasicClass\lstCC@ProcessOther\lst@alsoother %
-     \lstCC@ChangeBasicClass\lstCC@ProcessDigit\lst@ialsodigit %
-     \lstCC@ChangeBasicClass\lstCC@ProcessDigit\lst@alsodigit %
-     \lstCC@ChangeBasicClass\lstCC@ProcessLetter\lst@ialsoletter %
-     \lstCC@ChangeBasicClass\lstCC@ProcessLetter\lst@alsoletter}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{macro}{\lst@minus}
-% What is the |\ifx|\ldots{} in |\lst@minus| good for?
-% If you use typewriter fonts, it ensures that |----| is typeset |----| and not $-$$-$$-$$-$ as in version 0.17.
-% Bug encountered by \lsthelper{Dr. Jobst Hoffmann}{[email protected]}{1998/03/30}{\lst@minus\ and typewriter fonts}.
-%    \begin{macrocode}
-\def\lst@minus{\ifx\f@family\ttdefault-{}\else$-$\fi}
-\def\lst@dollar{\ifx\f@family\ttdefault\textdollar\else\textdollar\fi}
-\def\lst@asterisk{\ifx\f@family\ttdefault*\else\textasteriskcentered\fi}
-\def\lst@less{\ifx\f@family\ttdefault<\else\textless\fi}
-\def\lst@greater{\ifx\f@family\ttdefault>\else\textgreater\fi}
-\def\lst@backslash{\ifx\f@family\ttdefault\char92\else\textbackslash\fi}
-\def\lst@underscore{%
-    \ifx\f@family\ttdefault\char95\else\textunderscore\fi}
-\def\lst@lbrace{\ifx\f@family\ttdefault\char123\else\textbraceleft\fi}
-\def\lst@bar{\ifx\f@family\ttdefault|\else\textbar\fi}
-\def\lst@rbrace{\ifx\f@family\ttdefault\char125\else\textbraceright\fi}
-%    \end{macrocode}
-% |\ttdefault| is defined |\long|, so the |\ifx| doesn't work since |\f@family| isn't defined |\long|!
-% We go around this problem by redefining |\ttdefault| locally:
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}{\edef\ttdefault{\ttdefault}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{basicstyle}
-% \begin{aspect}{keywordstyle}
-% \begin{aspect}{nonkeywordstyle}
-% We shouldn't forget these style aspects.
-%    \begin{macrocode}
-\lst@Aspect{basicstyle}{\def\lst@basicstyle{#1}}
-\lst@Aspect{keywordstyle}{\def\lst@keywordstyle{#1}}
-\lst@Aspect{nonkeywordstyle}{\def\lst@nonkeywordstyle{#1}}
-%    \end{macrocode}
-% \lsthelper{Anders Edenbrandt}{[email protected]}{1997/04/22}{preload of .fd files} found a bug with \texttt{.fd} files.
-% Here's my solution: Since we will change catcodes, these files can't be read on demand --- it would yield to obscure error messages.
-% The |\setbox| sequence ensures (most times) that they are read before.
-% We simply typeset distinct characters from each \texttt{.fd} file.
-% Note: We never output that box.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@basicstyle %
-     \setbox\@tempboxa\hbox{\lst@loadfd %
-         {\lst@keywordstyle \lst@loadfd}%
-         {\lst@nonkeywordstyle \lst@loadfd}}}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{macro}{\lst@loadfd}
-% These are hopefully all necessary characters.
-%    \begin{macrocode}
-\def\lst@loadfd{a0\lst@asterisk\lst@less}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{ndkeywords}
-% \begin{aspect}{ndkeywordstyle}
-% \begin{aspect}{morendkeywords}
-% \begin{aspect}{deletendkeywords}
-% We define a second keyword class in the same manner if the user wants it.
-%    \begin{macrocode}
-\@ifundefined{lst@ndkeywords}{}{%
-\let\lst@ndkeywords\@empty \let\lst@ndkeywordstyle\@empty % init
-\lst@Aspect{ndkeywords}
-    {\lst@MakeSpecKeywordArg{#1}\let\lst@ndkeywords\lst@arg}
-\lst@AddToHook{SetLanguage}{\let\lst@ndkeywords\@empty}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifsensitive\else %
-         \lst@MakeMacroUppercase\lst@ndkeywords %
-     \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{ndkeywordstyle}{\def\lst@ndkeywordstyle{#1}}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{{\lst@ndkeywordstyle \lst@loadfd}}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{morendkeywords}
-    {\lst@MakeMoreSpecKeywordArg{,#1}%
-     \expandafter\lst@lAddTo\expandafter\lst@ndkeywords %
-         \expandafter{\lst@arg}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{deletendkeywords}
-    {\lst@MakeKeywordArg{#1}%
-     \lst@DeleteKeysIn\lst@ndkeywords\lst@arg}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{Output}
-    {\lst@ifmode\else %
-         \expandafter\lst@IfOneOf\the\lst@token\relax \lst@ndkeywords %
-             {\let\lst@thestyle\lst@ndkeywordstyle}{}%
-     \fi}
-%    \end{macrocode}
-% Finally we end the argument from |\@ifundefined|.
-%    \begin{macrocode}
-}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{aspect}{rdkeywords}
-% \begin{aspect}{rdkeywordstyle}
-% \begin{aspect}{morerdkeywords}
-% \begin{aspect}{deleterdkeywords}
-% That's the power of \lst-aspects: An optional third keyword class.
-%    \begin{macrocode}
-\@ifundefined{lst@rdkeywords}{}{%
-\let\lst@rdkeywords\@empty \let\lst@rdkeywordstyle\@empty % init
-\lst@Aspect{rdkeywords}
-    {\lst@MakeSpecKeywordArg{#1}\let\lst@rdkeywords\lst@arg}
-\lst@AddToHook{SetLanguage}{\let\lst@rdkeywords\@empty}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifsensitive\else %
-         \lst@MakeMacroUppercase\lst@rdkeywords %
-     \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{rdkeywordstyle}{\def\lst@rdkeywordstyle{#1}}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{{\lst@rdkeywordstyle \lst@loadfd}}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{morerdkeywords}
-    {\lst@MakeMoreSpecKeywordArg{,#1}%
-     \expandafter\lst@lAddTo\expandafter\lst@rdkeywords %
-         \expandafter{\lst@arg}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{deleterdkeywords}
-    {\lst@MakeKeywordArg{#1}%
-     \lst@DeleteKeysIn\lst@rdkeywords\lst@arg}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{Output}
-    {\lst@ifmode\else %
-         \expandafter\lst@IfOneOf\the\lst@token\relax \lst@rdkeywords %
-             {\let\lst@thestyle\lst@rdkeywordstyle}{}%
-     \fi}
-}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}\end{aspect}
-%
-%
-% \subsection{Export of indentifiers}
-%
-% \begin{aspect}{index}
-% We implement this aspect in the same manner.
-%    \begin{macrocode}
-\@ifundefined{lst@index}{}{%
-\lst@Aspect{index}{\lst@MakeSpecKeywordArg{#1}\let\lst@index\lst@arg}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifsensitive\else %
-         \lst@MakeMacroUppercase\lst@index %
-     \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{Output}
-    {\lst@ifmode\else %
-         \expandafter\lst@IfOneOf\the\lst@token\relax \lst@index %
-            {\expandafter\lst@indexmacro\expandafter{\the\lst@token}}{}%
-     \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{indexmacro}{\let\lst@indexmacro#1}
-\newcommand\lstindexmacro[1]{\index{{\ttfamily#1}}}
-\let\lst@index\@empty \let\lst@indexmacro\lstindexmacro % init
-}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{aspect}{procnamestyle}
-% \begin{aspect}{prockeywords}
-% \begin{aspect}{indexprocnames}
-% The 'idea' here is the usage of a global |\lst@ifprocname| indicating a preceding 'procedure keyword'.
-% All the other is known stuff.
-%    \begin{macrocode}
-\@ifundefined{lst@prockeywords}{}{%
-\lst@Aspect{prockeywords}{%
-    \lst@MakeSpecKeywordArg{#1}\let\lst@prockeywords\lst@arg}
-\lst@Aspect{procnamestyle}{\def\lst@procnamestyle{#1}}
-\lst@Aspect{indexprocnames}[t]{\lstKV@SetIfKey\lst@ifindexproc{#1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{\lst@procnamestyle\lst@loadfd}%
-     \lst@ifsensitive\else %
-         \lst@MakeMacroUppercase\lst@prockeywords %
-     \fi %
-     \lst@ifindexproc \ifx\lst@indexmacro\@undefined %
-         \let\lst@indexmacro\@gobble %
-     \fi \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{Output}
-    {\lst@ifmode\else %
-         \lst@ifprocname %
-             \let\lst@thestyle\lst@procnamestyle %
-             \expandafter\lst@indexmacro\expandafter{\the\lst@token}%
-             \lst@procnamefalse %
-         \else \expandafter%
-             \lst@IfOneOf\the\lst@token\relax \lst@prockeywords %
-                {\lst@procnametrue}{}%
-         \fi %
-     \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@procnametrue{\global\let\lst@ifprocname\iftrue}
-\def\lst@procnamefalse{\global\let\lst@ifprocname\iffalse}
-%    \end{macrocode}
-%    \begin{macrocode}
-\let\lst@prockeywords\@empty % init
-\lstset{procnamestyle={},indexprocnames=false}% init
-\lst@procnamefalse % init
-}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Labels}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \lsthelper{Rolf Niepraschk}{[email protected]}{1997/04/24}{labels} asked for this feature.
-%
-% \begin{aspect}{labelstyle}
-% \begin{aspect}{labelsep}
-% \begin{aspect}{labelstep}
-% The usual stuff:
-% Definition with check for legal step count, \ldots
-%    \begin{macrocode}
-\lst@Aspect{labelstyle}{\def\lst@labelstyle{#1}}
-\lst@Aspect{labelsep}{\def\lst@labelsep{#1}}
-\lst@Aspect{labelstep}%
-    {\ifnum #1>\m@ne %
-         \def\lst@labelstep{#1}%
-     \else %
-         \PackageError{Listings}{Nonnegative integer expected}%
-         {You can't use `#1' as step count for labels.^^J%
-          I'll forget it and proceed.}%
-     \fi}
-%    \end{macrocode}
-% and load of \texttt{.fd} files (if necessary).
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{\lst@stringstyle \lst@loadfd}}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{macro}{\lst@skiplabels}
-% But there are more things to do.
-%    \begin{macrocode}
-\newcount\lst@skiplabels % \global
-%    \end{macrocode}
-% We calculate how many lines must skip their label.
-% The formula is
-%	$$|\lst@skiplabels|=
-%		\textrm{\emph{first printing line}}\bmod|\lst@labelstep|.$$
-% Note that we use a nonpositive representative for |\lst@skiplabels|.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\ifnum\lst@labelstep>\z@ %
-         \global\lst@skiplabels\lst@firstline\relax %
-         \global\divide\lst@skiplabels\lst@labelstep %
-         \global\multiply\lst@skiplabels-\lst@labelstep %
-         \global\advance\lst@skiplabels\lst@firstline\relax %
-         \ifnum\lst@skiplabels>\z@ %
-             \global\advance\lst@skiplabels -\lst@labelstep\relax %
-         \fi %
-%    \end{macrocode}
-% If |\lst@labelstep| is nonpositive (in fact zero), no labels are printed:
-%    \begin{macrocode}
-     \else %
-         \let\lst@SkipOrPrintLabel\relax %
-     \fi}
-\lst@AddToHook{EveryLine}{\lst@SkipOrPrintLabel}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@SkipOrPrintLabel}
-% But default is this.
-% We use the fact that |\lst@skiplabels| is nonpositive.
-% The counter advances every line and if that counter is zero, we print a line number and decrement the counter by |\lst@labelstep|.
-%    \begin{macrocode}
-\def\lst@SkipOrPrintLabel{%
-    \ifnum\lst@skiplabels=\z@ %
-        \global\advance\lst@skiplabels-\lst@labelstep\relax %
-        \llap{\lst@labelstyle{\the\lst@lineno}\kern\lst@labelsep}%
-    \fi %
-    \global\advance\lst@skiplabels\@ne}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Parshape and lineskip}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@innerspread}
-% \begin{macro}{\lst@outerspread}
-% Just allocate these dimensions.
-%    \begin{macrocode}
-\newdimen\lst@innerspread \newdimen\lst@outerspread
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{aspect}{wholeline}
-% \begin{aspect}{indent}
-% \begin{aspect}{spread}
-% Usual stuff.
-%    \begin{macrocode}
-\lst@Aspect{wholeline}[t]{\lstKV@SetIfKey\lst@ifwholeline{#1}}
-\lst@Aspect{indent}{\def\lst@indent{#1}}
-\lst@Aspect{spread}{\lstspread@#1,,\relax}
-%    \end{macrocode}
-% \lsthelper{Harald Haders}{[email protected]}{1998/03/30}{inner- and outerspread} had the idea of two spreads (inner and outer).
-% We either divide the dimension by two or assign the two dimensions to inner- and outerspread.
-%    \begin{macrocode}
-\def\lstspread@#1,#2,#3\relax{%
-    \lst@innerspread#1\relax %
-    \ifx\@empty#2\@empty %
-        \divide\lst@innerspread\tw@\relax %
-        \lst@outerspread\lst@innerspread %
-    \else %
-        \lst@outerspread#2\relax %
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{wholeline=false,indent=\z@,spread=\z@}% init
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{macro}{\lst@parshape}
-% The definition itself is easy.
-% Note that we use this parshape every line (in fact every paragraph).
-% Furthermore we must repeat the parshape if we close a group level --- or the shape is forgotten.
-%    \begin{macrocode}
-\def\lst@parshape{%
-    \parshape\@ne %
-        \ifodd\c@page -\lst@innerspread\else -\lst@outerspread\fi %
-        \linewidth}
-\lst@AddToHookAtTop{EveryLine}{\lst@parshape}
-\lst@AddToHookAtTop{EndGroup}{\lst@parshape}
-%    \end{macrocode}
-% We calculate the line width and (inner/outer) indent for a listing.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\advance\linewidth\lst@innerspread %
-     \advance\linewidth\lst@outerspread %
-     \advance\linewidth-\lst@indent\relax %
-     \advance\lst@innerspread-\lst@indent\relax %
-     \advance\lst@outerspread-\lst@indent\relax %
-     \lst@ifwholeline %
-         \advance\linewidth\@totalleftmargin %
-     \else %
-         \advance\lst@innerspread-\@totalleftmargin %
-         \advance\lst@outerspread-\@totalleftmargin %
-     \fi %
-     \if@twoside\else \lst@outerspread\lst@innerspread \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{lineskip}
-% Finally we come to this attribute --- the introduction is due to communication with \lsthelper{Andreas Bartelt}{[email protected]}{1997/09/11}{problem with redefed \parskip; \lstlineskip introduced}.
-%    \begin{macrocode}
-\lst@Aspect{lineskip}{\def\lst@lineskip{#1}}
-\lst@AddToHook{BeforeSelectCharTable}{\parskip\lst@lineskip\relax}
-\lstset{lineskip=\z@}% init
-%    \end{macrocode}
-% \end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Frames}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-%
-% \begin{aspect}{framerulewidth}
-% \begin{aspect}{framerulesep}
-% \begin{aspect}{frametextsep}
-% We only have to store the arguments.
-%    \begin{macrocode}
-\lst@Aspect{framerulewidth}{\def\lst@framewidth{#1}}
-\lst@Aspect{framerulesep}{\def\lst@framesep{#1}}
-\lst@Aspect{frametextsep}{\def\lst@frametextsep{#1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{framerulewidth=.4pt,framerulesep=2pt,frametextsep=3pt}% init
-%    \end{macrocode}
-% \end{aspect}\end{aspect}\end{aspect}
-%
-% \begin{aspect}{frame}
-% The main aspect saves the argument, resets all supported types |tlrbTLRB| to |\relax| and defines the user specified frame.
-%    \begin{macrocode}
-\lst@Aspect{frame}
-    {\def\lst@frame{#1}%
-     \lstframe@\relax tlrbTLRB\relax %
-     \lstframe@\@empty#1\relax}
-%    \end{macrocode}
-% This submacro defines the macros to be equivalent to |#1| (which is |\relax| or |\@empty|).
-% The second argument is the list of characters terminated by |\relax|.
-%    \begin{macrocode}
-\def\lstframe@#1#2{%
-    \ifx\relax#2\else %
-        \expandafter\let\csname lstf@#2\endcsname#1%
-        \expandafter\lstframe@\expandafter#1%
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{frame={}}% init
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lst@framev}
-% \begin{macro}{\lst@frameV}
-% These macros typeset one or two vertical rules:
-%    \begin{macrocode}
-\def\lst@framev{\hbox{\strut\vrule width\lst@framewidth}}
-\def\lst@frameV{\hbox{\strut %
-    \vrule width\lst@framewidth\kern\lst@framesep %
-    \vrule width\lst@framewidth}}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@framelr}
-% We typeset left and right frame rule every line (if not made |\relax|).
-% Note that |\lst@framel| is possibly redefined and thus equivalent to |\lst@frameL|.
-%    \begin{macrocode}
-\lst@AddToHook{EveryLine}{\lst@framelr}
-\def\lst@framelr{%
-    \llap{\lst@framel\kern\lst@indent\kern\lst@frametextsep}%
-    \rlap{\kern\linewidth\kern\lst@frametextsep\lst@framer}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@frameh}
-% This is the main macro for horizontal lines.
-% The first parameter gives the size of the left and right corner.
-% The other two parameters typeset these corners (and get the size parameter).
-% Now: We move to the correct horizontal position, set the left corner, the horizontal line and the right corner.
-%    \begin{macrocode}
-\def\lst@frameh#1#2#3{%
-    \hbox to\z@{%
-        \kern\ifodd\c@page -\lst@innerspread\else -\lst@outerspread\fi %
-        \kern-\lst@indent %
-%    \end{macrocode}
-%    \begin{macrocode}
-        \kern-\lst@frametextsep %
-        \ifx\lstf@L\@empty %
-            \llap{#2#1}%
-        \else \ifx\lstf@l\@empty %
-            \llap{#20}%
-        \fi \fi %
-        \vrule\@width\lst@frametextsep %
-%    \end{macrocode}
-%    \begin{macrocode}
-        \vrule\@width\lst@indent %
-        \vrule\@width\linewidth\@height\lst@framewidth %
-%    \end{macrocode}
-%    \begin{macrocode}
-        \vrule\@width\lst@frametextsep %
-        \ifx\lstf@R\@empty %
-            \rlap{#3#1}%
-        \else \ifx\lstf@r\@empty %
-            \rlap{#30}%
-        \fi \fi %
-        \hss}}
-%    \end{macrocode}
-% Note: There are no paramaters with numbers 20 and 30.
-% It's |#2| respectively |#3| with size argument 0.
-% \end{macro}
-%
-% \begin{macro}{\lst@framet}
-% \begin{macro}{\lst@frameb}
-% \begin{macro}{\lst@frameT}
-% \begin{macro}{\lst@frameB}
-% Now we can derive the 'top' and 'bottom' frame macros quite easily:
-%    \begin{macrocode}
-\def\lst@framet{\lst@frameh0\lst@frameTL\lst@frameTR}%
-\let\lst@frameb\lst@framet
-\def\lst@frameT{%
-    \lst@frameh1\lst@frameTL\lst@frameTR %
-    \vskip\lst@framesep %
-    \lst@frameh0\lst@frameTL\lst@frameTR}
-\def\lst@frameB{%
-    \lst@frameh0\lst@frameBL\lst@frameBR %
-    \vskip\lst@framesep %
-    \lst@frameh1\lst@frameBL\lst@frameBR}
-%    \end{macrocode}
-% These macros are executed where needed.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\ifx\lstf@T\@empty %
-         \offinterlineskip\par\noindent\lst@frameT %
-     \else \ifx\lstf@t\@empty %
-         \offinterlineskip\par\noindent\lst@framet %
-     \else %
-         \let\lst@framet\relax %
-     \fi \fi %
-%    \end{macrocode}
-% \begin{TODO}
-% Replace |\offinterlineskip| by |\nointerlineskip|?
-% \end{TODO}
-% We look which frame types we have on the left and on the right.
-%    \begin{macrocode}
-     \let\lst@framel\relax \let\lst@framer\relax %
-     \ifx\lstf@L\@empty %
-         \let\lst@framel\lst@frameV %
-     \else %
-         \ifx\lstf@l\relax\else \let\lst@framel\lst@framev \fi %
-     \fi %
-     \ifx\lstf@R\@empty %
-         \let\lst@framer\lst@frameV %
-     \else %
-         \ifx\lstf@r\relax\else \let\lst@framer\lst@framev \fi %
-     \fi %
-%    \end{macrocode}
-% We can speed up things if there are no vertical frames.
-%    \begin{macrocode}
-     \ifx\lst@framel\relax \ifx\lst@framer\relax %
-         \let\lst@framelr\relax %
-     \fi \fi %
-%    \end{macrocode}
-% Finally we close the space between the horizontal rule and the first line (the 'depth' of the current line).
-%    \begin{macrocode}
-     \ifx\lst@framelr\relax\else \ifx\lst@framet\relax\else %
-         {\setbox\strutbox\hbox{%
-              \vrule\@height0pt\@depth.3\normalbaselineskip\@width\z@}%
-          \kern\ifodd\c@page-\lst@innerspread\else-\lst@outerspread\fi %
-          \lst@framelr}%
-     \fi \fi}
-%    \end{macrocode}
-% The frame at the bottom:
-%    \begin{macrocode}
-\lst@AddToHook{ExitVars}
-    {\ifx\lstf@B\@empty %
-         \offinterlineskip\everypar{}\par\noindent\lst@frameB %
-     \else \ifx\lstf@b\@empty %
-         \offinterlineskip\everypar{}\par\noindent\lst@framet %
-     \fi \fi}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lst@frameTL}
-% \begin{macro}{\lst@frameTR}
-% \begin{macro}{\lst@frameBL}
-% \begin{macro}{\lst@frameBR}
-% The 'corner' macros are left.
-% All save the vertical rule in a temporary box to zero the depth or height of that box.
-% Then we typeset the vertical and horizontal rule (in reversed order).
-%    \begin{macrocode}
-\def\lst@frameTL#1{%
-    \@tempdima\lst@framesep \advance\@tempdima\lst@framewidth %
-    \multiply\@tempdima#1\relax %
-    \setbox\@tempboxa\hbox to\z@{%
-        \vrule\@width\lst@framewidth\@height\z@\@depth\@tempdima\hss}%
-    \dp\@tempboxa\z@ %
-    \advance\@tempdima\lst@framewidth %
-    \box\@tempboxa \vrule\@width\@tempdima\@height\lst@framewidth}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@frameTR#1{%
-    \@tempdima\lst@framesep \advance\@tempdima\lst@framewidth %
-    \multiply\@tempdima#1\relax %
-    \setbox\@tempboxa\hbox to\z@{\hss %
-        \vrule\@width\lst@framewidth\@height\z@\@depth\@tempdima}%
-    \dp\@tempboxa\z@ %
-    \advance\@tempdima\lst@framewidth %
-    \vrule\@width\@tempdima\@height\lst@framewidth \box\@tempboxa}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@frameBL#1{%
-    \@tempdima\lst@framesep \advance\@tempdima\lst@framewidth %
-    \multiply\@tempdima#1\relax %
-    \advance\@tempdima\lst@framewidth %
-    \setbox\@tempboxa\hbox to\z@{%
-        \vrule\@width\lst@framewidth\@height\@tempdima\hss}%
-    \ht\@tempboxa\z@ %
-    \box\@tempboxa \vrule\@width\@tempdima\@height\lst@framewidth}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@frameBR#1{%
-    \@tempdima\lst@framesep \advance\@tempdima\lst@framewidth %
-    \multiply\@tempdima#1\relax %
-    \advance\@tempdima\lst@framewidth %
-    \setbox\@tempboxa\hbox to\z@{\hss %
-        \vrule\@width\lst@framewidth\@height\@tempdima}%
-    \ht\@tempboxa\z@ %
-    \vrule\@width\@tempdima\@height\lst@framewidth \box\@tempboxa}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}\end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Pre and post listing}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{pre}
-% \begin{aspect}{post}
-% A rather trivial section.
-%    \begin{macrocode}
-\lst@Aspect{pre}{\lstKV@OptArg\lstpre@[]{#1}}
-\lst@Aspect{post}{\lstKV@OptArg\lstpost@[]{#1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstpre@[#1]#2{%
-    \def\lst@prelisting{#2}\def\lst@@prelisting{#1}}
-\def\lstpost@[#1]#2{%
-    \def\lst@postlisting{#2}\def\lst@@postlisting{#1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{pre={},post={}}% init
-%    \end{macrocode}
-% \end{aspect}\end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{\TeX\ comment lines}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% Communication with \lsthelper{J\"orn Wilms}{[email protected]}{1997/07/07}{\TeX\ comments} is responsible for this feature.
-% Some characters have a special functionality in \TeX{}, e.g.\ the underbar or the dollar sign.
-% These meanings are unwanted while typesetting normal source code, i.e.\ we have to define our own character table.
-% But for the comment lines we must interrupt the current processing and switch back to the original meanings.
-% And at the end we must restore all previous things.
-%
-% \begin{aspect}{texcl}
-% Announcing the aspect:
-%    \begin{macrocode}
-\lst@Aspect{texcl}[t]{\lstKV@SetIfKey\lst@iftexcl{#1}}
-\lstset{texcl=false}% init
-%    \end{macrocode}
-% Things at EOL are easy, but we must allocate new modes for (\TeX) comment lines first.
-%    \begin{macrocode}
-\lst@NewMode\lst@TeXCLmode
-\lst@NewMode\lst@CLmode
-\lst@AddToHook{EOL}
-    {\ifnum\lst@mode=\lst@TeXCLmode %
-         \lst@LeaveAllModes \lst@ReenterModes %
-     \fi %
-     \ifnum\lst@mode=\lst@CLmode \lst@LeaveMode \fi}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@BeginCommentLine}
-% \begin{macro}{\lstCC@@BeginCommentLine}
-% The first macro starts comment lines indicated by a single character (like |%| in \TeX), whereas the second does this for comment lines indicated by two characters (like |//| in C++).
-% According to the macro naming these two macros belong more or less to section \ref{iCharacterClasses}.
-% But we present them here because of \TeX\ comment lines.
-%
-% We print preceding characters (if any), begin the comment and output the comment separator.
-%    \begin{macrocode}
-\def\lstCC@BeginCommentLine#1{%
-    \lst@NewLine \lst@PrintToken %
-    \lst@EnterMode{\lst@CLmode}{\lst@modetrue\lst@commentstyle}%
-    #1\relax %
-%    \end{macrocode}
-% If the user don't want \TeX\ comment lines, there is nothing more to do.
-% Otherwise we have to print the comment separator and interrupt the normal processing.
-%    \begin{macrocode}
-    \lst@iftexcl %
-        \lst@PrintToken %
-        \lst@LeaveMode \lst@InterruptModes %
-        \lst@EnterMode{\lst@TeXCLmode}{\lst@modetrue\lst@commentstyle}%
-    \fi}
-%    \end{macrocode}
-% Now comes the same, but we process a 'two character'-separator.
-%    \begin{macrocode}
-\def\lstCC@@BeginCommentLine#1#2{%
-    \lst@NewLine \lst@PrintToken %
-    \lst@EnterMode{\lst@CLmode}{\lst@modetrue\lst@commentstyle}%
-    #1\relax#2\relax %
-    \lst@iftexcl %
-        \lst@PrintToken %
-        \lst@LeaveMode \lst@InterruptModes %
-        \lst@EnterMode{\lst@TeXCLmode}{\lst@modetrue\lst@commentstyle}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{Doing output}
-%
-%
-% \subsection{Output aspects and helpers}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{flexiblecolumns}
-% Do you have any idea what to write here?
-%    \begin{macrocode}
-\lst@Aspect{flexiblecolumns}[t]{\lstKV@SetIfKey\lst@ifflexible{#1}}
-\lstset{flexiblecolumns=false}% init
-%    \end{macrocode}
-% We assign the correct output macros defined below.
-% As you can see there are three main macros, which handle letters, all other printing characters and tabulator stops.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifflexible %
-         \let\lst@Output\lst@OutputFlexible %
-         \let\lst@OutputOther\lst@OutputOtherFlexible %
-         \let\lst@GotoTabStop\lst@GotoTabStopFlexible %
-     \fi}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{aspect}{baseem}
-% We look whether or not the user gives two numbers, i.e.\ we test for a comma.
-%    \begin{macrocode}
-\lst@Aspect{baseem}{\lstbaseem@#1,,\relax}
-%    \end{macrocode}
-% Here we check for legal arguments \ldots
-%    \begin{macrocode}
-\def\lstbaseem@#1,#2,#3\relax{%
-    \def\lst@next{\PackageError{Listings}%
-        {Nonnegative number(s) expected}%
-        {Separate one or two such numbers by a comma, next time.^^J%
-         Now type <RETURN> to proceed.}}%
-    \ifdim #1em<\z@\else %
-        \def\lst@baseemfixed{#1}%
-        \let\lst@baseemflexible\lst@baseemfixed %
-%    \end{macrocode}
-% and do the comma test.
-%    \begin{macrocode}
-        \ifx\@empty#2\@empty %
-            \let\lst@next\relax %
-        \else \ifdim #2em<\z@\else %
-            \def\lst@baseemflexible{#2}%
-            \let\lst@next\relax %
-        \fi \fi %
-    \fi \lst@next}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{baseem={0.6,0.45}}% init
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lst@width}
-% The dimension holds the width of a single character box while typesetting a listing.
-%    \begin{macrocode}
-\newdimen\lst@width
-\lst@AddToHook{InitVars}
-    {\lst@width=\lst@ifflexible\lst@baseemflexible %
-                          \else\lst@baseemfixed\fi em\relax}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{tabsize}
-% We check for a legal argument before saving it.
-%    \begin{macrocode}
-\lst@Aspect{tabsize}
-    {\ifnum#1>\z@ %
-        \def\lst@tabsize{#1}%
-     \else %
-         \PackageError{Listings}{Strict positive integer expected}
-         {You can't use `#1' as tabulator length.^^J%
-          Type <RETURN> to forget it and to proceed.}%
-     \fi}
-%    \end{macrocode}
-% Default tabsize is 8 as proposed by \lsthelper{Rolf Niepraschk}{[email protected]}{1997/04/24}{tabsize=8}.
-%    \begin{macrocode}
-\lstset{tabsize=8}% init
-%    \end{macrocode}
-% \end{aspect}
-%
-% Before looking at the output macros, we have to introduce some registers.
-%
-% \begin{macro}{\lst@token}
-% \begin{macro}{\lst@length}
-% The token register contains the current character string, for example |char| if we have just read these characters and a whitespace before.
-% The counter |\lst@length| holds the length of the string and that's 4 in the example.
-%    \begin{macrocode}
-\newtoks\lst@token \newcount\lst@length
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVarsEOL}{\lst@token{}\lst@length\z@}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@lastother}
-% This is not a \TeX{} register.
-% This macro is equivalent to the last 'other' character, other in the sense of section \ref{iCharacterClasses}.
-%    \begin{macrocode}
-\lst@AddToHook{InitVarsEOL}{\let\lst@lastother\@empty}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@column}
-% \begin{macro}{\lst@pos}
-% With the two counters it is possible to determine the current column.
-% It's the sum of |\lst@column| and |\lst@length| plus one minus |\lst@pos| --- |\lst@pos| will be nonpositive.
-% It seems to be troublesome to decide whether a new line has just begun or not, i.e.\ if the current column number is one.
-% And that's true.
-%    \begin{macrocode}
-\newcount\lst@column \newcount\lst@pos % \global
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVarsEOL}{\global\lst@pos\z@ \global\lst@column\z@}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@lostspace}
-% The output macros have to keep track of the difference between the real and desired (current) line width; the latter one given by 'current column times |\lst@width|'.
-% More precisely, |\lst@lostspace| equals 'current column times |\lst@width|' minus 'width of so far printed line'.
-% Whenever this dimension is positive we can insert space to fix the column alignment.
-%    \begin{macrocode}
-\newdimen\lst@lostspace % \global
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVarsEOL}{\global\lst@lostspace\z@}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@UseLostSpace}
-% This is a service macro for the fixed and flexible column output.
-% We insert space and reset it (if and) only if |\lst@lostspace| is positive.
-%    \begin{macrocode}
-\def\lst@UseLostSpace{%
-    \ifdim\lst@lostspace>\z@ %
-        \kern\lst@lostspace \global\lst@lostspace\z@ %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@InsertLostSpace}
-% \begin{macro}{\lst@InsertHalfLostSpace}
-% Ditto, but insert always (even if negative).
-%    \begin{macrocode}
-\def\lst@InsertLostSpace{\kern\lst@lostspace \global\lst@lostspace\z@}
-\def\lst@InsertHalfLostSpace{%
-    \global\[email protected]\lst@lostspace \kern\lst@lostspace}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{aspect}{outputpos}
-% Note that there are two |\relax|es \ldots
-%    \begin{macrocode}
-\lst@Aspect{outputpos}{\lstoutputpos@#1\relax\relax}
-%    \end{macrocode}
-% or an empty argument would be bad here.
-% We simply test for |l|, |c| and |r|.
-% If none of them is given, we issue a warning and assume |r| --- it's default since it looks most bad to me.
-% The fixed column format makes use of |\lst@lefthss| and |\lst@righthss|, whereas the flexible needs only |\lst@leftinsert|.
-%    \begin{macrocode}
-\def\lstoutputpos@#1#2\relax{%
-    \ifx #1l%
-        \let\lst@lefthss\relax \let\lst@righthss\hss %
-        \let\lst@leftinsert\relax %
-    \else\ifx #1c%
-        \let\lst@lefthss\hss \let\lst@righthss\hss %
-        \let\lst@leftinsert\lst@InsertHalfLostSpace %
-    \else %
-        \let\lst@lefthss\hss \let\lst@righthss\relax %
-        \let\lst@leftinsert\lst@InsertLostSpace %
-        \ifx #1r\else \PackageWarning{Listings}%
-            {Unknown positioning for output boxes}%
-        \fi %
-    \fi\fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{outputpos=c}% init
-%    \end{macrocode}
-% \end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Dropping empty lines}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@NewLineMacro}
-% This macro is assigned to |\lst@NewLine|, which is executed whenever the (next) line is not empty.
-% Once called, it deactivates itself.
-%    \begin{macrocode}
-\def\lst@NewLineMacro{%
-    \global\let\lst@NewLine\relax \par\noindent\hbox{}}
-\lst@AddToHook{InitVars}{\global\let\lst@NewLine\lst@NewLineMacro}
-%    \end{macrocode}
-% What we have said about |\lst@NewLine| is not the whole truth.
-% Most times we'll assign |\lst@NewLineMacro|, but sometimes we append |\par\noindent\hbox{}| to prepare a new line, namely in the case that the last line has been empty.
-% Then |\lst@NewLine| deactivates itself and begins two, three or more (empty) lines.
-% This drops empty lines at the end of a listing.
-%    \begin{macrocode}
-\lst@AddToHook{EOL}
-    {\ifx\lst@NewLine\relax %
-        \global\let\lst@NewLine\lst@NewLineMacro %
-     \else %
-         \lst@AddTo\lst@NewLine{\par\noindent\hbox{}}%
-     \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Fixed columns}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@OutputOther}
-% This macro outputs a character string with nonletters.
-% If there is anything to output, we possibly start a new line.
-%    \begin{macrocode}
-\def\lst@OutputOther{%
-    \ifnum\lst@length=\z@\else %
-        \lst@NewLine \lst@UseLostSpace %
-%    \end{macrocode}
-% The box must take |\lst@length| characters, each |\lst@width| wide.
-%    \begin{macrocode}
-        \hbox to \lst@length\lst@width{%
-            \lst@lefthss %
-            \lsthk@OutputOther %
-            \expandafter\lst@FillOutputBox\the\lst@token\relax %
-            \lst@righthss}%
-%    \end{macrocode}
-% Finally we hold up the current column, empty the token and close the starting 'if token not empty'.
-%    \begin{macrocode}
-        \global\advance\lst@pos -\lst@length %
-        \lst@token{}\lst@length\z@ %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@Output}
-% We reset |\lst@lastother| and use |\lst@thestyle|.
-%    \begin{macrocode}
-\def\lst@Output{%
-    \let\lst@lastother\relax %
-    \ifnum\lst@length=\z@\else %
-        \lst@NewLine \lst@UseLostSpace %
-        \hbox to \lst@length\lst@width{%
-            \lst@lefthss %
-            \lsthk@Output \lst@thestyle{%
-                \expandafter\lst@FillOutputBox\the\lst@token\relax}%
-            \lst@righthss}%
-        \global\advance\lst@pos -\lst@length %
-        \lst@token{}\lst@length\z@ %
-    \fi}
-%    \end{macrocode}
-% Note that |\lst@lastother| becomes equivalent to |\relax| and not equivalent to |\@empty| as in all other places (e.g.\ InitVarsEOL).
-% I don't know whether this will be important in future or not.
-% \end{macro}
-%
-% \begin{macro}{\lst@FillOutputBox}
-% Filling up a box is easy.
-% If we come to the end (the |\relax| from above), we do nothing.
-% Otherwise we output the argument, insert dynamic space and call the macro again.
-%    \begin{macrocode}
-\def\lst@FillOutputBox#1{%
-    \ifx\relax#1\else #1\hss\expandafter\lst@FillOutputBox \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@GotoTabStop}
-% For fixed column format we only need to advance |\lst@lostspace| (which is inserted by the output macros above) and update the column.
-%    \begin{macrocode}
-\def\lst@GotoTabStop{%
-    \global\advance\lst@lostspace \lst@length\lst@width %
-    \global\advance\lst@column\lst@length \lst@length\z@}%
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Flexible columns}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@OutputOtherFlexible}
-% If there is something to output, we first insert the space lost by the flexible column format.
-% Then we typeset the box and update the lost space.
-% Note that we don't use any |\hss| here.
-%    \begin{macrocode}
-\def\lst@OutputOtherFlexible{%
-    \ifnum\lst@length=\z@\else %
-        \lst@NewLine \lst@UseLostSpace %
-        \setbox\@tempboxa\hbox{\lsthk@OutputOther\the\lst@token}%
-        \lst@CalcLostSpaceAndOutput %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@OutputFlexible}
-% Nothing is new here.
-%    \begin{macrocode}
-\def\lst@OutputFlexible{%
-    \let\lst@lastother\relax %
-    \ifnum\lst@length=\z@\else %
-        \lst@NewLine \lst@UseLostSpace %
-        \setbox\@tempboxa\hbox{%
-            \lsthk@Output \lst@thestyle{\the\lst@token}}%
-        \lst@CalcLostSpaceAndOutput %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@GotoTabStopFlexible}
-% Here we look whether or not the line already contains printing characters.
-%    \begin{macrocode}
-\def\lst@GotoTabStopFlexible{%
-    \ifx\lst@NewLine\relax %
-%    \end{macrocode}
-% If some characters are already printed, we output a box, which has the width of a blank space.
-% Possibly more space is inserted, but that's upto the current value of |\lst@lostspace|.
-%    \begin{macrocode}
-        \setbox\@tempboxa\hbox{\lst@outputblank}\@tempdima\wd\@tempboxa%
-        \setbox\@tempboxa\hbox{}\wd\@tempboxa\@tempdima %
-        \lst@CalcLostSpaceAndOutput %
-        \global\lst@pos\z@ %
-    \else %
-%    \end{macrocode}
-% Otherwise (no printed characters) we do the same as for fixed columns.
-%    \begin{macrocode}
-        \global\advance\lst@lostspace \lst@length\lst@width %
-        \global\advance\lst@column\lst@length \lst@length\z@ %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@CalcLostSpaceAndOutput}
-% The update of |\lst@lostspace| is simple, refer its definition above (difference between \ldots).
-%    \begin{macrocode}
-\def\lst@CalcLostSpaceAndOutput{%
-    \global\advance\lst@lostspace \lst@length\lst@width %
-    \global\advance\lst@lostspace-\wd\@tempboxa %
-%    \end{macrocode}
-% Moreover we keep track of |\lst@pos| and reset some variables.
-%    \begin{macrocode}
-    \global\advance\lst@pos -\lst@length %
-    \lst@token{}\lst@length\z@ %
-%    \end{macrocode}
-% Before |\@tempboxa| is output, we insert appropiate space if there is enough lost space.
-%    \begin{macrocode}
-    \ifdim\lst@lostspace>\z@ \lst@leftinsert \fi %
-    \box\@tempboxa}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Dropping the whole output}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@BeginDropOutput}
-% It's sometimes useful to process a part of a listing as usual, but to drop the output.
-% This macro does the main work and gets one argument, namely the internal mode it enters.
-% We save |\lst@NewLine|, restore it |\aftergroup| and redefine the output macros.
-%    \begin{macrocode}
-\def\lst@BeginDropOutput#1{%
-    \let\lst@BDOsave\lst@NewLine %
-    \lst@EnterMode{#1}%
-        {\lst@modetrue %
-         \let\lst@Output\lst@EmptyOutput %
-         \let\lst@OutputOther\lst@EmptyOutputOther %
-         \let\lst@GotoTabStop\lst@EmptyGotoTabStop %
-         \aftergroup\lst@BDORestore}}
-%    \end{macrocode}
-% Restoring |\lst@NewLine| is quite easy:
-%    \begin{macrocode}
-\def\lst@BDORestore{\global\let\lst@NewLine\lst@BDOsave}
-%    \end{macrocode}
-% Note that there is no |\lst@EndDropOutput| since this macro would be equivalent to |\lst@LeaveMode|.
-% \end{macro}
-%
-% \begin{macro}{\lst@EmptyOutputOther}
-% \begin{macro}{\lst@EmptyOutput}
-% \begin{macro}{\lst@EmptyGotoTabStop}
-% Here we only keep track of registers (possibly) needed by other processing macros.
-%    \begin{macrocode}
-\def\lst@EmptyOutputOther{%
-    \global\advance\lst@pos -\lst@length %
-    \lst@token{}\lst@length\z@}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@EmptyOutput{\let\lst@lastother\relax \lst@EmptyOutputOther}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lst@EmptyGotoTabStop{%
-    \global\advance\lst@column\lst@length \lst@length\z@}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Writing to an external file}
-%
-% The macros are defined (if and) only if the |doc| option is used.
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-\@ifundefined{lst@doc}{}{%
-%    \end{macrocode}
-% \endgroup
-%
-% \begin{macro}{\lstdoc@out}
-% The file we will write to.
-%    \begin{macrocode}
-\newwrite\lstdoc@out
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@BeginWriteFile}
-% redefines some macros to meet our purpose.
-% The file with name |#1| is opened at the end of the macro.
-%    \begin{macrocode}
-\def\lst@BeginWriteFile#1{%
-    \begingroup %
-    \lsthk@SetLanguage %
-    \let\lstCC@ifec\iffalse %
-    \let\lst@Output\lstdoc@Output %
-    \let\lst@OutputOther\lstdoc@Output %
-    \let\lst@GotoTabStop\lstdoc@GotoTabStop %
-    \let\lstCC@ProcessSpace\lstdoc@ProcessSpace %
-    \let\lst@MProcessListing\lstdoc@MProcessListing %
-    \let\smallbreak\relax %
-    \let\lst@prelisting\relax \let\lst@postlisting\relax %
-    \let\lst@@prelisting\relax \let\lst@@postlisting\relax %
-    \let\lstCC@Use\lstdoc@Use %
-    \let\lst@DeInit\lstdoc@DeInit %
-    \immediate\openout\lstdoc@out=#1\relax}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@EndWriteFile}
-% closes the file and restores original macro meanings.
-%    \begin{macrocode}
-\def\lst@EndWriteFile{\immediate\closeout\lstdoc@out \endgroup}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstdoc@Output}
-% keeps only track of horizontal position.
-%    \begin{macrocode}
-\def\lstdoc@Output{\global\advance\lst@pos -\lst@length \lst@length\z@}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstdoc@ProcessSpace}
-% \begin{macro}{\lstdoc@GotoTabStop}
-% We append the appropiate number of spaces.
-% Note that |\lstCC@Append| increases |\lst@length| by 1, thus we need -2.
-%    \begin{macrocode}
-\def\lstdoc@ProcessSpace{\lstCC@Append{ }}
-\def\lstdoc@GotoTabStop{%
-    \@whilenum \lst@length>\z@ \do %
-    {\lstCC@Append{ }\advance\lst@length-2\relax}}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lstdoc@MProcessListing}
-% writes one line to external file.
-%    \begin{macrocode}
-\def\lstdoc@MProcessListing{%
-    \immediate\write\lstdoc@out{\the\lst@token}%
-    \lst@token{}\lst@length\z@ %
-    \lst@BOLGobble}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstdoc@DeInit}
-% We write the rest to file and end processing.
-%    \begin{macrocode}
-\def\lstdoc@DeInit{%
-    \ifnum\lst@length=\z@\else %
-        \immediate\write\lstdoc@out{\the\lst@token}%
-    \fi %
-    \egroup \smallbreak\lst@postlisting \endgroup}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstdoc@Use}
-% Any processed character appends the character itself to |\lst@token| (but with catcode 12 or 10).
-% The original |\lstCC@Use| is defined in section \ref{iCharacterTables}.
-%    \begin{macrocode}
-\def\lstdoc@Use#1#2#3{%
-    \ifnum#2=\z@ %
-        \expandafter\@gobbletwo %
-    \else %
-        \catcode#2=\active \lccode`\~=#2\lccode`\/=#2%
-        \lowercase{\def~{\lstCC@Append{/}}}%
-    \fi %
-    \lstdoc@Use#1}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begingroup
-%    \begin{macrocode}
-}% of \@ifundefined{lst@doc}{}{%
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Keyword comments}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*keywordcomments>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{keywordcomment}
-% \begin{aspect}{doublekeywordcommentsemicolon}
-% The same stuff as for the other comment commands.
-%    \begin{macrocode}
-\lst@Aspect{keywordcomment}
-    {\lst@MakeKeywordArg{#1}\let\lst@KCkeywords\lst@arg %
-     \let\lst@DefKC\lstCC@KeywordComment}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@Aspect{doublekeywordcommentsemicolon}{\lstDKCS@#1}
-\gdef\lstDKCS@#1#2#3%
-    {\lst@MakeKeywordArg{#1}\let\lst@KCAkeywordsB\lst@arg %
-     \lst@MakeKeywordArg{#2}\let\lst@KCAkeywordsE\lst@arg %
-     \lst@MakeKeywordArg{#3}\let\lst@KCBkeywordsB\lst@arg %
-     \let\lst@DefKC\lstCC@DoubleKeywordCommentS}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{SelectCharTable}{\lst@DefKC}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifsensitive\else %
-         \lst@MakeMacroUppercase\lst@KCkeywords %
-         \lst@MakeMacroUppercase\lst@KCAkeywordsB %
-         \lst@MakeMacroUppercase\lst@KCAkeywordsE %
-         \lst@MakeMacroUppercase\lst@KCBkeywordsB %
-     \fi}
-\lst@AddToHook{SetLanguage}{%
-    \let\lst@DefKC\relax \let\lst@KCkeywords\@undefined %
-    \let\lst@KCAkeywordsB\@undefined \let\lst@KCAkeywordsE\@undefined %
-    \let\lst@KCBkeywordsB\@undefined}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}
-%
-% \begin{macro}{\lstCC@KeywordComment}
-% For this type of keyword comments we save the old output macro and install a new one.
-% Note that |\lstCC@KeywordComment| is executed after selecting the character table via |\lst@DefKC|.
-%    \begin{macrocode}
-\gdef\lstCC@KeywordComment{%
-    \let\lst@Output@\lst@Output \let\lst@Output\lst@KCOutput}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@KCOutput}
-% And now we look how the output works here.
-% It starts as all the time.
-% But if the current character sequence in |\lst@token| is one of the given keywords, we call a macro which starts and ends keyword comments.
-% |\lst@next| is redefined there.
-% After doing all this, we output the token as usual and go on.
-%    \begin{macrocode}
-\gdef\lst@KCOutput{%
-    \ifnum\lst@length=\z@\else %
-        \let\lst@next\relax %
-        \expandafter\lst@IfOneOf \the\lst@token\relax \lst@KCkeywords %
-            {\lst@KCOutput@\lst@BeginKC}{}%
-        \lst@Output@ \lst@next %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@KCOutput@}
-% Now we are in the situation that the current token is attached to a keyword comment.
-% By default |\lst@next| becomes equivalent to the first argument, which is either |\lst@BeginKC| or |\lst@BeginDKCA| or |\lst@BeginDKCB|.
-% Moreover we save the current token.
-%    \begin{macrocode}
-\gdef\lst@KCOutput@#1{\let\lst@next#1%
-    \expandafter\def\expandafter\lst@save\expandafter{\the\lst@token}%
-%    \end{macrocode}
-% If we are not in 'keyword comment mode', nothing else is done here.
-% But if we are, we must end the comment.
-% The problem: Closing the comment group also ruins the current character string in |\lst@token|.
-% The solution: We define a global macro to restore the token and |\lst@length|.
-% |\@gtempa| becomes
-% \begin{itemize}\item[]
-%	|\lst@token{|\meta{current character string}|}\lst@length|\meta{current length}|\relax|
-% \end{itemize}
-%    \begin{macrocode}
-    \lst@ifmode \ifnum\lst@mode=\lst@KCmode %
-        \xdef\@gtempa{%
-            \noexpand\lst@token{\the\lst@token}%
-            \noexpand\lst@length\the\lst@length\relax}%
-%    \end{macrocode}
-% This macro is executed after closing the comment group.
-% We redefine |\lst@next| just to |\relax|.
-%    \begin{macrocode}
-        \aftergroup\@gtempa \lst@LeaveMode \let\lst@next\relax %
-    \fi \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@BeginKC}
-% We call |\lstCC@BeginComment| and define |\lst@KCkeywords| to be the current token (possibly made upper case) since we want a matching keyword.
-% Note: It's a local definition, i.e.\ after ending the comment all comment starting keywords are restored.
-%    \begin{macrocode}
-\gdef\lst@BeginKC{%
-    \lstCC@BeginComment\lst@KCmode \let\lst@KCkeywords\lst@save %
-    \lst@ifsensitive\else \lst@MakeMacroUppercase\lst@KCkeywords \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@DoubleKeywordCommentS}
-% Let's look at the next macro collection.
-% The first macro is the same as the first from above --- except that we must install a different semicolon, which is done at the very beginning.
-%    \begin{macrocode}
-\gdef\lstCC@DoubleKeywordCommentS{%
-    \lstCC@EndKeywordComment{"003B}%
-    \let\lst@Output@\lst@Output \let\lst@Output\lst@DKCOutput}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@DKCOutput}
-% The second macro is also the same as above, but if we haven't found a keyword from the |KCA| list, we try the |KCB| list.
-%    \begin{macrocode}
-\gdef\lst@DKCOutput{%
-    \ifnum\lst@length=\z@\else %
-        \let\lst@next\relax %
-        \expandafter\lst@IfOneOf \the\lst@token\relax\lst@KCAkeywordsB %
-            {\lst@KCOutput@\lst@BeginDKCA}{%
-        \expandafter\lst@IfOneOf \the\lst@token\relax\lst@KCBkeywordsB %
-            {\lst@KCOutput@\lst@BeginDKCB}{}}%
-        \lst@Output@ \lst@next %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@BeginDKCA}
-% \begin{macro}{\lst@BeginDKCB}
-% To begin a keyword comment, we assign appropiate lists of keywords, which might end the comment.
-%    \begin{macrocode}
-\gdef\lst@BeginDKCA{\lstCC@BeginComment\lst@KCmode %
-    \let\lst@KCAkeywordsB\lst@KCAkeywordsE \let\lst@KCBkeywordsB\@empty}
-%    \end{macrocode}
-%    \begin{macrocode}
-\gdef\lst@BeginDKCB{\lstCC@BeginComment\lst@KCmode %
-    \let\lst@KCAkeywordsB\@empty \let\lst@KCBkeywordsB\@empty}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lstCC@EndKeywordComment}
-% Above we've installed a 'end keyword comment' semicolon.
-% Before reading further you should be familiar with section \ref{iCharacterTables}.
-% Roughly speaking we define commands there, which annouces the source code character $0041_{\mathrm{hex}}$='A' to be the upper case letter 'A'.
-% The macro here announces a character to end keyword comments.
-%    \begin{macrocode}
-\gdef\lstCC@EndKeywordComment#1{%
-    \lccode`\~=#1\lowercase{\lstCC@EndKeywordComment@~}{#1}}
-%    \end{macrocode}
-% Looking at the submacro, |#1| is an active character with ASCII code |#2|.
-% We must save a previous meaning of |#1| --- or we couldn't output the character since we've forgotten it.
-% Afterwards we can redefine it: If we are in comment mode and furthermore in keyword comment mode, the 'end keyword comment' character ends the comment, as desired.
-% Note that we output the old meaning of the character first.
-%    \begin{macrocode}
-\gdef\lstCC@EndKeywordComment@#1#2{%
-    \expandafter\let\csname lstCC@EKC#2\endcsname#1%
-    \def#1{%
-        \ifnum\lst@mode=\lst@KCmode %
-            \let\lstCC@next\lstCC@EndComment %
-        \else %
-            \let\lstCC@next\relax %
-        \fi %
-        \csname lstCC@EKC#2\endcsname \lstCC@next}}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</keywordcomments>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{Character classes}\label{iCharacterClasses}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \TeX{} knows sixteen category codes.
-% We define our own character classes here.
-% Each input character becomes active in the sense of \TeX{} and characters of different classes expand to different meanings.
-% We use the following ones:
-% \begin{itemize}
-% \item letters  ---  characters identifiers are of;
-% \item digits  ---  characters for identifiers or numerical constants;
-% \item spaces  ---  characters treated as blank spaces;
-% \item tabulators  ---  characters treated as tabulators;
-% \item stringizers  ---  characters beginning and ending strings;
-% \item comment indicators  ---  characters or character sequences beginning and ending comments;
-% \item special classes support particular programming languages;
-% \item others  ---  all other characters.
-% \end{itemize}
-% How these classes work together?
-% The digit '3' appends the digit to the current character string, e.g.\ |ear| becomes |ear3|.
-% The next nonletter causes the output of the gathered characters.
-% Then we collect all coming nonletters until reaching a letter again.
-% This causes the output of the nonletters, and so on.
-%
-% But there are more details.
-% Stringizers and comment indicators change the processing mode until the string or the comment is over.
-% For example, no keyword tests are done within a string or comment.
-% A tabulator immediately outputs the gathered characters, without looking whether they are letters or not.
-% Afterwards it is possible to determine the tabulator skip.
-% And there is one thing concerning spaces:
-% Many spaces following each other disturb the column alignment since they are not wide enough.
-% Hence, when column alignment is on, we output the space(s) preceding a space.
-%
-% The above classes can be divided into three types:
-% \begin{itemize}
-% \item The 'letter', 'digit' and 'other' class all put characters into the 'output queue' (using |\lstCC@Append| or |\lstCC@AppendOther|, see below).
-% \item	Stringizer, comment indicators and special classes don't affect the output queue directly.
-%	For example, before a character becomes a stringizer, the 'letter', 'digit' or 'other' meaning is saved.
-%	Now the stringizer accesses the output queue via this saved meaning.
-% \item Spaces and tabulators don't put any character into the output queue, but may affect the queue to do their job, as mentioned above.
-%	Instances of these classes are not overwritten (in contrast to letters, digits and others).
-% \end{itemize}
-% Some easy implementation before looking closer \ldots
-%
-% \begin{macro}{\lstCC@Append}
-% This macro appends the argument to the current character string and increases the counter |\lst@length|.
-%    \begin{macrocode}
-\def\lstCC@Append#1{\advance\lst@length\@ne %
-    \expandafter\lst@token\expandafter{\the\lst@token#1}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@AppendOther}
-% Nearly the same, but we save the argument (a single character or a single macro) in |\lst@lastother|.
-%    \begin{macrocode}
-\def\lstCC@AppendOther#1{\advance\lst@length\@ne \let\lst@lastother#1%
-    \expandafter\lst@token\expandafter{\the\lst@token#1}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ifletter}
-% This \texttt{if} indicates whether the last character has been a letter or not.
-%    \begin{macrocode}
-\def\lstCC@lettertrue{\let\lstCC@ifletter\iftrue}
-\def\lstCC@letterfalse{\let\lstCC@ifletter\iffalse}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{InitVars}{\lstCC@letterfalse}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@PrintToken}
-% This macro outputs the current character string in letter or nonletter mode.
-%    \begin{macrocode}
-\def\lst@PrintToken{%
-    \lstCC@ifletter %
-        \lst@Output\lstCC@letterfalse %
-    \else %
-        \lst@OutputOther \let\lst@lastother\@empty %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Character tables}\label{iCharacterTables}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% Before looking at interesting character classes we do some rather tedious coding.
-% Consider a source file of a programming language now.
-% For example, the character $41_{\mathrm{hex}}=65_{\mathrm{dec}}$ usually belongs to the letter class and represents the letter 'A'.
-% The listings package says |\lstCC@Use\lstCC@ProcessLetter|\ldots|{"41}{A}|\ldots\ to make this clear.
-% Roughly speaking it expands to |\def A{\lstCC@ProcessLetter A}|, but the first 'A' is active and the second not.
-%
-% \begin{macro}{\lstCC@Def}
-% \begin{macro}{\lstCC@Let}
-% For speed we won't used these helpers too often.
-% The letter 'A' definition from above could be achieved via |\lstCC@Def{"41}{\lstCC@ProcessLetter A}|.
-%    \begin{macrocode}
-\def\lstCC@Def#1{\catcode#1=\active\lccode`\~=#1\lowercase{\def~}}
-\def\lstCC@Let#1{\catcode#1=\active\lccode`\~=#1\lowercase{\let~}}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lst@SelectCharTable}
-% Each input character becomes active and gets the correct meaning here.
-% We change locally the catcode of the double quote for compatibility with \texttt{german.sty}.
-% Note that some macros take one argument and others a series of arguments which is terminated by |{"00}{}| (or an equivalent expression).
-%    \begin{macrocode}
-\begingroup \catcode`\"=12
-\gdef\lst@SelectCharTable{%
-    \lstCC@Tabulator{"09}%
-    \lstCC@Space{"20}%
-    \lstCC@Use \lstCC@ProcessOther %
-        {"21}!{"22}"{"23}\#{"25}\%{"26}\&{"27}'{"28}({"29})%
-        {"2A}\lst@asterisk{"2B}+{"2C},{"2D}\lst@minus{"2E}.%
-        {"2F}/{"3A}:{"3B};{"3C}\lst@less{"3D}={"3E}\lst@greater{"3F}?%
-        {"5B}[{"5C}\lst@backslash{"5D}]{"5E}\textasciicircum{"60}{`}%
-        {"7B}\lst@lbrace{"7C}\lst@bar{"7D}\lst@rbrace %
-        {"7E}\textasciitilde{"7F}-%
-        \z@\@empty %
-    \lstCC@Use \lstCC@ProcessDigit %
-        {"30}0{"31}1{"32}2{"33}3{"34}4{"35}5{"36}6{"37}7{"38}8{"39}9%
-        \z@\@empty %
-    \lstCC@Use \lstCC@ProcessLetter %
-        {"24}\lst@dollar{"40}@%
-        {"41}A{"42}B{"43}C{"44}D{"45}E{"46}F{"47}G{"48}H{"49}I{"4A}J%
-        {"4B}K{"4C}L{"4D}M{"4E}N{"4F}O{"50}P{"51}Q{"52}R{"53}S{"54}T%
-        {"55}U{"56}V{"57}W{"58}X{"59}Y{"5A}Z{"5F}\lst@underscore %
-        {"61}a{"62}b{"63}c{"64}d{"65}e{"66}f{"67}g{"68}h{"69}i{"6A}j%
-        {"6B}k{"6C}l{"6D}m{"6E}n{"6F}o{"70}p{"71}q{"72}r{"73}s{"74}t%
-        {"75}u{"76}v{"77}w{"78}x{"79}y{"7A}z%
-        \z@\@empty %
-%    \end{macrocode}
-% Define extended characters 128--255.
-%    \begin{macrocode}
-    \lstCC@ifec \lstCC@DefEC \fi %
-%    \end{macrocode}
-% Finally we call some (hook) macros and initialize the backslash if necessary.
-%    \begin{macrocode}
-    \lsthk@SelectCharTable %
-    \csname lstSCT@\lst@language\endcsname %
-    \csname lstSCT@\lst@language @\lst@dialect\endcsname %
-    \ifx\lstCC@Backslash\relax\else %
-        \lccode`\~="5C\lowercase{\let\lsts@backslash~}%
-        \lstCC@Let{"5C}\lstCC@Backslash %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@DefEC}
-% Currently each character in the range 128--255 is treated as a letter.
-%    \begin{macrocode}
-\catcode`\^^@=12
-\gdef\lstCC@DefEC{%
-    \lstCC@ECUse \lstCC@ProcessLetter %
-      ^^80^^81^^82^^83^^84^^85^^86^^87^^88^^89^^8a^^8b^^8c^^8d^^8e^^8f%
-      ^^90^^91^^92^^93^^94^^95^^96^^97^^98^^99^^9a^^9b^^9c^^9d^^9e^^9f%
-      ^^a0^^a1^^a2^^a3^^a4^^a5^^a6^^a7^^a8^^a9^^aa^^ab^^ac^^ad^^ae^^af%
-      ^^b0^^b1^^b2^^b3^^b4^^b5^^b6^^b7^^b8^^b9^^ba^^bb^^bc^^bd^^be^^bf%
-      ^^c0^^c1^^c2^^c3^^c4^^c5^^c6^^c7^^c8^^c9^^ca^^cb^^cc^^cd^^ce^^cf%
-      ^^d0^^d1^^d2^^d3^^d4^^d5^^d6^^d7^^d8^^d9^^da^^db^^dc^^dd^^de^^df%
-      ^^e0^^e1^^e2^^e3^^e4^^e5^^e6^^e7^^e8^^e9^^ea^^eb^^ec^^ed^^ee^^ef%
-      ^^f0^^f1^^f2^^f3^^f4^^f5^^f6^^f7^^f8^^f9^^fa^^fb^^fc^^fd^^fe^^ff%
-      ^^00}
-\endgroup
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{extendedchars}
-% The user aspect.
-%    \begin{macrocode}
-\lst@Aspect{extendedchars}[t]{\lstKV@SetIfKey\lstCC@ifec{#1}}
-\lstset{extendedchars=false}% init
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@Use}
-% Now we define the |\lstCC@|\ldots|Use| macros used above.
-% We either define the character with code |#2| to be |#1#3| (where |#1| is |\lstCC@ProcessLetter| for example) or we gobble the two token after |\fi| to terminate the loop.
-%    \begin{macrocode}
-\def\lstCC@Use#1#2#3{%
-    \ifnum#2=\z@ %
-        \expandafter\@gobbletwo %
-    \else %
-        \catcode#2=\active \lccode`\~=#2\lowercase{\def~}{#1#3}%
-    \fi %
-    \lstCC@Use#1}
-%    \end{macrocode}
-% Limitation: Each second argument to |\lstCC@Use| (beginning with the third one) must be exactly one character or one control sequence.
-% The reason is not the definition here.
-% |\lst@AppendOther| says |\let\lst@lastother#1| and that works with the mentioned limitation only.
-% I'll get over this since |\let| is faster than |\def|, and that's the motivation.
-% \emph{Caution}: Don't change that |\let| to a definition with |\def|.
-% All |\ifx\lst@lastother|\ldots{} in all character classes wouldn't work any more!
-% And rewriting all this would slow down the package.
-% Beware of that.
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ECUse}
-% Here we have two arguments only, namely |\lstCC@ProcessLetter|,\ldots\ and the character (and no character code).
-% Reaching end of list (|^^00|) we terminate the loop.
-% Otherwise we do the same as in |\lstCC@Use| if the character is not active.
-% But if the character is active, we save the meaning before redefinition.
-%    \begin{macrocode}
-\def\lstCC@ECUse#1#2{%
-    \ifnum`#2=\z@ %
-        \expandafter\@gobbletwo %
-    \else %
-        \ifnum\catcode`#2=\active %
-            \lccode`\~=`#2\lccode`\/=`#2\lowercase{\lstCC@ECUse@#1~/}%
-        \else %
-            \catcode`#2=\active \lccode`\~=`#2\lowercase{\def~}{#1#2}%
-        \fi %
-    \fi %
-    \lstCC@ECUse#1}
-%    \end{macrocode}
-% As mentioned, we save the meaning before redefinition.
-%    \begin{macrocode}
-\def\lstCC@ECUse@#1#2#3{%
-   \expandafter\let\csname lsts@EC#3\endcsname #2%
-   \edef#2{\noexpand#1\expandafter\noexpand\csname lsts@EC#3\endcsname}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@Tabulator}
-% \begin{macro}{\lstCC@Space}
-% The similar space and tabulator macros have one argument only (no loop and no macro or character).
-%    \begin{macrocode}
-\def\lstCC@Tabulator#1{\lstCC@Let{#1}\lstCC@ProcessTabulator}
-\def\lstCC@Space#1{\lstCC@Let{#1}\lstCC@ProcessSpace}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lstCC@ChangeBasicClass}
-% Finally we define a macro (collection) with the ability of moving a basic \emph{instance} of class to another class, e.g. making the digit '0' be a letter.
-% The word 'basic' means any instance defined with |\lstCC@Use| or |\lstCC@ECUse|.
-% The first argument of |\lstCC@ChangeBasicClass| gives the new class and the second argument is a macro containing a character sequence.
-% These characters are changed.
-% First we make all these characters active and call a submacro.
-%    \begin{macrocode}
-\def\lstCC@ChangeBasicClass#1#2{%
-    \ifx\@empty#2\else %
-        \expandafter\lst@MakeActive\expandafter{#2}%
-        \expandafter\lstCC@CBC@\expandafter#1\lst@arg\@empty %
-    \fi}
-%    \end{macrocode}
-% The submacro terminates (gobble two token after |\fi|) if it reaches |\@empty|.
-% Otherwise another submacro redfines the character.
-% Note that we expand the old meaning before calling the second submacro and that the second |\lstCC@CBC@@| is used as 'meaning' delimiter.
-%    \begin{macrocode}
-\def\lstCC@CBC@#1#2{%
-    \ifx\@empty#2%
-        \expandafter\@gobbletwo %
-    \else %
-        \expandafter\lstCC@CBC@@#2\lstCC@CBC@@#1#2%
-    \fi %
-    \lstCC@CBC@#1}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstCC@CBC@@#1#2\lstCC@CBC@@#3#4{\def#4{#3#2}}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Letters, digits and others}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lstCC@ProcessLetter}
-% To process a letter we look at the last character.
-% If it hasn't been a letter, we output the preceding other characters first and switch to letter mode.
-% Finally we append the current letter |#1|.
-%    \begin{macrocode}
-\def\lstCC@ProcessLetter#1{%
-    \lstCC@ifletter\else \lst@OutputOther\lstCC@lettertrue \fi %
-    \lstCC@Append{#1}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessOther}
-% 'Other' characters are the other way round.
-% If the last character has been a letter, the preceding letters are output and we switch to nonletter mode.
-% Finally we append the current other character.
-%    \begin{macrocode}
-\def\lstCC@ProcessOther#1{%
-    \lstCC@ifletter \lst@Output\lstCC@letterfalse \fi %
-    \lstCC@AppendOther{#1}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessDigit}
-% A digit simply appends the character to the current character string.
-% But we must use the right macro.
-% This allow digits to be part of an identifier or a numerical constant.
-%    \begin{macrocode}
-\def\lstCC@ProcessDigit#1{%
-    \lstCC@ifletter \lstCC@Append{#1}\else \lstCC@AppendOther{#1}\fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Tabulators and spaces}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% Here we have to take care of two things:
-% First dropping empty lines at the end of a listing, and second the flexible column format.
-% In both cases we use |\lst@lostspace| for the implementation.
-% Whenever this dimension is positive we insert that space before |\lst@token| is output.
-%
-% We've defined |\lst@EOLUpdate| to drop empty lines at the end of a listing.
-% |\lst@NewLine| isn't executed or reset in that case.
-% Instead we append control sequences.
-% But: Lines containing tabulators and spaces only should also be viewed as empty.
-% In order to achieve this tabulators and spaces at the beginning of a line advance |\lst@lostspace| and don't output any characters.
-% The space is inserted if there comes a letter for example.
-% If there are only tabulators and spaces, the line is 'empty' since we haven't done any output.
-%
-% We have to do more for flexible columns.
-% The whitespaces can fix the column alignment:
-% If the real line is wider than it should be (|\lst@lostspace|$<$0pt), a tabulator is at least one space wide; all the other width is used to make |\lst@lostspace| more positive.
-% Spaces do the same: If there are two or more spaces, at least one space is printed; the others fix the column alignment.
-% If we process a string, all spaces are output, of course.
-%
-% \begin{macro}{\lstCC@ProcessTabulator}
-% A tabulator outputs the preceding characters.
-%    \begin{macrocode}
-\def\lstCC@ProcessTabulator{%
-    \lst@PrintToken %
-%    \end{macrocode}
-% Then we must calculate how many columns we need to reach the next tabulator stop.
-% Each printed character decrements the counter |\lst@pos|.
-% Hence we can simply add |\lst@tabsize| until |\lst@pos| is strict positive.
-% That's all.
-% We assign it to |\lst@length|, reset |\lst@pos| \ldots
-%    \begin{macrocode}
-    \global\advance\lst@column -\lst@pos %
-    \@whilenum \lst@pos<\@ne \do %
-        {\global\advance\lst@pos\lst@tabsize}%
-    \lst@length\lst@pos \global\lst@pos\z@ %}
-%    \end{macrocode}
-% and go to the tabulator stop, e.g.\ |\lst@length| columns forward:
-%    \begin{macrocode}
-    \lst@GotoTabStop}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@AppendSpecialSpace}
-% Sometimes we have special spaces:
-% If there are at least two spaces, i.e.\ if the last character have been a space, we output preceding characters and advance |\lst@lostspace| to avoid alignment problems.
-% Otherwise we append a space to the current character string.
-% We'll need that macro soon.
-%    \begin{macrocode}
-\def\lstCC@AppendSpecialSpace{%
-    \ifx\lst@lastother\lst@outputblank %
-        \lst@OutputOther %
-        \global\advance\lst@lostspace\lst@width %
-        \global\advance\lst@pos\m@ne %
-    \else %
-        \lstCC@AppendOther\lst@outputblank %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lst@outputblank}
-% It's better not to forget this.
-%    \begin{macrocode}
-\def\lst@outputblank{\ }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessSpace}
-% If the last character has been a letter, we output the current character string and append one space.
-%    \begin{macrocode}
-\def\lstCC@ProcessSpace{%
-    \lstCC@ifletter %
-        \lst@Output\lstCC@letterfalse %
-        \lstCC@AppendOther\lst@outputblank %
-%    \end{macrocode}
-% Otherwise we look whether we are in string mode or not.
-% In the first case we must append a space; in the second case we must test if the hitherto line is empty.
-%    \begin{macrocode}
-    \else \ifnum\lst@mode=\lst@stringmode %
-        \lstCC@AppendOther\lst@outputblank %
-    \else \ifx\lst@NewLine\relax %
-%    \end{macrocode}
-% If the line is not empty we either advance |\lst@lostspace| or append a space to the current character string.
-%    \begin{macrocode}
-        \lstCC@AppendSpecialSpace %
-    \else \ifnum\lst@length=\z@ %
-%    \end{macrocode}
-% If the line is empty so far, we advance |\lst@lostspace|.
-% Otherwise we append the space.
-%    \begin{macrocode}
-            \global\advance\lst@lostspace\lst@width %
-            \global\advance\lst@pos\m@ne %
-        \else %
-            \lstCC@AppendSpecialSpace %
-        \fi %
-    \fi \fi \fi}
-%    \end{macrocode}
-% Note that this version works for fixed and flexible column output.
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Stringizer}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lst@legalstringizer}
-% Currently there are three different stringizer types: 'd'oubled, 'b'ackslashed and 'm'atlabed.
-% The naming of the first two is due to how the stringizer is represented in a string.
-% Pascal doubles it, i.e.\ the string |'| is represented by four single quotes |''''|, where the first and last enclose the string and the two middle quotes represent the desired stringizer.
-% In C++ we would write |"\""|: A backslash indicates that the next double quote belongs to the string and is not the end of string.
-% The matlabed version is described below.
-% I introduced it after communication with \lsthelper{Zvezdan V. Petkovic}{[email protected]}{1997/11/26}{'single stringizer' not a stringizer in Ada (and Matlab)}.
-%    \begin{macrocode}
-\def\lst@legalstringizer{d,b,m,bd,db}
-%    \end{macrocode}
-% Furthermore we have the two mixed types |bd| and |db|, which in fact equal |b|.
-% \end{macro}
-%
-% \begin{aspect}{stringizer}
-% Here we test whether the user type is supported or not (leading to an error message).
-% In the first case we (re-) define |\lst@DefStrings|.
-%    \begin{macrocode}
-\lst@Aspect{stringizer}{\lstKV@OptArg\lststringizer@[d]{#1}}
-\def\lststringizer@[#1]#2%
-    {\lst@IfOneOf#1\relax \lst@legalstringizer %
-         {\def\lst@DefStrings{\lstCC@Stringizer[#1]#2\@empty}}%
-         {\PackageError{Listings}{Illegal stringizer type `#1'}%
-          {Available types are \lst@legalstringizers.}}}
-\lst@AddToHook{SetLanguage}{\let\lst@DefStrings\@empty}
-\lst@AddToHook{SelectCharTable}{\lst@DefStrings}
-%    \end{macrocode}
-% The just added hook defines the strings after selecting the standard character table.
-% This adjusts the character table to the user's demands.
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@Stringizer}
-% This macro is similar to |\lstCC@ECUse|, but we build the 'use'd name before defining the characters \ldots
-%    \begin{macrocode}
-\def\lstCC@Stringizer[#1]{%
-    \expandafter\lstCC@Stringizer@ %
-        \csname lstCC@ProcessStringizer@#1\endcsname}
-\def\lstCC@Stringizer@#1#2{%
-    \ifx\@empty#2%
-        \expandafter\@gobbletwo %
-%    \end{macrocode}
-% which is terminated by |\@empty|.
-% Otherwise we save the old meaning in |\lsts@s|\meta{the character} (with catcode 12) and redefine it.
-%    \begin{macrocode}
-    \else %
-        \catcode`#2=\active \lccode`\~=`#2\lccode`\/=`#2%
-        \lowercase{%
-           \expandafter\let\csname lsts@s/\endcsname~%
-           \def~{#1/}}%
-    \fi %
-    \lstCC@Stringizer@#1}
-%    \end{macrocode}
-% And now we define all 'process stringizer' macros.
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessStringizer@d}
-% 'd' means no extra work.
-% Reaching the (first) stringizer enters string mode and coming to the next leaves it, and so on.
-% Then the character sequence |''''| produces the right output:
-% The second quote leaves string mode, but we enter it immediately since the stringizer is doubled.
-% And now the implementation.
-% First we output any preceding letters.
-%    \begin{macrocode}
-\def\lstCC@ProcessStringizer@d#1{%
-    \lstCC@ifletter \lst@Output\lstCC@letterfalse \fi %
-%    \end{macrocode}
-% If we already process a string, we execute the saved meaning and look whether the last other (that's the stringizer) is the matching stringizer --- a single quote must not end a string starting with a double quote.
-% The macro |\lstCC@EndString| is defined at the end of this section.
-%    \begin{macrocode}
-    \ifnum\lst@mode=\lst@stringmode %
-        \csname lsts@s#1\endcsname %
-        \ifx\lst@lastother\lstCC@closestring %
-            \lstCC@EndString %
-        \fi %
-    \else %
-        \lst@OutputOther %
-%    \end{macrocode}
-% If we don't process a string, we test whether or not a string is allowed.
-% |\lstCC@BeginString| enters string mode and defines the closing stringizer.
-% This 'begin string' macro gets one argument, hence we expand the control sequence name before executing the macro (if necessary).
-%    \begin{macrocode}
-        \lst@ifmode\else %
-            \expandafter\expandafter\expandafter\lstCC@BeginString %
-        \fi %
-        \csname lsts@s#1\endcsname %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessStringizer@b}
-% 'b' means an extra if: Only if the last other is not a backslash (5-th line) the stringizer can close the string.
-% The rest is the same as above.
-%    \begin{macrocode}
-\def\lstCC@ProcessStringizer@b#1{%
-    \lstCC@ifletter \lst@Output\lstCC@letterfalse \fi %
-    \ifnum\lst@mode=\lst@stringmode %
-        \let\lst@temp\lst@lastother \csname lsts@s#1\endcsname %
-        \ifx\lst@temp\lst@backslash\else %!def of "005C
-        \ifx\lst@lastother\lstCC@closestring %
-            \lstCC@EndString %
-        \fi \fi %
-    \else %
-        \lst@OutputOther %
-        \lst@ifmode\else %
-            \expandafter\expandafter\expandafter\lstCC@BeginString %
-        \fi %
-        \csname lsts@s#1\endcsname %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessStringizer@bd}
-% \begin{macro}{\lstCC@ProcessStringizer@db}
-% are just the same and the same as |\lstCC@ProcessStringizer@b|:
-%    \begin{macrocode}
-\let\lstCC@ProcessStringizer@bd\lstCC@ProcessStringizer@b
-\let\lstCC@ProcessStringizer@db\lstCC@ProcessStringizer@bd
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lstCC@ProcessStringizer@m}
-% 'm'atlabed is designed for programming languages where stringizers (for character or string literals) are also used for other purposes, like Matlab or Ada.
-% Here we enter string mode only if the last character has not been a letter and has not been a right parenthesis.
-% Hence, we have to move the |\lstCC@ifletter| and change the main |\else| part.
-% By the way: The stringizer is doubled in a string.
-%    \begin{macrocode}
-\def\lstCC@ProcessStringizer@m#1{%
-    \ifnum\lst@mode=\lst@stringmode %
-        \lstCC@ifletter \lst@Output\lstCC@letterfalse \fi %
-        \csname lsts@s#1\endcsname %
-        \ifx\lst@lastother\lstCC@closestring %
-            \lstCC@EndString %
-        \fi %
-    \else %
-%    \end{macrocode}
-% And now the real 'm' changes:
-%    \begin{macrocode}
-        \lstCC@ifletter %
-            \lst@Output\lstCC@letterfalse %
-        \else %
-            \lst@OutputOther %
-            \let\lstCC@next\relax %
-            \ifx\lst@lastother)\else \lst@ifmode\else %
-                \let\lstCC@next\lstCC@BeginString %
-            \fi \fi %
-            \expandafter\expandafter\expandafter\lstCC@next %
-        \fi %
-        \csname lsts@s#1\endcsname %
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{stringstyle}
-% \begin{aspect}{blankstring}
-% We insert some easy definitions.
-%    \begin{macrocode}
-\lst@Aspect{stringstyle}{\def\lst@stringstyle{#1}}
-%    \end{macrocode}
-% Thanks to \lsthelper{Knut M\"uller}{[email protected]}{1997/04/28}{\blankstringtrue} for reporting problem with |\blankstringtrue|.
-% The problem has gone.
-%    \begin{macrocode}
-\lst@Aspect{blankstring}[t]{\lstKV@SetIfKey\lst@ifblankstring{#1}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{blankstring=false}% init
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{\lst@stringstyle \lst@loadfd}}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}
-%
-% \begin{macro}{\lst@stringmode}
-% It's time for a new mode allocation:
-%    \begin{macrocode}
-\lst@NewMode\lst@stringmode
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@BeginString}
-% \begin{macro}{\lstCC@EndString}
-% To activate string mode we do te usual things, but here we also assign the correct closing stringizer and |\lst@outputblank|.
-% Note that you know that |\lst@NewLine| deactivates itself.
-%    \begin{macrocode}
-\def\lstCC@BeginString#1{%
-    \lst@NewLine %
-    \lst@EnterMode{\lst@stringmode}{\lst@modetrue\lst@stringstyle}%
-    #1%
-    \let\lstCC@closestring\lst@lastother %
-    \lst@ifblankstring\else \let\lst@outputblank\textvisiblespace \fi}
-%    \end{macrocode}
-% We terminate that mode selection after printing the collected other characters --- at least the closing stringizer.
-% And we reset some registers.
-%    \begin{macrocode}
-\def\lstCC@EndString{%
-    \lst@OutputOther \lst@LeaveMode \lst@token{}\lst@length\z@}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{aspect}{stringtest}
-% We |\let| the test macro |\relax| if necessary.
-%    \begin{macrocode}
-\lst@Aspect{stringtest}[t]{\lstKV@SetIfKey\lst@ifstringtest{#1}}
-\lst@AddToHook{SetLanguage}{\let\lst@ifstringtest\iftrue}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\lst@ifstringtest\else \let\lst@TestStringMode\relax \fi}
-%    \end{macrocode}
-% Default definition of the test macro:
-%    \begin{macrocode}
-\def\lst@TestStringMode{%
-     \ifnum\lst@mode=\lst@stringmode %
-         \PackageWarning{Listings}{String constant exceeds line}%
-         \lst@LeaveMode \lst@token{}\lst@length\z@ %
-     \fi}
-\lst@AddToHook{EOL}{\lst@TestStringMode}
-%    \end{macrocode}
-% \end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Comments}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{commentstyle}
-% Again we start with an easy definition.
-%    \begin{macrocode}
-\lst@Aspect{commentstyle}{\def\lst@commentstyle{#1}}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{\lst@commentstyle \lst@loadfd}}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@BeginComment}
-% \begin{macro}{\lstCC@@BeginComment}
-% \begin{macro}{\lstCC@EndComment}
-% These macros start and end a comment, respectively.
-% The |@@| version also eat (and output) one or two characters.
-% In that case the characters belong to the comment indicator.
-% |\relax| ensures that the characters are really eaten, i.e.\ the characters can't end the current comment or start a new one.
-% Note again that |\lst@NewLine| deactivates itself.
-%    \begin{macrocode}
-\def\lstCC@BeginComment#1{%
-    \lst@NewLine \lst@PrintToken %
-    \lst@EnterMode{#1}{\lst@modetrue\lst@commentstyle}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstCC@@BeginComment#1#2#3{%
-    \lst@NewLine \lst@PrintToken %
-    \lst@EnterMode{#1}{\lst@modetrue\lst@commentstyle}%
-    \lst@mode\lst@nomode #2\relax#3\relax \lst@mode#1\relax}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\lstCC@EndComment{%
-    \lst@PrintToken \lst@LeaveMode \let\lst@lastother\@empty}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lstCC@TestCArg}
-% Comment commands allow a single character like |!| or two characters like |//|.
-% The calling syntax of this testing macro is
-% \begin{macrosyntax}
-% \item	|\lstCC@TestCArg|\meta{characters to test}|\@empty\relax|\meta{macro}
-% \end{macrosyntax}
-% \meta{macro} is called after doing the test and gets three arguments:
-% The given two characters as active characters (where the second equals |\@empty| if and only if a single character is given), and the third is a catcode 12 version of the first character.
-%    \begin{macrocode}
-\begingroup \catcode`\^^@=\active
-\gdef\lstCC@TestCArg#1#2#3\relax#4{%
-    \lccode`\~=`#1\lccode`\/=`#1%
-    \ifx\@empty#2%
-        \lowercase{\def\lst@temp{~\@empty/}}%
-    \else \lccode`\^^@=`#2%
-        \lowercase{\def\lst@temp{~^^@/}}%
-    \fi %
-%    \end{macrocode}
-% If neither |#2| nor |#3| equals |\@empty|, the user has given more than two characters:
-%    \begin{macrocode}
-    \ifx\@empty#2\else \ifx\@empty#3\else \lstCC@TestCArgError \fi\fi %
-%    \end{macrocode}
-%    \begin{macrocode}
-    \expandafter #4\lst@temp}
-\endgroup
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@TestCArgError}
-%    \begin{macrocode}
-\def\lstCC@TestCArgError{%
-    \PackageError{Listings}{At most 2 characters allowed}%
-    {The package doesn't provide more than two characters here.^^J%
-     I'll simply use the first two only and proceed.}}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@next}
-% \begin{macro}{\lstCC@bnext}
-% \begin{macro}{\lstCC@enext}
-% We initialize some macros used in the sequel.
-%    \begin{macrocode}
-\lst@AddToHook{BeforeSelectCharTable}
-    {\let\lstCC@next\relax \let\lstCC@bnext\relax\let\lstCC@enext\relax}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lst@DefSC}
-% \begin{macro}{\lst@DefNC}
-% \begin{macro}{\lst@DefDC}
-% \begin{macro}{\lst@DefCL}
-% \begin{macro}{\lst@DefFCL}
-% These macros are redefined by comment aspects.
-% The comments are reset every language selection, and every listing we define the comment characters after selecting the standard character table.
-%    \begin{macrocode}
-\lst@AddToHook{SetLanguage}
-    {\let\lst@DefSC\relax \let\lst@DefNC\relax \let\lst@DefDC\relax %
-     \let\lst@DefCL\relax \let\lst@DefFCL\relax}
-\lst@AddToHook{SelectCharTable}
-    {\lst@DefSC \lst@DefNC \lst@DefDC \lst@DefCL \lst@DefFCL}
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}\end{macro}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsubsection{Comment lines}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{commentline}
-% We define the user aspect:
-%    \begin{macrocode}
-\lst@Aspect{commentline}{\def\lst@DefCL{\lstCC@CommentLine{#1}}}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@CommentLine}
-% Comment lines become undefined if the one and only argument is empty.
-%    \begin{macrocode}
-\def\lstCC@CommentLine#1{%
-    \ifx\@empty#1\@empty\else %
-        \lstCC@TestCArg#1\@empty\relax\lstCC@CommentLine@ %
-    \fi}
-%    \end{macrocode}
-% The next submacro actually defines the comment characters.
-% We save the old meaning --- or we couldn't use the original meaning any more.
-%    \begin{macrocode}
-\def\lstCC@CommentLine@#1#2#3{%
-    \expandafter\let\csname lsts@CL#3\endcsname#1%
-%    \end{macrocode}
-% The redefinitions:
-% If a single character indicates a comment, the next operation is either |\relax| (since no mode change is allowed) or |\lstCC@BeginCommentLine|.
-% And we execute the saved character meaning.
-%    \begin{macrocode}
-    \ifx\@empty#2%
-        \def#1{%
-            \lst@ifmode \let\lstCC@next\relax \else %
-                \let\lstCC@next\lstCC@BeginCommentLine %
-            \fi %
-            \expandafter\lstCC@next \csname lsts@CL#3\endcsname}%
-    \else %
-%    \end{macrocode}
-% Comment lines indicated by a sequence of two characters are just the same.
-% But: We enter comment mode (if and) only if the next character equals |#2|.
-% And we use a different macro to enter comment mode.
-%    \begin{macrocode}
-        \def#1##1{%
-            \let\lstCC@next\relax %
-            \lst@ifmode\else \ifx##1#2%
-                \let\lstCC@next\lstCC@@BeginCommentLine %
-            \fi \fi %
-            \expandafter\lstCC@next \csname lsts@CL#3\endcsname##1}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{fixedcommentline}
-% \begin{macro}{\lst@FCLmode}
-% Another user aspect \ldots
-%    \begin{macrocode}
-\lst@Aspect{fixedcommentline}{\lstKV@OptArg\lstfcommentline@[0]{#1}}
-\def\lstfcommentline@[#1]#2%
-    {\def\lst@DefFCL{\lstCC@FixedCL[#1]#2\@empty}}
-%    \end{macrocode}
-% and a mode allocation.
-%    \begin{macrocode}
-\lst@NewMode\lst@FCLmode
-%    \end{macrocode}
-% \end{macro}\end{aspect}
-%
-% \begin{macro}{\lstCC@FixedCL}
-% Note that we can't use |\lstCC@TestCArg| here since the argument might consist of more than two characters.
-% We enter a loop which is terminated by |\@empty|.
-%    \begin{macrocode}
-\def\lstCC@FixedCL[#1]#2{%
-    \ifx\@empty#2\else %
-        \lccode`\~=`#2\lccode`\/=`#2%
-        \lowercase{\lstCC@FixedCL@~/}{#1}%
-        \def\lstCC@next{\lstCC@FixedCL[#1]}%
-        \expandafter\lstCC@next %
-    \fi}
-%    \end{macrocode}
-% But now comes the same as above: We save the old meaning of |#1| and redefine it.
-% We enter comment mode (if and) only if the character is in column |#3|+1.
-%    \begin{macrocode}
-\def\lstCC@FixedCL@#1#2#3{%
-    \expandafter\let\csname lsts@FCL#2\endcsname#1%
-    \def#1{\let\lstCC@next\relax %
-        \lst@ifmode\else %
-            \@tempcnta\lst@column %
-            \advance\@tempcnta\lst@length %
-            \advance\@tempcnta-\lst@pos %
-            \ifnum\@tempcnta=#3%
-                \let\lstCC@next\lstCC@BeginCommentLine %
-            \fi %
-        \fi %
-        \expandafter\lstCC@next \csname lsts@FCL#2\endcsname}}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsubsection{Single and double comments}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{singlecomment}
-% \begin{aspect}{doublecomment}
-% Define the user commands \ldots
-%    \begin{macrocode}
-\lst@Aspect{singlecomment}{\def\lst@DefSC{\lstCC@SingleComment#1{}}}
-\lst@Aspect{doublecomment}{\def\lst@DefDC{\lstCC@DoubleComment#1{}{}{}}}
-%    \end{macrocode}
-% \end{aspect}\end{aspect}
-%
-% \begin{macro}{\lst@SCmode}
-% \begin{macro}{\lst@DCmodeA}
-% \begin{macro}{\lst@DCmodeB}
-% and allocate new internal modes.
-%    \begin{macrocode}
-\lst@NewMode\lst@SCmode \lst@NewMode\lst@DCmodeA\lst@NewMode\lst@DCmodeB
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lstCC@SingleComment}
-% \begin{macro}{\lstCC@DoubleComment}
-% All must be done twice here, for the beginning and end of a comment.
-% The use of additional arguments like |{SC}\lst@SCmode| make it possible to define single and double comments with the same macros.
-%    \begin{macrocode}
-\def\lstCC@SingleComment#1#2{%
-    \ifx\@empty#1\@empty\else %
-        \lstCC@TestCArg#1\@empty\relax\lstCC@CommentB{SC}\lst@SCmode %
-        \lstCC@TestCArg#2\@empty\relax\lstCC@CommentE{SC}\lst@SCmode %
-    \fi}
-%    \end{macrocode}
-% Note the order: We define 'begin comment' and afterwards 'end comment'.
-% This becomes important if |#1| equals |#2|, for example.
-% Each such comment definition saves the old character meaning, which is executed after doing all comment specific.
-% If we define 'end comment' first and then 'begin comment', |#1| would start a comment and then execute the old definition, which is 'end comment'.
-% Since we are in comment mode now (and since |#1| equals |#2|), 'end comment' leaves comment mode immediately.
-% That would be very bad!
-%    \begin{macrocode}
-\def\lstCC@DoubleComment#1#2#3#4{%
-    \ifx\@empty#1\@empty\else %
-        \lstCC@TestCArg#1\@empty\relax\lstCC@CommentB{DCA}\lst@DCmodeA %
-        \lstCC@TestCArg#3\@empty\relax\lstCC@CommentB{DCB}\lst@DCmodeB %
-        \lstCC@TestCArg#2\@empty\relax\lstCC@CommentE{DCA}\lst@DCmodeA %
-        \lstCC@TestCArg#4\@empty\relax\lstCC@CommentE{DCB}\lst@DCmodeB %
-    \fi}
-%    \end{macrocode}
-% \end{macro}\end{macro}
-%
-% \begin{macro}{\lstCC@CommentB}
-% is not different from |\lstCC@CommentLine@| at all:
-% The save name |#3| there is replaced by |B#4#3| and instead of |\lst@CLmode| we use |#5|.
-%    \begin{macrocode}
-\def\lstCC@CommentB#1#2#3#4#5{%
-    \expandafter\let\csname lsts@B#4#3\endcsname#1%
-    \ifx\@empty#2%
-        \def#1{%
-            \lst@ifmode \let\lstCC@bnext\relax \else %
-                \def\lstCC@bnext{\lstCC@BeginComment#5}%
-            \fi %
-            \lstCC@bnext \csname lsts@B#4#3\endcsname}%
-    \else %
-        \def#1##1{%
-            \let\lstCC@bnext\relax %
-            \lst@ifmode\else \ifx##1#2%
-                \def\lstCC@bnext{\lstCC@@BeginComment#5}%
-            \fi \fi %
-            \expandafter\lstCC@bnext \csname lsts@B#4#3\endcsname##1}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@CommentE}
-% Here we insert |\ifnum\lst@mode=#5| (6-th line), where |#5| is |\lst@SCmode| for example.
-% This ensures that comment delimiters match each other.
-%    \begin{macrocode}
-\def\lstCC@CommentE#1#2#3#4#5{%
-    \expandafter\let\csname lsts@E#4#3\endcsname#1%
-    \ifx\@empty#2%
-        \def#1{%
-            \def\lstCC@enext{\csname lsts@E#4#3\endcsname}%
-            \lst@ifmode \ifnum\lst@mode=#5%
-                \def\lstCC@enext{\csname lsts@E#4#3\endcsname %
-                    \lstCC@EndComment}%
-            \fi \fi %
-            \lstCC@enext}%
-    \else %
-        \def#1##1{%
-            \def\lstCC@enext{\csname lsts@E#4#3\endcsname ##1}%
-            \lst@ifmode \ifnum\lst@mode=#5\ifx##1#2%
-                \def\lstCC@enext{\csname lsts@E#4#3\endcsname ##1%
-                    \lstCC@EndComment}%
-            \fi \fi \fi %
-            \lstCC@enext}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsubsection{Nested comments}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{nestedcomment}
-% The user aspect \ldots
-%    \begin{macrocode}
-\lst@Aspect{nestedcomment}{\lstnestedcomment@#1}
-\def\lstnestedcomment@#1#2%
-    {\def\@tempa{#1}\def\@tempb{#2}%
-     \ifx\@tempa\@tempb \ifx\@tempa\@empty\else %
-         \PackageError{Listings}{Identical delimitors}%
-         {These delimitors make no sense with nested comments.}%
-     \fi \fi %
-     \def\lst@DefNC{\lstCC@NestedComment{#1}{#2}}}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@NestedComment}
-% and the internal macro.
-%    \begin{macrocode}
-\def\lstCC@NestedComment#1#2{%
-    \ifx\@empty#1\@empty\else %
-        \lstCC@TestCArg#2\@empty\relax\lstCC@NCommentE %
-        \lstCC@TestCArg#1\@empty\relax\lstCC@NCommentB %
-    \fi}
-%    \end{macrocode}
-% Note the order: We define 'end comment' and afterwards 'begin comment'.
-% \end{macro}
-%
-% \begin{macro}{\lstCC@NCommentB}
-% The redefinition of the character is different now.
-% Since we define nested comments, we have to count the comment depth.
-% If we already process a nested comment, we increase that depth by making |\lst@mode| more negative.
-%    \begin{macrocode}
-\def\lstCC@NCommentB#1#2#3{%
-    \let\lsts@BNC #1%
-    \ifx\@empty#2%
-        \def#1{%
-            \let\lstCC@bnext\relax %
-            \lst@ifmode %
-                \ifnum\lst@mode<\z@ %
-                    \advance\lst@mode\m@ne %
-                \fi %
-            \else %
-                \def\lstCC@bnext{\lstCC@BeginComment\m@ne}%
-            \fi %
-            \lstCC@bnext \lsts@BNC}%
-    \else %
-        \def#1##1{%
-            \let\lstCC@bnext\relax %
-            \lst@ifmode %
-                \ifnum\lst@mode<\z@ \ifx##1#2%
-                    \advance\lst@mode\m@ne %
-                \fi \fi %
-            \else %
-                \ifx##1#2%
-                    \def\lstCC@bnext{\lstCC@@BeginComment\m@ne}%
-                \fi %
-            \fi %
-            \lstCC@bnext \lsts@BNC ##1}%
-    \fi}
-%    \end{macrocode}
-% \begin{TODO}
-% The third argument (|\catcode| 12 version of the first) is unused so far --- also in |\lst@NCommentE|.
-% If we are in need of 'double' nested comments, we will use this argument for the save name, as we've already done it for normal double comments (and comment lines).
-% \end{TODO}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@NCommentE}
-% If we are in nested comment mode, we either end the comment or decrease the comment depth by making |\lst@mode| less negative.
-%    \begin{macrocode}
-\def\lstCC@NCommentE#1#2#3{%
-    \let\lsts@ENC #1%
-    \ifx\@empty#2%
-        \def#1{%
-            \let\lstCC@enext\relax %
-            \lst@ifmode \ifnum\lst@mode<\z@ %
-                \ifnum\lst@mode=\m@ne %
-                    \let\lstCC@enext\lstCC@EndComment %
-                \else %
-                    \advance\lst@mode\@ne %
-                \fi
-            \fi \fi %
-            \lsts@ENC \lstCC@enext}%
-    \else %
-        \def#1##1{%
-            \def\lstCC@enext{\lsts@ENC ##1}%
-            \ifx##1#2%
-                \lst@ifmode \ifnum\lst@mode<\z@ %
-                    \ifnum\lst@mode=\m@ne %
-                        \def\lstCC@enext{%
-                            \lsts@ENC ##1\lstCC@EndComment}%
-                    \else %
-                        \advance\lst@mode\@ne %
-                    \fi
-                \fi \fi %
-            \fi %
-            \lstCC@enext}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Escape characters}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% The introduction of this character class is due to a communication with \lsthelper{Rui Oliveira}{[email protected]}{1998/06/05}{escape characters}.
-%
-% \begin{macro}{\lstCC@Escape}
-% gets three arguments all in all.
-% The first is the escape character, the second is executed when the escape starts and the third right before ending it.
-% We use the same grouping mechanism as for \TeX\ comment lines.
-%    \begin{macrocode}
-\def\lstCC@Escape#1{\lccode`\~=`#1\lowercase{\lstCC@Escape@~}}
-\def\lstCC@Escape@#1#2#3{%
-    \def#1{%
-        \lst@NewLine\lst@UseLostSpace \lst@PrintToken %
-        \lst@InterruptModes %
-        \lst@EnterMode{\lst@TeXmode}{\lst@modetrue}%
-%    \end{macrocode}
-% After doing the grouping we must define the character to end the escape.
-%    \begin{macrocode}
-        \catcode`#1=\active %
-        \def#1{#3\lst@LeaveAllModes \lst@ReenterModes}%
-        #2}}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@NewMode\lst@TeXmode
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{aspect}{escapechar}
-% This aspect defines |\lst@DefEsc|, which is executed after selecting the standard character table.
-%    \begin{macrocode}
-\lst@Aspect{escapechar}
-    {\ifx\@empty#1\@empty %
-         \let\lst@DefEsc\relax %
-     \else %
-         \def\lst@DefEsc{\lstCC@Escape{#1}\@empty\@empty}%
-     \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lstset{escapechar={}}% init
-\lst@AddToHook{SelectCharTable}{\lst@DefEsc}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{aspect}{mathescape}
-% A switch tested after character table selection.
-% We use |\lstCC@Escape| with math shifts as arguments.
-%    \begin{macrocode}
-\lst@Aspect{mathescape}[t]{\lstKV@SetIfKey\lst@ifmathescape{#1}}
-\lstset{mathescape=false}% init
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{SelectCharTable}
-    {\lst@ifmathescape \lstCC@Escape{\$}{$}{$}\fi}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lst@DontEscapeToLaTeX}
-% This macro came in handy.
-%    \begin{macrocode}
-\def\lst@DontEscapeToLaTeX{%
-    \let\lst@iftexcl\iffalse %
-    \let\lst@DefEsc\relax %
-    \let\lst@ifmathescape\iffalse}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{More \texttt{lst}-aspects and classes}
-%
-%
-% \subsection{Form feeds}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{formfeed}
-% We begin with the announcement --- the introduction is due to communication with \lsthelper{Jan Braun}{[email protected]}{1998/04/27}{\lstformfeed}.
-%    \begin{macrocode}
-\lst@Aspect{formfeed}{\def\lst@formfeed{#1}}
-\lstset{formfeed=\bigbreak}% init
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{SelectCharTable}{\lstCC@Let{`\^^L}\lstCC@FormFeed}
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lstCC@FormFeed}
-% Here we either execute some macros or append them to |\lst@NewLine|.
-%    \begin{macrocode}
-\def\lstCC@FormFeed{%
-    \lst@PrintToken %
-    \ifx\lst@NewLine\relax %
-        \lst@EOLUpdate \lst@formfeed %
-    \else %
-        \lst@lAddTo\lst@NewLine{\lst@EOLUpdate \lst@formfeed}%
-    \fi}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{\TeX\ control sequences}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*tex>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{texcs}
-% In general, it's the same as |keywords|, but control sequences are case sensitive, have a preceding backslash, \ldots
-%    \begin{macrocode}
-\lst@Aspect{texcs}{\def\lst@texcs{#1}}
-\lst@AddToHook{SetLanguage}{\let\lst@texcs\@empty}
-%    \end{macrocode}
-%    \begin{macrocode}
-\lst@AddToHook{Output}
-    {\lst@ifmode\else \ifx\lst@lastother\lst@backslash %
-         \expandafter\lst@IfOneOf\the\lst@token\relax \lst@texcs %
-             {\let\lst@thestyle\lst@keywordstyle}%
-             {\let\lst@thestyle\relax}%
-     \fi \fi}
-%    \end{macrocode}
-% \end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</tex>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Compiler directives in C}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*c>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{cdirectives}
-% First some usual stuff:
-%    \begin{macrocode}
-\lst@Aspect{cdirectives}
-    {\lst@MakeKeywordArg{,#1}\let\lst@cdirectives\lst@arg}
-\lst@AddToHook{SetLanguage}{\let\lst@cdirectives\relax}
-%    \end{macrocode}
-% If the user has defined directives, we redefine the character |#| (but save the old meaning before):
-%    \begin{macrocode}
-\lst@AddToHook{SelectCharTable}
-    {\ifx\lst@cdirectives\relax\else %
-         \lccode`\~=`\#\lowercase{\let\lsts@CCD~\def~}%
-         {\lst@ifmode\else %
-%    \end{macrocode}
-% We enter 'directive mode' only if we are in column 1.
-% Note that 'directive mode' is |\lst@egroupmode| without setting |\lst@ifmode| true.
-%    \begin{macrocode}
-              \@tempcnta\lst@column %
-              \advance\@tempcnta\lst@length %
-              \advance\@tempcnta-\lst@pos %
-              \ifnum\@tempcnta=\z@ %
-                  \lst@EnterMode{\lst@egroupmode}%
-                      {\expandafter\lst@lAddTo\expandafter\lst@keywords%
-                          \expandafter{\lst@cdirectives}}%
-              \fi %
-          \fi %
-          \ifnum\lst@mode=\lst@egroupmode %
-              {\lst@keywordstyle\lsts@CCD\lst@PrintToken}%
-          \else \lsts@CCD %
-          \fi}%
-     \fi}
-%    \end{macrocode}
-% \end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</c>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{PODs in Perl}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*perl>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{printpod}
-% We begin with two user commands, which I introduced after communication with \lsthelper{Michael Piotrowski}{[email protected]}{1997/11/11}{\lstprintpodtrue/false}.
-%    \begin{macrocode}
-\lst@Aspect{printpod}[t]{\lstKV@SetIfKey\lst@ifprintpod{#1}}
-\lstset{printpod=false}% init
-%    \end{macrocode}
-% \end{aspect}
-%
-% \begin{macro}{\lst@PODmode}
-% Define a new mode and use |\global| since we are (possibly) in a driver file and thus inside a group.
-%    \begin{macrocode}
-\global\lst@NewMode\lst@PODmode
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@PODcut}
-% We'll need the active character string |cut|:
-%    \begin{macrocode}
-\lst@MakeActive{cut}\global\let\lstCC@PODcut\lst@arg %
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessPOD}
-% And now the POD character class; only |=| will belong to it.
-% If we are in column 1 \ldots
-%    \begin{macrocode}
-\gdef\lstCC@ProcessPOD{%
-    \let\lstCC@next\relax %
-    \@tempcnta\lst@column %
-    \advance\@tempcnta\lst@length %
-    \advance\@tempcnta-\lst@pos %
-    \ifnum\@tempcnta=\z@ %
-%    \end{macrocode}
-% and if we are already in POD mode, we either end it or proceed according to whether next characters are |cut| or not.
-%    \begin{macrocode}
-        \ifnum\lst@mode=\lst@PODmode %
-            \def\lstCC@next{\lst@IfNextChars\lstCC@PODcut %
-                {\lstCC@ProcessEndPOD}%
-                {\lsts@POD\lst@eaten}}%
-        \else %
-%    \end{macrocode}
-% If we are in column 1 and not in POD mode, we either start a usual comment or drop the output.
-%    \begin{macrocode}
-            \lst@ifprintpod %
-                \lstCC@BeginComment\lst@PODmode %
-            \else %
-                \lst@BeginDropOutput\lst@PODmode %
-            \fi %
-            \let\lstCC@next\lsts@POD %
-        \fi %
-    \fi \lstCC@next}%
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstCC@ProcessEndPOD}
-% If the character behind |=cut| is neither |^^M| nor |^^J|, we don't end the POD.
-%    \begin{macrocode}
-\gdef\lstCC@ProcessEndPOD#1{%
-    \let\lstCC@next\lstCC@ProcessEndPOD@ %
-    \ifnum`#1=`\^^M\else \ifnum`#1=`\^^J\else %
-        \def\lstCC@next{\lsts@POD\lst@eaten#1}%
-    \fi \fi %
-    \lstCC@next}
-%    \end{macrocode}
-% The ending actions depend on |\lst@ifprintpod|: Print |=cut| (or not) and end the POD.
-%    \begin{macrocode}
-\gdef\lstCC@ProcessEndPOD@{%
-    \lst@ifprintpod \lsts@POD\lst@eaten\lst@PrintToken \fi %
-    \lst@LeaveMode}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</perl>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{Special use of \texttt{\#} in Perl}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*perl>
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lstCC@SpecialUseAfter}
-% We need |#| not to begin a comment in Perl if it follows |$|.
-% We'll define a special use of |#| after |$| via |\lstCC@SpecialUseAfter{\$}{\#}{\lstCC@ProcessOther\#}| where the third argument is executed coming to |$#|.
-% Note that the submacro gets two of the three arguments.
-%    \begin{macrocode}
-\gdef\lstCC@SpecialUseAfter#1{%
-    \lccode`\~=`#1\lccode`\/=`#1\lowercase{\lstCC@SpecialUseAfter@~/}}
-%    \end{macrocode}
-% We save the old meaning of the first character (|$|) and redefine it to check for the character |#3|.
-%    \begin{macrocode}
-\gdef\lstCC@SpecialUseAfter@#1#2#3#4{%
-    \expandafter\let\csname lsts@SUA#2\endcsname#1%
-    \def#1##1{%
-        \ifnum`##1=`#3%
-            \def\lstCC@next{\csname lsts@SUA#3\endcsname\relax #4}%
-        \else %
-            \def\lstCC@next{\csname lsts@SUA#3\endcsname ##1}%
-        \fi %
-        \lstCC@next}}
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-%</perl>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{Epilogue}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% Most initialization has already been done, see all |% init| marked lines.
-% Here is more:
-%    \begin{macrocode}
-\lstset{labelsep=5pt,sensitive=true}
-\lstdefinelanguage{}{}
-\lstdefinestyle{}
-    {basicstyle={},%
-     keywordstyle=\bfseries,nonkeywordstyle={},%
-     commentstyle=\itshape,stringstyle={},%
-     labelstyle={},labelstep=0}
-\lst@mode=\z@
-\lstset{language={},style={}}
-%    \end{macrocode}
-% Finally we load compatibility mode, a patch file and the configuration file.
-%    \begin{macrocode}
-\@ifundefined{[email protected]}{}{\input{lst017.sty}}
-\InputIfFileExists{lstpatch.sty}{}{}
-\InputIfFileExists{listings.cfg}{}{}
-%    \end{macrocode}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \section{Interfaces to other packages}
-%
-%
-% \subsection{Compatibility mode}
-%
-% \begingroup
-%    \begin{macrocode}
-%<*0.17>
-%    \end{macrocode}
-% \endgroup
-% We give a warning first.
-%    \begin{macrocode}
-\message{^^J%
-*** You have requested compatibility mode `0.17'.^^J%
-*** This mode is for documents created for version 0.17 only.^^J%
-*** I T\@spaces I S\@spaces N O T\@spaces F U L L Y\@spaces %
-C O M P A T I B L E.^^J^^J}
-%    \end{macrocode}
-%
-%
-% \paragraph{Language names.}
-%
-% Since some programming languages changed their names, we define aliases here.
-%    \begin{macrocode}
-\lstalias[]{blank}[]{}
-\lstalias{cpp}{C++}
-\lstalias[vc]{C++}[Visual]{C++}
-\lstalias{comal}{Comal 80}
-\lstalias{modula}{Modula-2}
-\lstalias{oberon}{Oberon-2}
-\lstalias[]{pxsc}[XSC]{Pascal}
-\lstalias[]{tp}[Borland6]{Pascal}
-\lstalias{pli}{PL/I}
-%    \end{macrocode}
-%
-%
-% \paragraph{User commands.}
-%
-% Old commands in terms of keys:
-%    \begin{macrocode}
-\def\inputlisting{%
-    \@ifnextchar[\inputlisting@{\inputlisting@[1,999999]}}
-\def\inputlisting@[#1,#2]{\lstinputlisting[first=#1,last=#2]}
-%    \end{macrocode}
-%    \begin{macrocode}
-\newcommand\selectlisting[2][]{\lstset{language=[#1]#2}}
-\def\listingtrue{\lstset{print=true}}
-\def\listingfalse{\lstset{print=false}}
-\def\tablength#1{\lstset{tabsize=#1}}\tablength{4}% init
-\def\keywordstyle#1{\lstset{keywordstyle={#1}}}
-\def\commentstyle#1{\lstset{commentstyle={#1}}}
-\def\stringstyle#1{\lstset{stringstyle={#1}}}
-\def\labelstyle#1{\lstset{labelstyle={#1}}}
-\newcommand\stringizer[2][d]{\lstset{stringizer=[#1]#2}}
-\def\blankstringtrue{\lstset{blankstring=true}}
-\def\blankstringfalse{\lstset{blankstring=false}}
-\def\spreadlisting#1{\lstset{spread={#1}}}
-\def\prelisting#1{\def\lst@pre{#1}}
-\def\postlisting#1{\def\lst@post{#1}}
-\def\normallisting{%
-    \lstset{style={},spread=\z@,pre={},post={}}}
-\def\keywords#1{\lstset{keywords={#1}}}
-\def\morekeywords#1{\lstset{morekeywords={#1}}}
-\def\sensitivetrue{\lstset{sensitive=true}}
-\def\sensitivefalse{\lstset{sensitive=false}}
-\let\lst@stringblank\textvisiblespace
-%    \end{macrocode}
-% We define the (new) old environment.
-%    \begin{macrocode}
-\lst@Environment{listing}[1][]\is
-    {\ifx\@empty#1\@empty\else \lst@AddToLOL{#1}{}\fi}
-    {}
-%    \end{macrocode}
-%
-%
-% \paragraph{Comments.}
-%
-% The implementation of old comment commands in terms of the new ones is all the same:
-% If the last argument is empty, we remove the comment; otherwise we execute the new key with correct syntax.
-%    \begin{macrocode}
-\def\DeclareCommentLine#1\relax{%
-    \ifx\@empty#1\@empty %
-        \let\lst@DefCL\relax %
-    \else %
-        \lstset{commentline=#1}%
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\DeclareSingleComment#1 #2\relax{%
-    \ifx\@empty#2\@empty %
-        \let\lst@DefSC\relax \let\lst@DefDC\relax %
-    \else %
-        \lstset{singlecomment={#1}{#2}}%
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\DeclarePairedComment#1\relax{
-    \ifx\@empty#1\@empty %
-        \let\lst@DefSC\relax \let\lst@DefDC\relax %
-    \else %
-        \lstset{singlecomment={#1}{#1}}%
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\DeclareNestedComment#1 #2\relax{%
-    \ifx\@empty#2\@empty %
-        \let\lst@DefSC\relax \let\lst@DefDC\relax %
-    \else %
-        \lstset{nestedcomment={#1}{#2}}%
-    \fi}
-%    \end{macrocode}
-%    \begin{macrocode}
-\def\DeclareDoubleComment#1 #2 #3 #4\relax{%
-    \ifx\@empty#4\@empty %
-        \let\lst@DefSC\relax \let\lst@DefDC\relax %
-    \else %
-        \lstset{doublecomment={#1}{#2}{#3}{#4}}%
-    \fi}
-%    \end{macrocode}
-% \begingroup
-%    \begin{macrocode}
-%</0.17>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \subsection{\textsf{fancyvrb}}
-%
-% \lsthelper{Denis Girou}{[email protected]}{1998/07/26}{fancyvrb} asked whether \textsf{fancyvrb} and \textsf{listings} could work together.
-% Here's the first try.
-% \begingroup
-%    \begin{macrocode}
-%<*kernel>
-%    \end{macrocode}
-% \endgroup
-% \begin{aspect}{fancyvrb}
-% We set the boolean and input the interface file (first time only).
-%    \begin{macrocode}
-\lst@Aspect{fancyvrb}[t]{%
-    \lstKV@SetIfKey\lst@iffancyvrb{#1}%
-    \lstfancyvrb@}
-\def\lstfancyvrb@{\input{lstfvrb.sty}\lstfancyvrb@}
-%    \end{macrocode}
-% \end{aspect}
-% \begingroup
-%    \begin{macrocode}
-%</kernel>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*fancyvrb>
-%    \end{macrocode}
-% We will use |@|-protected names:
-%    \begin{macrocode}
-\begingroup \makeatletter
-%    \end{macrocode}
-% \endgroup
-% \begin{macro}{\lstFV@Def}
-% \begin{macro}{\lstFV@Let}
-% \begin{macro}{\lstFV@Use}
-% \begin{macro}{\lstFV@ECUse}
-% \begin{macro}{\lstFV@Tabulator}
-% \begin{macro}{\lstFV@Space}
-% \begin{macro}{\lstFV@Stringizer@}
-% These are copies of the |\lstCC@|\ldots\ macros, but all catcode changes are removed.
-%    \begin{macrocode}
-\gdef\lstFV@Def#1{\lccode`\~=#1\lowercase{\def~}}%
-\gdef\lstFV@Let#1{\lccode`\~=#1\lowercase{\let~}}%
-%    \end{macrocode}
-%    \begin{macrocode}
-\gdef\lstFV@Use#1#2#3{%
-    \ifnum#2=\z@ %
-        \expandafter\@gobbletwo %
-    \else %
-        \lccode`\~=#2\lowercase{\def~}{#1#3}%
-    \fi %
-    \lstFV@Use#1}%
-%    \end{macrocode}
-%    \begin{macrocode}
-\gdef\lstFV@ECUse#1#2{%
-    \ifnum`#2=\z@ %
-        \expandafter\@gobbletwo %
-    \else %
-        \ifnum\catcode`#2=\active %
-            \lccode`\~=`#2\lccode`\/=`#2\lowercase{\lstCC@ECUse@#1~/}%
-        \else %
-            \lccode`\~=`#2\lowercase{\def~}{#1#2}%
-        \fi %
-    \fi %
-    \lstFV@ECUse#1}%
-%    \end{macrocode}
-%    \begin{macrocode}
-\gdef\lstFV@Tabulator#1{\lstFV@Let{#1}\lstCC@ProcessTabulator}%
-\gdef\lstFV@Space#1{\lstFV@Let{#1}\lstCC@ProcessSpace}%
-%    \end{macrocode}
-%    \begin{macrocode}
-\gdef\lstFV@Stringizer@#1#2{%
-    \ifx\@empty#2%
-        \expandafter\@gobbletwo %
-    \else %
-        \lccode`\~=`#2\lccode`\/=`#2%
-        \lowercase{%
-            \expandafter\let\csname lsts@s/\endcsname~%
-            \def~{#1/}}%
-    \fi %
-    \lstFV@Stringizer@#1}%
-%    \end{macrocode}
-% \end{macro}\end{macro}\end{macro}\end{macro}
-% \end{macro}\end{macro}\end{macro}
-%
-% \begin{macro}{\lstFV@FancyVerbFormatLine}
-% This macro will be assigned to |\FancyVerbFormatLine|: We convert the argument and typeset it.
-%    \begin{macrocode}
-\gdef\lstFV@FancyVerbFormatLine#1{%
-    \let\lstenv@arg\@empty\lstenv@AddArg{#1}%
-    \lstenv@arg \lst@PrintToken\lst@EOLUpdate}%
-%    \end{macrocode}
-% \begin{TODO}
-% This old macro is overwritten below.
-% \end{TODO}
-% \end{macro}
-%
-% \begin{macro}{\lstfancyvrb@}
-% The command assigns some new macros (if it's not already done).
-%    \begin{macrocode}
-\gdef\lstfancyvrb@{%
-    \ifx\FV@VerbatimBegin\lstFV@VerbatimBegin\else %
-        \let\lstFV@OldVB\FV@VerbatimBegin %
-        \let\lstFV@OldVE\FV@VerbatimEnd %
-        \let\FV@VerbatimBegin\lstFV@VerbatimBegin %
-        \let\FV@VerbatimEnd\lstFV@VerbatimEnd %
-    \fi %
-%    \end{macrocode}
-% And we assign the correct |\FancyVerbFormatLine| macro.
-%    \begin{macrocode}
-    \lst@iffancyvrb %
-        \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine\else %
-            \let\lstFV@FVFL\FancyVerbFormatLine %
-            \let\FancyVerbFormatLine\lstFV@FancyVerbFormatLine %
-        \fi %
-    \else %
-        \ifx\lstFV@FVFL\@undefined\else %
-            \let\FancyVerbFormatLine\lstFV@FVFL %
-        \fi %
-    \fi}%
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstFV@VerbatimBegin}
-% We initialize things if necessary.
-%    \begin{macrocode}
-\gdef\lstFV@VerbatimBegin{%
-    \lstFV@OldVB %
-    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine %
-        \lst@DontEscapeToLaTeX %
-        \let\smallbreak\relax \let\normalbaselines\relax %
-        \let\lst@prelisting\relax \let\lst@postlisting\relax %
-        \def\lst@firstline{1}\def\lst@lastline{999999}%
-%    \end{macrocode}
-%    \begin{macrocode}
-        \let\lstCC@Use\lstFV@Use %
-        \let\lstCC@ECUse\lstFV@ECUse %
-        \let\lstCC@Tabulator\lstFV@Tabulator %
-        \let\lstCC@Space\lstFV@Space %
-        \let\lstCC@Stringizer@\lstFV@Stringizer@ %
-%    \end{macrocode}
-%    \begin{macrocode}
-        \def\lst@next{%
-            \lst@Init\relax %
-            \everypar{}\global\let\lst@NewLine\relax}%
-        \expandafter\lst@next %
-    \fi}%
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstFV@VerbatimEnd}
-% A (particular) box and macro must exist after |\lst@DeInit|.
-% We store them globally.
-%    \begin{macrocode}
-\gdef\lstFV@VerbatimEnd{%
-    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine %
-        \global\setbox\lstFV@gtempboxa\box\@tempboxa %
-        \global\let\@gtempa\FV@ProcessLine %
-        \lst@DeInit %
-        \let\FV@ProcessLine\@gtempa %
-        \setbox\@tempboxa\box\lstFV@gtempboxa %
-    \fi %
-    \lstFV@OldVE}%
-%    \end{macrocode}
-%    \begin{macrocode}
-\newbox\lstFV@gtempboxa %
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\lstFV@FancyVerbFormatLine}
-% A slightly different definition now: |\lstenv@AddArg{#1}| has been replaced by |\lstFV@Convert#1@|.
-% The '@' terminates the input |#1|.
-%    \begin{macrocode}
-\gdef\lstFV@FancyVerbFormatLine#1{%
-    \let\lst@arg\@empty\lstFV@Convert#1@%
-    \lst@arg \lst@PrintToken\lst@EOLUpdate}%
-%    \end{macrocode}
-% And this macro is to be defined right now.
-%    \begin{macrocode}
-\gdef\lstFV@Convert{%
-    \@ifnextchar\bgroup{\lstFV@Convert@Arg}{\lstFV@Convert@}}%
-%    \end{macrocode}
-% Coming to a begin group character ('\{' with catcode 1) we convert the and add the conversion together with group delimiters to |\lst@arg|.
-% We also add |\lst@PrintToken|, which prints all collected characters before we forget them.
-% Finally we continue the conversion.
-%    \begin{macrocode}
-\gdef\lstFV@Convert@Arg#1{%
-    {\let\lst@arg\@empty \lstFV@Convert#1@\global\let\@gtempa\lst@arg}%
-    \expandafter\lst@lAddTo\expandafter\lst@arg\expandafter{%
-    \expandafter{\@gtempa\lst@PrintToken}}%
-    \lstFV@Convert}%
-%    \end{macrocode}
-% If we haven't found a |\bgroup|, we look whether we've found the end of the input.
-% If not, we convert one token ((non)active character or control sequence) and continue conversion.
-%    \begin{macrocode}
-\gdef\lstFV@Convert@#1{%
-    \ifx @#1\else %
-        \expandafter\lstFV@Convert@@\string#1\@empty\@empty\relax{#1}%
-        \expandafter\lstFV@Convert %
-    \fi}%
-%    \end{macrocode}
-% |\string#1| from above expands to 'backslash + some characters' if |#1| is a control sequence.
-% In this case the argument |#2| here equals not |\@empty|.
-% The other implication: If |#2| equals |\@empty|, |\string#1| necessarily expanded to a single character, which can't be a control sequence (|\escapechar>=0| granted).
-% Thus, we add an active character if and only if the second argument equals |\@empty|, and we append the control sequence otherwise.
-% In the latter case we must print all preceding characters (and all the lost space).
-%    \begin{macrocode}
-\gdef\lstFV@Convert@@#1#2#3\relax#4{%
-    \ifx\@empty#2%
-        \lccode`\~=`#4\lowercase{\lst@lAddTo\lst@arg~}%
-    \else %
-        \lst@lAddTo\lst@arg{\lst@UseLostSpace\lst@PrintToken#4}%
-    \fi}%
-%    \end{macrocode}
-% \end{macro}
-% \begingroup
-%    \begin{macrocode}
-\endgroup %
-%    \end{macrocode}
-%    \begin{macrocode}
-%</fancyvrb>
-%    \end{macrocode}
-% \endgroup
-%
-%
-% \begingroup\small
-% \section{History}
-% Only major changes after version 0.15 are listed here.
-% Previous changes are still present in the \texttt{.dtx}-file.
-% Introductory version numbers of the user commands are listed in the user's guide.
-% \renewcommand\labelitemi{--}
-% \begin{itemize}
-% \iffalse
-% \item[0.1] from 1996/03/09
-%	\item test version to look whether package is possible or not
-% \item[0.11] from 1996/08/19
-%	\item additional blank option (= language)
-%	\item alignment improved by rewriting some macros
-% \item[0.12] from 1997/01/16
-%	\item nearly 'perfect' alignment now
-% \item[0.13] from 1997/02/11
-%	\item additional languages: Eiffel, Fortran 90, Modula-2, Pascal XSC
-%	\item load on demand: language specific macros moved to driver files
-%	\item comments are declared now and not implemented for each language again (this makes the \TeX{} sources easier to read)
-% \item[0.14] from 1997/02/18
-%	\item user's guide rewritten
-%	\item implementation guide uses macro environment from the doc package
-%	\item (non) case sensitivity implemented, e.g.\ Pascal is not
-%	\item multiple stringizer implemented, i.e.\ Modula-2 handles both string types: quotes and double quotes
-%	\item comment declaration is user-accessible now
-%	\item package compatible to \verb!german.sty! now
-% \item[0.15] from 1997/04/18
-%	\item additional languages: Java, Turbo Pascal
-%	\item package renamed from listing.dtx to listings.dtx, since there is already a package named listing
-% \fi
-% \item[0.16] from 1997/06/01
-% \iffalse
-%	\item changed '$<$' to '$>$' in \verb!\lst@SkipUptoFirst!
-%   \item bug removed: \verb!\lst@Init! must be placed before \verb!\lst@SkipUptoFirst!
-% \fi
-%   \item listing environment rewritten
-% \item[0.17] from 1997/09/29
-%	\item |\spreadlisting| works correct now (e.g.\ page numbers move not right any more)
-%	\item speed up things (quick 'if parameter empty', all |\long| except one removed, faster \verb!\lst@GotoNextTabStop!, etc.)
-%	\item alignment of wide other characters improved (e.g.\ $==$)
-% \iffalse
-%	\item many new languages: Ada, Algol, Cobol, Comal 80, Elan, Fortran 77, Lisp, Logo, Matlab, Oberon, Perl, PL/I, Simula, SQL, \TeX{}
-% \fi
-% \item[pre-0.18] from 1998/03/24 (unpublished)
-%	\item bug concerning |\labelstyle| removed (now oldstylenum example works)
-%	\item experimental implementation of character classes
-% \item[0.19] from 1998/11/09
-%	\item character classes and \lst-aspects (new) seem to be the ultimate, all became implemented in these terms
-%	\item \lst-aspects became an application (new) to \textsf{keyval} and hooks
-%	\item \textsf{fancyvrb} support
-% \end{itemize}
-%
-%
-% \setcounter{IndexColumns}{2}
-% \PrintIndex
-%
-%
-% \Finale
-%
-\endinput
+% \iffalse
+%
+% Trademarks appear throughout this documentation without any trademark
+% symbol, so you can't assume that a name is free. There is no intention
+% of infringement; the usage is to the benefit of the trademark owner.
+%
+%
+%  S O F T W A R E   L I C E N S E
+% =================================
+%
+% The files  listings.dtx  and  listings.ins  and all files generated
+% from only these two files are referred to as `the listings package'
+% or simply `the package'. A `driver' is generated from  lstdrvrs.dtx.
+%
+% Copyright.
+%   The listings package is copyright 1996--2002 Carsten Heinz.
+%   The language drivers are copyright 1997/1998/1999/2000/2001/2002 any
+%   individual author listed in the driver files.
+%
+% Distribution and warranty.
+%   The listings package as well as lstdrvrs.dtx and all drivers are
+%   distributed under the terms of the LaTeX Project Public License
+%   from CTAN archives in directory  macros/latex/base/lppl.txt.
+%   Either version 1.0 or, at your option, any later version.
+%
+% Use of the package.
+%   The listings package is free software. However, if you distribute the
+%   package as part of a commercial product or if you use the package to
+%   prepare a commercial document (books, journals, and so on), I'd like
+%   to encourage you to make a donation to the LaTeX3 fund. The size of
+%   this `license fee' should depend on the value of the package for your
+%   product. For more information about LaTeX see
+%      http://www.latex-project.org
+%
+%   No matter whether you use the package for a commercial or non-commercial
+%   document, please send me a copy of the document (.dvi, .ps, .pdf,
+%   hardcopy, etc.) to support further development---it is easier to
+%   introduce new features or simplify things if I see how the package is
+%   used by other people.
+%
+% Modification advice.
+%   Permission is granted to modify the listings package as well as
+%   lstdrvrs.dtx. You are not allowed to distribute a modified version
+%   of the package or lstdrvrs.dtx unless you change the file names and
+%   provide the original files. In any case it is better to contact the
+%   address below; other users will welcome removed bugs, new features,
+%   and additional programming languages.
+%
+% Contacts.
+%   Send comments and ideas on the package, error reports and additional
+%   programming languages to
+%
+%       Carsten Heinz
+%       Tellweg 6
+%       42275 Wuppertal
+%       Germany
+%
+%   or preferably to
+%
+%       [email protected]
+%
+% end of software license
+%
+%
+%<*driver>
+\documentclass[a4paper]{ltxdoc}
+\DisableCrossrefs
+\OnlyDescription
+
+\usepackage{lstdoc}
+\makeindex
+
+\begin{document}
+    \DocInput{listings.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+%^^A
+%^^A  Command/key to aspect relation
+%^^A ================================
+%^^A
+%\lstisaspect[strings]{string,morestring,deletestring,stringstyle,showstringspaces}
+%\lstisaspect[comments]{comment,morecomment,deletecomment,commentstyle}
+%\lstisaspect[pod]{printpod,podcomment}
+%\lstisaspect[escape]{texcl,escapebegin,escapeend,escapechar,escapeinside,mathescape}
+%\lstisaspect[keywords]{sensitive,classoffset,keywords,morekeywords,deletekeywords,keywordstyle,ndkeywords,morendkeywords,deletendkeywords,ndkeywordstyle,keywordsprefix,otherkeywords}
+%\lstisaspect[emph]{emph,moreemph,deleteemph,emphstyle}
+%\lstisaspect[tex]{texcs,moretexcs,deletetexcs,texcsstyle}
+%\lstisaspect[directives]{directives,moredirectives,deletedirectives,directivestyle}
+%\lstisaspect[html]{keywordsinside,usekeywordsinside}
+%\lstisaspect[keywordcomments]{keywordcomment,morekeywordcomment,deletekeywordcomment,keywordcommentsemicolon}
+%\lstisaspect[index]{index,moreindex,deleteindex,indexstyle,\string\lstindexmacro}
+%\lstisaspect[procnames]{procnamestyle,indexprocnames,procnamekeys,moreprocnamekeys,deleteprocnamekeys}
+%\lstisaspect[style]{style,\string\lstdefinestyle,\string\lst@definestyle,\string\lststylefiles}
+%\lstisaspect[language]{language,alsolanguage,defaultdialect,\string\lstalias,\string\lstdefinelanguage,\string\lst@definelanguage,\string\lstloadlanguages,\string\lstlanguagefiles}
+%\lstisaspect[formats]{format,fmtindent,\string\lstdefineformat,\string\lst@defineformat,\string\lstformatfiles}
+%\lstisaspect[labels]{numbers,numberstyle,numbersep,stepnumber,numberblanklines,firstnumber,\string\thelstnumber}
+%\lstisaspect[lineshape]{xleftmargin,xrightmargin,resetmargins,linewidth,lineskip,breaklines,breakindent,breakautoindent,prebreak,postbreak}
+%\lstisaspect[frames]{framexleftmargin,framexrightmargin,framextopmargin,framexbottommargin,backgroundcolor,fillcolor,rulecolor,rulesepcolor,rulesep,framerule,framesep,frameshape,frameround,frame}
+%\lstisaspect[make]{makemacrouse}
+%\lstisaspect[fancyvrb]{fancyvrb}
+%\lstisaspect[lgrind]{lgrindef,\string\lstlgrindeffile}
+%\lstisaspect[hyper]{hyperref,morehyperref,deletehyperref,hyperanchor,hyperlink}
+%\lstisaspect[kernel]{basewidth,fontadjust,columns,flexiblecolumns,identifierstyle,^^A
+%   tabsize,showtabs,tab,showspaces,keepspaces,formfeed,SelectCharTable,^^A
+%   MoreSelectCharTable,extendedchars,alsoletter,alsodigit,alsoother,excludedelims,^^A
+%   literate,basicstyle,print,firstline,lastline,nolol,captionpos,abovecaptionskip,^^A
+%   belowcaptionskip,label,title,caption,\string\lstlistingname,boxpos,float,^^A
+%   floatplacement,aboveskip,belowskip,everydisplay,showlines,emptylines,gobble,name,^^A
+%   \string\lstname,\string\lstlistlistingname,\string\lstlistoflistings,^^A
+%   \string\lstnewenvironment,\string\lstinline,\string\lstinputlisting,lstlisting,^^A
+%   \string\lstloadaspects,\string\lstset,\string\thelstlisting,\string\lstaspectfiles,^^A
+%   inputencoding,delim,moredelim,deletedelim}
+%\lstisaspect[doc]{lstsample,lstxsample}^^A environment
+%
+%^^A
+%^^A  The long awaited beginning of documentation
+%^^A =============================================
+%^^A
+%\newbox\abstractbox
+%\setbox\abstractbox=\vbox{
+%	\begin{abstract}
+%	The \packagename{listings} package is a source code printer for \LaTeX.
+%	You can typeset stand alone files as well as listings with an environment
+%   similar to \texttt{verbatim} as well as you can print code snippets using
+%   a command similar to |\verb|.
+%	Many parameters control the output and if your preferred programming
+%   language isn't already supported, you can make your own definition.
+%	\end{abstract}}
+%
+% \title{\vspace*{-2\baselineskip}The \textsf{Listings} Package}
+% \author{Copyright 1996--2002\\ Carsten Heinz \textless\lstemail\textgreater}
+% \date{2002/04/01\footnote{Documentation revised 2002/10/13: table
+% \ref{uPredefinedLanguages} of predefined languages and credits in
+% section \ref{uClosingAndCredits} have been updated. Patch file 1.0\,i
+% of same date includes several bug-fixes.}^^A
+% \enspace\enspace Version 1.0\\ \box\abstractbox}
+% \def\lstemail{\href{mailto:[email protected]}{\texttt{[email protected]}}}
+% \ifhyper
+%    \hypersetup{pdfsubject=Package guide,pdfauthor=Carsten Heinz <[email protected]>}
+% \fi
+%
+% \csname @twocolumntrue\endcsname
+% \maketitle
+%^^A \enlargethispage{2\baselineskip}
+% \csname @starttoc\endcsname{toc}
+% \onecolumn
+%
+%
+% \section*{Preface}
+%
+% \paragraph{Reading this manual}
+% If you are experienced with the \packagename{listings} package, you should
+% read the paragraph ``\emph{News and changes}'' below. Otherwise read section
+% \lstref{uGettingStarted} step by step and then go on with
+% section \ref{uTheNextSteps}.
+%
+% \paragraph{News and changes}
+% This is the first release of the package with a major version number unequal
+% to zero. And many changes have been made since version 0.21.
+% One main task was to synchronize the keys of \packagename{listings} and
+% \packagename{fancyvrb}. So user's of both packages can switch between them
+% without learning new keys---as long as the same functionality is provided.
+% The table lists (hopefully) all renamed keys and all removed keys.
+% \begin{table}[hbp]
+% \footnotesize
+% \begin{center}
+% \begin{tabular}{rlrl}
+% \emph{0.21}&\emph{now}&\emph{0.21}&\emph{now}\\[1ex]
+% \texttt{first}          & \texttt{firstline}          & ---                     & \texttt{numbers}\\
+% \texttt{last}           & \texttt{lastline}           & \texttt{labelstep}      & \texttt{stepnumber}\\
+% \texttt{stringspaces}   & \texttt{showstringspaces}   & \texttt{labelstyle}     & \texttt{numberstyle}\\
+% \texttt{visiblespaces}  & \texttt{showspaces}         & \cs{thelstlabel}        & \cs{thelstnumber}\\
+% \texttt{visibletabs}    & \texttt{showtabs}           & \texttt{labelsep}       & \texttt{numbersep}\\
+% \texttt{framerulewidth} & \texttt{framerule}          & \texttt{firstlabel}     & \texttt{firstnumber}\\
+% \texttt{framerulesep}   & \texttt{rulesep}            & \texttt{advancelabel}   & ---\\
+% \texttt{frametextsep}   & \texttt{framesep}           & \texttt{spread}         & ---\\
+% \texttt{framespread}    & superceded by               & \texttt{indent}         & \texttt{xleftmargin}$^3$\\
+%                         & \texttt{framexleftmargin}   &  ---                    & \texttt{xrightmargin}\\
+%                         & \texttt{framexrightmargin}  & \texttt{wholeline}      & \texttt{resetmargins}\\
+%                         & \texttt{framextopmargin}    & \texttt{defaultclass}   & \texttt{classoffset}\\
+%                         & \texttt{framexbottommargin} & \texttt{stringtest}     & ---\\
+% \texttt{framerulecolor} & \texttt{rulecolor}$^1$      & \texttt{outputpos}      & ---\\
+%  ---                    & \texttt{columns}$^2$
+% \end{tabular}
+% \end{center}
+% \parindent=20pt\relax
+% \par\indent $^1$ \emph{All} color-keys require now an explicit \cs{color} command in the value.
+% \par\indent $^2$ Please look at section \ref{uFixedAndFlexibleColumns}.
+% \par\indent $^3$ Now frames are also moved!
+% \end{table}
+% As stated in the footnote, some keys changed their behaviour, for example
+% you will have to write \keyname{backgroundcolor}|=\color|\marg{color}
+% instead of omitting the color command as in version 0.21. Another
+% modification is that the name argument of \texttt{lstlisting} has been
+% replaced by the key \keyname{name} and an addon to \keyname{firstnumber}.
+% But don't panic, you don't need to remove all empty name arguments in your
+% old sources, the argument is still allowed.
+%
+% The package documentation has also been revised. Please notice the new
+% sections \ref{uLanguageDefinitions} and \ref{uDelimiters}.
+%
+% Eventually note that all experimental features and all \dag-marked keys might
+% change in future. All others are fixed!
+%
+% \paragraph{Thanks}
+% There are many people I have to thank for fruitful communication, posting
+% their ideas, giving error reports, adding programming languages to
+% \texttt{lstdrvrs.dtx}, and so on. Their names are listed in section
+% \ref{uClosingAndCredits}.
+%
+% \vfill
+% \paragraph{Trademarks}
+% Trademarks appear throughout this documentation without any trademark
+% symbol; they are the property of their respective trademark owner.
+% There is no intention of infringement; the usage is to the benefit of the
+% trademark owner.
+%
+%
+% \clearpage
+%
+%
+% \part{User's guide}
+%
+%
+% \section{Getting started}\label{uGettingStarted}
+%
+%
+% \subsection{A minimal file}\label{uAMinimalFile}
+%
+% Before using the \packagename{listings} package, you should be familiar with
+% the \LaTeX\ typesetting system. You need not to be an expert.
+% Here is a minimal file for \packagename{listings}.
+% \begin{verbatim}
+%    \documentclass{article}
+%    \usepackage{listings}
+%    \begin{document}
+%      \lstset{language=Pascal}
+%      % Insert Pascal examples here.
+%    \end{document}\end{verbatim}
+% Now type in this first example and run it through \LaTeX.
+% \begin{advise}
+% \item Must I do that really?
+%       \advisespace
+%       Yes and no. Some books about programming say this is good.
+%       What a mistake! Typing takes time---wasted if the code is clear to
+%       you. And if you need that time to understand what is going on, the
+%       author of the book should reconsider the concept of presenting the
+%       crucial things---you might want to say that about this guide even---or
+%       you're simply unexperienced with programming. If only the latter case
+%       applies, you should spend more time on reading (good) books about
+%       programming, (good) documentations, and (good) source code from other
+%       people. Of course you should also make your own experiments.
+%       You will learn a lot. However, running the example through \LaTeX\ 
+%       shows whether the \packagename{listings} package is installed.
+% \item The example doesn't work.
+%       \advisespace
+%       Are the two packages \packagename{listings} and \packagename{keyval}
+%       installed on your system? Read section \ref{rInstallation} on the
+%       installation process. If this doesn't help, you should consult your
+%       system administrator, the local \TeX\ and \LaTeX\ guides, or a \TeX\ 
+%       FAQ. And after you checked \emph{all} these sources, you might want to
+%       write a post to a \TeX\ newsgroup like \texttt{comp.text.tex}.
+% \item Should I read the software license before using this package?
+%       \advisespace
+%       Yes, but read this \emph{Getting started} section first to decide
+%       whether you are willing to use the package.^^A ;-)
+% \end{advise}
+%
+%
+% \subsection{Typesetting listings}
+%
+% Three types of source codes are supported: code snippets, code segments, and
+% listings of stand alone files; the first inside paragraphs and the others as
+% separate paragraphs---the difference is the same as between text style and
+% display style formulas.
+% \begin{advise}
+% \item No matter what kind of source you have, if a listing contains national
+%       characters like \'e, \L, \"a, or whatever, you must tell it the
+%       package! Section \lstref{uSpecialCharacters} discusses this issue.
+% \end{advise}
+%
+% \paragraph{Code snippets}
+% The well-known \LaTeX\ command |\verb| typesets code snippets verbatim.
+% The new command |\lstinline| pretty-prints the code, for example
+%`\lstinline!var i:integer;!' is typeset by
+%`{\rstyle|\lstinline|}|!var i:integer;!|'. The exclamation marks delimit
+% the code and can be replaced by any character not in the code;
+% |\lstinline$var i:integer;$| gives the same result.
+%
+% \paragraph{Displayed code}
+% The \texttt{lstlisting} environment typesets the enclosed source code. Like
+% most examples, the following one shows verbatim \LaTeX\ code on the right
+% and the result on the left. You might take the right-hand side, put it into
+% the minimal file, and run it through \LaTeX.
+% \begin{lstsample}[lstlisting]{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% It can't be easier.
+% \begin{advise}
+% \item That's not true. The name `\texttt{listing}' is shorter.
+%       \advisespace
+%       Indeed. But other packages already define environments with that name.
+%       To be compatible with such packages, all commands and environments of
+%       the \packagename{listings} package use the prefix `\texttt{lst}'.
+% \end{advise}
+% The environment provides an optional argument. It tells the package to
+% perform special tasks, for example, to print only the lines 2--5:
+% \begin{lstsample}{\lstset{frame=trbl,framesep=0pt}\label{gFirstKey=ValueList}}{}
+%    \begin{lstlisting}[firstline=2,
+%                       lastline=5]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Hold on! I've several questions.
+%       Where comes the frame from and what is it good for?
+%       \advisespace
+%       You can put frames around all listings except code snippets.
+%       You will learn it later. The frame shows that empty lines at the end
+%       of listings aren't printed. This is line 5 in the example.
+% \item Hey, you can't drop my empty lines!
+%       \advisespace
+%       You can tell the package not to drop them:
+%       The key `\ikeyname{showlines}' controls these empty lines and is
+%       described in section \ref{rTypesettingListings}. Warning: First
+%       read ahead on how to use keys in general.
+% \item I get obscure error messages when using `\ikeyname{firstline}'.
+%       \advisespace
+%       That shouldn't happen. Make a bug report as described in section
+%       \lstref{uTroubleshooting}.
+% \end{advise}
+%
+% \paragraph{Stand alone files}
+% Finally we come to |\lstinputlisting|, the command to pretty-print stand
+% alone files. It has one optional and one file name argument.
+% Note that you possibly need to specify the relative path to the file.
+% Here now the result is printed below the verbatim code since both together
+% don't fit the text width.
+% \begin{lstsample}{\lstset{comment=[l]\%,columns=fullflexible}}{\lstset{alsoletter=\\,emph=\\lstinputlisting,emphstyle=\rstyle}\lstaspectindex{\lstinputlisting}{}}
+%    \lstinputlisting[lastline=4]{listings.sty}
+% \end{lstsample}
+% \begin{advise}
+% \item The spacing is different in this example.
+%       \advisespace
+%       Yes. The two previous examples have aligned columns, i.e.~columns with
+%       identical numbers have the same horizontal position---this package
+%       makes small adjustments only. The columns in the example here are not
+%       aligned. This is explained elsewhere (keyword: full flexible column
+%       format).
+% \end{advise}
+%
+% Now you know all pretty-printing commands and environments. It remains
+% to learn the parameters which control the work of the \packagename{listings}
+% package. This is, however, the main task. Here are some of them.
+%
+%
+% \subsection{Figure out the appearance}\label{gFigureOutTheAppearance}
+%
+% Keywords are typeset bold, comments in italic shape, and spaces in strings
+% appear as \textvisiblespace. You don't like these settings? Look at this:
+%\ifcolor
+% \begin{lstxsample}[basicstyle,keywordstyle,identifierstyle,commentstyle,stringstyle,showstringspaces]
+%    \lstset{% general command to set parameter(s)
+%        basicstyle=\small,          % print whole listing small
+%        keywordstyle=\color{black}\bfseries\underbar,
+%                                    % underlined bold black keywords
+%        identifierstyle=,           % nothing happens
+%        commentstyle=\color{white}, % white comments
+%        stringstyle=\ttfamily,      % typewriter type for strings
+%        showstringspaces=false}     % no special string spaces
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}[basicstyle,keywordstyle,identifierstyle,commentstyle,stringstyle,showstringspaces]
+%    \lstset{% general command to set parameter(s)
+%        basicstyle=\small,          % print whole listing small
+%        keywordstyle=\bfseries\underbar,
+%                                    % underlined bold keywords
+%        identifierstyle=,           % nothing happens
+%        commentstyle=\itshape,      % default
+%        stringstyle=\ttfamily,      % typewriter type for strings
+%        showstringspaces=false}     % no special string spaces
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+%\ifcolor
+% \begin{advise}
+% \item You've requested white coloured comments, but I can see the comment
+%       on the left side.
+%       \advisespace
+%       There are a couple of possible reasons:
+%       (1) You've printed the documentation on nonwhite paper.
+%       (2) If you are viewing this documentation as a \texttt{.dvi}-file, your
+%           viewer seems to have problems with colour specials. Try to print
+%           the page on white paper.
+%       (3) If a printout on white paper shows the comment, the colour
+%           specials aren't suitable for your printer or printer driver.
+%           Recreate the documentation and try it again---and ensure that
+%           the \packagename{color} package is well-configured.
+% \end{advise}
+%\fi
+% The styles use two different kinds of commands. |\ttfamily| and |\bfseries|
+% both take no arguments but |\underbar| does; it underlines the following
+% argument. In general, the \emph{very last} command might read exactly one
+% argument, namely some material the package typesets. There's one exception.
+% The last command of \ikeyname{basicstyle} \emph{must not} read any
+% tokens---or you will get deep in trouble.
+% \begin{advise}
+% \item `|basicstyle=\small|' looks fine, but comments look really bad with
+%       `|commentstyle=\tiny|' and empty basic style, say.
+%       \advisespace
+%       Don't change the font size inside listings.
+% \item But I really want it!
+%       \advisespace
+%       The package adjusts internal data after selecting the basic style at
+%       the beginning of each listing. This is a problem if you change the
+%       font size for comments or strings, for example.
+%       Section \ref{rColumnAlignment} shows how to overcome this.
+%       But once again: Don't change the font size inside listings unless you
+%       really know what you are doing.
+% \end{advise}
+%
+% \paragraph{Warning}\label{wStrikingStyles}
+% You should be very careful with striking styles; the last example is rather
+% moderate---it can get horrible. \emph{Always use decent highlighting.}
+% Unfortunately it is difficult to give more recommendations since they depend
+% on the type of document you're creating. Slides or other presentations often
+% require more striking styles than books, for example.
+% In the end, it's \emph{you} who have to find the golden mean!
+%
+%
+% \subsection{Seduce to use}\label{gSeduceToUse}
+%
+% You know all pretty-printing commands and some main parameters. Here now
+% comes a small and incomplete overview of other features. The table of
+% contents and the index also provide information.
+%
+% \paragraph{Line numbers}
+% are available for all displayed listings, e.g.~tiny numbers on the left, each
+% second line, with 5pt distance to the listing:
+% \begin{lstxsample}[numbers,numberstyle,stepnumber,numbersep]
+%    \lstset{numbers=left, numberstyle=\tiny, stepnumber=2, numbersep=5pt}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item I can't get rid of line numbers in subsequent listings.
+%       \advisespace
+%       `|numbers=none|' turns them off.
+% \item Can I use these parameters in the optional arguments?
+%       \advisespace
+%       Of course. Note that optional arguments modify values for one
+%       particular listing only: you change the appearance, step or distance
+%       of line numbers for a single listing. The previous values are
+%       restored afterwards.
+% \end{advise}
+% The environment allows you to interrupt your listings: you can end a listing
+% and continue it later with the correct line number even if there are other
+% listings in between. Read section \ref{uLineNumbers} for a thorough
+% discussion.
+%
+% \paragraph{Floating listings}
+% Displayed listings may float:
+% \begin{lstsample}{\lstset{frame=tb}}{}
+%    \begin{lstlisting}[float,caption=A floating example]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% Don't care about the parameter \ikeyname{caption} now. And if you put the
+% example into the minimal file and run it through \LaTeX, please don't wonder:
+% you'll miss the horizontal rules since they are described elsewhere.
+% \begin{advise}
+% \item \LaTeX's float mechanism allows to determine the placement of floats.
+%       What's about that?
+%       \advisespace
+%       You can write `|float=tp|', for example.
+% \end{advise}
+%
+% \paragraph{Other features}
+% There are still features not mentioned so far: automatic breaking of long
+% lines, the possibility to use \LaTeX\ code in listings, automated indexing,
+% or personal language definitions.
+% One more little teaser? Here you are. But note that the result is not
+% produced by the \LaTeX\ code on the right alone. The main parameter is
+% hidden.
+% \begin{lstsample}{\lstset{literate={:=}{{$\gets$}}1 {<=}{{$\leq$}}1 {>=}{{$\geq$}}1 {<>}{{$\neq$}}1}}{}
+%    \begin{lstlisting}
+%    if (i<=0) then i := 1;
+%    if (i>=0) then i := 0;
+%    if (i<>0) then i := 0;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% You're not sure whether you should use \packagename{listings}?
+% Read the next section!
+%
+%
+% \subsection{Alternatives}
+%
+% \begin{advise}
+% \item Why do you list alternatives?
+%       \advisespace
+%       Well, it's always good to know the competitors.^^A :-)
+% \item I've read the descriptions below and the \packagename{listings} package
+%       seems to incorporate all the features. Why should I use one of the
+%       other programs?
+%       \advisespace
+%       Firstly, the descriptions give a taste and not a complete overview,
+%       secondly, \packagename{listings} lacks some properties, and eventually,
+%       you should use the program matching your needs most precisely.
+% \end{advise}
+% This package is certainly not the final utility for typesetting source code.
+% Other programs do their job very well---if you are not satisfied with
+% \packagename{listings}. Some are independent of \LaTeX, other come as
+% separate program plus \LaTeX\ package, and other more are packages which
+% don't pretty-print the source code. The second type inlcudes converters,
+% cross compilers, and preprocessors. Such programs create \LaTeX\ files
+% you can use in your document or stand alone ready-to-run \LaTeX\ files.
+%
+% Note that I'm not dealing with any literate programming tool here, which
+% could also be an alternative. However, you should have heard of the
+% \texttt{WEB} system, the tool Prof.~Donald E.~Knuth developed and made use
+% of to document and implement \TeX.
+%
+% \paragraph{\packagename{a2ps}}
+% started as `ASCII to PostScript' converter, but today you can invoke the
+% program with \texttt{--pretty-print=}\meta{language} option. If your
+% favourite programming language is not already supported, you can write your
+% own so-called style sheet. You can request line numbers, borders, headers,
+% multiple pages per sheet, and many more. You can even print symbols like
+% $\forall$ or $\alpha$ instead of their verbose forms. If you just want
+% program listings and not a document with some listings, this is the best
+% choice.
+%
+% Visit the home page at
+% \href{http://www.infres.enst.fr/~demaille/a2ps}^^A
+%      {http://www.infres.enst.fr/\textasciitilde demaille/a2ps}.
+%
+% \paragraph{\packagename{cvt2ltx}}
+% is a family of `source code to \LaTeX' converters for C, Objective C, \Cpp,
+% IDL and Perl. Different styles, line numbers and other qualifiers can be
+% chosen by command-line option. Unfortunately it isn't documented how other
+% programming languages can be added.
+%
+% Available via ftp from
+% \href{ftp://axp3.sv.fh-mannheim.de/cvt2latex}^^A
+%      {ftp://axp3.sv.fh-mannheim.de/cvt2latex}.
+%
+% \paragraph{\packagename{\Cpp2\LaTeX}}
+% is a C/\Cpp\ to \LaTeX\ converter. You can specify the fonts for comments,
+% directives, keywords, and strings, or the size of a tabulator. But as far as
+% I know you can't number lines.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/support/C++2LaTeX-1_1pl1}^^A
+%      {\textrm{CTAN}/support/C++2LaTeX-1\textunderscore 1pl1}.
+%
+% \paragraph{\packagename{S\LaTeX}}
+% is a pretty-printing Scheme program (invokes \LaTeX\ automatically)
+% especially designed for Scheme and other Lisp dialects. It supports stand
+% alone files, text and display listings, and you can even nest the
+% commands/environments if you use \LaTeX\ code in comments, for example.
+% Keywords, constants, variables, and symbols are definable and use of
+% different styles is possible. No line numbers.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/support/slatex}^^A
+%      {\textrm{CTAN}/support/slatex}.
+%
+% \paragraph{\packagename{tiny\textunderscore c2ltx}}
+% is a C/\Cpp/Java to \LaTeX\ converter based on \packagename{cvt2ltx} (or the
+% other way round?). It supports line numbers, block comments, \LaTeX\ code
+% in/as comments, and smart line breaking. Font selection and tabulators are
+% hard-coded, i.e.~you have to rebuild the program if you want to change the
+% appearance.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/support/tiny_c2l}^^A
+%      {\textrm{CTAN}/support/tiny\textunderscore c2l}.
+%
+% \paragraph{\packagename{listing}}
+% ---note the missing \packagename{s}---is not a pretty-printer and the
+% aphorism about documentation at the end of \texttt{listing.sty} is not
+% true.\space ^^A :-)
+% It defines |\listoflistings| and a nonfloating environment for listings.
+% All font selection and indention must be done by hand. However, it's
+% useful if you have another tool doing that work, e.g.~\packagename{LGrind}.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/contrib/other/misc}^^A
+%      {\textrm{CTAN}/macros/latex/contrib/other/misc}.
+%
+% \begin{advise}
+% \item Why don't you list \packagename{LGrind}?
+%       \advisespace
+%       \packagename{LGrind} contains nonfree code and became nonfree software.
+%       It is a cross compiler and comes with many predefined programming
+%       languages. It supports code snippets, displayed listings, line numbers
+%       to the left or right, arbitrary \LaTeX\ code in the source code,
+%       printing symbols instead of verbose names, font setup, and more.
+%       It is available via ftp from
+%       \href{ftp://ftp.dante.de/tex-archive/nonfree/support/lgrind}
+%            {\textrm{CTAN}/nonfree/support/lgrind}.
+% \end{advise}
+%
+% \paragraph{\packagename{alg}}
+% provides essentially the same functionality as \packagename{algorithms}.
+% So read the next paragraph and note that the syntax will be different.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/contrib/other/alg}^^A
+%      {\textrm{CTAN}/macros/latex/contrib/other/alg}.
+%
+% \paragraph{\packagename{algorithms}}
+% goes a quite different way. You describe an algorithm and the package
+% formats it, for example
+% \begin{center}
+% \begin{minipage}{0.45\linewidth}
+%\ifalgorithmic
+%    \begin{algorithmic}
+%    \IF {$i\leq0$}
+%    \STATE $i\gets1$
+%    \ELSE\IF {$i\geq0$}
+%    \STATE $i\gets0$
+%    \ENDIF\ENDIF
+%    \end{algorithmic}
+%\else
+%    \packagename{algorithms} not installed.
+%\fi
+% \end{minipage}
+% \begin{minipage}{0.45\linewidth}
+% \begin{verbatim}
+%\begin{algorithmic}
+%\IF{$i\leq0$}
+%\STATE $i\gets1$
+%\ELSE\IF{$i\geq0$}
+%\STATE $i\gets0$
+%\ENDIF\ENDIF
+%\end{algorithmic}\end{verbatim}
+% \end{minipage}
+% \end{center}
+% As this example shows, you get a good looking algorithm even from a bad
+% looking input. The package provides a lot more constructs like |for|-loops,
+% |while|-loops, or comments. You can request line numbers, `ruled', `boxed'
+% and floating algorithms, a list of algorithms, and you can customize the
+% terms \textbf{if}, \textbf{then}, and so on.
+%
+% Available from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/contrib/supported/algorithms}^^A
+%      {\textrm{CTAN}/macros/latex/contrib/supported/algorithms}.
+%
+% \paragraph{\packagename{pretprin}}
+% is a package for pretty-printing texts in formal languages---as the title
+% in TUGboat, Volume 19 (1998), No.~3 states. It provides environments which
+% pretty-print \emph{and} format the source code. Analyzers for Pascal and
+% Prolog are defined; adding other languages is easy---if you are or get a bit
+% familiar with automatons and formal languages.
+%
+% Available from
+% \href{http://www.mimuw.edu.pl/~wolinski/pretprin.html}^^A
+%      {http://www.mimuw.edu.pl/\textasciitilde wolinski/pretprin.html}.
+%
+% \paragraph{\packagename{alltt}}
+% defines an environment similar to \texttt{verbatim} except that |\|, |{| and
+% |}| have their usual meanings. This means that you can use commands in the
+% verbatims, e.g.~select different fonts or enter math mode.
+%
+% This package is part of the \LaTeX\ base distribution.
+%
+% \paragraph{\packagename{moreverb}}
+% requires \packagename{verbatim} and provides verbatim output to a file,
+% `boxed' verbatims and line numbers.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/contrib/supported/moreverb}^^A
+%      {\textrm{CTAN}/macros/latex/contrib/supported/moreverb}.
+%
+% \paragraph{\packagename{verbatim}}
+% defines an improved version of the standard \texttt{verbatim} environment and
+% a command to input files verbatim.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/required/tools}^^A
+%      {\textrm{CTAN}/macros/latex/required/tools}.
+%
+% \paragraph{\packagename{fancyvrb}}
+% is, roughly spoken, a super set of \packagename{alltt},
+% \packagename{moreverb}, and \packagename{verbatim}, but many more parameters
+% control the output. The package provides frames, line numbers on the left or
+% on the right, automatic line breaking (difficult), and more. For example, an
+% interface to \packagename{listings} exists, i.e.~you can pretty-print source
+% code automatically.
+% The package \packagename{fvrb-ex} builds above \packagename{fancyvrb} and
+% defines environments to present examples similar to the ones in this guide.
+%
+% Available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/contrib/supported/fancyvrb}^^A
+%      {\textrm{CTAN}/macros/latex/contrib/supported/fancyvrb}.
+%
+%
+% \section{The next steps}\label{uTheNextSteps}
+%
+% Now, before actually using the \packagename{listings} package, you should
+% \emph{really} read the software license. It does not cost much time and
+% provides information you probably need to know.
+%
+%
+% \subsection{Software license}\label{uSoftwareLicense}
+%
+% The files \texttt{listings.dtx} and \texttt{listings.ins} and all
+% files generated from only these two files are referred to as `the
+% \packagename{listings} package' or simply `the package'. A `driver'
+% is generated from \texttt{lstdrvrs.dtx}.
+%
+% \paragraph{Copyright}
+%   The \packagename{listings} package is copyright 1996--2002 Carsten Heinz.
+%   The drivers are copyright 1997/1998/1999/2000/2001/2002 any individual
+%   author listed in the driver files.
+%
+% \paragraph{Distribution and warranty}
+%   The \packagename{listings} package as well as \texttt{lstdrvrs.dtx} and all
+%   drivers are distributed under the terms of the \LaTeX\ Project Public
+%   License from CTAN archives in directory |macros/latex/base/lppl.txt|,
+%   either version 1.0 or any later version.
+%
+% \paragraph{Use of the package}
+%   The \packagename{listings} package is \emph{free} software. However, if you
+%   distribute the package as part of a commercial product or if you use the
+%   package to prepare a commercial document (books, journals, and so on),
+%   I'd like to encourage you to make a donation to the \LaTeX3 fund.
+%   The size of this `license fee' should depend on the value of the package
+%   for your product. For more information about \LaTeX3 see
+% \href{http://www.latex-project.org}^^A
+%      {http://www.latex-project.org}.
+%
+%   No matter whether you use the package for a commercial or non-commercial
+%   document, please send me a copy of the document (\texttt{.dvi},
+%   \texttt{.ps}, \texttt{.pdf}, hardcopy, etc.) to support further
+%   development---it is easier to introduce new features or simplify things
+%   if I see how the package is used by other people.
+%
+% \paragraph{Modification advice}
+%   Permission is granted to modify the \packagename{listings} package as well
+%   as \texttt{lstdrvrs.dtx}. You are not allowed to distribute a modified
+%   version of the \packagename{listings} package or \texttt{lstdrvrs.dtx}
+%   unless you change the file names \emph{and} provide the original files.
+%   In any case it is better to contact the address below; other users will
+%   welcome removed bugs, new features, and additional programming languages.
+%
+% \paragraph{Contacts}
+%   Read section \lstref{uTroubleshooting} on how to submit a bug report.
+%   Send all other comments, ideas, and additional programming languages to
+%   \emph{Carsten Heinz, Tellweg 6, 42275 Wuppertal, Germany} or preferably to
+%   \lstemail\ using \texttt{listings} in the subject.
+%
+% \paragraph{Mailing list}
+%   This is mainly an announcement list regarding new versions, bugs, patches,
+%   and work-arounds. So I recommend it for system administrators, maintainers
+%   of \LaTeX\ installations, or people who absolutely need the latest bugs.
+%   To join the list, send an email to \lstemail\ with subject
+%   \texttt{subscribe listings}.
+%
+%
+% \subsection{Package loading}\label{uPackageLoading}
+%
+% As usual in \LaTeX, the package is loaded by
+%    |\usepackage[|\meta{options}|]{listings}|,
+% where |[|\meta{options}|]| is optional and gives a comma separated list of
+% options. Each either loads an additional \packagename{listings} aspect, or
+% changes default properties. Usually you don't have to take care of such
+% options. But in some cases it could be necessary: if you want to compile
+% documents created with an earlier version of this package or if you use
+% special features. Here's an incomplete list of possible options.
+% \begin{advise}
+% \item Where is a list of all options?
+%       \advisespace
+%       In the developer's guide since they were introduced to debug the
+%       package more easily. Read section \ref{uHowTos} on how to get that
+%       guide.
+% \end{advise}
+% \begin{description}
+% \item[\normalfont\texttt{0.21}]\leavevmode
+%
+%       compiles a document created with version 0.21.
+%
+% \item[\normalfont\texttt{draft}]\leavevmode
+%
+%       The package prints no stand alone files, but shows the captions and
+%       defines the corresponding labels.
+%       Note that a global |\documentclass|-option \texttt{draft} is
+%       recognized, so you don't need to repeat it as a package option.
+%
+% \item[\normalfont\texttt{savemem}]\leavevmode
+%
+%       tries to save some of \TeX's memory. If you switch between languages
+%       often, it could also reduce compile time. But all this depends on the
+%       particular document and its listings.
+% \end{description}
+% Note that various experimental features also need explicit loading via
+% options. Read the respective lines in section \ref{rExperimentalFeatures}.
+%
+% \medbreak
+% After package loading it is recommend to load all used dialects of programming
+% languages with the following command. It is faster to load several languages
+% with one command than loading each language on demand.
+% \begin{syntax}
+% \item {\rstyle\icmdname\lstloadlanguages}\marg{comma separated list of languages}
+%
+%       Each language is of the form \oarg{dialect}\meta{language}. Without
+%       the optional \oarg{dialect} the package loads a default dialect. So
+%       write `|[Visual]C++|' if you want Visual \Cpp\ and `|[ISO]C++|' for
+%       ISO \Cpp. Both together can be loaded by the command
+%       |\lstloadlanguages{[Visual]C++,[ISO]C++}|.
+%
+%       Table \ref{uPredefinedLanguages} on page \pageref{uPredefinedLanguages}
+%       shows all defined languages and their dialects.
+% \end{syntax}
+%^^A After or even before language loading, you might want to define default
+%^^A dialects---just to be independent of configuration files.
+%
+%
+% \subsection{The key=value interface}\label{uTheKey=ValueInterface}
+%
+% This package uses the \packagename{keyval} package from the
+% \packagename{graphics} bundle by David Carlisle. Each parameter is
+% controlled by an associated key and a user supplied value. For example,
+% \ikeyname{firstline} is a key and |2| a valid value for this key.
+%
+% The command {\rstyle\icmdname\lstset} gets a comma separated list of
+% ``key|=|value'' pairs. The first list with more than a single entry is on
+% page \pageref{gFirstKey=ValueList}: |firstline=2,lastline=5|.
+% \begin{advise}
+% \item So I can write `|\lstset{firstline=2,lastline=5}|' once for all?
+%       \advisespace
+%       No. `\ikeyname{firstline}' and `\ikeyname{lastline}' belong to a small
+%       set of
+%       keys which are used on individual listings. However, your command is
+%       not illegal---it has no effect. You have to use these keys inside the
+%       optional argument of the environment or input command.
+% \item What's about a better example of a key|=|value list?
+%       \advisespace
+%       There is one in section \ref{gFigureOutTheAppearance}.
+% \item `|language=[77]Fortran|' does not work inside an optional argument.
+%       \advisespace
+%       You must put braces around the value if a value with optional argument
+%       is used inside an optional argument. In the case here write
+%       `|language={[77]Fortran}|' to select Fortran 77.
+% \item If I use the `\ikeyname{language}' key inside an optional argument, the
+%       language isn't active when I typeset the next listing.
+%       \advisespace
+%       All parameters set via `|\lstset|' keep their values up to the end of
+%       the current environment or group. Afterwards the previous values are
+%       restored. The optional parameters of the two pretty-printing commands
+%       and the `\texttt{lstlisting}' environment take effect on the particular
+%       listing only, i.e.~values are restored immediately. For example, you
+%       can select a main language and change it for special listings.
+% \item \icmdname\lstinline\ has an optional argument?
+%       \advisespace
+%       Yes. And from this fact comes a limitation: you can't use the left
+%       bracket `|[|' as delimiter except you specify at least an empty
+%       optional argument as in `|\lstinline[][var i:integer;[|'.
+%       If you forget this, you will either get a ``runaway argument'' error
+%       from \TeX, or an error message from the \packagename{keyval} package.
+% \end{advise}
+%
+%
+% \subsection{Programming languages}\label{uProgrammingLanguages}
+%
+% You already know how to activate programming languages---at least Pascal.
+% An optional parameter selects particular dialects of a language. For example,
+% |language=[77]Fortran| selects Fortran 77 and |language=[XSC]Pascal| does the
+% same for Pascal XSC. The general form is
+%    {\rstyle\ikeyname{language}}|=|\oarg{dialect}\meta{language}.
+% If you want to get rid of keyword, comment, and string detection, use
+% |language={}| as argument to |\lstset| or as optional argument.
+%
+% Table \ref{uPredefinedLanguages} shows all predefined languages and dialects.
+% Use the listed names as \meta{language} and \meta{dialect}, respectively. If
+% no dialect or `empty' is given in the table, just don't specify a dialect.
+% Each underlined dialect is default; it is selected if you leave out
+% the optional argument. The predefined defaults are the newest language
+% versions or standard dialects.
+%^^A
+%^^A  Make table of predefined languages.
+%^^A
+%\let\lstlanguages\empty
+%\makeatletter
+%\@for\lst@temp:={lstlang1.sty,lstlang2.sty,lstlang3.sty}\do
+%    {\IfFileExists\lst@temp{}{\let\lstlanguages\relax}}
+%\makeatother
+%\ifx\lstlanguages\relax
+%    \PackageWarningNoLine{Listings}
+%        {Standard drivers not available.\MessageBreak
+%         Please check your installation.\MessageBreak
+%         Compilation aborted}
+%    \csname @@end\expandafter\endcsname
+%\fi
+%\lstscanlanguages\lstlanguages{lstlang1.sty,lstlang2.sty,lstlang3.sty}{}^^A
+%\def\topfigrule{\hrule\kern-0.4pt\relax}^^A
+%\let\botfigrule\topfigrule
+%\belowcaptionskip=\smallskipamount
+% \begin{table}[tb]
+% \small
+% \caption{Predefined languages.
+%          Note that some definitions are preliminary, for example HTML and XML.
+%          Each underlined dialect is default dialect}\label{uPredefinedLanguages}^^A
+% \makeatletter
+% \setbox\@tempboxa\hbox{^^A
+%    \InputIfFileExists{listings.cfg}{\lst@InputCatcodes}{}}^^A
+% \lstprintlanguages\lstlanguages
+% \end{table}
+%^^A
+%^^A end of table
+%^^A
+%\lstset{defaultdialect=[doc]Pascal}^^A restore
+% \begin{advise}
+% \item How can I define default dialects?
+%       \advisespace
+%       Check section \ref{rLanguagesAndStyles} for `\keyname{defaultdialect}'.
+% \item I have C code mixed with assembler lines. Can \packagename{listings}
+%       pretty-print such source code, i.e.~highlight keywords and comments of
+%       both languages?
+%       \advisespace
+%       `\ikeyname{alsolanguage}|=|\oarg{dialect}\meta{language}' selects a
+%       language additionally to the active one. So you only have to write a
+%       language definition for your assembler dialect, which doesn't interfere
+%       with the definition of C, say. Moreover you might want to use the key
+%       `\keyname{classoffset}' described in section \ref{rLanguagesAndStyles}.
+% \item How can I define my own language?
+%       \advisespace
+%       This is discussed in section \ref{rLanguageDefinitions}. And if you
+%       think that other people could benefit by your definition, you might
+%       want to send it to the address in section \ref{uSoftwareLicense}.
+%       Then it will be published under the \LaTeX\ Project Public License.
+% \end{advise}
+% Note that the arguments \meta{language} and \meta{dialect} are case
+% insensitive and that spaces have no effect.
+%
+%
+% \subsection{Special characters}\label{uSpecialCharacters}
+%
+%
+% \paragraph{Tabulators}
+% You might get unexpected output if your sources contain tabulators.
+% The package assumes tabulator stops at columns 9, 17, 25, 33, and so on.
+% This is predefined via |tabsize=8|. If you change the eight to the number
+% $n$, you will get tabulator stops at columns $n+1,2n+1,3n+1,$ and so on.
+% \begin{lstsample}[tabsize]{}{}
+%    \lstset{tabsize=2}
+%    \begin{lstlisting}
+%    123456789
+%    	{ one tabulator }
+%    		{ two tabs }
+%    123		{ 123 + two tabs }
+%    \end{lstlisting}
+% \end{lstsample}
+% For better illustration, the left-hand side uses |tabsize=2| but the verbatim
+% code |tabsize=4|. Note that |\lstset| modifies the values for all following
+% listings in the same environment or group. This is no problem here since the
+% examples are typeset inside minipages. If you want to change settings for a
+% single listing, use the optional argument.
+%
+%
+% \paragraph{Visible tabulators and spaces}
+% One can make spaces and tabulators visible:
+% \begin{lstsample}[showspaces,showtabs,tab]{}{}
+%    \lstset{showspaces=true,
+%            showtabs=true,
+%            tab=\rightarrowfill}
+%    \begin{lstlisting}
+%        for i:=maxint to 0 do
+%        begin
+%    	{ do nothing }
+%        end;
+%    \end{lstlisting}
+% \end{lstsample}
+% If you request \ikeyname{showspaces} but no \ikeyname{showtabs},
+% tabulators are converted to visible spaces.
+% The default definition of \ikeyname{tab} produces a `wide visible space'
+% \lstinline[showtabs]!	!. So you might want to use |$\to$|, |$\dashv$|
+% or something else instead.
+% \begin{advise}
+% \item Some sort of advice: (1) You should really indent lines of source code
+%       to make listings more readable. (2) Don't indent some lines with
+%       spaces and others via tabulators. Changing the tabulator size (of your
+%       editor or pretty-printing tool) completely disturbs the columns.
+%       (3) As a consequence, never share your files with differently tab sized
+%       people!^^A true only if you use tabulators, just :-)
+% \item To make the \LaTeX\ code more readable, I indent the environments'
+%       program listings. How can I remove that indention in the output?
+%       \advisespace
+%       Read `How to gobble characters' in section \ref{uHowTos}.
+% \end{advise}
+%
+%
+% \paragraph{Form feeds}
+% Another special character is a form feed causing an empty line by default.
+% {\rstyle\ikeyname{formfeed}}|=\newpage| would result in a new page every
+% form feed. Please note that such definitions (even the default) might get
+% in conflict with frames.
+%
+%
+% \paragraph{National characters}
+% If you type in such characters directly as characters of codes 128--255 and
+% use them also in listings, let the package know it---or you'll get really
+% funny results. {\rstyle\ikeyname{extendedchars}}|=true| allows and
+% |extendedchars=false| prohibits extended characters in listings. If you use
+% them, you should load \packagename{fontenc}, \packagename{inputenc} and/or
+% any other package which defines the characters.
+% \begin{advise}
+% \item I have problems using \packagename{inputenc} together with
+%       \packagename{listings}.
+%       \advisespace
+%       This could be a compatibility problem. Make a bug report as described
+%       in section \lstref{uTroubleshooting}.
+% \end{advise}
+% The extended characters don't cover Arabic, Chinese, Hebrew, Japanese, and so
+% on. Read section \ref{uNationalCharacters} for details on work-arounds.
+%
+%
+% \subsection{Line numbers}\label{uLineNumbers}
+%
+% You already know the keys \ikeyname{numbers}, \ikeyname{numberstyle},
+% \ikeyname{stepnumber}, and \ikeyname{numbersep} from section
+% \ref{gSeduceToUse}. Here now we deal with continued listings.
+% You have two options to get consistent line numbering across listings.
+%
+% \begin{lstsample}[firstnumber]{\lstset{numbers=left,numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    \begin{lstlisting}[firstnumber=100]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    \end{lstlisting}
+%    And we continue the listing:
+%    \begin{lstlisting}[firstnumber=last]
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% In the example, \ikeyname{firstnumber} is initially set to 100; some lines
+% later the value is \texttt{last}, which continues the numbering of the last
+% listing. Note that the empty line at the end of the first part is not printed
+% here, but it counts for line numbering. You should also notice that you can
+% write |\lstset{firstnumber=last}| once and get consecutively numbered code
+% lines---except you specify something different for a particular listing.
+%
+% On the other hand you can use |firstnumber=auto| and name your listings.
+% Listings with identical names (case sensitive!) share a line counter.
+% \begin{lstsample}[name]{\lstset{numbers=left,numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    \begin{lstlisting}[name=Test]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    \end{lstlisting}
+%    And we continue the listing:
+%    \begin{lstlisting}[name=Test]
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% The next |Test| listing goes on with line number {\makeatletter\lstno@Test},
+% no matter whether there are other listings in between.
+% \begin{advise}
+% \item Okay. And how can I get decreasing line numbers?
+%       \advisespace
+%       Sorry, what?
+%       \advisespace
+%       Decreasing line numbers as on page \pageref{rDecreasingLabels}.
+%       \advisespace
+%       May I suggest to demonstrate your individuality by other means?
+%       If you differ, you should try a negative `\ikeyname{stepnumber}'
+%       (together with `\ikeyname{firstnumber}').
+% \end{advise}
+%
+% Read section \ref{uHowTos} on how to reference line numbers.
+%
+%
+% \subsection{Layout elements}
+%
+% It's always a good idea to structure the layout by vertical space,
+% horizontal lines, or different type sizes and typefaces. The best to stress
+% whole listings are---not all at once---colours, frames, vertical space, and
+% captions. The latter are also good to refer to listings, of course.
+%
+% \paragraph{Vertical space}
+% The keys {\rstyle\ikeyname{aboveskip}} and {\rstyle\ikeyname{belowskip}}
+% control the vertical space above and below displayed listings. Both keys get
+% a dimension or skip as value and are initialized to |\medskipamount|.
+%
+% \paragraph{Frames}
+% The key \ikeyname{frame} takes the verbose values \keyvalue{none},
+% \keyvalue{leftline}, \keyvalue{topline}, \keyvalue{bottomline},
+% \keyvalue{lines} (top and bottom), \keyvalue{single} for single frames, or
+% \keyvalue{shadowbox}.
+% \begin{lstsample}[frame]{}{}
+%    \begin{lstlisting}[frame=single]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item The rules aren't aligned.
+%       \advisespace
+%       This could be a bug of this package or a problem with your
+%       \texttt{.dvi} driver. \emph{Before} sending a bug report to the package
+%       author, modify the parameters described in section \ref{rFrames}
+%       heavily. And do this step by step!
+%       For example, begin with `|framerule=10mm|'. If the rules are
+%       misaligned by the same (small) amount as before, the problem does not
+%       come from the rule width. So continue with the next parameter.
+% \end{advise}
+% Alternatively you can control the rules at the \texttt{t}op, \texttt{r}ight,
+% \texttt{b}ottom, and \texttt{l}eft directly by using the four initial letters
+% for single rules and their upper case versions for double rules.
+% \begin{lstsample}[frame]{}{}
+%    \begin{lstlisting}[frame=trBL]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that a corner is drawn if and only if both adjacent rules are requested.
+% You might think that the lines should be drawn up to the edge, but what's
+% about round corners? The key \ikeyname{frameround} must get exactly four
+% characters as value. The first character is attached to the upper right
+% corner and it continues clockwise. `\texttt{t}' as character makes the
+% corresponding corner round.
+% \begin{lstsample}[frameround]{}{}
+%    \lstset{frameround=fttt}
+%    \begin{lstlisting}[frame=trBL]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that \ikeyname{frameround} has been used together with |\lstset| and thus
+% the value affects all following listings in the same group or environment.
+% Since the listing is inside a \texttt{minipage} here, this is no problem.
+% \begin{advise}
+% \item Dont' use frames all the time, in particular not with short listings.
+%       This would emphasize nothing. Use frames for $10\%$ or even less of
+%       your listings, for your most important ones.
+% \item If you use frames on floating listings, do you really want frames?
+%       \advisespace
+%       No, I want to separate floats from text.
+%       \advisespace
+%       Then it is better to redefine \LaTeX's `|\topfigrule|' and
+%       `|\botfigrule|'. For example, you could write
+%       `|\renewcommand*\topfigrule{\hrule\kern-0.4pt\relax}|' and make the
+%       same definition for |\botfigrule|.
+% \end{advise}
+%
+% \paragraph{Captions}
+% Now we come to \ikeyname{caption} and \ikeyname{label}. You might guess that
+% they can be used in the same manner as \LaTeX's |\caption| and |\label|
+% commands:
+% \begin{lstsample}[caption,label]{\lstset{xleftmargin=.05\linewidth}}{}
+%    \begin{lstlisting}[caption={Useless code},label=useless]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Afterwards you could refer to the listing via |\ref{useless}|. By default
+% such a listing gets an entry in the list of listings, which can be printed
+% with the command {\rstyle\icmdname\lstlistoflistings}. The key
+% {\rstyle\ikeyname{nolol}} suppresses an entry for both the environment or
+% the input command. Moreover, you can specify a short caption for the list
+% of listings:
+%    \keyname{caption}|={|\oarg{short}\meta{long}|}|.
+% Note that the whole value is enclosed in braces since an optional value is
+% used in an optional argument.
+%
+% If you don't want the label \texttt{\lstlistingname} plus number, you should
+% use \ikeyname{title}:
+% \begin{lstsample}[title]{\lstset{xleftmargin=.05\linewidth}}{}
+%    \begin{lstlisting}[title={`Caption' without label}]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Something goes wrong with `\keyname{title}' in my document: in front of
+%       the title is a delimiter.
+%       \advisespace
+%       The result depends on the document class; some are not compatible.
+%       Contact the package author for a work-around.
+% \end{advise}
+%
+% \paragraph{Colours}
+% One more element. You need the \packagename{color} package and can then
+% request coloured background via
+% \ikeyname{backgroundcolor}|=|\meta{color command}.
+% \begin{advise}
+% \item Great! I love colours.
+%       \advisespace
+%       Fine, yes, really. And I like to remind you of the warning about
+%       striking styles on page \pageref{wStrikingStyles}.
+% \end{advise}
+%\ifcolor
+% \begin{lstxsample}[backgroundcolor]
+%    \lstset{backgroundcolor=\color{yellow}}
+% \end{lstxsample}
+%\else
+% \begin{verbatim}
+%    color package not installed\end{verbatim}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}[frame=single,
+%                       framerule=0pt]
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% The example also shows how to get coloured space around the whole listing:
+% use a frame whose rules has no width.
+%
+%
+% \subsection{Emphasize identifiers}\label{uEmphasizeIdentifiers}
+%
+% Recall the pretty-printing commands and environment. |\lstinline| prints
+% code snippets, |\lstinputlisting| whole files, and \texttt{lstlisting}
+% pieces of code which reside in the \LaTeX\ file. And what are these
+% different `types' of source code good for? Well, it just happens that a
+% sentence contains a code fragment. Whole files are typically included in or
+% as an appendix. Nevertheless some books about programming also include such
+% listings in normal text sections---to increase the number of pages.
+% Nowadays source code should be shipped on disk or CD-ROM and only the main
+% header or interface files should be typeset for reference. So, please, don't
+% misuse the \packagename{listings} package. But let's get back to the topic.
+%
+% Obviously `\texttt{lstlisting} source code' isn't used to make an executable
+% program from. Such source code has some kind of educational purpose or even
+% didactic.
+% \begin{advise}
+% \item What's the difference between educational and didactic?
+%       \advisespace
+%       Something educational can be good or bad, true or false.
+%       Didactic is true by definition.^^A :-)
+% \end{advise}
+% Usually \emph{keywords} are highlighted when the package typesets a piece of
+% source code. This isn't necessary for readers knowing the programming
+% language well. The main matter is the presentation of interface, library or
+% other functions or variables. If this is your concern, here come the right
+% keys. Let's say, you want to emphasize the functions |square| and |root|,
+% for example, by underlining them. Then you could do it like this:
+% \begin{lstxsample}[emph,emphstyle]
+%    \lstset{emph={square,root},emphstyle=\underbar}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Note that the list of identifiers |{square,root}| is enclosed in
+%       braces. Otherwise the \packagename{keyval} package would complain
+%       about an undefined key \keyname{root} since the comma finishes the
+%       key=value pair.
+%       Note also that you \emph{must} put braces around the value if you
+%       use an optional argument of a key inside an optional argument of a
+%       pretty-printing command. Though it is not necessary, the following
+%       example uses these braces. They are typically forgotten when they
+%       become necessary,
+% \end{advise}
+%
+% Both keys have an optional \meta{class number} argument for multiple
+% identifier lists:
+%\ifcolor
+% \begin{lstxsample}[emph,emphstyle]
+%    \lstset{emph={square},      emphstyle=\color{red},
+%            emph={[2]root,base},emphstyle={[2]\color{blue}}}
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}[emph,emphstyle]
+%    \lstset{emph={square},      emphstyle=\underbar,
+%            emph={[2]root,base},emphstyle={[2]\fbox}}
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item What is the maximal \meta{class number}?
+%       \advisespace
+%       $2^{31}-1=2\,147\,483\,647$. But \TeX's memory will exceed before you
+%       can define so many different classes.
+% \end{advise}
+%
+% One final hint: Keep the lists of identifiers disjoint. Never use a keyword
+% in an `emphasize' list or one name in two different lists. Even if your
+% source code is highlighted as expected, there is no guarantee that it is
+% still the case if you change the order of your listings or if you use the
+% next release of this package.
+%
+%
+%\iffalse
+% \subsection{*Listing alignment}\label{uListingAlignment}
+%
+% The examples are typeset with centered \texttt{minipage}s. That's the reason
+% why you can't see that line numbers are printed in the margin. Now we
+% separate the minipage margin and the minipage by a vertical rule:
+% \begin{lstsample}{\lstset{frame=l,framesep=0pt,numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    Some text before
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% The listing is lined up with the normal text. The parameter \ikeyname{xleftmargin}
+% moves the listing to the right (or left if the dimension is negative).
+% \begin{lstsample}{\lstset{frame=l,framesep=0pt,numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    Some text before
+%    \begin{lstlisting}[xleftmargin=15pt]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+%
+%    \begin{lstlisting}{ }
+%    Write('Insensitive');
+%    WritE('keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% Note again that optional arguments change settings for single listings.
+%
+% If you use environments like \texttt{itemize} or \texttt{enumerate}, there
+% is `natural' indention coming from these environments. By default the
+% \packagename{listings} package respects this. But you might use
+% |resetmargins=true| (or |false|) to make your own decision. You can use it
+% together with |xleftmargin|, of course.
+% \begin{advise}
+% \item I get heavy overfull |\hbox|es from some listings.
+%       \advisespace
+%       This comes from long lines in your listings. You have some options
+%       to get rid of the overful |\hbox|es. Firstly I recommend to typeset
+%       listings in smaller fonts than the surrounding text, for example
+%       `|basicstyle=\small|'. Secondly you might want to use the flexible
+%       column format. Thirdly you can increase the line width or set it
+%       explicitly, refer section \ref{rMarginsAndLineShape}.
+%       If all this doesn't help, you might want to change
+%       `\ikeyname{basewidth}', but be careful! The two unknown items are
+%       explained in the next section.
+% \end{advise}
+%
+% You might need to control the vertical position of listings with the
+% \ikeyname{boxpos} key, for example, if you use them in \texttt{minipage} or
+% \texttt{tabular} environments. Here `listings' means \texttt{lstlisting} or
+% |\lstinputlisting|. As the following example shows, you can even place such
+% listings inside paragraphs, but you must force the package to do this by
+% enclosing the listing in |\hbox{| and |}|.
+% \begin{advise}
+% \item Is it good form to use the \TeX-primitive `|\hbox|' in a \LaTeX\ 
+%       document?
+%       \advisespace
+%       No, it's not. But \LaTeX's `|\mbox|' does not work in this example:
+% \end{advise}
+% \begin{lstsample}{}{}
+%    Here are some multi-line listings inside a paragraph.
+%    The `boxpos' key controls their vertical alignment:
+%    \hbox{\begin{lstlisting}[boxpos=c]
+%    center
+%    center
+%    \end{lstlisting}}
+%    \hbox{\begin{lstlisting}[boxpos=b]
+%    bottom baseline
+%    bottom baseline
+%    \end{lstlisting}}
+%    \hbox{\begin{lstlisting}[boxpos=t]
+%    top baseline
+%    top baseline
+%    \end{lstlisting}}
+% \end{lstsample}
+%\fi
+%
+%
+% \subsection{Indexing}\label{uIndexing}
+%
+% is just like emphasizing identifiers---I mean the usage:
+% \begin{lstxsample}[index]
+%    \lstset{index={square},index={[2]root}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Of course, you can't see anything here. You will have to look at the index.
+% \begin{advise}
+% \item Why the `\ikeyname{index}' key is able to work with multiple identifier
+%       lists?
+%       \advisespace
+%       This question is strongly related to the `{\rstyle\ikeyname{indexstyle}}'
+%       key. Someone might want to create multiple indexes or want to insert
+%       prefixes like `|constants|', `|functions|', `|keywords|', and so on.
+%       The `\ikeyname{indexstyle}' key works like the other style keys except
+%       that the last token \emph{must} take an argument, namely the
+%       (printable form of the) current identifier.
+%
+%       You can define `|\newcommand\indexkeywords[1]{\index{keywords, #1}}|'
+%       and make similar definitions for constant or function names. Then
+%       `|indexstyle=[1]\indexkeywords|' might meet your purpose. This becomes
+%       easier if you want to create multiple indexes with the
+%       \packagename{index} package
+% (\href{ftp://ftp.dante.de/tex-archive/macros/latex/contrib/supported/camel}
+%       {CTAN/macros/latex/contrib/supported/camel}).
+%       If you have defined appropriate new indexes, it is possible to write
+%       `|indexstyle=\index[keywords]|', for example.
+%
+% \item Let's say, I want to index all keywords. It would be annoying to
+%       type in all the keywords again, specifically if the used programming
+%       language changes frequently.
+%       \advisespace
+%       Just read ahead.
+% \end{advise}
+% The \ikeyname{index} key has in fact two optional arguments. The first is the
+% well-known \meta{class number}, the second is a comma separated list of other
+% keyword classes whose identifiers are indexed. The indexed identifiers then
+% change automatically with the defined keywords---not automagically, it's not
+% an illusion.^^A :-)
+%
+% Eventually you need to know the names of the keyword classes. It's usually
+% the key name followed by a class number, for example, |emph2|, |emph3|,
+% \ldots, |keywords2| or |index5|. But there is no number for the first order
+% classes |keywords|, |emph|, |directives|, and so on.
+% \begin{advise}
+% \item `|index=[keywords]|' does not work.
+%       \advisespace
+%       The package can't guess which optional argument you mean. Hence you
+%       must specify both if you want to use the second one. You should try
+%       `|index=[1][keywords]|'.
+% \end{advise}
+%
+%
+% \subsection{Fixed and flexible columns}\label{uFixedAndFlexibleColumns}
+%
+% The first thing a reader notices---except different styles for keywords,
+% etc.---is the column alignment. Arne John Glenstrup invented the flexible
+% column format in 1997. Since then some efforts were made to develop this
+% branch farther. Currently three column formats are provided: fixed, flexible,
+% and full flexible. Take a close look at the following examples.
+% \begin{center}
+% \lstset{style={},language={}}
+% \def\sample{\begin{lstlisting}^^J WOMEN\ \ are^^A
+%                               ^^J \ \ \ \ \ \ \ MEN^^A
+%                               ^^J WOMEN are^^A
+%                               ^^J better MEN^^J \end{lstlisting}}
+% \begin{tabular}{@{}c@{\qquad\quad}c@{\qquad\quad}c@{\qquad\quad}c@{}}
+% {\rstyle\ikeyname{columns}}|=| & \texttt{fixed} & \texttt{flexible} & \texttt{fullflexible}\\
+%          & (at {\makeatletter\lst@widthfixed})
+%          & (at {\makeatletter\lst@widthflexible})
+%          & (at {\makeatletter\lst@widthflexible})\\
+% \noalign{\medskip}
+%   \lstset{basicstyle=\ttfamily,basewidth=0.51em}\sample
+% & \lstset{columns=fixed}\sample
+% & \lstset{columns=flexible}\sample
+% & \lstset{columns=fullflexible}\sample
+% \end{tabular}
+% \end{center}
+% \begin{advise}
+% \item Why are women better men?
+%       \advisespace
+%       Do you want to philosophize? Well, have I ever said that the
+%       statement ``women are better men'' is true? I can't even remember this
+%       about ``women are men'' \ldots ^^A ;-))
+% \end{advise}
+% In the abstract one can say: The fixed column format ruins the spacing
+% intended by the font designer, while the flexible formats ruin the column
+% alignment (possibly) intended by the programmer. Common to all is that the
+% input characters are translated into a sequence of basic output units like
+% \begingroup \lstset{gobble=6,xleftmargin=\leftmargini}
+% \makeatletter
+%^^A  Make \fbox around each output unit.
+% \fboxsep=0pt
+% \def\lst@alloverstyle#1{\fbox{\kern-\fboxrule\strut#1}\kern-\fboxrule}
+% \begin{lstlisting}[basewidth=1em]
+%     if x=y then write('align')
+%            else print('align');
+% \end{lstlisting}
+% Now, the fixed format puts $n$ characters into a box of width $n\times{}
+% $`base width', where the base width is {\makeatletter\lst@widthfixed} in the
+% example. The format shrinks and stretches the space between the characters
+% to make them fit the box. As shown in the example, some character strings look
+%    \hbox to 2em{b\hss a\hss d}
+% or
+%    \hbox to 2em{w\hss o\hss r\hss s\hss e},
+% but the output is vertically aligned.
+% \endgroup
+%
+% If you don't need or like this, you should use a flexible format. All
+% characters are typeset at their natural width. In particular, they never
+% overlap. If a word requires more space than reserved, the rest of the line
+% simply moves to the right. The difference between the two formats is that the
+% full flexible format cares about nothing else and the normal flexible format
+% tries to fix the column alignment if a character string needs less space
+% than `reserved'. In the flexible example above, the two MENs are vertically
+% aligned since some space has been inserted in the fourth line to fix the
+% alignment. In the full flexible format, the two MENs are not aligned.
+%
+% Note that both flexible modes printed the two blanks in the first line as a
+% single blank, but for different reasons: the normal flexible format fixes
+% the column alignment and the full flexible format doesn't care about the
+% second space.
+%
+%
+% \section{Advanced techniques}\label{uAdvancedTechniques}
+%
+%
+% \subsection{Style definitions}
+%
+% It is obvious that a pretty-printing tool like this requires some kind of
+% language selection and definition. The first has already been described and
+% the latter is convered by the next section. However, it is very convenient
+% to have the same for printing styles: at a central place of your document
+% they can be modified easily and the changes take effect on all listings.
+%
+% Similar to languages,
+%    {\rstyle\ikeyname{style}}|=|\meta{style name}
+% activates a previously defined style. A definition is as easy:
+%    {\rstyle|\lstdefinestyle|}\marg{style name}\marg{key=value list}.
+% Keys not used in such a definition are untouched by the corresponding style
+% selection, of course. For example, you could write
+% \begin{verbatim}
+%   \lstdefinestyle{numbers}
+%       {numbers=left, stepnumber=1, numberstyle=\tiny, numbersep=10pt}
+%   \lstdefinestyle{nonumbers}
+%       {numbers=none}\end{verbatim}
+% and switch from listings with line numbers to listings without ones and vice
+% versa simply by |style=nonumbers| and |style=numbers|, respectively.
+% \begin{advise}
+% \item You could even write
+%           `|\lstdefinestyle{C++}{language=C++,style=numbers}|'.
+%       Style and language names are independent of each other and so might
+%       coincide. Moreover it is possible to activate other styles.
+%
+% \item It's easy to crash the package using styles. Write
+%       '|\lstdefinestyle{crash}{style=crash}|' and '|\lstset{style=crash}|'.
+%       \TeX's capacity will exceed, sorry [parameter stack size]. Only bad
+%       boys use such recursive calls, but only good girls use this package.
+%       Thus the problem is of minor interest.^^A :-)
+% \end{advise}
+%
+%
+% \subsection{Language definitions}\label{uLanguageDefinitions}
+%
+% This is like style definitions except for an optional dialect name and an
+% optional base language---and, of course, a different command name and
+% specialized keys. In the simple case it's
+%    {\rstyle|\lstdefinelanguage|}\marg{language name}\marg{key=value list}.
+% For many programming languages it is sufficient to specify keywords and
+% standard function names, comments, and strings. Let's look at an example.
+% \begin{lstxsample}[morekeywords,sensitive,morecomment,morestring]
+%    \lstdefinelanguage{rock}
+%      {morekeywords={one,two,three,four,five,six,seven,eight,
+%          nine,ten,eleven,twelve,o,clock,rock,around,the,tonight},
+%       sensitive=false,
+%       morecomment=[l]{//},
+%       morecomment=[s]{/*}{*/},
+%       morestring=[b]",
+%      }
+% \end{lstxsample}
+% \begingroup \csname lst@EndWriteFile\endcsname
+% \bigbreak
+%
+% \noindent
+% There isn't much to say about keywords. They are defined like identifiers
+% you want to emphasize. Additionally you need to specify whether they are
+% case sensitive or not. And yes: you could insert |[2]| in front of the
+% keyword \texttt{one} to define the keywords as `second order' and print them
+% in |keywordstyle={[2]...}|.
+% \begin{advise}
+% \item I get a `\texttt{Missing = inserted for }|\ifnum|' error when I select
+%       my language.
+%       \advisespace
+%       Did you forget the comma after `|keywords={...}|'? And if you encounter
+%       unexpected characters after selecting a language (or style), you have
+%       probably forgotten a different comma or you have given to many
+%       arguments to a key, for example, |morecomment=[l]{--}{!}|.
+% \end{advise}
+%
+% So let's turn to comments and strings. Each value starts with a
+% \emph{mandatory} \oarg{type} argument followed by a changing number of
+% opening and closing delimiters. Note that each delimiter (pair) requires a
+% key=value on its own, even if types are equal. Hence, you'll need to insert
+% \texttt{morestring=[b]'} if single quotes open and close string or character
+% literals in the same way as double quotes do in the example.
+%
+% Eventually you need to know the types and their numbers of delimiters. The
+% reference guide contains full lists, here we discuss only the most common.
+% For strings these are {\rstyle\texttt{b}} and {\rstyle\texttt{d}} with one
+% delimiter each. This delimiter opens and closes the string and inside a
+% string it is either escaped by a \texttt backslash or it is \texttt doubled.
+% The comment type {\rstyle\texttt{l}} requires exactly one delimiter, which
+% starts a comment on any column. This comment goes up to the end of line.
+% The other two most common comment types are {\rstyle\texttt{s}} and
+% {\rstyle\texttt{n}} with two delimiters each. The first delimiter opens a
+% comment which is terminated by the second delimiter. In contrast to the
+% \texttt s-type, \texttt n-type comments can be nested.
+% \begin{lstxsample}[b,d,l,s,n]
+%    \lstset{morecomment=[l]{//},
+%            morecomment=[s]{/*}{*/},
+%            morecomment=[n]{(*}{*)},
+%            morestring=[b]",
+%            morestring=[d]'}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    "str\"ing "    not a string
+%    'str''ing '    not a string
+%    // comment line
+%    /* comment/**/ not a comment
+%    (* nested (**) still comment
+%       comment  *) not a comment
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Is it \emph{that} easy?
+%       \advisespace
+%       Almost. There are some troubles you can run into. For example, if
+%       `\texttt{-*}' starts a comment line and `\texttt{-*-}' a string
+%       (unlikely but possible), then you must define the shorter delimiter
+%       first.
+%       Another problem: by default some characters are not allowed inside
+%       keywords, for example `\texttt{-}', `\texttt{:}', `\texttt{.}', and
+%       so on. The reference guide covers this problem by introducing some
+%       more keys, which let you adjust the standard character table
+%       appropriately. But note that white space characters are prohibited
+%       inside keywords.
+% \end{advise}
+% Finally remember that this section is only an introduction to language
+% definitions. There are more keys and possibilities.
+%
+%
+% \subsection{Delimiters}\label{uDelimiters}
+%
+% You already know two special delimiter classes: comments and strings.
+% However, their full syntax hasn't been described so far. For example,
+% \ikeyname{commentstyle} applies to all comments---except you specify
+% something different. The \emph{optional} \oarg{style} argument follows the
+% \emph{mandatory} \oarg{type} argument.
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{morecomment=[l][keywordstyle]{//},
+%            morecomment=[s][\color{white}]{/*}{*/}}
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}
+%    \lstset{morecomment=[l][keywordstyle]{//},
+%            morecomment=[s][\underbar]{/*}{*/}}
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    // bold comment line
+%    a single /* comment */
+%    \end{lstlisting}
+% \end{lstsample}
+% As you can see, you have the choice between specifying the style explicitly
+% by \LaTeX\ commands or implicitly by other style keys. But, you're right,
+% some implicitly defined styles have no seperate keys, for example the second
+% order keyword style. Here---and never with the number 1---you just append
+% the order to the base key: \texttt{keywordstyle2}.
+%
+% You ask for an application? Here you are: one can define different printing
+% styles for `subtypes' of a comment, for example
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{morecomment=[s][\color{blue}]{/*+}{*/},
+%            morecomment=[s][\color{red}]{/*-}{*/}}
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}
+%    \lstset{morecomment=[s][\upshape]{/*+}{*/},
+%            morecomment=[s][\bfseries]{/*-}{*/}}
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{\lstset{morecomment=[s]{/*}{*/}}}{}
+%    \begin{lstlisting}
+%    /*  normal comment */
+%    /*+    keep cool   */
+%    /*-     danger!    */
+%    \end{lstlisting}
+% \end{lstsample}
+% Here, the comment style is not applied to the second and third line.
+% \begin{advise}
+% \item Please remember that both `extra' comments must be defined \emph{after}
+%       the normal comment, since the delimiter `\texttt{/*}' is a substring of
+%       `\texttt{/*+}' and `\texttt{/*-}'.
+%
+% \item I have another question. Is `\texttt{language=}\meta{different
+%       language}' the only way to remove such additional delimiters?
+%       \advisespace
+%       Call {\rstyle\ikeyname{deletecomment}} and/or
+%       {\rstyle\ikeyname{deletestring}} with the same arguments to remove
+%       the delimiters (but you don't need to provide the optional style
+%       argument).
+% \end{advise}
+% Eventually, you might want to use the prefix \texttt{i} on any comment type.
+% Then the comment is not only invisible, it is completely discarded from the
+% output!
+% \begin{lstxsample}[is]
+%    \lstset{morecomment=[is]{/*}{*/}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    begin /* comment */ end
+%    begin/* comment */end
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% Okay, and now for the real challenges. More general delimiters can be defined
+% by the key {\rstyle\ikeyname{moredelim}}. Legal types are {\rstyle\texttt{l}}
+% and {\rstyle\texttt{s}}. These types can be preceded by an \texttt{i}, but
+% this time \emph{only the delimiters} are discarded from the output. This way
+% you can select styles by markers.
+% \begin{lstxsample}
+%    \lstset{moredelim=[is][\ttfamily]{|}{|}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    roman |typewriter|
+%    \end{lstlisting}
+% \end{lstsample}
+% You can even let the package detect keywords, comments, strings, and other
+% delimiters inside the contents.
+% \begin{lstxsample}
+%    \lstset{moredelim=*[s][\itshape]{/*}{*/}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    /* begin
+%      (* comment *)
+%       ' string ' */
+%    \end{lstlisting}
+% \end{lstsample}
+% Moreover, you can force the styles being applied cumulative.
+% \begin{lstxsample}
+%    \lstset{moredelim=**[is][\ttfamily]{|}{|}, % cumulative
+%            moredelim=*[s][\itshape]{/*}{*/}}  % not so
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    /* begin
+%       ' string '
+%       |typewriter| */
+%
+%    | begin
+%     ' string '
+%     /*typewriter*/ |
+%    \end{lstlisting}
+% \end{lstsample}
+% Look carefully at the output and note the differences. The second
+% \texttt{begin} is not printed in bold typewriter type since standard
+% \LaTeX\ has no such font.
+%
+% This suffices for an introduction. Now go and find some more applications.
+%
+%
+% \subsection{Closing and credits}\label{uClosingAndCredits}
+%
+% You've seen a lot of keys but you are far away from knowing all of them.
+% The next step is the real use of the \packagename{listings} package.
+% Please take the following advices. Firstly, look up the known commands and
+% keys in the reference guide to get a notion of the notation there. Secondly,
+% poke about around these keys to learn some other parameters. Then, hopefully,
+% you'll be prepared if you encounter any problems or need some special things.
+%
+% \begin{advise}
+% \item
+% There is one question `you' haven't asked all the last pages: who is to
+% blame. The author has written the guides, coded the \packagename{listings}
+% package and some language drivers. Other people defined more languages or
+% contributed their ideas; many others made bug reports, but only the first
+% bug finder is listed.
+%^^A
+%^^A Thanks for error reports (first bug finder only), new programming
+%^^A languages, etc.
+%^^A Special thanks for communication which lead to kernel extensions.
+%^^A
+% Special thanks go to (alphabetical order)
+% \begin{quote}
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth
+%   \lstthanks{Andreas~Bartelt}{[email protected]},
+%   \lstthanks{Jan~Braun}{[email protected]},
+%   \lstthanks{Denis~Girou}{[email protected]},
+%   \lstthanks{Arne~John~Glenstrup}{[email protected]},
+%   \lstthanks{Frank~Mittelbach}{[email protected]},
+%   \lstthanks{Rolf~Niepraschk}{[email protected]},
+%   \lstthanks{Rui~Oliveira}{[email protected]},
+%   \lstthanks{Jens~Schwarzer}{[email protected]}, and
+%   \lstthanks{Boris~Veytsman}{[email protected]}.
+% \end{quote}
+% Moreover I wish to thank
+% \begin{quote}
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth
+%   \lstthanks{Bj{\o}rn~{\AA}dlandsvik}{[email protected]},
+%   \lstthanks{Gaurav~Aggarwal}{[email protected]},
+%   \lstthanks{Jason~Alexander}{[email protected]},
+%   \lstthanks{Donald~Arseneau}{[email protected]},
+%   \lstthanks{Claus~Atzenbeck}{[email protected]},
+%   \lstthanks{Peter~Bartke}{[email protected]} (big thankyou), ^^A beta tester
+%   \lstthanks{Oliver~Baum}{[email protected]},
+%   \lstthanks{Ralph~Becket}{[email protected]},
+%   \lstthanks{Olaf~Trygve~Berglihn}{[email protected]}, ^^A {1999/11/29}{3-char comment delimiter don't work (Python)}
+%   \lstthanks{Peter~Biechele}{[email protected]},
+%   \lstthanks{Kai~Below}{[email protected]},
+%   \lstthanks{Beat~Birkhofer}{[email protected]},
+%   \lstthanks{Fr\'ed\'eric~Boulanger}{[email protected]},
+%   \lstthanks{Martin~Brodbeck}{[email protected]},
+%   \lstthanks{Walter~E.~Brown}{[email protected]},
+%   \lstthanks{Achim~D.~Brucker}{[email protected]},
+%   \lstthanks{David~Carlisle}{[email protected]},
+%   \lstthanks{Bradford~Chamberlain}{[email protected]},
+%   \lstthanks{Patrick~Cousot}{[email protected]},
+%   \lstthanks{Xavier~Cr\'egut}{[email protected]},
+%   \lstthanks{Holger~Danielsson}{[email protected]},
+%   \lstthanks{Andreas~Deininger}{[email protected]},
+%   \lstthanks{Robert~Denham}{[email protected]},
+%   \lstthanks{Detlev~Dr\"oge}{[email protected]},
+%   \lstthanks{Anders~Edenbrandt}{[email protected]},
+%   \lstthanks{Chris~Edwards}{[email protected]},
+%   \lstthanks{David~John~Evans}{[email protected]},
+%   \lstthanks{Daniel~Gerigk}{[email protected]},
+%   \lstthanks{KP~Gores}{[email protected]},
+%   \lstthanks{Christian~Gudrian}{[email protected]},
+%   \lstthanks{Carsten~Hamm}{[email protected]},
+%   \lstthanks{Harald~Harders}{[email protected]},
+%   \lstthanks{Christian~Haul}{[email protected]},
+%   \lstthanks{Aidan~Philip~Heerdegen}{[email protected]},
+%   \lstthanks{Jim~Hefferon}{[email protected]},
+%   \lstthanks{Heiko~Heil}{[email protected]},
+%   \lstthanks{J\"urgen~Heim}{[email protected]},
+%   \lstthanks{Dr.~Jobst~Hoffmann}{[email protected]},
+%   \lstthanks{Torben~Hoffmann}{[email protected]},
+%   \lstthanks{Richard~Hoefter}{[email protected]},
+%   \lstthanks{Berthold~H\"ollmann}{[email protected]},
+%   \lstthanks{Hermann~H\"uttler}{[email protected]},
+%   \lstthanks{Ralf~Imh\"auser}{[email protected]},
+%   \lstthanks{R.~Isernhagen}{[email protected]},
+%   \lstthanks{Oldrich~Jedlicka}{[email protected]},
+%   \lstthanks{Marcin~Kasperski}{[email protected]},
+%   \lstthanks{Christian~Kindinger}{[email protected]},
+%   \lstthanks{Steffen~Klupsch}{[email protected]},
+%   \lstthanks{Peter~K\"oller}{[email protected]} (big thankyou), ^^A beta tester
+%   \lstthanks{Stefan~Lagotzki}{[email protected]},
+%   \lstthanks{Rene~H.~Larsen}{[email protected]},
+%   \lstthanks{Olivier~Lecarme}{[email protected]},
+%   \lstthanks{Thomas~Leduc}{[email protected]},
+%   \lstthanks{Dr.~Peter~Leibner}{[email protected]},
+%   \lstthanks{Thomas~Leonhardt}{[email protected]} (big thankyou), ^^A beta tester
+%   \lstthanks{Magnus~Lewis-Smith}{[email protected]},
+%   \lstthanks{Knut~Lickert}{[email protected]},
+%   \lstthanks{Kris~Luyten}{no email available},
+%   \lstthanks{Jos\'e~Romildo~Malaquias}{[email protected]},
+%   \lstthanks{Andreas~Matthias}{[email protected]},
+%   \lstthanks{Knut~M\"uller}{[email protected]},
+%   \lstthanks{Svend~Tollak~Munkejord}{[email protected]},
+%   \lstthanks{Gerd~Neugebauer}{[email protected]},
+%   \lstthanks{Torsten~Neuer}{[email protected]},
+%   \lstthanks{Michael~Niedermair}{[email protected]},
+%   \lstthanks{Heiko~Oberdiek}{[email protected]},
+%   \lstthanks{Markus~Pahlow}{[email protected]},
+%   \lstthanks{Zvezdan~V.~Petkovic}{[email protected]},
+%   \lstthanks{Michael~Piefel}{[email protected]},
+%   \lstthanks{Michael~Piotrowski}{[email protected]},
+%   \lstthanks{Manfred~Piringer}{[email protected]},
+%   \lstthanks{Vincent~Poirriez}{[email protected]},
+%   \lstthanks{Adam~Prugel-Bennett}{[email protected]},
+%   \lstthanks{Ralf~Quast}{[email protected]},
+%   \lstthanks{Aslak~Raanes}{[email protected]},
+%   \lstthanks{Venkatesh~Prasad~Ranganath}{[email protected]},
+%   \lstthanks{Georg~Rehm}{[email protected]},
+%   \lstthanks{Fermin~Reig}{[email protected]},
+%   \lstthanks{Detlef~Reimers}{[email protected]},
+%   \lstthanks{Stephen~Reindl}{[email protected]},
+%   \lstthanks{Peter~Ruckdeschel}{[email protected]},
+%   \lstthanks{Magne~Rudshaug}{[email protected]},
+%   \lstthanks{Vespe~Savikko}{[email protected]},
+%   \lstthanks{Gunther~Schmidl}{[email protected]},
+%   \lstthanks{Jochen~Schneider}{[email protected]},
+%   \lstthanks{Martin~Steffen}{[email protected]},
+%   \lstthanks{Andreas~Stephan}{[email protected]},
+%   \lstthanks{Gabriel~Tauro}{[email protected]},
+%   \lstthanks{Winfried~Theis}{[email protected]},
+%   \lstthanks{Jens~T.~Berger~Thielemann}{[email protected]},
+%   \lstthanks{Kalle~Tuulos}{[email protected]},
+%   \lstthanks{Gregory~Van~Vooren}{[email protected]},
+%   \lstthanks{Thorsten~Vitt}{[email protected]},
+%   \lstthanks{Herbert~Voss}{[email protected]} (big thankyou), ^^A beta tester
+%   \lstthanks{Herfried~Karl~Wagner}{[email protected]},
+%   \lstthanks{Dominique~de~Waleffe}{[email protected]},
+%   \lstthanks{Michael~Weber}{[email protected]},
+%   \lstthanks{Sonja~Weidmann}{[email protected]},
+%   \lstthanks{Herbert~Weinhandl}{[email protected]},
+%   \lstthanks{Michael~Wiese}{[email protected]},
+%   \lstthanks{J\"orn~Wilms}{[email protected]},
+%   \lstthanks{Kai~Wollenweber}{[email protected]},
+%   \lstthanks{Ulrich~G.~Wortmann}{[email protected]}, and
+%   \lstthanks{Timothy~Van~Zandt}{[email protected]}.
+% \end{quote}
+% There are probably other people who contributed to this package.
+% If I've missed your name, send an email.
+% \end{advise}
+%
+%
+% \part{Reference guide}
+%
+%
+% \section{Main reference}\label{rMainReference}
+%
+% Your first training is completed. Now that you've left the User's guide, the
+% friend telling you what to do has gone. Get more practice and become a
+% journeyman!^^A :-)
+% \begin{advise}
+% \item Actually, the friend hasn't gone. There are still some advices, but
+%       only from time to time.
+% \end{advise}
+%
+%
+% \subsection{How to read the reference}
+%
+% Commands, keys and environments are presented as follows.
+% \begin{syntax}
+% \item[1.0,default,hints] \texttt{command}, \texttt{environment} or
+%       \keyname{key} with \meta{parameters}
+%
+%       This field contains the explanation; here we describe the other fields.
+%
+%       If present, the label in the left margin provides extra information:
+%       `\textit{addon}' indicates additionally introduced functionality,
+%       `\textit{changed}' a modified key, `\textit{data}' a command just
+%       containing data (which is therefore adjustable via |\renewcommand|),
+%       and so on. Some keys and functionality are `\emph{bug}'-marked or
+%       with a \dag-sign. These features might change in future or could be
+%       removed, so use them with care.
+%
+%       If there is verbatim text touching the right margin, it is the
+%       predefined value. Note that some keys default to this value every
+%       listing, namely the keys which can be used on individual listings only.
+%
+%       The label in the right margin is the current version number and marks
+%       newly introduced features.
+% \end{syntax}
+% Regarding the parameters, please keep in mind the following:
+% \begin{enumerate}
+% \item A list always means a comma separated list. You must put braces around
+%       such a list. Otherwise you'll get in trouble with the
+%       \packagename{keyval} package; it complains about an undefined key.
+% \item You must put parameter braces around the whole value of a key if you
+%       use an \oarg{optional argument} of a key inside an optional
+%       \oarg{key=value list}:
+%       |\begin{lstlisting}[caption=|{\rstyle|{|}|[one]two|{\rstyle|}|}|]|.
+% \item Brackets `|[ ]|' usually enclose optional arguments and must be typed
+%       in verbatim. Normal brackets `[ ]' always indicate an optional argument
+%       and must not be typed in. Thus |[*]| must be typed in exactly as is,
+%       but [|*|] just gets |*| if you use this argument.
+% \item A vertical rule indicates an alternative, e.g.~^^A
+%       \meta{\alternative{true,false}} allows either \texttt{true} or
+%       \texttt{false} as arguments.
+% \item If you want to enter one of the special characters |{}#%\|, this
+%       character must be escaped with a backslash. This means that you must
+%       write |\}| for the single character `right brace'---but of course not
+%       for the closing paramater character.
+% \end{enumerate}
+%
+%
+% \subsection{Typesetting listings}\label{rTypesettingListings}
+%
+% \begin{syntax}
+% \item[0.19] \rcmdname\lstset\marg{key=value list}
+%
+%       sets the values of the specified keys, see also section
+%       \ref{uTheKey=ValueInterface}.
+%       The parameters keep their values up to the end of the current group.
+%       In opposition, all optional \meta{key=value list}s below modify the
+%       parameters for single listings only.
+%
+% \item[0.18] \rcmdname\lstinline\oarg{key=value list}\meta{character}\meta{source code}\meta{same character}
+%
+%       works like |\verb| but respects the active language and style. These
+%       listings use flexible columns except requested differently in the
+%       optional argument. You can write `|\lstinline!var i:integer;!|' and
+%       get `\lstinline!var i:integer;!'.
+%
+%       Since the command first looks ahead for an optional argument, you must
+%       provide at least an empty one if you want to use |[| as
+%       \meta{character}.
+%
+%       \dag\ An experimental implementation has been done to support the
+%       syntax |\lstinline|\oarg{key=value list}\marg{source code}. Try it if
+%       you want and report success and failure. A known limitation is that
+%       inside another argument the last source code token must not be an
+%       explicit space token---and, of course, using a listing inside another
+%       argument is itself experimental, see section \ref{rListingsInsideArguments}.
+%
+% \item[0.15,,changed] |\begin{|\texttt{\rstyle lstlisting}|}|\oarg{key=value list}
+%
+%       \leavevmode\hspace*{-\leftmargini}|\end{|\texttt{\rstyle lstlisting}|}|
+%
+%       typesets the code in between as a displayed listing.
+%
+%       In contrast to the environment of the \packagename{verbatim} package,
+%       \LaTeX\ code on the same line and after the end of environment is
+%       typeset respectively executed.
+%
+% \item[0.1] \rcmdname\lstinputlisting\oarg{key=value list}\marg{file name}
+%
+%       typesets the stand alone source code file as a displayed listing.
+% \end{syntax}
+%
+%
+% \subsection{Space and placement}
+%
+% \begin{syntax}
+% \item[0.20,floatplacement,addon] \rkeyname{float}|=|[|*|]\meta{subset of \textup{\texttt{tbph}}}\syntaxor\rkeyname{float}
+%
+%       makes sense on individual displayed listings only and lets them float.
+%       The argument controls where \LaTeX\ is \emph{allowed} to put the float:
+%       at the top or bottom of the current/next page, on a separate page, or
+%       here where the listing is.
+%
+%       The optional star can be used to get a double-column float in a
+%       two-column document.
+%
+% \item[0.21,tbp] \rkeyname{floatplacement}|=|\meta{place specifiers}
+%
+%       is used as place specifier if \keyname{float} is used without value.
+%
+% \item[0.21,\medskipamount] \rkeyname{aboveskip}|=|\meta{dimension}
+% \item[0.21,\medskipamount] \rkeyname{belowskip}|=|\meta{dimension}
+%
+%       define the space above and below displayed listings.
+%
+% \item[0.17,0pt,\dag] \rkeyname{lineskip}|=|\meta{dimension}
+%
+%       specifies additional space between lines in listings.
+%
+% \item[0.18,c,\dag] \rkeyname{boxpos}|=|\meta{\alternative{b,c,t}}
+%
+%       Sometimes the \packagename{listings} package puts a |\hbox| around a
+%       listing---or it couldn't be printed or even processed correctly.
+%       The key determines the vertical alignment to the surrounding material:
+%       bottom baseline, centered or top baseline.
+% \end{syntax}
+%
+%
+% \subsection{The printed range}
+%
+% \begin{syntax}
+% \item[0.12,true,changed] \rkeyname{print}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{print}
+%
+%       controls whether an individual displayed listing is typeset. Even if
+%       set false, the respective caption is printed and the label is defined.
+%
+%       Note: If the package is loaded without the \texttt{draft} option, you
+%       can use this key together with |\lstset|. In the other case the key
+%       can only be used to typeset particular listings despite of the
+%       \texttt{draft} option.
+%
+% \item[0.1,1,renamed] \rkeyname{firstline}|=|\meta{number}
+% \item[0.1,9999999,renamed] \rkeyname{lastline}|=|\meta{number}
+%
+%       can be used on individual listings only. They determine the physical
+%       input lines used to print displayed listings.
+%
+% \item[0.20,false] \rkeyname{showlines}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{showlines}
+%
+%       If true, the package prints empty lines at the end of listings.
+%       Otherwise these lines are dropped (but they count for line numbering).
+%
+% \item[1.0] \rkeyname{emptylines}|=|[|*|]\meta{number}
+%
+%       sets the maximum of empty lines allowed. If there is a block of more
+%       than \meta{number} empty lines, only \meta{number} ones are printed.
+%       Without the optional star, line numbers can be disturb when blank
+%       lines are omitted; with the star, the lines keep their original
+%       numbers.
+%
+% \item[0.19,0] \rkeyname{gobble}|=|\meta{number}
+%
+%       gobbles \meta{number} characters at the beginning of each
+%       \emph{environment} code line. This key has no effect on \cs{lstinline}
+%       or \cs{lstinputlisting}.
+%
+%       Tabulators expand to \ikeyname{tabsize} spaces before they are gobbled.
+%       Code lines with less than \ikeyname{gobble} characters are considered
+%       empty, but never indent the end of environment by more characters.
+% \end{syntax}
+%
+%
+% \subsection{Languages and styles}\label{rLanguagesAndStyles}
+%
+% Please note that the arguments \meta{language}, \meta{dialect}, and
+% \meta{style name} are case insensitive and that spaces have no effect.
+% \begin{syntax}
+% \item[0.18,{{}}] \rkeyname{style}|=|\meta{style name}
+%
+%       activates the key=value list stored with |\lstdefinestyle|.
+%
+% \item[0.19] \rcmdname\lstdefinestyle\marg{style name}\marg{key=value list}
+%
+%       stores the key=value list.
+%
+% \item[0.17,{{}}] \rkeyname{language}|=|\oarg{dialect}\meta{language}
+%
+%       activates a (dialect of a) programming language. The `empty' default
+%       language detects no keywords, no comments, no strings, and so on.
+%       Without specifying \meta{dialect}, the package chooses a default
+%       dialect.
+%
+%       Table \ref{uPredefinedLanguages} on page \pageref{uPredefinedLanguages}
+%       lists all languages and dialects provided by \texttt{lstdrvrs.dtx}.
+%       The predefined default dialects are underlined.
+%
+% \item[0.21] \rkeyname{alsolanguage}|=|\oarg{dialect}\meta{language}
+%
+%       selects the (dialect of a) programming language additionally to the
+%       current active one. Note that some language definitions interfere with
+%       each other and are plainly incompatible.
+%
+%       Take a look at the \ikeyname{classoffset} key in section
+%       \ref{rFigureOutTheAppearance} if you want to highlight the keywords
+%       of the languages differently.
+%
+% \item[0.19] \rkeyname{defaultdialect}|=|\oarg{dialect}\meta{language}
+%
+%       defines \meta{dialect} as default dialect for \meta{language}.
+%       If you have defined a default dialect other than empty, for example
+%       |defaultdialect=[iama]fool|, you can't select the empty dialect, even
+%       not with |language=[]fool|.
+% \end{syntax}
+%
+% Eventually here's a small list of language specific keys.
+% \begin{syntax}
+% \item[0.19,false,optional] \rkeyname{printpod}|=|\meta{\alternative{true,false}}
+%
+%       prints or drops PODs in Perl.
+%
+% \item[0.20,true,\dag optional] \rkeyname{usekeywordsinside}|=|\meta{\alternative{true,false}}
+%
+%       The package either use the first order keywords for HTML or prints all
+%       identifiers inside |<>| in keyword style.
+%
+% \item[0.20,true,optional] \rkeyname{makemacrouse}|=|\meta{\alternative{true,false}}
+%
+%       Make specific: Macro use of identifiers, which are defined as first
+%       order keywords, also prints the surrounding |$(| and |)| in keyword
+%       style. e.g.~you could get
+%           \textbf{\textdollar(}\textbf{strip} \textdollar(BIBS)\textbf{)}.
+%       If deactivated you get
+%           \textdollar(\textbf{strip} \textdollar(BIBS)).
+% \end{syntax}
+%
+%
+% \subsection{Figure out the appearance}\label{rFigureOutTheAppearance}
+%
+% \begin{syntax}
+% \item[0.18,{{}}] \rkeyname{basicstyle}|=|\meta{basic style}
+%
+%       is selected at the beginning of each listing. You could use
+%       |\footnotesize|, |\small|, |\itshape|, |\ttfamily|, or something like
+%       that. The last token of \meta{basic style} must not read any following
+%       characters.
+%
+% \item[0.18,{{}}] \rkeyname{identifierstyle}|=|\meta{style}
+% \item[0.11,\itshape] \rkeyname{commentstyle}|=|\meta{style}
+% \item[0.12,{{}}] \rkeyname{stringstyle}|=|\meta{style}
+%
+%       determine the style for non-keywords, comments, and strings. The
+%       \emph{last} token might be an one-parameter command like |\textbf| or
+%       |\underbar|.
+%
+% \item[0.11,\bfseries] \rkeyname{keywordstyle}|=|\oarg{number}\meta{style}
+% \item[0.19,keywordstyle] \rkeyname{ndkeywordstyle}|=|\meta{style}
+%
+%       are used to print keywords and second order keywords (if defined).
+%       The optional \meta{number} argument is the class number to which the
+%       style should be applied.
+%       |ndkeywordstyle=...| is equivalent to |keywordstyle=[2]...|.
+%
+% \item[1.0,0] \rkeyname{classoffset}|=|\meta{number}
+%
+%       is added to all class numbers before the styles, keywords, identifiers,
+%       etc.~are assigned. The example below defines the keywords directly;
+%       you could do it indirectly by selection two different languages.
+% \end{syntax}
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{classoffset=0,
+%            morekeywords={one,three,five},keywordstyle=\color{red},
+%            classoffset=1,
+%            morekeywords={two,four,six},keywordstyle=\color{blue},
+%            classoffset=0}% restore default
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}
+%    \lstset{classoffset=0,
+%            morekeywords={one,three,five},keywordstyle=\itshape,
+%            classoffset=1,
+%            morekeywords={two,four,six},keywordstyle=\bfseries},
+%            classoffset=0}% restore default
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    one two three
+%    four five six
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{syntax}
+% \item[0.20,keywordstyle,optional] \rkeyname{texcsstyle}|=|\meta{style}
+% \item[0.20,keywordstyle,optional] \rkeyname{directivestyle}|=|\meta{style}
+%
+%       determine the style of \TeX\ control sequences and directives.
+%       Note that these key are present only if you've chosen an appropriate
+%       language.
+%
+% \item[0.21] \rkeyname{emph}|=|\oarg{number}\marg{identifier list}
+% \item[0.21] \rkeyname{moreemph}|=|\oarg{number}\marg{identifier list}
+% \item[0.21] \rkeyname{deleteemph}|=|\oarg{number}\marg{identifier list}
+% \item[0.21] \rkeyname{emphstyle}|=|\oarg{number}\marg{style}
+%
+%       define, add and remove the \meta{identifier list} from `emphasize
+%       class \meta{number}' respectively define the style for that class.
+%       If you don't give an optional argument, the package assumes
+%       \meta{number}$\,=1$.
+%
+%       These keys are described more detailed in section
+%       \ref{uEmphasizeIdentifiers}.
+%
+% \item[1.0] \rkeyname{delim}|=|[\texttt*[\texttt*]]\texttt[\meta{type}\texttt][\texttt[\meta{style}\texttt]]\meta{delimiter\textup(s\textup)}
+% \item[1.0] \rkeyname{moredelim}|=|[\texttt*[\texttt*]]\texttt[\meta{type}\texttt][\texttt[\meta{style}\texttt]]\meta{delimiter\textup(s\textup)}
+% \item[1.0] \rkeyname{deletedelim}|=|[\texttt*[\texttt*]]\texttt[\meta{type}\texttt]\meta{delimiter\textup(s\textup)}
+%
+%       deletes all previously defined delimiters (but neither strings nor
+%       comments) and defines the user supplied delimiter, adds the specified
+%       delimiter, or removes it.
+%
+%       In the first two cases \meta{style} is used to print the delimited
+%       code (and the delimiters). Here, \meta{style} could be something like
+%       |\bfseries| or |\itshape|, or it could refer to other styles via
+%       \texttt{keywordstyle}, \texttt{keywordstyle2}, \texttt{emphstyle},
+%       etc.
+%
+%       Supported types are \texttt{l} and \texttt{s}, see the comment keys in
+%       section \ref{uLanguageDefinitions} for an explanation. If you use the
+%       prefix \texttt i, i.e.~\texttt{il} or \texttt{is}, the delimiters are
+%       not printed, which is some kind of invisibility.
+%
+%       If you use one optional star, the package will detect keywords,
+%       comments, and strings inside the delimited code. With both optional
+%       stars, aditionally the style is applied cumulative, see section
+%       \ref{uDelimiters}.
+% \end{syntax}
+%
+%
+% \subsection{Getting all characters right}
+%
+% \begin{syntax}
+% \item[0.18,false] \rkeyname{extendedchars}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{extendedchars}
+%
+%       allows or prohibits extended characters in listings, that means
+%       (national) characters of codes 128--255. If you use extended
+%       characters, you should load \packagename{fontenc} and/or
+%       \packagename{inputenc}, for example.
+%
+% \item[1.0,{{}}] \rkeyname{inputencoding}|=|\meta{encoding}
+%
+%       determines the input encoding. The usage of this key requires the
+%       \packagename{inputenc} package; nothing happens if it's not loaded.
+%
+% \item[0.12,8] \rkeyname{tabsize}|=|\meta{number}
+%
+%       sets tabulator stops at columns $\meta{number}+1$, $2\cdot\meta{number}+1$, $3\cdot\meta{number}+1$, and so on.
+%       Each tabulator in a listing moves the current column to the next
+%       tabulator stop.
+%
+% \item[0.20,false,renamed] \rkeyname{showtabs}|=|\meta{\alternative{true,false}}
+%
+%       make tabulators visible or invisible. A visible tabulator looks like
+%       \lstinline[showtabs]!	!, but that can be changed. If you choose
+%       invisible tabulators but visible spaces, tabulators are converted to
+%       an appropriate number of spaces.
+%
+% \item[0.20] \rkeyname{tab}|=|\meta{tokens}
+%
+%       \meta{tokens} is used to print a visible tabulator. You might want to use |$\to$|, |$\mapsto$|, |$\dashv$| or something like that instead of the strange default definition.
+%
+% \item[0.20,false,renamed] \rkeyname{showspaces}|=|\meta{\alternative{true,false}}
+%
+%       lets all blank spaces appear {\textvisiblespace} or as blank spaces.
+%
+% \item[0.12,true,renamed] \rkeyname{showstringspaces}|=|\meta{\alternative{true,false}}
+%
+%       lets blank spaces in strings appear {\textvisiblespace} or as blank
+%       spaces.
+%
+% \item[0.19,\bigbreak] \rkeyname{formfeed}|=|\meta{tokens}
+%
+%       Whenever a listing contains a form feed \meta{tokens} is executed.
+% \end{syntax}
+%
+%
+% \subsection{Line numbers}\label{rLineNumbers}
+%
+% \begin{syntax}
+% \item[1.0,none] \rkeyname{numbers}|=|\meta{\alternative{none,left,right}}
+%
+%       makes the package either print no line numbers, or put them on the
+%       left or the right side of a listing.
+%
+% \item[0.16,1,renamed] \rkeyname{stepnumber}|=|\meta{number}
+%
+%       All lines with ``line number $\equiv 0$ modulo \meta{number}'' get a
+%       line number. 
+%       If you turn line numbers on and off with \keyname{numbers}, the
+%       parameter \keyname{stepnumber} will keep its value. Alternatively you
+%       can turn them off via |stepnumber=0| and on with a nonzero number and
+%       keep the value of \keyname{numbers}.
+%
+% \item[0.16,{{}},renamed] \rkeyname{numberstyle}|=|\meta{style}
+%
+%       determines the font and size of the numbers.
+%
+% \item[0.19,10pt,renamed] \rkeyname{numbersep}|=|\meta{dimension}
+%
+%       is the distance between number and listing.
+%
+% \item[1.0,true] \rkeyname{numberblanklines}|=|\meta{\alternative{true,false}}
+%
+%       If this is set to false, blank lines get no printed line number.
+%
+% \item[0.20,auto,{renamed,addon}] \rkeyname{firstnumber}|=|\meta{\alternative{auto,last,\normalfont\meta{number}}}
+%
+%       \texttt{auto} lets the package choose the first number: a new listing
+%       starts with number one, a named listing continues the most recent
+%       same-named listing (see below), and a stand alone file begins with
+%       the number corresponding to the first input line.
+%
+%       \texttt{last} continues the numbering of the most recent listing and
+%       \meta{number} sets it to the number.
+%
+% \item[1.0] \rkeyname{name}|=|\meta{name}
+%
+%       names a listing. Displayed environment-listings with the same name
+%       share a line counter.
+%
+% \item[0.20,\arabic{lstnumber},{renamed,data}] \rcmdname\thelstnumber
+%
+%       prints the lines' numbers.
+% \end{syntax}
+% We show an example on how to redefine |\thelstnumber|. But if you test it,
+% you won't get the result shown on the left.
+% \begin{lstxsample}
+%    \renewcommand*\thelstnumber{\oldstylenums{\the\value{lstnumber}}}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{stepnumber=-1}\label{rDecreasingLabels}}{}
+%    \begin{lstlisting}[numbers=left,
+%                       firstnumber=753]
+%    begin { empty lines }
+%
+%
+%
+%
+%
+%
+%    end; { empty lines }
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{advise}
+% \item
+% The example shows a sequence $n,n+1,\ldots,n+7$ of 8 three-digit figures such that the sequence contains each digit $0,1,\ldots,9$.
+% But 8 is not minimal with that property.
+% Find the minimal number and prove that it is minimal.
+% How many minimal sequences do exist?
+%
+% Now look at the generalized problem:
+% Let $k\in\{1,\ldots,10\}$ be given.
+% Find the minimal number $m\in\{1,\ldots,10\}$ such that there is a sequence $n,{n+1},\ldots,\allowbreak{n+m-1}$ of $m$ $k$-digit figures which contains each digit $\{0,\ldots,9\}$.
+% Prove that the number is minimal.
+% How many minimal sequences do exist?
+%
+% If you solve this problem with a computer, write a \TeX\ program!
+% \end{advise}
+%
+%
+% \subsection{Captions}
+%
+% In despite of \LaTeX\ standard behaviour, captions and floats are independent
+% from each other here; you can use captions with non-floating listings.
+% \begin{syntax}
+% \item[0.21] \rkeyname{title}|=|\meta{title text}
+%
+%       is used for a title without any numbering or label.
+%
+% \item[0.20] \rkeyname{caption}|={|\oarg{short}\meta{caption text}|}|
+%
+%       The caption is made of \cs{lstlistingname} followed by a running
+%       number, a seperator, and \meta{caption text}. Either the caption text
+%       or, if present, \meta{short} will be used for the list of listings.
+%
+% \item[0.21] \rkeyname{label}|=|\meta{name}
+%
+%       makes a listing referable via |\ref|\marg{name}.
+%
+% \item[0.16] \rcmdname\lstlistoflistings
+%
+%       prints a list of listings. Each entry is with descending priority
+%       either the short caption, the caption, the file name or the name of the
+%       listing, see also the key \keyname{name} in section \ref{rLineNumbers}.
+%
+% \item[1.0] \rkeyname{nolol}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{nolol}
+%
+%       If true, the listing does not make it into the list of listings.
+%
+% \item[0.16,Listings,data] \rcmdname\lstlistlistingname
+%
+%       The header name for the list of listings.
+%
+% \item[0.20,Listing,data] \rcmdname\lstlistingname
+%
+%       The caption label for listings.
+%
+% \item[0.20,\arabic{lstlisting},data] \rcmdname\thelstlisting
+%
+%       prints the running number of the caption.
+%
+% \item[0.19,,re-introduced] \rcmdname\lstname
+%
+%		prints the name of the current listing which is either the file name or
+%       the name defined by the \keyname{name} key. This command can be used to
+%       define a caption or title template, for example by
+%       |\lstset{caption=\lstname}|.
+%
+% \item[0.20,t] \rkeyname{captionpos}|=|\meta{subset of \textup{\texttt{tb}}}
+%
+%       specifies the positions of the caption: top and/or bottom of the
+%       listing.
+%
+% \item[0.20,\smallskipamount] \rkeyname{abovecaptionskip}|=|\meta{dimension}
+% \item[0.20,\smallskipamount] \rkeyname{belowcaptionskip}|=|\meta{dimension}
+%
+%       is the vertical space above respectively below each caption.
+% \end{syntax}
+%
+%
+% \subsection{Margins and line shape}\label{rMarginsAndLineShape}
+%
+% \begin{syntax}
+% \item[0.21,\linewidth] \rkeyname{linewidth}|=|\meta{dimension}
+%
+%       defines the base line width for listings. The following three keys are
+%       taken into account additionally.
+%
+% \item[0.19,0pt,renamed] \rkeyname{xleftmargin}|=|\meta{dimension}
+% \item[1.0,0pt] \rkeyname{xrightmargin}|=|\meta{dimension}
+%
+%       The dimensions are used as extra margins on the left and right. Line
+%       numbers and frames both move respectively shrink or grow accordingly.
+%
+% \item[0.19,false,renamed] \rkeyname{resetmargins}|=|\meta{\alternative{true,false}}
+%
+%       If true indention from list environments like \texttt{enumerate} or
+%       \texttt{itemize} is reset, i.e.~not used.
+%
+% \item[0.20,false] \rkeyname{breaklines}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{breaklines}
+%
+%       activates or deactivates automatic line breaking of long lines.
+%
+% \item[0.20,{{}}] \rkeyname{prebreak}|=|\meta{tokens}
+% \item[0.20,{{}}] \rkeyname{postbreak}|=|\meta{tokens}
+%
+%       \meta{tokens} appear at the end of the current line respectively at the beginning of the next (broken part of the) line.
+%
+%       You must not use dynamic space (in particular spaces) since internally we use |\discretionary|.
+%       However |\space| is redefined to be used inside \meta{tokens}.
+%
+% \item[0.20,20pt] \rkeyname{breakindent}|=|\meta{dimension}
+%
+%       is the indention of the second, third, \ldots\ line of broken lines.
+%
+% \item[0.20,true] \rkeyname{breakautoindent}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{breakautoindent}
+%
+%       activates or deactivates automatic indention of broken lines. This
+%       indention is used additionally to \ikeyname{breakindent}, see the
+%       example below.
+%       Visible spaces or visible tabulators might set this auto
+%       indention to zero.
+% \end{syntax}
+% In the following example we use tabulators to create long lines, but the
+% verbatim part uses |tabsize=1|.
+% \begin{lstxsample}
+%    \lstset{postbreak=\space, breakindent=5pt, breaklines}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{string=[d]",tabsize=6}}{\lstset{tabsize=1}\hfuzz=1in}
+%    \begin{lstlisting}
+%    		"A long string is broken!"
+%    			"Another long line."
+%    \end{lstlisting}
+%
+%    \begin{lstlisting}[breakautoindent
+%                                 =false]
+%    		{ Now auto indention is off. }
+%    \end{lstlisting}
+% \end{lstsample}
+%
+%
+% \subsection{Frames}\label{rFrames}
+%
+% \begin{syntax}
+% \item[1.0,none] \rkeyname{frame}|=|\meta{\alternative{none,leftline,topline,bottomline,lines,single,shadowbox}}
+%
+%       draws either no frame, a single line on the left, at the top, at the
+%       bottom, at the top and bottom, a whole single frame, or a shadowbox.
+%
+%       Note that \packagename{fancyvrb} supports the same frame types except
+%       \texttt{shadowbox}. The shadow color is \keyname{rulesepcolor}, see
+%       below.
+%
+% \item[0.19,{{}},changed] \rkeyname{frame}|=|\meta{subset of \textup{\texttt{trblTRBL}}}
+%
+%		The characters \texttt{trblTRBL} are attached to lines at the top and
+%       bottom of a listing and to lines on the right and left. Upper case
+%       characters are used to draw double rules. So |frame=tlrb| draws a
+%       single frame and |frame=TL| double lines at the top and on the left.
+%
+%       Note that frames usually reside outside the listing's space.
+%
+% \item[0.20,ffff] \rkeyname{frameround}|=|\meta{\alternative{t,f}}\meta{\alternative{t,f}}\meta{\alternative{t,f}}\meta{\alternative{t,f}}
+%
+%       The four letters are attached to the top right, bottom right, bottom
+%       left and top left corner. In this order. \texttt{t} makes the
+%       according corner round. If you use round corners, the rule width is
+%       controlled via |\thinlines| and |\thicklines|.
+%
+%       Note: The size of the quarter circles depends on \keyname{framesep}
+%       and is independent of the extra margins of a frame. The size is
+%       possibly adjusted to fit \LaTeX's circle sizes.
+%
+% \item[0.19,3pt,renamed] \rkeyname{framesep}|=|\meta{dimension}
+% \item[0.19,2pt,renamed] \rkeyname{rulesep}|=|\meta{dimension}
+%
+%		control the space between frame and listing and between double rules.
+%
+% \item[0.19,0.4pt,renamed] \rkeyname{framerule}|=|\meta{dimension}
+%
+%		controls the width of the rules.
+%
+% \item[1.0,0pt] \rkeyname{framexleftmargin}|=|\meta{dimension}
+% \item[1.0,0pt] \rkeyname{framexrightmargin}|=|\meta{dimension}
+% \item[1.0,0pt] \rkeyname{framextopmargin}|=|\meta{dimension}
+% \item[1.0,0pt] \rkeyname{framexbottommargin}|=|\meta{dimension}
+%
+%       are the dimensions which are used additionally to \keyname{framesep}
+%       to make up the margin of a frame.
+%
+% \item[0.21,,changed] \rkeyname{backgroundcolor}|=|\meta{color command}
+% \item[0.21,,{renamed,changed}] \rkeyname{rulecolor}|=|\meta{color command}
+% \item[1.0] \rkeyname{fillcolor}|=|\meta{color command}
+% \item[1.0] \rkeyname{rulesepcolor}|=|\meta{color command}
+%
+%       specify the colour of the background, the rules, the space between
+%       `text box' and first rule, and of the space between two rules,
+%       respectively.
+%       Note that the value requires a |\color| command, for example
+%       \keyname{rulecolor}|=\color{blue}|.
+% \end{syntax}
+% \ikeyname{frame} does not work with |fancyvrb=true| or when the package
+% internally makes a |\hbox| around the listing! And there are certainly more
+% problems with other commands. Take the time to make a (bug) report.
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{framexleftmargin=5mm, frame=shadowbox, rulesepcolor=\color{blue}}
+% \end{lstxsample}
+%\else
+%    \lstset{framexleftmargin=5mm, frame=shadowbox}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}[numbers=left]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% Do you want exotic frames?
+% Try the following key if you want for example
+% \begin{lstsample}{\lstset{frameshape={RYRYNYYYY}{yny}{yny}{RYRYNYYYY}}}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{syntax}
+% \item[0.20,,\dag] \rkeyname{frameshape}|=|\marg{top shape}\marg{left shape}\marg{right shape}\marg{bottom shape}
+%
+%       gives you full control over the drawn frame parts.
+%       The arguments are not case sensitive.
+%
+%       Both \meta{left shape} and \meta{right shape} are `left-to-right'
+%       \alternative{y,n} character sequences (or empty). Each |y| lets the
+%       package draw a rule, otherwise the rule is blank. These vertical rules
+%       are drawn `left-to-right' according to the specified shapes.
+%       The example above uses |yny|.
+%
+%       \meta{top shape} and \meta{bottom shape} are `left-rule-right'
+%       sequences (or empty). The first `left-rule-right' sequence is attached
+%       to the most inner rule, the second to the next, and so on.
+%       Each sequence has three characters: `rule' is either |y| or |n|;
+%       `left' and `right' are |y|, |n| or |r| (which makes a corner round).
+%       The example uses |RYRYNYYYY| for both shapes:
+%       |RYR| describes the most inner (top and bottom) frame shape, |YNY|
+%       the middle, and |YYY| the most outer.
+% \end{syntax}
+% To summarize, the example above used
+% \begin{verbatim}
+%    \lstset{frameshape={RYRYNYYYY}{yny}{yny}{RYRYNYYYY}}\end{verbatim}
+% Note that you are not resticted to two or three levels.
+% However you'll get in trouble if you use round corners when they are too big.
+%
+%
+% \subsection{Indexing}
+%
+% \begin{syntax}
+% \item[0.19] \rkeyname{index}|=|\oarg{number}\oarg{keyword classes}\marg{identifiers}
+% \item[0.21] \rkeyname{moreindex}|=|\oarg{number}\oarg{keyword classes}\marg{identifiers}
+% \item[0.21] \rkeyname{deleteindex}|=|\oarg{number}\oarg{keyword classes}\marg{identifiers}
+%
+%       define, add and remove \meta{identifiers} and \meta{keyword classes}
+%       from the index class list \meta{number}. If you don't specify the
+%       optional number, the package assumes \meta{number} $=1$.
+%
+%		Each appearance of the explicitly given identifiers and each appearance
+%       of the identifiers of the specified \meta{keyword classes} is indexed.
+%       For example, you could write |index=[1][keywords]| to index all
+%       keywords. Note that |[1]| is required here---otherwise we couldn't use
+%       the second optional argument.
+%
+% \item[0.19,\lstindexmacro] \rkeyname{indexstyle}|=|\oarg{number}\meta{tokens \textup(one-parameter command\textup)}
+%
+%       \meta{tokens} actually indexes the identifiers for the list
+%       \meta{number}. In contrast to the style keys, \meta{tokens}
+%       \emph{must} read exactly one parameter, namely the identifier.
+%       Default definition is\icmdname{\lstindexmacro}\vspace*{-\itemsep}
+% \begin{verbatim}
+%    \newcommand\lstindexmacro[1]{\index{{\ttfamily#1}}}\end{verbatim}
+%       \vspace*{-\itemsep}which you shouldn't modify.
+%       Define your own indexing commands and use them as argument to this key.
+% \end{syntax}
+% Section \ref{uIndexing} describes this feature in detail.
+%
+%
+% \subsection{Column alignment}\label{rColumnAlignment}
+%
+% \begin{syntax}
+% \item[1.0,{[c]fixed}] \rkeyname{columns}|=|\oarg{\alternative{c,l,r}}\meta{\alternative{fixed,flexible,fullflexible}}
+%
+%       selects the respective column format, refer section
+%       \ref{uFixedAndFlexibleColumns}.
+%
+%       The optional |c|, |l|, or |r| controls the horizontal orientation of
+%       smallest output units (keywords, identifiers, etc.). The arguments work
+%       as follows, where vertical bars visualize the effect:
+%           $\vert$\lstinline[columns={[c]fixed}]!listing!$\vert$,
+%           $\vert$\lstinline[columns={[l]fixed}]!listing!$\vert$, and
+%           $\vert$\lstinline[columns={[r]fixed}]!listing!$\vert$
+%       in fixed column mode,
+%           $\vert$\lstinline[columns={[c]flexible}]!listing!$\vert$,
+%           $\vert$\lstinline[columns={[l]flexible}]!listing!$\vert$, and
+%           $\vert$\lstinline[columns={[r]flexible}]!listing!$\vert$
+%       with flexible columns, and
+%           $\vert$\lstinline[columns={[c]fullflexible}]!listing!$\vert$,
+%           $\vert$\lstinline[columns={[l]fullflexible}]!listing!$\vert$, and
+%           $\vert$\lstinline[columns={[r]fullflexible}]!listing!$\vert$
+%       with full flexible columns.
+%
+% \item[0.18,false] \rkeyname{flexiblecolumns}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{flexiblecolumns}
+%
+%       selects the most recently selected flexible or fixed column format,
+%       refer to section \ref{uFixedAndFlexibleColumns}.
+%
+% \item[0.21,false,\dag] \rkeyname{keepspaces}|=|\meta{\alternative{true,false}}
+%
+%       |keepspaces=true| tells the package not to drop spaces to fix column
+%       alignment and always converts tabulators to spaces.
+%
+% \item[0.16] \rkeyname{basewidth}|=|\meta{dimension}\syntaxor
+% \item[0.18,{{0.6em,0.45em}}] \rkeyname{basewidth}|={|\meta{fixed}|,|\meta{flexible mode}|}|
+%
+%       sets the width of a single character box for fixed and flexible column
+%       mode (both to the same value or individually).
+%
+% \item[0.20,false] \rkeyname{fontadjust}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{fontadjust}
+%
+%       If true the package adjusts the base width every font selection.
+%       This makes sense only if \ikeyname{basewidth} is given in font specific
+%       units like `em' or `ex'---otherwise this boolean has no effect.
+%
+%       After loading the package, it doesn't adjust the width every font
+%       selection: it looks at \ikeyname{basewidth} each listing and uses the
+%       value for the whole listing. This is possibly inadequate if the style
+%       keys in section \ref{rFigureOutTheAppearance} make heavy font size
+%       changes, see the example below.
+%
+%       Note that this key might disturb the column alignment and might have an
+%       effect on the keywords' appearance!
+% \end{syntax}
+% \begin{lstsample}{\lstset{basicstyle=\normalsize}}{}
+%    \lstset{commentstyle=\scriptsize}
+%    \begin{lstlisting}
+%    { scriptsize font
+%      doesn't look good }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{lstsample}{\lstset{basicstyle=\normalsize,commentstyle=\scriptsize}}{}
+%    \begin{lstlisting}[fontadjust]
+%    { scriptsize font
+%      looks better now }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+%
+% \subsection{Escaping to \LaTeX}\label{rEscapingToLaTeX}
+%
+% \textbf{Note:} {\itshape Any escape to \LaTeX\ may disturb the column
+% alignment since the package can't control the spacing there.}
+% \begin{syntax}
+% \item[0.18,false] \rkeyname{texcl}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{texcl}
+%
+%       activates or deactivates \LaTeX\ comment lines. If activated, comment
+%       line delimiters are printed as usual, but the comment line text (up to
+%       the end of line) is read as \LaTeX\ code and typeset in comment style.
+% \end{syntax}
+% The example uses \Cpp\ comment lines (but doesn't say how to define them).
+% Without |\upshape| we would get \textit{calculate} since the comment style
+% is |\itshape|.
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \begin{lstlisting}[texcl]
+%    // \upshape calculate $a_{ij}$
+%      A[i][j] = A[j][j]/A[i][j];
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{syntax}
+% \item[0.19,false] \rkeyname{mathescape}|=|\meta{\alternative{true,false}}
+%
+%       activates or deactivates special behaviour of the dollar sign.
+%       If activated a dollar sign acts as \TeX's text math shift.
+%
+%       This key is useful if you want to typeset formulas in listings.
+%
+% \item[0.19,{{}}] \rkeyname{escapechar}|=|\meta{character}\syntaxor\rkeyname{escapechar}|={}|
+%
+%       If not empty the given character escapes the user to \LaTeX: all code
+%       between two such characters is interpreted as \LaTeX\ code. Note that
+%       \TeX's special characters must be entered with a preceding backslash,
+%       e.g.~|escapechar=\%|.
+%
+% \item[0.20,{{}}] \rkeyname{escapeinside}|=|\meta{character}\meta{character}\syntaxor\rkeyname{escapeinside}|={}|
+%
+%       Is a generalization of \ikeyname{escapechar}. If the value is not
+%       empty, the package escapes to \LaTeX\ between the first and second
+%       character.
+%
+% \item[0.20,{{}}] \rkeyname{escapebegin}|=|\meta{tokens}
+% \item[0.20,{{}}] \rkeyname{escapeend}|=|\meta{tokens}
+%
+%       The tokens are executed at the beginning respectively at the end of
+%       each escape, in particular for \ikeyname{texcl}.
+%       See section \ref{uNationalCharacters} for an application.
+% \end{syntax}
+%
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \begin{lstlisting}[mathescape]
+%    // calculate $a_{ij}$
+%      $a_{ij} = a_{jj}/a_{ij}$;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \begin{lstlisting}[escapechar=\%]
+%    // calc%ulate $a_{ij}$%
+%      %$a_{ij} = a_{jj}/a_{ij}$%;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \lstset{escapeinside=`'}
+%    \begin{lstlisting}
+%    // calc`ulate $a_{ij}$'
+%      `$a_{ij} = a_{jj}/a_{ij}$';
+%    \end{lstlisting}
+% \end{lstsample}
+% In the first example the comment line up to $a_{ij}$ has been typeset by the
+% \packagename{listings} package in comment style. The $a_{ij}$ itself is
+% typeset in `\TeX\ math mode' without comment style. About the half
+% comment line of the second example has been typeset by this package.
+% The rest is in `\LaTeX\ mode'.
+%
+% To avoid problems with the current and future version of this package:
+% \begin{enumerate}
+% \item Don't use any command of the \packagename{listings} package when you
+%       have escaped to \LaTeX.
+% \item Any environment must start and end inside the same escape.
+% \item You might use |\def|, |\edef|, etc., but do not assume that the
+%       definitions are present later---except they are |\global|.
+% \item |\if \else \fi|, groups, math shifts |$| and |$$|, \ldots\ must be
+%       balanced each escape.
+% \item \ldots
+% \end{enumerate}
+% Expand that list yourself and mail me about new items.
+%
+%
+% \subsection{Interface to \textsf{fancyvrb}}
+%
+% The \packagename{fancyvrb} package---fancy verbatims---from Timothy van Zandt
+% provides macros for reading, writing and typesetting verbatim code. It has
+% some remarkable features the \packagename{listings} package doesn't have.
+% (Some are possible, but you must find somebody who implements them ; -- ).
+% \begin{syntax}
+% \item[0.19,,bug] \rkeyname{fancyvrb}|=|\meta{\alternative{true,false}}
+%
+%       activates or deactivates the interface. If active, verbatim code is
+%       read by \packagename{fancyvrb} but typeset by \packagename{listings},
+%       i.e.~with emphasized keywords, strings, comments, and so on.
+%       Internally we use a very special definition of |\FancyVerbFormatLine|.
+%
+%       This interface works with |Verbatim|, |BVerbatim| and |LVerbatim|.
+%       But you shouldn't use \packagename{fancyvrb}'s \keyname{defineactive}.
+%       (As far as I can see it doesn't matter since it does nothing at all,
+%       but for safety \ldots)
+%       If \packagename{fancyvrb} and \packagename{listings} provide similar
+%       functionality, you should use \packagename{fancyvrb}'s.
+%
+%       Bug (\keyname{commandchars}): If you use \packagename{fancyvrb}'s
+%       \keyname{commandchars}, the used commands must not take arguments from
+%       the verbatim code except the source code which is actually typeset.
+%       For example, |\textcolor{red}{keyword}| is illegal since |red| is (used
+%       to select the colour and) not typeset. There is an easy work-around:
+%       write |\newcommand*\myred{\textcolor{red}}| and use |\myred{keyword}|
+%       inside the verbatim code.
+% \end{syntax}
+%
+% \iffancyvrb
+% \begin{lstsample}{}{}
+%    \lstset{morecomment=[l]\ }% :-)
+%    \fvset{commandchars=\\\{\}}
+%
+%    \begin{BVerbatim}
+%    First verbatim line.
+%    \fbox{Second} verbatim line.
+%    \end{BVerbatim}
+%
+%    \par\vspace{72.27pt}
+%
+%    \lstset{fancyvrb}
+%    \begin{BVerbatim}
+%    First verbatim line.
+%    \fbox{Second} verbatim line.
+%    \end{BVerbatim}
+%    \lstset{fancyvrb=false}
+% \end{lstsample}
+% The lines typeset by the \packagename{listings} package are wider since the
+% default \ikeyname{basewidth} equals not the width of a single typewriter type
+% character. Moreover note that the first space begins a comment as defined at
+% the beginning of the example.
+% \else
+% \begin{center}
+%    \packagename{fancyvrb} seems to be unavailable on your platform, thus the
+%    example couldn't be printed here.
+% \end{center}
+% \fi
+%
+%
+% \subsection{Environments}\label{rEnvironments}
+%
+% If you want to define your own pretty-printing environments, try the
+% following command. The syntax comes from \LaTeX's |\newenvironment|.
+% \begin{syntax}
+% \item[0.19] \rcmdname\lstnewenvironment\\
+%       \marg{name}\oarg{number}\oarg{opt.~default~arg.}\\
+%       |{|\meta{starting code}|}|\\
+%       |{|\meta{ending code}|}|
+% \end{syntax}
+% As a simple example we could just select a particular language.
+% \begin{lstxsample}
+%    \lstnewenvironment{pascal}
+%        {\lstset{language=pascal}}
+%        {}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{pascal}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{pascal}
+% \end{lstsample}
+% Doing other things is as easy, for example, using more keys and adding an
+% optional argument to adjust settings each listing:
+% \begin{verbatim}
+%\lstnewenvironment{pascalx}[1][]
+%    {\lstset{language=pascal,numbers=left,numberstyle=\tiny,float,#1}}
+%    {}\end{verbatim}
+%
+%
+% \subsection{Language definitions}\label{rLanguageDefinitions}
+%
+% You should first read section \ref{uLanguageDefinitions} for an introduction
+% to language definitions. Otherwise you're probably unprepared for the full
+% syntax of |\lstdefinelanguage|.
+% \begin{syntax}
+% \item[0.19] \rcmdname\lstdefinelanguage\syntaxnewline[\oarg{dialect}]\marg{language}\syntaxnewline[\oarg{base dialect}\marg{and base language}]\syntaxnewline\marg{key=value list}\syntaxnewline[\oarg{list of required aspects \textup(keywordcomments,texcs,etc.\textup)}]
+%
+%		defines the (given dialect of the) programming language \meta{language}.
+%       If the language definition is based on another definition, you must
+%       specify the whole \oarg{base dialect}\marg{and base language}. Note
+%       that an empty \meta{base dialect} uses the default dialect!
+%
+%       The last optional argument should specify all required aspects. This is
+%       a delicate point since the aspects are described in the developer's
+%       guide. You might use existing languages as templates. For example,
+%       ANSI C uses \aspectname{keywords}, \aspectname{comments},
+%       \aspectname{strings} and \aspectname{directives}.
+%
+%       \icmdname{\lst@definelanguage} has the same syntax and is used to
+%       define languages in the driver files.
+%
+% \begin{advise}
+% \item Where should I put my language definition?
+%       \advisespace
+%       If you need the language for one particular document, put it into
+%       the preamble of that document. Otherwise create the local file
+%       `\texttt{lstlang0.sty}' or add the definition to that file, but use
+%       `|\lst@definelanguage|' instead of `|\lstdefinelanguage|'.
+%       However, you might want to send the definition to the address in
+%       section \ref{uSoftwareLicense}. Then it will be published under the
+%       \LaTeX\ Project Public License.
+% \end{advise}
+%
+% \item[0.18] \rcmdname\lstalias\marg{alias}\marg{language}
+%
+%       defines an alias for a programming language. Each \meta{alias} is
+%       redirected to the same dialect of \meta{language}.
+%       It's also possible to define an alias for one particular dialect only:
+%
+% \item[0.18] \rcmdname\lstalias\oarg{alias dialect}\marg{alias}\oarg{dialect}\marg{language}
+%
+%       Here all four parameters are \emph{nonoptional} and an alias with empty
+%       \meta{dialect} will select the default dialect. Note that aliases
+%       can't be nested: The two aliases `|\lstalias{foo1}{foo2}|' and
+%       `|\lstalias{foo2}{foo3}|' redirect |foo1| \emph{not} to |foo3|.
+% \end{syntax}
+% All remaining keys in this section are intended to build language
+% definitions. \emph{No other key should be used in such a definition!}
+%
+%
+% \paragraph{Keywords}
+% We begin with keyword building keys. Note: {\itshape If you want to enter
+% {\upshape|\|, |{|, |}|, |%|, |#|} or {\upshape|&|} inside or as an argument
+% here or below, you must do it with a preceding backslash!}
+% \begin{syntax}
+% \item[1.0,,{\dag bug}] \rkeyname{keywordsprefix}|=|\meta{prefix}
+%
+%       All identifiers starting with \meta{prefix} will be printed as first
+%       order keywords.
+%
+%       Bugs: Currently there are several limitations.
+%       (1) The prefix is always case sensitive.
+%       (2) Only one prefix can be defined at the same time.
+%       (3) If used `standalone', the key might work only after selecting a
+%           nonempty language (and switching back to the empty language if
+%           necessary).
+%       (4) The key does not respect the value of \keyname{classoffset} and
+%           has no optional class \meta{number} argument.
+%
+% \item[0.11] \rkeyname{keywords}|=|\oarg{number}\marg{list of keywords}
+% \item[0.11] \rkeyname{morekeywords}|=|\oarg{number}\marg{list of keywords}
+% \item[0.18] \rkeyname{deletekeywords}|=|\oarg{number}\marg{list of keywords}
+%
+%       define, add to or remove the keywords from keyword list \meta{number}.
+%       The use of \keyname{keywords} is discouraged since it deletes all
+%       previously defined keywords in the list and is thus incompatible with
+%       the \keyname{alsolanguage} key.
+%
+%       Please note the keys \ikeyname{alsoletter} and \ikeyname{alsodigit}
+%       below if you use unusual charaters in keywords.
+%
+% \item[0.19] \rkeyname{ndkeywords}|=|\marg{list of keywords}
+% \item[0.19] \rkeyname{morendkeywords}|=|\marg{list of keywords}
+% \item[0.19] \rkeyname{deletendkeywords}|=|\marg{list of keywords}
+%
+%       define, add to or remove the keywords from keyword list 2.
+%       The use of \keyname{ndkeywords} is discouraged.
+%
+% \item[0.19,,optional] \rkeyname{texcs}|=|\marg{list of control sequences \textup(without backslashes\textup)}
+% \item[0.20,,optional] \rkeyname{moretexcs}|=|\marg{list of control sequences \textup(without backslashes\textup)}
+% \item[0.21,,optional] \rkeyname{deletetexcs}|=|\marg{list of control sequences \textup(without backslashes\textup)}
+%
+%       Ditto for control sequences in \TeX\ and \LaTeX.
+%
+% \item[0.18,,optional] \rkeyname{directives}|=|\marg{list of compiler directives}
+% \item[0.21,,optional] \rkeyname{moredirectives}|=|\marg{list of compiler directives}
+% \item[0.21,,optional] \rkeyname{deletedirectives}|=|\marg{list of compiler directives}
+%
+%       defines compiler directives in C, \Cpp, Objective-C, and POV.
+%
+% \item[0.14] \rkeyname{sensitive}|=|\meta{\alternative{true,false}}
+%
+%       makes the keywords, control sequences, and directives case sensitive
+%       and insensitive, respectively. This key affects the keywords, control
+%       sequences, and directives only when a listing is processed. In all
+%       other situations they are case sensitive, for example,
+%       |deletekeywords={save,Test}| removes `save' and `Test', but neither
+%       `SavE' nor `test'.
+%
+% \item[0.19] \rkeyname{alsoletter}|=|\marg{character sequence}
+% \item[0.19] \rkeyname{alsodigit}|=|\marg{character sequence}
+% \item[0.19] \rkeyname{alsoother}|=|\marg{character sequence}
+%
+%       All identifiers (keywords, directives, and such) begin with a letter
+%       and goes on with alpha-numeric characters (letters and digits).
+%       For example, if you write
+%           |keywords={one-two,\#include}|,
+%       the minus must become a digit and the sharp a letter since the
+%       keywords can't be detected otherwise.
+%
+%       Table \ref{rStdCharTable} show the standard configuration of the
+%       \packagename{listings} package. The three keys overwrite the default
+%       behaviour. Each character of the sequence becomes a letter, digit
+%       and other, respectively.
+%
+% \item[0.20] \rkeyname{otherkeywords}|=|\marg{keywords}
+%
+%       Each given `keyword' is printed in keyword style, but without changing
+%       the `letter', `digit' and `other' status of the characters. This key
+%       is designed to define keywords like |=>|, |->|, |-->|, |--|, |::|, and
+%       so on. If one keyword is a subsequence of another (like |--| and
+%       |-->|), you must specify the shorter first.
+%
+% \item[0.20,,{\dag optional}] \rkeyname{keywordsinside}|=|\meta{character}\meta{character}\syntaxor\rkeyname{keywordsinside}|={}|
+%
+%       The first order keywords are active only between the first and second
+%       character. This key is used for HTML.
+% \end{syntax}
+%
+% \begin{table}[tb]
+% \caption{Standard character table}\label{rStdCharTable}
+% \begin{tabular}{ll}
+% class & characters\\
+% \noalign{\smallskip}
+% letter & \texttt{A B C D E F G H I J K L M N O P Q R S T U V W X Y Z}\\
+%        & \texttt{a b c d e f g h i j k l m n o p q r s t u v w x y z}\\
+%        & \texttt{@ \textdollar\ } |_|\\
+% digit  & \texttt{0 1 2 3 4 5 6 7 8 9}\\
+% other  & \texttt{!\ " \#\ \%\ \&\ ' ( ) * + , - .\ / :\ ; < = > ?}\\
+%        & {\catcode`\|=12\texttt{[ \char92\ ] \textasciicircum\ \char123\ | \char125\ \textasciitilde}}\\
+% space  & chr(32)\\
+% tabulator & chr(9)\\
+% form feed & chr(12)\\
+% \noalign{\smallskip}
+% \end{tabular}
+% \par\noindent
+% Note: Extended characters of codes 128--255 (if defined) are \emph{currently}
+% letters.
+% \end{table}
+%
+%
+% \paragraph{Strings}
+% \begin{syntax}
+% \item[0.12] \rkeyname{string}|=|\oarg{\alternative{b,d,m,bd}}\marg{delimiter \textup(character\textup)}
+% \item[0.21] \rkeyname{morestring}|=|\oarg{\alternative{b,d,m,bd}}\marg{delimiter}
+% \item[0.21] \rkeyname{deletestring}|=|\oarg{\alternative{b,d,m,bd}}\marg{delimiter}
+%
+%       define, add to or delete the delimiter from the list of string
+%       delimiters. Starting and ending delimiters are the same, i.e.~in the
+%       source code the delimiters must match each other.
+%
+%       The optional argument is the type and controls how the delimiter itself
+%       is represented in a string or character literal: it is escaped by a
+%       |b|ackslash, |d|oubled (or both is allowed via |bd|) or it is
+%       `|m|atlabed'.
+%       The latter one is a special type for Ada and Matlab and possibly more
+%       languages where the string delimters are also used for other purposes.
+%       In general the delimiter is also doubled, but a string does not start
+%       after a letter, a right parenthesis, or a right bracket.
+% \end{syntax}
+%
+%
+% \paragraph{Comments}
+% \begin{syntax}
+% \item[0.13] \rkeyname{comment}|=|\oarg{type}\meta{delimiter\textup(s\textup)}
+% \item[0.21] \rkeyname{morecomment}|=|\oarg{type}\meta{delimiter\textup(s\textup)}
+% \item[0.21] \rkeyname{deletecomment}|=|\oarg{type}\meta{delimiter\textup(s\textup)}
+%
+%       Ditto for comments, but some types require more than a single
+%       delimiter. The following overview uses \keyname{morecomment} as the
+%       only example.
+%
+% \item[0.13] \keyname{morecomment}|=[l]|\meta{delimiter}
+%
+%       The delimiter starts a comment line, which in general starts with the
+%       delimiter and ends at end of line. If the character sequence |//|
+%       should start a comment line (like in \Cpp, Comal 80 or Java),
+%       |morecomment=[l]=//| is the correct declaration. For Matlab it
+%       would be |morecomment=[l]\%|---note the preceding backslash.
+%
+% \item[0.13] \keyname{morecomment}|=[s]|\marg{delimiter}\marg{delimiter}
+%
+%       Here we have two delimiters. The second ends a comment starting with
+%       the first delimiter. If you require two such comments you can use this
+%       type twice. C, Java, PL/I, Prolog and SQL all define single comments
+%       via |morecomment=[s]{/*}{*/}|, and Algol does it with
+%       |morecomment=[s]{\#}{\#}|, which means that the sharp delimits both
+%       beginning and end of a single comment.
+%
+% \item[0.13] \keyname{morecomment}|=[n]|\marg{delimiter}\marg{delimiter}
+%
+%       is similar to type |s|, but comments can be nested. Identical arguments
+%       are not allowed---think a while about it!
+%       Modula-2 and Oberon-2 use |morecomment=[n]{(*}{*)}|.
+%
+% \item[0.18,,changed] \keyname{morecomment}|=[f][]|\oarg{n=preceding columns}\meta{delimiter}
+%
+%       The delimiter starts a comment line if and only if it appears on a
+%       fixed column-number, namely if it is in column $n$ (zero based).
+%
+% \item[0.17,,optional] \rkeyname{keywordcomment}|=|\marg{keywords}
+% \item[0.21,,optional] \rkeyname{morekeywordcomment}|=|\marg{keywords}
+% \item[0.21,,optional] \rkeyname{deletekeywordcomment}|=|\marg{keywords}
+%
+%       A keyword comment begins with a keyword and ends with the same keyword.
+%       Consider |keywordcomment={comment,co}|. Then
+%       `\textbf{comment}\allowbreak\ldots\textbf{comment}' and
+%       `\textbf{co}\ldots\textbf{co}' are comments.
+%
+% \item[0.17,,optional] \rkeyname{keywordcommentsemicolon}|=|\marg{keywords}\marg{keywords}\marg{keywords}
+%
+%       The definition of a `keyword comment semicolon' requires three keyword
+%       lists, e.g.~|{end}{else,end}{comment}|. A semicolon always ends such a
+%       comment. Any keyword of the first argument begins a comment and any
+%       keyword of the second argument ends it (and a semicolon also);
+%       a comment starting with any keyword of the third argument is terminated
+%       with the next semicolon only. In the example all possible comments are
+%       `\textbf{end}\ldots\textbf{else}', `\textbf{end}\ldots\textbf{end}'
+%       (does not start a comment again) and `\textbf{comment}\ldots;' and
+%       `\textbf{end}\ldots;'.
+%       Maybe a curious definition, but Algol and Simula use such comments.
+%
+%       Note: The keywords here need not to be a subset of the defined
+%       keywords. They won't appear in keyword style if they aren't.
+%
+% \item[0.17,,optional] \rkeyname{podcomment}|=|\meta{\alternative{true,false}}
+%
+%       activates or deactivates PODs---Perl specific.
+% \end{syntax}
+%
+%
+% \subsection{Installation}\label{rInstallation}
+%
+% \paragraph{Software installation}
+% \begin{enumerate}
+% \item Following the \TeX\ directory structure (TDS), you should put the files
+%       of the \packagename{listings} package into directories as follows:
+%       \begin{center}
+%       \begin{tabular}{lcl}
+%       \texttt{listings.dvi}&$\to$&\texttt{texmf/doc/latex/listings}\\
+%       \texttt{listings.dtx}, \texttt{listings.ins},\\
+%       \texttt{lstdrvrs.dtx},
+%       \texttt{lstpatch.sty}&$\to$&\texttt{texmf/source/latex/listings}
+%       \end{tabular}
+%       \end{center}
+%       Note that you possibly don't have a patch file \texttt{lstpatch.sty}.
+%       If you don't use the TDS, simply adjust the directories below.
+% \item	Create the directory \texttt{texmf/tex/latex/listings} or remove all
+%       files except \texttt{lst}\meta{whatever}\texttt{0.sty} and
+%       \texttt{lstlocal.cfg} from that directory.
+% \item	Change the working directory to \texttt{texmf/source/latex/listings}
+%       and run \texttt{listings.ins} through \TeX.
+% \item Move the generated files to \texttt{texmf/tex/latex/listings} if this
+%       is not already done.
+%       \begin{center}
+%       \begin{tabular}{lcl}
+%       \texttt{listings.sty}, \texttt{lstmisc.sty},
+%           &&\qquad(kernel and add-ons)\\
+%       \texttt{listings.cfg},
+%           &&\qquad(configuration file)\\
+%       \texttt{lstlang}\meta{number}\texttt{.sty},
+%           &&\qquad(language drivers)\\
+%       \texttt{lstpatch.sty}&$\to$&\texttt{texmf/tex/latex/listings}
+%       \end{tabular}
+%       \end{center}
+% \item If your \TeX\ implementation uses a file name database, update it.
+% \item If you receive a patch file later on, put it where
+%       \texttt{listings.sty} is (and update file name database).
+% \end{enumerate}
+% Note that \packagename{listings} requires at least version 1.10 of the
+% \packagename{keyval} package included in the \packagename{graphics} bundle by
+% David Carlisle. This bundle is available via ftp from
+% \href{ftp://ftp.dante.de/tex-archive/macros/latex/required/graphics}
+%      {CTAN/macros/latex/required/graphics}.
+%
+%
+% \paragraph{Software configuration}
+% Read this only if you encounter problems with the standard configuration or
+% if you want the package to suit foreign languages, for example.
+%
+% Never modify a file from the \packagename{listings} package, in particular
+% not the configuration file. Each new installation or new version overwrites
+% it. The software license allows modification, but I can't recommend it.
+% It's better to create one or more of the files
+% \begin{center}
+% \begin{tabular}{lcl}
+% \texttt{lstmisc0.sty} & for & local add-ons
+%                               (see developer's guide),\\
+% \texttt{lstlang0.sty} & for & local language definitions
+%                               (see \ref{rLanguageDefinitions}), and\\
+% \texttt{lstlocal.cfg} & as  & local configuration file
+% \end{tabular}
+% \end{center}
+% and put it/them to the other \packagename{listings} files. These three files
+% are not touched by a new installation except you remove them.
+% If \texttt{lstlocal.cfg} exists, it is loaded after \texttt{listings.cfg}.
+% You might want to change one of the following parameters.
+% \begin{syntax}
+% \item[,,data] \rcmdname\lstaspectfiles\quad contains~\rlap{\texttt{\lstaspectfiles}}
+% \item[,,data] \rcmdname\lstlanguagefiles\quad contains~\rlap{\texttt{\lstlanguagefiles}}
+%
+%       The package uses the specified files to find add-ons and language
+%       definitions.
+% \end{syntax}
+% Moreover you might want to adjust
+%   \icmdname\lstlistlistingname,
+%   \icmdname\lstlistingname,
+%   \ikeyname{defaultdialect},
+%   \icmdname\lstalias, or
+%   \icmdname\lstalias
+% as described in earlier section.
+%
+%
+% \section{Experimental features}\label{rExperimentalFeatures}
+%
+% This section describes the more or less unestablished parts of this package.
+% It's unlikely that they are all removed (except it is stated explicitly), but
+% they are liable to (heavy) changes and improvements. Such features have been
+% \dag-marked in the last sections. So, if you find anything \dag-marked here,
+% you should be very, very careful.
+%
+%
+% \subsection{Listings inside arguments}\label{rListingsInsideArguments}
+%
+% There are some things to consider if you want to use |\lstinline| or the
+% listing environment inside arguments. Since \TeX\ reads the argument before
+% the `\lst-macro' is executed, this package can't do anything to preserve the
+% input: spaces shrink to one space, the tabulator and the end of line are
+% converted to spaces, \TeX's comment character is not printable, and so on.
+% Hence, \emph{you} must work a bit more. You have to put a backslash in front
+% of each of the following four characters: |\{}%|. Moreover you must protect
+% spaces in the same manner if: (i) there are two or more spaces following each
+% other or (ii) the space is the first character in the line.
+% That's not enough: Each line must be terminated with a `line feed' |^^J|.
+% And you can't escape to \LaTeX\ inside such listings!
+%
+% The easiest examples are with |\lstinline| since we need no line feed.
+% \begin{verbatim}
+%\footnote{\lstinline{var i:integer;} and
+%          \lstinline!protected\ \ spaces! and
+%          \fbox{\lstinline!\\\{\}\%!}}\end{verbatim}
+% yields\lstset{language=Pascal}\footnote{\lstinline{var i:integer;} and
+%          \lstinline!protected\ \ spaces! and
+%          \fbox{\lstinline!\\\{\}\%!}}
+% if the current language is Pascal. Note that this example shows another
+% experimental feature: use of argument braces as delimiters. This is
+% described in section \ref{rTypesettingListings}.
+%
+% And now an environment example:
+% \begin{lstsample}{\lstset{language={}}}{}
+%    \fbox{%
+%    \begin{lstlisting}^^J
+%    \ !"#$\%&'()*+,-./^^J
+%    0123456789:;<=>?^^J
+%    @ABCDEFGHIJKLMNO^^J
+%    PQRSTUVWXYZ[\\]^_^^J
+%    `abcdefghijklmno^^J
+%    pqrstuvwxyz\{|\}~^^J
+%    \end{lstlisting}}
+% \end{lstsample}
+% \begin{advise}
+% \item You might wonder that this feature is still experimental. The reason:
+%       You shouldn't use listings inside arguments; it's not always safe.
+% \end{advise}
+%
+%
+% \subsection{\dag\ Export of identifiers}\label{rExportOfIdentifiers}
+%
+% It would be nice to export function or procedure names. In general that's a
+% dream so far. The problem is that programming languages use various syntaxes
+% for function and procedure declaration or definition. A general interface is
+% completely out of the scope of this package---that's the work of a compiler
+% and not of a pretty-printing tool. However, it is possible for particular
+% languages: in Pascal each function or procedure definition and variable
+% declaration is preceded by a particular keyword.
+% Note that you must request the following keys with \texttt{procnames} option:
+% |\usepackage[procnames]{listings}|.
+% \begin{syntax}
+% \item[0.19,{{}},{\dag renamed,optional}] \rkeyname{procnamekeys}|=|\marg{keywords}
+% \item[0.21,,\dag optional] \rkeyname{moreprocnamekeys}|=|\marg{keywords}
+% \item[0.21,,\dag optional] \rkeyname{deleteprocnamekeys}|=|\marg{keywords}
+%
+%		each specified keyword indicates a function or procedure definition.
+%		Any identifier following such a keyword appears in `procname' style.
+%		For Pascal you might use\vspace{-.5\baselineskip}
+% \begin{verbatim}
+%    procnamekeys={program,procedure,function}\end{verbatim}
+%
+% \item[0.19,keywordstyle,\dag optional] \rkeyname{procnamestyle}|=|\meta{style}
+%
+%		defines the style in which procedure and function names appear.
+%
+% \item[0.19,false,\dag optional] \rkeyname{indexprocnames}|=|\meta{\alternative{true,false}}
+%
+%		If activated, procedure and function names are also indexed.
+% \end{syntax}
+% \begin{TODO}
+% The \aspectname{procnames} aspect is unsatisfactory (since unchanged for more
+% than three years). It marks and indexes the function definitions so far, but
+% it would be possible to mark also the following function calls, for example.
+% A key could control whether function names are added to a special keyword
+% class, which then appears in `procname' style. But should these names be
+% added globally? There are good reasons for both. Of course, we would also
+% need a key to reset the name list.
+% \end{TODO}
+%
+%
+% \subsection{\dag\ Hyper references}\label{rHyperReferences}
+%
+% This very small aspect must be requested via \texttt{hyper} option since it
+% is experimental. One perspective for the future is to combine this aspect
+% with \aspectname{procnames}. Then it should be possible to click on a
+% function name and jump to its definition, for example.
+% \begin{syntax}
+% \item[0.21,,{\dag optional}] \rkeyname{hyperref}|=|\marg{identifiers}
+% \item[0.21,,{\dag optional}] \rkeyname{morehyperref}|=|\marg{identifiers}
+% \item[0.21,,{\dag optional}] \rkeyname{deletehyperref}|=|\marg{identifiers}
+%
+%       Hyper references the specified identifiers (via \packagename{hyperref}
+%       package). A `click' on such an identifier jumps to the previous
+%       occurrence.
+%
+% \item[0.21,\hyper@@anchor,{\dag optional}] \rkeyname{hyperanchor}|=|\meta{two-parameter macro}
+% \item[0.21,\hyperlink,{\dag optional}] \rkeyname{hyperlink}|=|\meta{two-parameter macro}
+%
+%       The macros are used to set an hyper anchor and link, respectively.
+%       The defaults are suited for the \packagename{hyperref} package.
+% \end{syntax}
+%
+%
+% \subsection{Literate programming}
+%
+% We begin with an example and hide the crucial key=value list.
+% \begin{lstsample}{\lstset{literate={:=}{{$\gets$}}1 {<=}{{$\leq$}}1 {>=}{{$\geq$}}1 {<>}{{$\neq$}}1}}{}
+%    \begin{lstlisting}
+%    var i:integer;
+%
+%    if (i<=0) i := 1;
+%    if (i>=0) i := 0;
+%    if (i<>0) i := 0;
+%    \end{lstlisting}
+% \end{lstsample}
+% Funny, isn't it? We could write |i := 0| respectively i| |$\gets$| |0
+% instead, but that's not literate!^^A :-)
+% Now you might want to know how this has been done. Have a \emph{close}
+% look at the following key.
+% \begin{syntax}
+% \item[0.20,,\dag] \rkeyname{literate}|=|\meta{replacement item}\ldots\meta{replacement item}
+%
+%       First note that there are no commas between the items. Each item
+%       consists of three arguments:
+%           \marg{replace}\marg{replacement text}\marg{length}.
+%       \meta{replace} is the original character sequence.
+%       Instead of printing these characters, we use \meta{replacement text},
+%       which takes the width of \meta{length} characters in the output.
+%
+%       Each `printing unit' in \meta{replacement text} \emph{must} be braced
+%       except it's a single character. For example, you must put braces
+%       around |$\leq$|.
+%       If you want to replace |<-1->| by |$\leftarrow1\rightarrow$|, the
+%       replacement item would be |{<-1->}{{$\leftarrow$}1{$\rightarrow$}}3|.
+%       Note the braces around the arrows.
+%
+%       If one \meta{replace} is a subsequence of another \meta{replace}, you
+%       must use the shorter sequence first. For example, |{-}| must be used
+%       before |{--}| and this before |{-->}|.
+% \end{syntax}
+% In the example above I've used
+% \begin{verbatim}
+%  literate={:=}{{$\gets$}}1 {<=}{{$\leq$}}1 {>=}{{$\geq$}}1 {<>}{{$\neq$}}1\end{verbatim}
+% \begin{TODO}
+% Of course, it's good to have keys for adding and removing single
+% \meta{replacement item}s. Maybe the key(s) should work in the same fashion
+% as the string and comment definitions, i.e.~one item per key=value.
+% This way it would be easier to provide better auto-detection in case of a
+% subsequence.
+% \end{TODO}
+%
+%
+% \subsection{\textsf{LGrind} definitions}\label{rLGrindDefinitions}
+%
+% Yes, it's a nasty idea to steal language definitions from other programs.
+% Nevertheless, it's possible for the \packagename{LGrind} definition
+% file---at least partially. Please note that this file must be found by
+% \TeX.
+% \begin{syntax}
+% \item[0.21,,{optional}] \rkeyname{lgrindef}|=|\meta{language}
+%
+%       scans the \texttt{lgrindef} language definition file for
+%       \meta{language} and activates it if present. Note that not all
+%       \packagename{LGrind} capabilities have a \packagename{listings}
+%       analogue.
+%
+%       Note that `Linda' language doesn't work properly since it defines
+%       compiler directives with preceding `|#|' as keywords.
+%
+% \item[0.21,lgrindef.,{data,optional}] \rcmdname\lstlgrindeffile
+%
+%       contains the (path and) name of the definition file.
+% \end{syntax}
+%
+%
+% \subsection{\dag\ Automatic formatting}
+%
+% \lstloadaspects{formats}^^A
+% The automatic source code formatting is far away from being good. First of
+% all, there are no general rules on how source code should be formatted. So
+% `format definitions' must be flexible. This flexibility requires a complex
+% interface, a powerful `format definition' parser, and lots of code lines
+% behind the scenes. Currently, format definitions aren't flexible enough
+% (possibly not the definitions but the results). A single `format item' has
+% the form 
+% \begin{itemize}\item[]
+%     \meta{input chars}|=|\oarg{exceptional chars}\meta{pre}\oarg{\texttt{\string\string}}\meta{post}
+% \end{itemize}
+% Whenever \meta{input chars} aren't followed by one of the \meta{exceptional
+% chars}, formatting is done according to the rest of the value. If |\string|
+% isn't specified, the input characters aren't printed (except it's an
+% identifier or keyword). Otherwise \meta{pre} is `executed' before printing
+% the original character string and \meta{post} afterwards. These two are
+% `subsets' of
+% \begin{itemize}
+% \item |\newline| ---ensuring a new line;
+% \item |\space| ---ensuring a whitespace;
+% \item |\indent| ---increasing indention;
+% \item |\noindent| ---descreasing indention.
+% \end{itemize}
+% Now we can give an example.\lstaspectindex{\lstdefineformat}{}\lstaspectindex{format}{}
+% \begin{lstxsample}
+%    \lstdefineformat{C}{%
+%        \{=\newline\string\newline\indent,%
+%        \}=\newline\noindent\string\newline,%
+%        ;=[\ ]\string\space}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{language={}}}{}
+%    \begin{lstlisting}[format=C]
+%    for (int i=0;i<10; i++){/* wait */};
+%    \end{lstlisting}
+% \end{lstsample}
+% Not good. But there is a (too?) simple work-around:
+% \begin{lstxsample}
+%    \lstdefineformat{C}{%
+%        \{=\newline\string\newline\indent,%
+%        \}=[;]\newline\noindent\string\newline,%
+%        \};=\newline\noindent\string\newline,%
+%        ;=[\ ]\string\space}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{language={}}}{}
+%    \begin{lstlisting}[format=C]
+%    for (int i=0;i<10; i++){/* wait */};
+%    \end{lstlisting}
+% \end{lstsample}
+% Sometimes the problem is just to find a suitable format definition.
+% Further formatting is complicated.
+% Here are only three examples with increasing level of difficulty.
+% \begin{enumerate}
+% \item Insert horizontal space to separate function/procedure name and
+%       following parenthesis or to separate arguments of a function,
+%       e.g.~add the space after a comma (if inside function call).
+% \item Smart breaking of long lines. Consider long `and/or' expressions.
+%       Formatting should follow the logical structure!
+% \item Context sensitive formatting rules. It can be annoying if empty
+%       or small blocks take three or more lines in the output---think of
+%       scrolling down all the time. So it would be nice if the block
+%       formatting was context sensitive.
+% \end{enumerate}
+% Note that this is a very first and clumsy attempt to provide automatic
+% formatting---clumsy since the problem isn't trivial. Any ideas are welcome.
+% Implementations also. Eventually you should know that you must request format
+% definitions at package loading, e.g.~via |\usepackage[formats]{listings}|.
+%
+%
+% \section{Forthcoming ?}
+%
+% This section is rather rudimentary. It just lists some things I don't want
+% to forget.
+%
+% First of all, I'd like to support even more languages, for example Maple,
+% PostScript, Reduce, and so on. Fortunately my lifetime is limited, so other
+% people may do that work. Please (e-)mail me your language definitions.
+%
+% Then, there are several ideas for the future. Some have already been stated
+% as `to do's; some came from other people and are stated below; some more are
+% far from being implemented,
+%   e.g.~\keyname{linerange}|=|\oarg{inter}\marg{line range list}
+% which prints all lines in the range and executes \meta{inter} when omitting
+% some code lines. The main problem here are frames and background colours;
+% what should happen to them? In fact, the problem is how this can be coded.
+% Another idea is to change the background colour (or the basic style) for
+% particular code blocks. This, too, is not easy.
+%
+%^^A Auto-detect whether surplus space (from spaces and tabs) isn't needed to fix
+%^^A alignment of wide character combinations like |==| or |<>|.
+%^^A
+%^^A Make package compatible to calc package.
+%^^A
+%^^A Rewrite \lst@LAS, \lst@DefDriver, \lst@Require to distinguish loading
+%^^A of languages (which don't need base languages at once) and aspects
+%^^A (which need required aspects to be loaded).
+%
+% \lsthelper{Vincent~Poirriez}{1999/11/18}{code examples inside caml comments}:
+% Inside caml comments, |[| and |]| should print the code in
+% between in basicstyle (or another newly introduced style). Nesting of these
+% `code example delimiters' is allowed, e.g.~|(* [[x;y]] *)|.
+%
+% \lsthelper{Claus~Atzenbeck}{1999/12/03}{`extendedchars=false' doesn't issue
+% warning when extended characters are used}: issue warning in final mode if
+% \ikeyname{extendedchars}|=false| but extended chars are used.
+%
+% \lsthelper{Andreas~Matthias}{2000/01/04}{define header/footer to print
+% the listing name}: Make the header/footer print the listing name.
+%
+%
+% \part{Tips and tricks}
+%
+% Note: This part of the documentation is under construction.
+% Section \ref{uHowTos} must be sorted by topic and ordered in some way.
+% Moreover a new section `Examples' is planned, but not written.
+%
+%
+% \section{Troubleshooting}\label{uTroubleshooting}
+%
+% If you're faced with a \packagename{listings}' package problem, there are
+% some steps you should undergo before you make a bug report. First you should
+% consult the reference guide whether the problem is already known. If not,
+% create a \emph{minimal} file which reproduced the problem. Follow these
+% instructions:
+% \begin{enumerate}
+% \item Start from the minimal file in section \ref{uAMinimalFile}.
+% \item Add the \LaTeX\ code which causes the problem, but keep it short.
+%       In particular, keep the number of additional packages small.
+% \item Remove some code from the file (and the according packages) until the
+%       problem disappears. Then you've found a crucial piece.
+% \item Add this piece of code again and start over with step 3 until all code
+%       and all packages are substantial.
+% \item You now have a minimal file. Send a bug report to the address on the
+%       first page of this documentation and include the minimal file together
+%       with the created \texttt{.log}-file. If you use a very special package
+%       (i.e.~not on CTAN), also include the package if its software license
+%       allows it.
+% \end{enumerate}
+%
+%
+% \section{How tos}\label{uHowTos}
+%
+%
+% \subsubsection*{How to reference line numbers}
+% You want to put |\label{|\meta{whatever}|}| into a \LaTeX\ escape which is
+% inside a comment whose delimiters aren't printed? The compiler won't see the
+% \LaTeX\ code since inside a comment, and the \packagename{listings} package
+% won't print anything since the delimiters are dropped and |\label| doesn't
+% produce any printable output. Well, your wish is granted.
+%
+% In Pascal, for example, you could make the package recognize the `special'
+% comment delimiters |(*@| and |@*)| as begin-escape and end-escape sequences.
+% Then you can use this special comment for |\label|s and other things.
+% \begin{lstsample}{\lstset{numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    \lstset{escapeinside={(*@}{@*)}}
+%
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { comment }(*@\label{comment}@*)
+%    end;
+%    \end{lstlisting}
+%    Line \ref{comment} shows a comment.
+% \end{lstsample}
+% \begin{advise}
+% \item Can I use `|(*@|' and `|*)|' instead?
+%       \advisespace
+%       Yes.
+% \item Can I use `|(*|' and `|*)|' instead?
+%       \advisespace
+%       Sure. If you want this.
+% \item Can I use `|{@|' and `|@}|' instead?
+%       \advisespace
+%       No, never! The second delimiter is not allowed. The character `|@|' is
+%       defined to check whether the escape is over. But reading the lonely
+%       `end-argument' brace, \TeX\ encounters the error `\texttt{Argument of @
+%       has an extra \char125}'. Sorry.
+% \item Can I use `|{|' and `|}|' instead?
+%       \advisespace
+%       No. Again the second delimiter is not allowed. Here now \TeX\ would
+%       give you a `\texttt{Runaway argument}' error. Since `|}|' is defined to
+%       check whether the escape is over, it won't work as `end-argument' brace.
+% \item And how can I use a comment line?
+%       \advisespace
+%       For example, write `|escapeinside={//*}{\^^M}|'. Here |\^^M| represents
+%       the end of line character.
+% \end{advise}
+%
+%
+% \subsubsection*{How to gobble characters}
+% To make your \LaTeX\ code more readable, you might want to indent your
+% \texttt{lstlisting} listings. This indention must be removed for
+% pretty-printing. If you indent each code line by three characters, you can
+% remove them via |gobble=3|:
+% \begin{lstsample}{}{\lstset{showspaces}}
+%    \begin{lstlisting}[gobble=3]
+%    1  for i:=maxint to 0 do
+%     2 begin
+%      3    { do nothing }
+%    123end;
+%
+%       Write('Case insensitive ');
+%       WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that empty lines as well as the beginning and the end of the environment
+% need not to respect the indention. But never indent the end by more than
+% `\ikeyname{gobble}' characters. Moreover note that tabulators expand to
+% |tabsize| spaces before we gobble.
+% \begin{advise}
+% \item Could I use `\ikeyname{gobble}' together with `|\lstinputlisting|'?
+%       \advisespace
+%       Yes, but it has no effect.
+%
+% \item Note that `\ikeyname{gobble}' can also be set via `|\lstset|'.
+% \end{advise}
+%
+%
+% \subsubsection*{How to include graphics}
+% \lsthelper{Herbert~Weinhandl}{1999/09/06}{listings + eps} found a very easy
+% way to include graphics in listings. Thanks for contributing this idea---an
+% idea I never have had.
+%
+% Some programming languages allow the dollar sign to be part of an identifier.
+% But except for intermediate function names or library functions, this
+% character is most often unused. The \packagename{listings} package defines
+% the \ikeyname{mathescape} key, which lets `|$|' escape to \TeX's math mode.
+% This makes the dollar character an excellent candidate for our purpose here:
+% use a package which can include a graphic, set \ikeyname{mathescape} true,
+% and include the graphic between two dollar signs, which are inside a comment.
+%
+% The following example is originally from a header file I got from Herbert.
+% For the presentation here I use the \texttt{lstlisting} environment and an
+% excerpt from the header file. The |\includegraphics| command is from
+% David Carlisle's \packagename{graphics} bundle.
+% \begin{verbatim}
+%   \begin{lstlisting}[mathescape=true]
+%   /*
+%    $ \includegraphics[height=1cm]{defs-p1.eps} $
+%    */
+%   typedef struct {
+%     Atom_T          *V_ptr;   /* pointer to Vacancy in grid    */
+%     Atom_T          *x_ptr;   /* pointer to (A|B) Atom in grid */
+%   } ABV_Pair_T;
+%   \end{lstlisting}\end{verbatim}
+% The result looks pretty good. Unfortunately you can't see it.
+%
+%
+% \subsubsection*{How to get closed frames on each page}
+% The package supports closed frames only for listings which don't cross pages.
+% If a listing is split on two pages, there is neither a bottom rule at the
+% bottom of a page, nor a top rule on the following page. If you insist on
+% these rules, you might want to use \texttt{framed.sty} by Donald Arseneau.
+% Then you could write
+% \begin{verbatim}
+%    \begin{framed}
+%    \begin{lstlisting}
+%      or \lstinputlisting{...}
+%    \end{lstlisting}
+%    \end{framed}\end{verbatim}
+% The package also provides a \texttt{shaded} environment. If you use it, you
+% shouldn't forget to define \texttt{shadecolor} with the \packagename{color}
+% package.
+%
+%
+% \subsubsection*{How to print national characters with $\Lambda$ and \packagename{listings}}\label{uNationalCharacters}
+%
+% Apart from typing in national characters directly, you can use the `escape'
+% feature described in section \ref{rEscapingToLaTeX}. 
+% The keys \ikeyname{escapechar}, \ikeyname{escapeinside}, and \ikeyname{texcl}
+% allow partial usage of \LaTeX\ code.
+%
+% Now, if you use $\Lambda$ (Lambda, the \LaTeX\ pendant to Omega) and want,
+% for example, Arabic comment lines, you need not to write |\begin{arab}|
+% \ldots\ |\end{arab}| each escaped comment line. This can be automated:
+% \begin{verbatim}
+%    \lstset{escapebegin=\begin{arab},escapeend=\end{arab}}
+%
+%    \begin{lstlisting}[texcl]
+%    // Replace text by Arabic comment.
+%    for (int i=0; i<1; i++) { };
+%    \end{lstlisting}\end{verbatim}
+% If your programming language doesn't have comment lines, you'll have to use
+% \ikeyname{escapechar} or \ikeyname{escapeinside}:
+% \begin{verbatim}
+%    \lstset{escapebegin=\begin{greek},escapeend=\end{greek}}
+%
+%    \begin{lstlisting}[escapeinside=`']
+%    /* `Replace text by Greek comment.' */
+%    for (int i=0; i<1; i++) { };
+%    \end{lstlisting}\end{verbatim}
+% Note that the delimiters |`| and |'| are essential here. The example doesn't
+% work without them. There is a more clever way if the comment delimiters of
+% the programming language are single characters like the braces in Pascal:
+% \begin{verbatim}
+%    \lstset{escapebegin=\textbraceleft\begin{arab},
+%            escapeend=\end{arab}\textbraceright}
+%
+%    \begin{lstlisting}[escapeinside=\{\}]
+%    for i:=maxint to 0 do
+%    begin
+%        { Replace text by Arabic comment. }
+%    end;
+%    \end{lstlisting}\end{verbatim}
+% Please note that the `interface' to $\Lambda$ is completely untested.
+% Reports are welcome!
+%
+%
+% \subsubsection*{How to get bold typewriter type keywords}
+% Many people asked for bold typewriter fonts since they aren't included in
+% the \LaTeX\ standard distribution. Here now one answer on how to use them
+% in spite of that.
+% \begin{advise}
+% \item Please note that I personally don't regard the following as a good
+%       solution. Such a bold typewriter type is too heavy. It would be better
+%       to use a light version of \texttt{cmtt} as basic font and \texttt{cmtt}
+%       or a \emph{slightly} heavier type for keywords.
+%
+% \item Why don't you tell us how to use the better solution?
+%       \advisespace
+%       A light version of \texttt{cmtt} doesn't exist. If it's once available,
+%       you can do a similar job as described below.
+% \end{advise}
+% First of all, you'll need Metafont source files for bold typewriter, e.g.~
+% \texttt{cmbtt8.mf}, \texttt{cmbtt9.mf} and \texttt{cmbtt10.mf} from
+% \href{ftp://ftp.dante.de/tex-archive/fonts/cm/mf-extra/bold}
+%      {CTAN/fonts/cm/mf-extra/bold}.
+% Secondly you have to create \texttt{.tfm}-files, i.e.~run the Metafont
+% program on these sources. This is possibly done automatically when you use
+% the fonts in a document. Finally you must tell \LaTeX\ that you've installed
+% bold typewriter fonts. Just use
+% \begin{verbatim}
+%    \DeclareFontShape{OT1}{cmtt}{bx}{n}
+%         {<5><6><7><8>cmbtt8%
+%          <9>cmbtt9%
+%          <10><10.95>cmbtt10%
+%          <12><14.4><17.28><20.74><24.88>cmbtt10%
+%          }{}\end{verbatim}
+% in the preamble of your document. If you use these fonts often, you might
+% want to make a local copy of \texttt{ot1cmtt.fd} and replace the declaration
+% there. But note that you're not allowed to distributed the modified file
+% under its original name!
+%
+%
+% \subsubsection*{How to get the developer's guide}
+% In the \emph{source directory} of the listings package, i.e.~where
+% \texttt{listings.dtx} is, create the file \texttt{ltxdoc.cfg} with the
+% following contents.
+% \begin{verbatim}
+%    \AtBeginDocument{\AlsoImplementation}\end{verbatim}
+% Then run \texttt{listings.dtx} through \LaTeX\ twice, run Makeindex,
+% and one last time \LaTeX\ on \texttt{listings.dtx}. This creates the whole
+% documentation including User's guide, Reference guide, Developer's guide,
+% and Implementation.
+%
+%
+% \makeatletter
+% \def\index@prologue{\section*{Index}\markboth{Index}{Index}}
+% \makeatother
+%^^A \StopEventually{\lstcheckreference\setcounter{IndexColumns}{2}\PrintIndex}
+% \StopEventually{\setcounter{IndexColumns}{2}\PrintIndex}
+%
+%
+% \part{Developer's guide}
+%
+% First I must apologize for this developer's guide since some parts are not
+% explained as good as possible. But note that you are in a pretty good shape:
+% this developer's guide exists! ^^A :-)
+% You might want to peak into section \ref{dPackageExtensions} before reading
+% section \ref{dBasicConcepts}.
+%
+%
+% \section{Basic concepts}\label{dBasicConcepts}
+%
+% The functionality of the \packagename{listings} package appears to be
+% divided into two parts: on the one hand commands which actually typeset
+% listings and on the other via |\lstset| adjustable parameters. Both could
+% be implemented in terms of \lst-aspects, which are simply collections of
+% public keys and commands and internal hooks and definitions. The package
+% defines a couple of aspects, in particular the kernel, the main engine.
+% Other aspects drive this engine, and language and style definitions tell
+% the aspects how to drive. The relations between car, driver and assistant
+% driver are exactly reproduced---and I'll be your driving instructor.
+%
+%
+% \subsection{Package loading}\label{dPackageLoading}
+%
+% Each option in |\usepackage[|\meta{options}|]{listings}| loads an aspect or
+% \emph{prevents} the package from loading it if the aspect name is
+% \emph{preceded by an exclamation mark}. This mechanism was designed to clear
+% up the dependencies of different package parts and to debug the package. For
+% this reason there is another option:
+% \begin{syntax}
+% \item[0.21,,option] \texttt{noaspects}\leavevmode
+%
+%       deletes the list of aspects to load. Note that, for example, the
+%       option lists |0.21,!labels,noaspects| and |noaspects| are essentially
+%       the same: the kernel is loaded and no other aspect.
+% \end{syntax}
+% This is especially useful for aspect-testing since we can load exactly the
+% required parts. Note, however, that an aspect is loaded later if a predefined
+% programming language requests it. One can load aspects also by hand:
+% \begin{syntax}
+% \item[0.20] |\lstloadaspects|\marg{comma separated list of aspect names}
+%
+%       loads the specified aspects if they are not already loaded.
+% \end{syntax}
+% Here now is a list of all aspects and related keys and commands---in the hope
+% that this list is complete.
+% \begin{description}
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth\relax
+% \item[\aspectname{strings}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{strings}
+%
+% \item[\aspectname{comments}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{comments}
+%
+% \item[\aspectname{pod}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{pod}
+%
+% \item[\aspectname{escape}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{escape}
+%
+% \item[\aspectname{writefile}] requires 1 |\toks|, 1 |\write|
+%
+%       |\lst@BeginWriteFile|, |\lst@BeginAlsoWriteFile|, |\lst@EndWriteFile|
+%
+% \item[\aspectname{style}]\leavevmode
+%
+%       empty style, \lstprintaspectkeysandcmds{style}
+%
+% \item[\aspectname{language}]\leavevmode
+%
+%       empty language, \lstprintaspectkeysandcmds{language}
+%
+% \item[\aspectname{keywords}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{keywords}
+%
+% \item[\aspectname{emph}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{emph}
+%
+% \item[\aspectname{html}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{html}
+%
+% \item[\aspectname{tex}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{tex}
+%
+% \item[\aspectname{directives}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{directives}
+%
+% \item[\aspectname{index}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{index}
+%
+% \item[\aspectname{procnames}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{procnames}
+%
+% \item[\aspectname{keywordcomments}]
+%       requires \aspectname{keywords}, \aspectname{comments}
+%
+%       \lstprintaspectkeysandcmds{keywordcomments}
+%
+% \item[\aspectname{labels}] requires 2 |\count|
+%
+%       \lstprintaspectkeysandcmds{labels}
+%
+% \item[\aspectname{lineshape}] requires 2 |\dimen|
+%
+%       \lstprintaspectkeysandcmds{lineshape}
+%
+% \item[\aspectname{frames}] requires \aspectname{lineshape}
+%
+%       \lstprintaspectkeysandcmds{frames}
+%
+% \item[\aspectname{make}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{make}
+%
+% \item[\aspectname{doc}] requires \aspectname{writefile} and 1 |\box|
+%
+%       \lstprintaspectkeysandcmds{doc}
+%
+% \item[\aspectname{0.21}] defines old keys in terms of the new ones.
+% \item[\aspectname{fancyvrb}] requires 1 |\box|
+%
+%       \lstprintaspectkeysandcmds{fancyvrb}
+%
+% \item[\aspectname{lgrind}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{lgrind}
+%
+% \item[\aspectname{hyper}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{hyper}
+% \end{description}
+% The kernel allocates 6 |\count|, 4 |\dimen| and 1 |\toks|.
+% Moreover it defines the following keys, commands, and environments:
+% \begin{itemize}\item[]
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth\relax
+%       \lstprintaspectkeysandcmds{kernel}, \keyname{fancyvrb}
+% \end{itemize}
+%
+%
+% \subsection{How to define \lst-aspects}\label{dHowToDefineLstAspects}
+%
+% There are at least three ways to add new functionality: (a) you write an
+% aspect of general interest, send it to me, and I'll just paste it into the
+% implementation; (b) you write a `local' aspect not of general interest; or
+% (c) you have an idea for an aspect and make me writing it. (a) and (b) are
+% good choices.^^A :-)
+%
+% An aspect definition starts with |\lst@BeginAspect| plus arguments and ends
+% with the next |\lst@EndAspect|. In particular, aspect definitions can't be
+% nested.
+% \begin{syntax}
+% \item[0.20] |\lst@BeginAspect|[\oarg{list of required aspects}]\marg{aspect name}
+% \item[0.20] |\lst@EndAspect|
+% \end{syntax}
+% The optional list is a comma separated list of required aspect names.
+% The complete aspect is not defined in each of the following cases:
+% \begin{enumerate}
+% \item \meta{aspect name} is empty.
+% \item The aspect is already defined.
+% \item A required aspect is neither defined nor loadable via
+%       |\lstloadaspects|.
+% \end{enumerate}
+% Consequently you can't define a part of an aspect and later on another part.
+% But it is possible to define aspect $A_1$ and later aspect $A_2$ which
+% requires $A_1$.
+% \begin{advise}
+% \item Put local add-ons into `\texttt{lstmisc0.sty}'---this file is searched
+%       first by default. If you want to make add-ons for one particular
+%       document just replace the surrounding `|\lst@BeginAspect|' and
+%       `|\lst@EndAspect|' by `|\makeatletter|' and `|\makeatother|' and use
+%       the definitions in the preamble of your document. However, you have to
+%       load required aspects on your own.
+% \end{advise}
+% You can put any \TeX\ material in between the two commands, but note that
+% definitions must be |\global| if you need them later---\LaTeX's |\newcommand|
+% makes local definitions and can't be preceded by |\global|. So use the
+% following commands, |\gdef|, and commands described in later sections.
+% \begin{syntax}
+% \item[0.20] |\lst@UserCommand|\meta{macro}\meta{parameter text}\marg{replacement text}
+%
+%       The macro is (mainly) equivalent to |\gdef|. The purpose is to
+%       distinguish user commands and internal global definitions.
+%
+% \item[0.19] |\lst@Key|\marg{key name}\marg{init value}[\oarg{default value}]\marg{definition}
+% \item[0.19] |\lst@Key|\marg{key name}|\relax|[\oarg{default value}]\marg{definition}
+%
+%       defines a key using the \packagename{keyval} package from David
+%       Carlisle. \meta{definition} is the replacement text of a macro with
+%       one parameter. The argument is either the value from `key=value' or
+%       \meta{default value} if no `=value' is given. The helper macros
+%       |\lstKV@...| below might simplify \meta{definition}.
+%
+%       The key is not initialized if the second argument is |\relax|.
+%       Otherwise \meta{init value} is the initial value given to the key.
+%       Note that we locally switch to |\globalsdefs=1| to ensure that
+%       initialization is not effected by grouping.
+%
+% \item[0.19] |\lst@AddToHook|\marg{name of hook}\marg{\TeX\ material}
+%
+%       adds \TeX\ material at predefined points. Section \ref{dHooks} lists
+%       all hooks and where they are defined respectively executed.
+%       |\lst@AddToHook{A}{\csa}| before |\lst@AddToHook{A}{\csb}|
+%       \emph{does not} guarantee that |\csa| is executed before |\csb|.
+%
+% \item[0.20] |\lst@AddToHookExe|\marg{name of hook}\marg{\TeX\ material}
+%
+%       also executes \meta{\TeX\ material} for initialization. You might use
+%       local variables---local in the sense of \TeX\ and/or usual programming
+%       languages---but when the code is executed for initialization all
+%       assignments are global: we set |\globaldefs| locally to one.
+%
+% \item[0.20] |\lst@UseHook|\marg{name of hook}
+%
+%       executes the hook.
+% \end{syntax}
+% \begin{advise}
+% \item Let's look at two examples. The first extends the package by adding
+%       some hook-material. If you want status messages, you might write
+% \begin{verbatim}
+%    \lst@AddToHook{Init}{\message{\MessageBreak Processing listing ...}}
+%    \lst@AddToHook{DeInit}{\message{complete.\MessageBreak}}\end{verbatim}
+%       The second example introduces two keys to let the user control the
+%       messages. The macro |\lst@AddTo| is described in section
+%       \ref{dGeneralPurposeMacros}.
+% \begin{verbatim}
+%   \lst@BeginAspect{message}
+%   \lst@Key{message}{Annoying message.}{\gdef\lst@message{#1}}
+%   \lst@Key{moremessage}\relax{\lst@AddTo\lst@message{\MessageBreak#1}}
+%   \lst@AddToHook{Init}{\typeout{\MessageBreak\lst@message}}
+%   \lst@EndAspect\end{verbatim}
+%       However, there are certainly aspects which are more useful.
+% \end{advise}
+% The following macros can be used in the \meta{definition} argument of the
+% |\lst@Key| command to evaluate the argument. The additional prefix |KV|
+% refers to the \packagename{keyval} package.
+% \begin{syntax}
+% \item[0.19] |\lstKV@SetIf|\marg{value}\meta{if macro}
+%
+%       \meta{if macro} becomes |\iftrue| if the first character of
+%       \meta{value} equals |t| or |T|. Otherwise it becomes |\iffalse|.
+%       Usually you will use |#1| as \meta{value}.
+%
+% \item[1.0] \cs{lstKV@SwitchCases}\marg{value}\\
+%   |{|\meta{string 1}|&|\meta{execute 1}|\\|\\
+%   | |\meta{string 2}|&|\meta{execute 2}|\\|\\
+%   \hbox to 3em{\hfill\vdots}\\
+%   | |\meta{string $n$}|&|\meta{execute $n$}|}|\marg{else}
+%
+%       Either execute \meta{else} or the \meta{value} matching part.
+%
+% \item[0.20] |\lstKV@TwoArg|\marg{value}\marg{subdefinition}
+% \item[0.20] |\lstKV@ThreeArg|\marg{value}\marg{subdefinition}
+% \item[0.20] |\lstKV@FourArg|\marg{value}\marg{subdefinition}
+%
+%       \meta{subdefinition} is the replacement text of a macro with two,
+%       three, and four parameters. We call this macro with the arguments given
+%       by \meta{value}. Empty arguments are added if necessary.
+%
+% \item[0.19] |\lstKV@OptArg|\oarg{default arg.}\marg{value}\marg{subdefinition}
+%
+%       |[|\meta{default arg.}|]| is \emph{not} optional. \meta{subdefinition}
+%       is the replacement text of a macro with parameter text |[##1]##2|.
+%       Note that the macro parameter character |#| is doubled since used
+%       within another macro. \meta{subdefinition} accesses these arguments
+%       via |##1| and |##2|.
+%
+%       \meta{value} is usually the argument |#1| passed by the
+%       \packagename{keyval} package. If \meta{value} has no optional argument,
+%       \meta{default arg.} is inserted to provide the arguments to
+%       \meta{subdefinition}.
+%
+% \item[0.21] |\lstKV@XOptArg|\oarg{default arg.}\marg{value}\meta{submacro}
+%
+%       Same as |\lstKV@OptArg| but the third argument \meta{submacro} is
+%       already a definition and not replacement text.
+%
+% \item[0.20] |\lstKV@CSTwoArg|\marg{value}\marg{subdefinition}
+%
+%       \meta{value} is a \texttt comma \texttt separated list of one or two
+%       arguments. These are given to the subdefinition which is the
+%       replacement text of a macro with two parameters. An empty second
+%       argument is added if necessary.
+% \end{syntax}
+% \begin{advise}
+% \item One more example. The key `\keyname{sensitive}' belongs to the aspect
+%       \aspectname{keywords}. Therefore it is defined in between
+%       `|\lst@BeginAspect{keywords}|' and `|\lst@EndAspect|', which is not shown
+%       here.
+% \begin{verbatim}
+%   \lst@Key{sensitive}\relax[t]{\lstKV@SetIf{#1}\lst@ifsensitive}
+%   \lst@AddToHookExe{SetLanguage}{\let\lst@ifsensitive\iftrue}\end{verbatim}
+%       The last line is equivalent to
+% \begin{verbatim}
+%   \lst@AddToHook{SetLanguage}{\let\lst@ifsensitive\iftrue}
+%   \global\let\lst@ifsensitive\iftrue\end{verbatim}
+%       We initialize the variable globally since the user might request an
+%       aspect in a group. Afterwards the variable is used locally---there is
+%       no |\global| in \meta{\TeX\ material}. Note that we could define and
+%       init the key as follows:
+% \begin{verbatim}
+%   \lst@Key{sensitive}t[t]{\lstKV@SetIf{#1}\lst@ifsensitive}
+%   \lst@AddToHook{SetLanguage}{\let\lst@ifsensitive\iftrue}\end{verbatim}
+%\end{advise}
+%
+%
+% \subsection{Internal modes}\label{dInternalModes}
+%
+% You probably know \TeX's conditional commands |\ifhmode|, |\ifvmode|,
+% |\ifmmode|, and |\ifinner|. They tell you whether \TeX\ is in (restricted)
+% horizontal or (internal) vertical or in (nondisplay) mathematical mode. For
+% example, true |\ifhmode| and true |\ifinner| indicate restricted horizontal
+% mode, which means that you are in a |\hbox|. The typical user doesn't care
+% about such modes; \TeX/\LaTeX\ manages all this. But since you're reading the
+% developer's guide, we discuss the analogue for the \packagename{listings}
+% package now. It uses modes to distinguish comments from strings, `comment
+% lines' from `single comments', and so on.
+%
+% The package is in `no mode' before reading the source code. In the phase of
+% initialization it goes to `processing mode'. Afterwards the mode depends on
+% the actual source code. For example, consider the line
+% \begin{verbatim}
+%    "string" // comment\end{verbatim}
+% and assume \texttt{language=C++}. Reading the string delimiter, the package
+% enters `string mode' and processes the string. The matching closing delimiter
+% leaves the mode, i.e.\ switches back to the general `processing mode'. Coming
+% to the two slashes, the package detects a comment line; it therefore enters
+% `comment line mode' and outputs the slashes. Usually this mode lasts to the
+% end of line.
+%
+% But with \texttt{textcl=true} the \aspectname{escape} aspect immediately
+% leaves `comment line mode', interrupts the current mode sequence, and enters
+% `\TeX\ comment line mode'. At the end of line we reenter the previous mode
+% sequence `no mode' $\to$ 'processing mode'. This escape to \LaTeX\ works
+% since `no mode' implies that \TeX's characters and catcodes are present,
+% whereas `processing mode' means that \packagename{listings}' characters and
+% catcodes are active.
+%
+% \begin{table}[htbp]
+% \caption{Internal modes}\label{dDefinedInternalModes}
+% \def\lsttabspace{\hspace*{1em}\hfill}
+% \begin{tabular}{@{}lp{0.56\linewidth}@{}}
+% aspect\lsttabspace\meta{mode name} & Usage/We are processing \ldots\\
+% \noalign{\smallskip}
+% kernel\lsttabspace |\lst@nomode| &
+%       If this mode is active, \TeX's `character table' is present; the other
+%       implication is not true. Any other mode \emph{may} imply that catcodes
+%       and\nobreak/\allowbreak or definitions of characters are changed.
+% \\
+%       \lsttabspace |\lst@Pmode| &
+%       is a general processing mode. If active we are processing a listing,
+%       but haven't entered a more special mode.
+% \\
+%       \lsttabspace |\lst@GPmode| &
+%       general purpose mode for language definitions.
+% \\
+% \aspectname{pod}\lsttabspace |\lst@PODmode| &
+%       \ldots~a POD---Perl specific.
+% \\
+% \aspectname{escape}\lsttabspace |\lst@TeXLmode| &
+%       \ldots~a comment line, but \TeX's character table is present---except
+%       the EOL character, which is needed to terminate this mode.
+% \\
+%       \lsttabspace |\lst@TeXmode| &
+%       indicates that \TeX's character table is present (except one user
+%       specified character, which is needed to terminate this mode).
+% \\
+% \aspectname{directives}\lsttabspace |\lst@CDmode| &
+%       indicates that the current line began with a compiler directive.
+% \\
+% \aspectname{keywordcomments}\lsttabspace |\lst@KCmode| &
+%       \ldots~a keyword comment.
+% \\
+%       \lsttabspace |\lst@KCSmode| &
+%       \ldots~a keyword comment which can be terminated by a semicolon only.
+% \\
+% \aspectname{html}\lsttabspace |\lst@insidemode| &
+%       Active if we are between \texttt{<} and \texttt{>}.
+% \\
+% \aspectname{make}\lsttabspace |\lst@makemode| &
+%       Used to indicate a keyword.
+% \end{tabular}
+% \end{table}
+% Table \ref{dDefinedInternalModes} lists all static modes and which aspects
+% they belong to. Most features use dynamically created mode numbers, for
+% example all strings and comments. Each aspect may define its own mode(s)
+% simply by allocating it/\allowbreak them inside the aspect definition.
+% \begin{syntax}
+% \item[0.19] |\lst@NewMode|\meta{mode \textup(control sequence\textup)}
+%
+%       defines a new static mode, which is a nonnegative integer assigned to
+%       \meta{mode}. \meta{mode} should have the prefix \texttt{lst@} and
+%       suffix \texttt{mode}.
+%
+% \item[0.21] |\lst@UseDynamicMode|\marg{token\textup(s\textup)}
+%
+%       inserts a dynamic mode number as argument to the token(s).
+%
+%       This macro cannot be used to get a mode number when an aspect is
+%       loaded or defined. It can only be used every listing in the process
+%       of initialization, e.g.~to define comments when the character table
+%       is selected.
+%
+% \item[0.19,,changed] |\lst@EnterMode|\meta{mode}\marg{start tokens}
+%
+%       opens a group level, enters the mode, uses \meta{style} as the current
+%       style, and executes \meta{start tokens}. Note that the style and start
+%       tokens are read as one single argument and that there must be braces
+%       around the style.
+%
+%       Use |\lst@modetrue| in \meta{start tokens} to prohibit future mode
+%       changes---except leaving the mode, of course. You must test yourself
+%       whether you're allowed to enter, see below.
+%
+% \item[0.19] |\lst@LeaveMode|
+%
+%       returns to the previous mode by closing a group level if and only if
+%       the current mode isn't |\lst@nomode| already. You must test yourself
+%       whether you're allowed to leave a mode, see below.
+%
+%\iffalse
+% \item[0.19] |\lst@LeaveAllModes|
+%
+%       returns to |\lst@nomode|.
+%       This is some kind of emergency macro, so don't use it!
+%\fi
+%
+% \item[0.19] |\lst@InterruptModes|
+% \item[0.19] |\lst@ReenterModes|
+%
+%       The first command returns to |\lst@nomode|, but saves the current mode
+%       sequence on a special stack. Afterwards the second macro returns to the
+%       previous mode. In between these commands you may enter any mode you
+%       want. In particular you can interrupt modes, enter some modes, and say
+%       `interrupt modes' again. Then two re-enters will take you back in front
+%       of the first `interrupt modes'.
+%
+%       Remember that |\lst@nomode| implies that \TeX's character table is
+%       active.
+% \end{syntax}
+% Some variables show the internal state of processing. You are allowed to read
+% them, but \emph{direct write access is prohibited}. Note: |\lst@ifmode| is
+% \emph{not} obsolete since there is no relation between the boolean and the
+% current mode. It will happen that we enter a mode without setting
+% |\lst@ifmode| true, and we'll set it true without assigning any mode!
+% \begin{syntax}
+% \item[0.18,,counter] |\lst@mode|
+%
+%       keeps the current mode number. Use |\ifnum\lst@mode=|\meta{mode name}
+%       to test against a mode. Don't modify the counter directly!
+%
+% \item[0.18,,boolean] |\lst@ifmode|
+%
+%       No mode change is allowed if this boolean is true---except leaving the
+%       current mode. Use |\lst@modetrue| to modify this variable, but do it
+%       only in \meta{start tokens}.
+%
+% \item[1.0,,boolean] |\lst@ifLmode|
+%
+%       Indicates whether the current mode ends at end of line.
+% \end{syntax}
+%
+%
+% \subsection{Hooks}\label{dHooks}
+%
+% Several problems arise if you want to define an aspect.
+% You should and/or must
+%   (a) find additional functionality (of general interest) and implement it,
+%   (b) create the user interface, and
+%   (c) interface with the \packagename{listings} package, i.e.~find correct
+%       hooks and insert appropriate \TeX\ material.
+% (a) is out of the scope of this developer's guide. The commands |\lstKV@...|
+% in section \ref{dHowToDefineLstAspects} might help you with (b). Here now we
+% describe all hooks of the \packagename{listings} package.
+%
+% All hooks are executed inside an overall group. This group starts somewhere
+% near the beginning and ends somewhere at the end of each listing. Don't make
+% any other assumptions on grouping. So define variables globally if it's
+% necessary---and be alert of side effects if you don't use your own groups.
+% \begin{syntax}
+% \item \hookname{AfterBeginComment}
+%
+%       is executed after the package has entered comment mode.
+%       The starting delimiter is usually typeset when the hook is called.
+%
+% \item \hookname{BoxUnsafe}
+%
+%       Contains all material to deactivate all commands and registers which
+%       are possibly unsafe inside |\hbox|. It is used whenever the package
+%       makes a box around a listing and for \packagename{fancyvrb} support.
+%
+% \item \hookname{DeInit}
+%
+%       Called at the very end of a listing but before closing the box from
+%       \hookname{BoxUnsafe} or ending a float.
+%
+% \item \hookname{DetectKeywords}
+%
+%       This \hookname{Output} subhook is executed if and only if mode changes
+%       are allowed, i.e.~if and only if the package doesn't process a comment,
+%       string, and so on---see section \ref{dInternalModes}.
+%
+% \item \hookname{DisplayStyle}
+%
+%       deactivates/activates features for displaystyle listings.
+%
+% \item \hookname{EmptyStyle}
+%
+%       Executed to select the `empty' style---except the user has redefined
+%       the style.
+%
+% \item \hookname{EndGroup}
+%
+%       Executed whenever the package closes a group, e.g.~at end of comment or
+%       string.
+%
+% \item \hookname{EOL}
+%
+%       Called at each end of \emph{input} line, right before
+%       \hookname{InitVarsEOL}.
+%
+% \item \hookname{EveryLine}
+%
+%       Executed at the beginning of each \emph{output} line, i.e.~more than
+%       once for broken lines. This hook must not change the horizontal or
+%       vertical position.
+%
+% \item \hookname{EveryPar}
+%
+%       Executed once for each input line when the output starts. This hook
+%       must not change the horizontal or vertical position.
+%
+%^^A \item \hookname{ExcludeDelims}
+%^^A
+%^^A       Executed by the \keyname{excludedelims} key before the excluded
+%^^A       delimiters are determined.
+%^^A
+% \item \hookname{ExitVars}
+%
+%       Executed right before \hookname{DeInit}.
+%
+% \item \hookname{FontAdjust}
+%
+%       adjusts font specific internal values (currently |\lst@width| only).
+%
+% \item \hookname{Init}
+%
+%       Executed once each listing to initialize things before the character
+%       table is changed. It is called after \hookname{PreInit} and before
+%       \hookname{InitVars}.
+%
+% \item \hookname{InitVars}
+%
+%       Called to init variables each listing.
+%
+% \item \hookname{InitVarsBOL}
+%
+%       initializes variables at the beginning of each input line.
+%
+% \item \hookname{InitVarsEOL}
+%
+%       updates variables at the end of each input line.
+%
+% \item \hookname{ModeTrue}
+%
+%       executed by the package when mode changes become illegal.
+%       Here keyword detection is switched off for comments and strings.
+%
+% \item \hookname{OnEmptyLine}
+%
+%       executed \emph{before} the package outputs an empty line.
+%
+% \item \hookname{OnNewLine}
+%
+%       executed \emph{before} the package starts one or more new lines,
+%       i.e.~before saying |\par\noindent\hbox{}| (roughly speaking).
+%
+% \item \hookname{Output}
+%
+%       Called before an identifier is printed.
+%       If you want a special printing style, modify |\lst@thestyle|.
+%
+% \item \hookname{OutputBox}
+%
+%       used inside each output box. Currently it is only used to make the
+%       package work together with Lambda---hopefully.
+%
+% \item \hookname{OutputOther}
+%
+%       Called before other character strings are printed.
+%       If you want a special printing style, modify |\lst@thestyle|.
+%
+% \item \hookname{PostOutput}
+%
+%       Called after printing an identifier or any other output unit.
+%
+% \item \hookname{PostTrackKeywords}
+%
+%       is a very special \hookname{Init} subhook to insert keyword tests and
+%       define keywords on demand.
+%       This hook is called after \hookname{TrackKeywords}.
+%
+% \item \hookname{PreInit}
+%
+%       Called right before \hookname{Init} hook.
+%
+% \item \hookname{PreSet}
+%
+%       Each typesetting command/environment calls this hook to initialize
+%       internals before any user supplied key is set.
+%
+% \item \hookname{SelectCharTable}
+%
+%       is executed after the package has selected the standard character
+%       table. Aspects adjust the character table here and define string and
+%       comment delimiters, and such.
+%
+% \item \hookname{SetFormat}
+%
+%       Called before internal assignments for setting a format are made.
+%       This hook determines which parameters are reset every format selection.
+%
+% \item \hookname{SetStyle}
+%
+%       Called before internal assignments for setting a style are made.
+%       This hook determines which parameters are reset every style selection.
+%
+% \item \hookname{SetLanguage}
+%
+%       Called before internal assignments for setting a language are made.
+%       This hook determines which parameters are reset every language
+%       selection.
+%
+% \item \hookname{TextStyle}
+%
+%       deactivates/activates features for textstyle listings.
+%
+% \item \hookname{TrackKeywords}
+%
+%       is a very special \hookname{Init} subhook to insert keyword tests and
+%       define keywords on demand.
+%       This hook is called before \hookname{PostTrackKeywords}.
+% \end{syntax}
+%
+%
+% \subsection{Character tables}\label{dCharacterTables}
+%
+% Now you know how a car looks like, and you can get a driving license if you
+% take some practice. But you will have difficulties if you want to make heavy
+% alterations to the car. So let's take a closer look and come to the most
+% difficult part: the engine. We'll have a look at the big picture and fill in
+% the details step by step. For our purpose it's good to override \TeX's
+% character table. First we define a standard character table which contains
+% \begin{itemize}
+% \item letters: characters identifiers are out of,
+% \item digits: characters for identifiers or numerical constants,
+% \item spaces: characters treated as blank spaces,
+% \item tabulators: characters treated as tabulators,
+% \item form feeds: characters treated as form feed characters, and
+% \item others: all other characters.
+% \end{itemize}
+% This character table is altered depending on the current programming language.
+% We may define string and comment delimiters or other special characters.
+% Table \ref{rStdCharTable} on page \pageref{rStdCharTable} shows the standard
+% character table. It can be modified with the keys \keyname{alsoletter},
+% \keyname{alsodigit}, and \keyname{alsoother}.
+%
+% How do these `classes' work together? Let's say that the current character
+% string is `|tr|'. Then letter `|y|' simply appends the letter and we get
+% `|try|'. The next nonletter (and nondigit) causes the output of the
+% characters. Then we collect all coming nonletters until reaching a letter
+% again. This causes the output of the nonletters, and so on. Internally each
+% character becomes active in the sense of \TeX\ and is defined to do the right
+% thing, e.g.~we say
+% \begin{verbatim}
+%    \def A{\lst@ProcessLetter A}\end{verbatim}
+% where the first `|A|' is active and the second has letter catcode 11.
+% The macro |\lst@ProcessLetter| gets one token and treats it as a letter.
+% The following macros exist, where the last three get no explicit argument.
+% \begin{syntax}
+% \item[0.18] |\lst@ProcessLetter| \meta{spec.\ token}
+% \item[0.18] |\lst@ProcessDigit| \meta{spec.\ token}
+% \item[0.18] |\lst@ProcessOther| \meta{spec.\ token}
+% \item[0.18] |\lst@ProcessTabulator|
+% \item[0.18] |\lst@ProcessSpace|
+% \item[0.20] |\lst@ProcessFormFeed|
+% \end{syntax}
+% \meta{spec.\ token} is supposed to do two things. Usually it expands to
+% a printable version of the character. But if |\lst@UM| is equivalent to
+% |\@empty|, \meta{spec.\ token} must expand to a \emph{character token}.
+% For example, the sharp usually expands to |\#|, which is defined via
+% |\chardef| and is not a character token. But if |\lst@UM| is equivalent to
+% |\@empty|, the sharp expands to the character `|#|' (catcode 12). Note:
+% \emph{Changes to} |\lst@UM| \emph{must be locally.}  However, there should
+% be no need to do such basic things yourself. The \packagename{listings}
+% package provides advanced macros which use that feature,
+% e.g.~|\lst@InstallKeywords| in section \ref{dKeywordsAndWorkingIdentifiers}.
+%
+% \begin{syntax}
+% \item[0.18] |\lst@Def|\marg{character code}\meta{parameter text}\marg{definition}
+% \item[0.18] |\lst@Let|\marg{character code}\meta{token}
+%
+%       defines the specified character respectively assigns \meta{token}.
+%       The catcode table if not affected. Be careful if your definition has
+%       parameters: it is not safe to read more than one character ahead.
+%       Moreover, the argument can be \emph{arbitrary}; somtimes it's the next
+%       source code character, sometimes it's some code of the
+%       \packagename{listings} package, e.g.~|\relax|, |\@empty|, |\else|,
+%       |\fi|, and so on. Therefore don't use \TeX's ord-operator |`| on such
+%       an argument, e.g.~don't write |\ifnum`#1=65| to test against `|A|'.
+%
+%       |\lst@Def| and |\lst@Let| are relatively slow. The real definition of
+%       the standard character table differs from the following example, but it
+%       could begin with
+% \begin{verbatim}
+%    \lst@Def{9}{\lst@ProcessTabulator}
+%    \lst@Def{32}{\lst@ProcessSpace}
+%    \lst@Def{48}{\lst@ProcessDigit 0}
+%    \lst@Def{65}{\lst@ProcessLetter A}\end{verbatim}
+%
+%\iffalse
+% \item[0.20] |\lst@activecharstrue|
+% \item[0.20] |\lst@activecharsfalse|
+%
+%       control whether selecting the character table also makes all characters
+%       active (standard/extended). This is usually true and therefore default.
+%       Only the \packagename{fancyvrb} interface sets it locally false.
+%\fi
+% \end{syntax}
+% That's enough for the moment. Section \ref{dUsefulInternalDefinitions}
+% presents advanced definitions to manipulate the character table, in
+% particular how to add new comment or string types.
+%
+%
+% \subsection{On the output}
+%
+% The \packagename{listings} package uses some variables to keep the output
+% data. Write access is not recommended. Let's start with the easy ones.
+% \begin{syntax}
+% \item[0.17,,data] |\lst@lastother|
+%
+%       equals \meta{spec.\ token} version of the last processed
+%       nonidentifier-character. Since programming languages redefine the
+%       standard character table, we use the original \meta{spec.\ token}.
+%       For example, if a double quote was processed last, |\lst@lastother|
+%       is not equivalent to the macro which enters and leaves string mode.
+%       It's equivalent to |\lstum@"|, where |"| belongs to the control
+%       sequence. Remember that \meta{spec.\ token} expands either to a
+%       printable or to a token character.
+%
+%       |\lst@lastother| is equivalent to |\@empty| if such a character is not
+%       available, e.g.~at the beginning of a line. Sometimes an indentifier
+%       has already been printed after processing the last `other' character,
+%       i.e.~the character is far, far away. In this case |\lst@lastother|
+%       equals |\relax|.
+%
+% \item[0.17] |\lst@outputspace|
+%
+%       Use this predefined \meta{spec.\ token} (obviously for character code
+%       32) to test against |\lst@lastother|.
+%
+% \item[0.20] |\lstum@backslash|
+%
+%       Use this predefined \meta{spec.\ token} (for character code 92) to test
+%       against |\lst@lastother|. In the replacement text for |\lst@Def| one
+%       could write |\ifx| |\lst@lastother| |\lstum@backslash| \ldots\ to test
+%       whether the last character has been a backslash.
+%
+% \item[0.20] |\lst@SaveOutputDef|\marg{character code}\meta{macro}
+%
+%       Stores the \meta{spec.\ token} corresponding to \meta{character code}
+%       in \meta{macro}. This is the only safe way to get a correct meaning to
+%       test against |\lst@lastother|, for example
+%           |\lst@SaveOutputDef{"5C}\lstum@backslash|.
+%
+%       You'll get a ``runaway argument'' error if \meta{character code} is not
+%       between 33 and 126 (inclusive).
+% \end{syntax}
+% Now let's turn to the macros dealing a bit more with the output data and
+% state.
+% \begin{syntax}
+% \item[1.0] |\lst@XPrintToken|
+%
+%       outputs the current character string and resets it. This macro keeps
+%       track of all variables described here.
+%
+% \item[0.18,,token] |\lst@token|
+%
+%       contains the current character string. Each `character' usually
+%       expands to its printable version, but it must expand to a character
+%       token if |\lst@UM| is equivalent to |\@empty|.
+%
+% \item[0.12,,counter] |\lst@length|
+%
+%       is the length of the current character string.
+%
+% \item[0.12,,dimension] |\lst@width|
+%
+%       is the width of a single character box.
+%
+% \item[0.20,,global dimension] |\lst@currlwidth|
+%
+%       is the width of so far printed line.
+%
+% \item[0.18,,global counter] |\lst@column|
+% \item[0.12,,global counter] |\lst@pos| (nonpositive)
+%
+%       |\lst@column|$-$|\lst@pos| is the length of the so far printed line.
+%       We use two counters since this simplifies tabulator handling:
+%       |\lst@pos| is a nonpositive representative of `length of so far
+%       printed line' modulo \keyname{tabsize}.
+%       It's usually not the biggest nonpositive representative.
+%
+% \item[0.20] |\lst@CalcColumn|
+%
+%       |\@tempcnta| gets |\lst@column| $-$ |\lst@pos| $+$ |\lst@length|.
+%       This is the current column number minus one, or the current column
+%       number zero based.
+%
+% \item[0.18,,global dimension] |\lst@lostspace|
+%
+%       equals `lost' space: desired current line width minus real line width.
+%       Whenever this dimension is positive the flexible column format can use
+%       this space to fix the column alignment.
+% \end{syntax}
+%
+%
+% \section{Package extensions}\label{dPackageExtensions}
+%
+%
+% \subsection{Keywords and working identifiers}\label{dKeywordsAndWorkingIdentifiers}
+%
+% The \aspectname{keywords} aspect defines two main macros. Their respective
+% syntax is shown on the left. On the right you'll find examples how the
+% package actually defines some keys.
+% \begin{syntax}
+% \item[0.21]
+%   \cs{lst@InstallFamily}
+%
+%   \marg{prefix}\syntaxfill \texttt k\\
+%   \marg{name}\syntaxfill |{keywords}|\\
+%   \marg{style name}\syntaxfill |{keywordstyle}|\\
+%   \marg{style init}\syntaxfill |\bfseries|\\
+%   \marg{default style name}\syntaxfill |{keywordstyle}|\\
+%   \marg{working procedure}\syntaxfill |{}|\\
+%   \meta{\alternative{l,o}}\syntaxfill |l|\\
+%   \meta{\alternative{d,o}}\syntaxfill |d|
+%
+%       installs either a keyword or `working' class of identifiers according
+%       to whether \meta{working procedure} is empty.
+%
+%       The three keys \meta{name}, \keyname{more}\meta{name} and
+%       \keyname{delete}\meta{name}, and if not empty \meta{style name} are
+%       defined. The first order member of the latter one is initialized with
+%       \meta{style init} if not equivalent to |\relax|. If the user leaves a
+%       class style undefined, \meta{default style name} is used instead.
+%       Thus, make sure that this style is always defined. In the example,
+%       the first order keywordstyle is set to |\bfseries| and is the default
+%       for all other classes.
+%
+%       If \meta{working procedure} is not empty, this code is executed when
+%       reaching such an (user defined) identifier. \meta{working procedure}
+%       takes exactly one argument, namely the class number to which the
+%       actual identifier belongs to. If the code uses variables and requires
+%       values from previous calls, you must define these variables
+%       |\global|ly. It's not sure whether working procedures are executed
+%       inside a (separate) group or not.
+%
+%       \texttt l indicates a language key, i.e.~the lists are reset every
+%       language selection. \texttt o stands for `other' key.
+%       The keyword respectively working test is either installed at the
+%       \hookname{DetectKeyword} or \hookname{Output} hook according to
+%       \meta{\alternative{d,o}}.
+%
+% \item[0.20]
+%   \cs{lst@InstallKeywords}
+%
+%   \marg{prefix}\syntaxfill \texttt{cs}\\
+%   \marg{name}\syntaxfill |{texcs}|\\
+%   \marg{style name}\syntaxfill |{texcsstyle}|\\
+%   \marg{style init}\syntaxfill |\relax|\\
+%   \marg{default style name}\syntaxfill |{keywordstyle}|\\
+%   \marg{working procedure}\syntaxfill see below\\
+%   \meta{\alternative{l,o}}\syntaxfill |l|\\
+%   \meta{\alternative{d,o}}\syntaxfill |d|
+%
+%       Same parameters, same functionality with one execption. The macro
+%       installs exactly one keyword class and not a whole family. Therefore
+%       the argument to \meta{working procedure} is constant (currently empty).
+%
+%       The working procedure of the example reads as follows.\vspace*{-.5\baselineskip}
+% \begin{verbatim}
+%    {\ifx\lst@lastother\lstum@backslash
+%         \let\lst@thestyle\lst@texcsstyle
+%     \fi}\end{verbatim}
+%\vspace*{-.5\baselineskip}
+%       What does this procedure do? First of all it is called only if a
+%       keyword from the user supplied list (or language definition) is found.
+%       The procedure now checks for a preceding backslash and sets the output
+%       style accordingly.
+%
+%\iffalse
+% \item[0.20] |\lst@InstallTest|\marg{prefix}\syntaxbreak
+%       |\lst@|\meta{name}|@list||\lst@|\meta{name}~|\lst@g|\meta{name}|@list||\lst@g|\meta{name}\syntaxbreak
+%       |\lst@g|\meta{name}|@sty|~\meta{\alternative{w,s}}\meta{\alternative{d,o}}
+%
+%       installs a `working identifier' test or keyword style depending on
+%       \meta{\alternative{w,s}}. |\lst@g|\meta{name}|@sty| contains the
+%       working procedure or style macro. Note that the behaviour of the tests
+%       depends on the \texttt{savemem} option.
+%       The keyword respectively working test is either installed at the
+%       \hookname{DetectKeyword} or \hookname{Output} hook according to
+%       \meta{\alternative{d,o}}.
+%
+%^^A    Either each call of this macro or each different \meta{prefix} inserts
+%^^A    another test (depending on the \texttt{savemem} option).
+%
+%       |\lst@|\meta{name} contains the current identifier list and
+%       |\lst@|\meta{name}|@list| a `|\lst@|\meta{$n_i$}|\lst@g|\meta{$n_i$}'
+%       sequence of currently used classes. If no other classes are used,
+%       this equals |\lst@|\meta{name}|\lst@g|\meta{name}. The global versions
+%       |\lst@g|\ldots\ are used to keep track of the keywords.
+%       (This description needs improvement.)
+%\fi
+% \end{syntax}
+%
+%
+% \subsection{Delimiters}
+%
+% We describe two stages: adding a new delimiter type to an existing class of
+% delimiters and writing a new class. Each class has its name; currently exist
+% \texttt{Comment}, \texttt{String}, and \texttt{Delim}. As you know, the
+% latter and the first both provide the type \texttt l, but there is no string
+% which starts with the given delimiter and ends at end of line. So we'll add
+% it now!
+%
+% First of all we extend the list of string types by
+% \begin{verbatim}
+%    \lst@AddTo\lst@stringtypes{,l}\end{verbatim}
+% Then we must provide the macro which takes the user supplied delimiter and
+% makes appropriate definitions. The command name consists of the prefix
+% |\lst@|, the delimiter name, |DM| for using dynamic modes, and |@| followed
+% by the type.
+% \begin{verbatim}
+%    \gdef\lst@StringDM@l#1#2\@empty#3#4#5{%
+%        \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}\end{verbatim}
+% You can put these three lines into a \texttt{.sty}-file or surround them by
+% |\makeatletter| and |\makeatother| in the preamble of a document.
+% And that's all!
+%{\makeatletter
+%\lst@AddTo\lst@stringtypes{,l}
+%\gdef\lst@StringDM@l#1#2\@empty#3#4#5{^^A
+%   \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}
+%}
+% \begin{lstsample}{}{}
+%    \lstset{string=[l]//}
+%    \begin{lstlisting}
+%    // This is a string.
+%    This isn't a string.
+%    \end{lstlisting}
+% \end{lstsample}
+% You want more details, of course. Let's begin with the arguments.
+% \begin{itemize}
+% \item The first argument \emph{after} |\@empty| is used to start the
+%       delimiter. It's provided by the delimiter class.
+% \item The second argument \emph{after} |\@empty| is used to end the
+%       delimiter. It's also provided by the delimiter class. We didn't
+%       need it in the example, see the explanation below.
+% \item The third argument \emph{after} |\@empty| is
+%       \marg{style}\meta{start tokens}.
+%       This with a preceding |\def\lst@currstyle| is used as argument to
+%       |\lst@EnterMode|. The delimiter class also provides it. In the
+%       example we `extended' |#5| by |\lst@Lmodetrue| (line mode true).
+%       The mode automatically ends at end of line, so we didn't need the
+%       end-delimiter argument.
+% \end{itemize}
+% And now for the other arguments. In case of dynamic modes, the first argument
+% is the mode number. Then follow the user supplied  delimiter(s) whose number
+% must match the remaining arguments up to |\@empty|. For non-dynamic modes,
+% you must either allocate a static mode yourself or use a predefined mode
+% number. The delimiters then start with the first argument.
+%
+% Eventually let's look at the replacement text of the macro. The sequence
+% |\lst@CArg #2\relax| puts two required arguments after |\lst@DefDelimB|.
+% The syntax of the latter macro is
+% \begin{syntax}
+% \item[1.0] \cs{lst@DefDelimB}
+%
+%   |{|\meta{1st}\meta{2nd}\marg{rest}|}|\syntaxfill |{//{}}|\\
+%   \meta{save 1st}\syntaxfill |\lst@c/0|\\
+%   \marg{execute}\syntaxfill|{}|\\
+%   \marg{delim~exe~modetrue}\syntaxfill|{}|\\
+%   \marg{delim~exe~modefalse}\syntaxfill|{}|\\
+%   \meta{start-delimiter macro}\syntaxfill|#3|\\
+%   \meta{mode number}\syntaxfill |{#1}|\\
+%   |{|\marg{style}\meta{start tokens}|}|\syntaxfill |{#5\lst@Lmodetrue}|
+%
+%       defines \meta{1st}\meta{2nd}\meta{rest} as starting-delimiter.
+%       \meta{execute} is executed when the package comes to \meta{1st}.
+%       \meta{delim~exe~modetrue} and \meta{delim~exe~modefalse} are
+%       executed only if the whole delimiter \meta{1st}\meta{2nd}\meta{rest}
+%       is found. Exactly one of them is called depending on |\lst@ifmode|.
+%
+%       By default the package enters the mode if the delimiter is found
+%       \emph{and} |\lst@ifmode| is false. Internally we make an appropriate
+%       definition of |\lst@bnext|, which can be gobbled by placing
+%       |\@gobblethree| at the very end of \meta{delim exe modefalse}.
+%       One can provide an own definition (and gobble the default).
+%
+%       \meta{save 1st} must be an undefined macro and is used internally to
+%       store the previous meaning of \meta{1st}. The arguments \meta{2nd}
+%       and/or \meta{rest} are empty if the delimiter has strictly less than
+%       three characters. All characters of \meta{1st}\meta{2nd}\meta{rest}
+%       must already be active (if not empty).
+%       That's not a problem since the macro |\lst@CArgX| does this job.
+%   
+% \item[1.0] \cs{lst@DefDelimE}
+%
+%   |{|\meta{1st}\meta{2nd}\marg{rest}|}|\\
+%   \meta{save 1st}\\
+%   \marg{execute}\\
+%   \marg{delim~exe~modetrue}\\
+%   \marg{delim~exe~modefalse}\\
+%   \meta{end-delimiter macro}\\
+%   \meta{mode number}
+%
+%       Ditto for ending-delimiter with slight differences:
+%       \meta{delim~exe~modetrue} and \meta{delim~exe~modefalse} are executed
+%       depending on whether |\lst@mode| equals \meta{mode}.
+%
+%       The package ends the mode if the delimiter is found and |\lst@mode|
+%       equals \meta{mode}. Internally we make an appropriate definition of
+%       |\lst@enext| (not |\lst@bnext|), which can be gobbled by placing
+%       |\@gobblethree| at the very end of \meta{delim exe modetrue}.
+%
+% \item[1.0] \cs{lst@DefDelimBE}
+%
+%   followed by the same eight arguments as for |\lst@DefDelimB| and \ldots\\
+%   \meta{end-delimiter macro}
+%
+%       This is a combination of |\lst@DefDelimB| and |\lst@DefDelimE| for the
+%       case of starting and ending delimiter being the same.
+% \end{syntax}
+% We finish the first stage by examining two easy examples.
+% \texttt d-type strings are defined by
+% \begin{verbatim}
+%    \gdef\lst@StringDM@d#1#2\@empty#3#4#5{%
+%        \lst@CArg #2\relax\lst@DefDelimBE{}{}{}#3{#1}{#5}#4}\end{verbatim}
+% (and an entry in the list of string types).
+% Not a big deal. Ditto \texttt d-type comments:
+% \begin{verbatim}
+%    \gdef\lst@CommentDM@s#1#2#3\@empty#4#5#6{%
+%        \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+%        \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}\end{verbatim}
+% Here we just need to use both |\lst@DefDelimB| and |\lst@DefDelimE|.
+% \goodbreak
+%
+% So let's get to the second stage. For illustration, here's the definition of
+% the \texttt{Delim} class. The respective first argument to the service macro
+% makes it delete all delimiters of the class, add the delimiter, or delete
+% the particular delimiter only.
+% \begin{verbatim}
+%    \lst@Key{delim}\relax{\lst@DelimKey\@empty{#1}}
+%    \lst@Key{moredelim}\relax{\lst@DelimKey\relax{#1}}
+%    \lst@Key{deletedelim}\relax{\lst@DelimKey\@nil{#1}}\end{verbatim}
+% The service macro itself calls another macro with appropriate arguments.
+% \begin{verbatim}
+%    \gdef\lst@DelimKey#1#2{%
+%        \lst@Delim{}#2\relax{Delim}\lst@delimtypes #1%
+%                    {\lst@BeginDelim\lst@EndDelim}
+%            i\@empty{\lst@BeginIDelim\lst@EndIDelim}}\end{verbatim}
+% We have to look at those arguments. Above you can see the actual arguments
+% for the \texttt{Delim} class, below are the \texttt{Comment} class ones.
+% Note that the user supplied value covers the second and third line of
+% arguments.
+% \begin{syntax}
+% \item[0.21,,changed]
+%   \cs{lst@Delim}
+%
+%   \meta{default style macro}\syntaxfill \cs{lst@commentstyle}\\ \relax
+%   [\texttt*[\texttt*]]\texttt[\meta{type}\texttt][\texttt[\meta{style}\texttt][\texttt[\meta{type option}\texttt]]]\\
+%   \meta{delimiter\textup(s\textup)}\cs{relax}\syntaxfill|#2|\cs{relax}\\
+%   \marg{delimiter name}\syntaxfill|{Comment}|\\
+%   \meta{delimiter types macro}\syntaxfill\texttt{\cs{lst@commenttypes}}\\
+%   \alternative{\cs{@empty},\cs{@nil},\cs{relax}}\syntaxfill|#1|\\
+%   \marg{begin- and end-delim macro}\syntaxfill|{|\cs{lst@BeginComment}\cs{lst@EndComment}|}|\\
+%   \meta{extra prefix}\syntaxfill |i|\\
+%   \meta{extra conversion}\syntaxfill |\@empty|\\
+%   \marg{begin- and end-delim macro}\syntaxfill|{|\cs{lst@BeginIComment}\cs{lst@EndIComment}|}|
+%
+%   Most arguments should be clear. We'll discuss the last four. Both
+%   \marg{begin- and end-delim macro} must contain exactly two control
+%   sequences, which are given to |\lst@|\meta{name}[|DM|]|@|\meta{type}
+%   to begin and end a delimiter. These are the arguments |#3| and |#4| in our
+%   first example of |\lst@StringDM@l|. Depending on whether the user chosen
+%   type starts with \meta{extra prefix}, the first two or the last control
+%   sequences are used.
+%
+%   By default the package takes the delimiter(s), makes the characters active,
+%   and places them after |\lst@|\meta{name}[|DM|]|@|\meta{type}. If the user
+%   type starts with \meta{extra prefix}, \meta{extra conversion} might change
+%   the definition of |\lst@next| to choose a different conversion. The default
+%   is equivalent to |\lst@XConvert| with |\lst@false|.
+%
+%   Note that \meta{type} never starts with \meta{extra prefix} since it is
+%   discarded. The functionality must be fully implemented by choosing a
+%   different \marg{begin- and end-delim macro} pair.
+% \end{syntax}
+% You might need to know the syntaxes of the \meta{begin- and end-delim macro}s.
+% They are called as follows.
+% \begin{syntax}
+% \item[0.21] |\lst@Begin|\meta{whatever}
+%
+%   \marg{mode}
+%   |{|\marg{style}\meta{start tokens}|}|
+%   \meta{delimiter}|\@empty|
+%
+% \item[0.21] |\lst@End|\meta{whatever}
+%
+%   \marg{mode}
+%   \meta{delimiter}|\@empty|
+% \end{syntax}
+% The existing macros are internally defined in terms of |\lst@DelimOpen| and
+% |\lst@DelimClose|, see the implementation.
+%
+%
+% \subsection{Getting the kernel run}
+%
+% If you want new pretty-printing environments, you should be happy with
+% section \ref{rEnvironments}. New commands like |\lstinline| or
+% |\lstinputlisting| are more difficult. Roughly speaking you must follow
+% these steps.
+% \begin{enumerate}
+% \item Open a group to make all changes local.
+% \item \meta{Do whatever you want.}
+% \item Call |\lsthk@PreSet| in any case.
+% \item Now you \emph{might } want to (but need not) use |\lstset| to set some
+%       new values.
+% \item \meta{Do whatever you want.}
+% \item Execute |\lst@Init\relax| to finish initialization.
+% \item \meta{Do whatever you want.}
+% \item Eventually comes the source code, which is processed by the kernel.
+%       You must ensure that the characters are either not already read or all
+%       active. Moreover \emph{you} must install a way to detect the end of the
+%       source code. If you've reached the end, you must \ldots
+% \item \ldots\ call |\lst@DeInit| to shutdown the kernel safely.
+% \item \meta{Do whatever you want.}
+% \item Close the group from the beginning.
+% \end{enumerate}
+% For example, consider the |\lstinline| command in case of being not inside an
+% argument. Then the steps are as follows.
+% \begin{enumerate}
+% \item |\leavevmode\bgroup| opens a group.
+% \item |\def\lst@boxpos{b}| `baseline' aligns the listing.
+% \item |\lsthk@PreSet|
+% \item |\lstset{flexiblecolumns,#1}| (|#1| is the user provided
+%       key=value list)
+% \item |\lsthk@TextStyle| deactivates all features not safe here.
+% \item |\lst@Init\relax|
+% \item |\lst@Def{`#1}{\lst@DeInit\egroup}| installs the `end inline'
+%       detection, where |#1| is the next character after |\lstinline|.
+%       Moreover chr(13) is redefined to end the fragment in the same way but
+%       also issues an error message.
+% \item Now comes the source code and \ldots
+% \item \ldots\ |\lst@DeInit| (from |\lst@Def| above) ends the code snippet
+%       correctly.
+% \item Nothing.
+% \item |\egroup| (also from |\lst@Def|) closes the group.
+% \end{enumerate}
+% The real definition is different since we allow source code inside arguments.
+% Read also section \ref{iTheInputCommand} if you really want to write
+% pretty-printing commands.
+%
+%
+% \section{Useful internal definitions}\label{dUsefulInternalDefinitions}
+%
+% This section requires an update.
+%
+%
+% \subsection{General purpose macros}\label{dGeneralPurposeMacros}
+%
+% \begin{syntax}
+% \item[0.19] |\lst@AddTo|\meta{macro}\marg{\TeX~material}
+%
+%       adds \meta{\TeX~material} globally to the contents of \meta{macro}.
+%
+% \item[0.20] |\lst@Extend|\meta{macro}\marg{\TeX~material}
+%
+%       calls |\lst@AddTo| after the first token of \meta{\TeX~material} is
+%       |\expand|ed|after|. For example, |\lst@Extend \a \b| merges the
+%       contents of the two macros and stores it globally in |\a|.
+%
+% \item[0.19] |\lst@lAddTo|\meta{macro}\marg{\TeX~material}
+% \item[0.20] |\lst@lExtend|\meta{macro}\marg{\TeX~material}
+%
+%       are local versions of |\lst@AddTo| and |\lst@Extend|.
+%
+% \item[0.18] |\lst@DeleteKeysIn|\meta{macro}\meta{macro \textup(keys to remove\textup)}
+%
+%       Both macros contain a comma separated list of keys (or keywords). All
+%       keys appearing in the second macro are removed (locally) from the first.
+%
+% \item[0.19] |\lst@ReplaceIn|\meta{macro}\meta{macro \textup(containing replacement list\textup)}
+% \item[0.20] |\lst@ReplaceInArg|\meta{macro}\marg{replacement list}
+%
+%       The replacement list has the form $a_1b_1$\ldots$a_nb_n$, where each
+%       $a_i$ and $b_i$ is a character sequence (enclosed in braces if
+%       necessary) and may contain macros, but the first token of $b_i$ must
+%       not be equivalent to |\@empty|. Each sequence $a_i$ inside the first
+%       macro is (locally) replaced by $b_i$.
+%       The suffix |Arg| refers to the \emph{braced} second argument instead of
+%       a (nonbraced) macro. It's a hint that we get the `real' argument and
+%       not a `pointer' to the argument.
+%
+% \item[0.20] |\lst@IfSubstring|\marg{character sequence}\meta{macro}\marg{then}\marg{else}
+%
+%       \meta{then} is executed if \meta{character sequence} is a substring of
+%       the contents of \meta{macro}. Otherwise \meta{else} is called.
+%
+% \item[0.12] |\lst@IfOneOf|\meta{character sequence}|\relax|\meta{macro}\marg{then}\marg{else}
+%
+%       |\relax| terminates the first parameter here since it is faster than
+%       enclosing it in braces. \meta{macro} contains a comma separated list
+%       of identifiers. If the character sequence is one of these indentifiers,
+%       \meta{then} is executed, and otherwise \meta{else}.
+%
+% \item[0.21] |\lst@Swap|\marg{tok1}\marg{tok2}
+%
+%       changes places of the following two tokens or arguments \emph{without}
+%       inserting braces. For example, |\lst@Swap{abc}{def}| expands to
+%       |defabc|.
+%
+% \item[0.18] |\lst@IfNextChars|\meta{macro}\marg{then}\marg{else}
+% \item[0.19] |\lst@IfNextCharsArg|\marg{character sequence}\marg{then}\marg{else}
+%
+%       Both macros execute either \meta{then} or \meta{else} according to
+%       whether the given character sequence respectively the contents of the
+%       given macro is found (after the three arguments). Note an important
+%       difference between these macros and \LaTeX's |\@ifnextchar|:
+%       We remove the characters behind the arguments until it is possible to
+%       decide which part must be executed. However, we save these characters
+%       in the macro |\lst@eaten|, so they can be inserted using \meta{then} or
+%       \meta{else}.
+%
+% \item[0.19] |\lst@IfNextCharActive|\marg{then}\marg{else}
+%
+%       executes \meta{then} if next character is active, and \meta{else}
+%       otherwise.
+%
+% \item[0.20] |\lst@DefActive|\meta{macro}\marg{character sequence}
+%
+%       stores the character sequence in \meta{macro}, but all characters
+%       become active. The string \emph{must not} contain a begin group, end
+%       group or escape character (|{}\|); it may contain a left brace, right
+%       brace or backslash with other meaning (= catcode). This command
+%       would be quite surplus if \meta{character sequence} is not already read
+%       by \TeX\ since such catcodes can be changed easily. It is explicitly
+%       allowed that the charcaters have been read, e.g.~in
+%       |\def\test{\lst@DefActive\temp{ABC}}|!
+%
+%       Note that this macro changes |\lccode|s 0--9 without restoring them.
+%
+% \item[0.20] |\lst@DefOther|\meta{macro}\marg{character sequence}
+%
+%       stores \meta{character sequence} in \meta{macro}, but all characters
+%       have catcode 12. Moreover all spaces are removed and control sequences
+%       are converted to their name without preceding backslash. For example,
+%       |\{ Chip \}| leads to |{Chip}| where all catcodes are 12---internally
+%       the primitive |\meaning| is used.
+%
+% \iffalse
+% \item[0.19] |\lst@MakeActive|\marg{character sequence}
+%
+%       stores the character sequence in |\lst@arg| and has the same
+%       restrictions as |\lst@DefActive|. If fact, the latter definition uses
+%       this macro here.
+% \fi
+% \end{syntax}
+%
+%
+% \subsection{Character tables manipulated}\label{dCharacterTablesManipulated}
+%
+% \begin{syntax}
+% \item[0.20] |\lst@SaveDef|\marg{character code}\meta{macro}
+%
+%       Saves the current definition of the specified character in
+%       \meta{macro}. You should always save a character definition before you
+%       redefine it! And use the saved version instead of writing directly
+%       |\lst@Process|\ldots---the character could already be redefined and
+%       thus not equivalent to its standard definition.
+%
+% \item[0.20] |\lst@DefSaveDef|\marg{character code}\meta{macro}\meta{parameter text}\marg{definition}
+% \item[0.20] |\lst@LetSaveDef|\marg{character code}\meta{macro}\meta{token}
+%
+%       combine |\lst@SaveDef| and |\lst@Def| respectively |\lst@Let|.
+% \end{syntax}
+% Of course I shouldn't forget to mention \emph{where} to alter the character
+% table. Hook material at \hookname{SelectCharTable} makes permanent changes,
+% i.e.~it effects all languages. The following two keys can be used in any
+% language definition and effects the particular language only.
+% \begin{syntax}
+% \item[0.20] |SelectCharTable=|\meta{\TeX\ code}
+% \item[0.20] |MoreSelectCharTable=|\meta{\TeX\ code}
+%
+%       uses \meta{\TeX\ code} (additionally) to select the character table.
+%       The code is executed after the standard character table is selected,
+%       but possibly before other aspects make more changes. Since previous
+%       meanings are always saved and executed inside the new definition, this
+%       should be harmless.
+% \end{syntax}
+% Here come two rather useless examples. Each point (full stop) will cause a
+% message `|.|' on the terminal and in the |.log| file if language |useless| is
+% active:
+% \begin{verbatim}
+%   \lstdefinelanguage{useless}
+%       {SelectCharTable=\lst@DefSaveDef{46}% save chr(46) ...
+%            \lsts@point             % ... in \lsts@point and ...
+%            {\message{.}\lsts@point}% ... use new definition
+%       }\end{verbatim}
+% If you want to count points, you could write
+% \begin{verbatim}
+%   \newcount\lst@points % \global
+%   \lst@AddToHook{Init}{\global\lst@points\z@}
+%   \lst@AddToHook{DeInit}{\message{Number of points: \the\lst@points}}
+%   \lstdefinelanguage[2]{useless}
+%       {SelectCharTable=\lst@DefSaveDef{46}\lsts@point
+%            {\global\advance\lst@points\@ne \lsts@point}
+%       }\end{verbatim}
+% |% \global| indicates that the allocated counter is used globally. We zero
+% the counter at the beginning of each listing, display a message about the
+% current value at the end of a listing, and each processed point advances the
+% counter by one.
+%
+% \begin{syntax}
+% \item[0.21] |\lst@CArg|\meta{active characters}|\relax|\meta{macro}
+%
+%       The string of active characters is split into \meta{1st}, \meta{2nd},
+%       and \marg{rest}. If one doesn't exist, an empty argument is used. Then
+%       \meta{macro} is called with |{|\meta{1st}\meta{2nd}\marg{rest}|}| plus
+%       a yet undefined control sequence \meta{save 1st}. This macro is
+%       intended to hold the current definition of \meta{1st}, so \meta{1st}
+%       can be redefined without loosing information.
+%
+% \item[0.19] |\lst@CArgX|\meta{characters}|\relax|\meta{macro}
+%
+%       makes \meta{characters} active before calling |\lst@CArg|.
+%
+% \item[0.21] |\lst@CDef{|\meta{1st}\meta{2nd}\marg{rest}|}|\meta{save 1st}\marg{execute}\marg{pre}\marg{post}
+%
+%       should be used in connection with |\lst@CArg| or |\lst@CArgX|, i.e.~as
+%       \meta{macro} there. \meta{1st}, \meta{2nd}, and \meta{rest} must be
+%       active characters and \meta{save 1st} must be an undefined control
+%       sequence.
+%
+%       Whenever the package reaches the character \meta{1st} (in a listing),
+%       \meta{execute} is executed. If the package detects the whole string
+%       \meta{1st}\meta{2nd}\meta{rest}, we additionally execute \meta{pre},
+%       then the string, and finally \meta{post}.
+%
+% \item[0.21] |\lst@CDefX|\meta{1st}\meta{2nd}\marg{rest}\meta{save 1st}\marg{execute}\marg{pre}\marg{post}
+%
+%       Ditto except that we execute \meta{pre} and \meta{post} without the
+%       original string if we reach \meta{1st}\meta{2nd}\meta{rest}.
+%       This means that the string is replaced by \meta{pre}\meta{post} (with
+%       preceding \meta{execute}).
+% \end{syntax}
+% As the final example, here's the definition of |\lst@DefDelimB|.
+% \begin{verbatim}
+%    \gdef\lst@DefDelimB#1#2#3#4#5#6#7#8{%
+%        \lst@CDef{#1}#2%
+%            {#3}%
+%            {\let\lst@bnext\lst@CArgEmpty
+%             \lst@ifmode #4\else
+%                 #5%
+%                 \def\lst@bnext{#6{#7}{#8}}%
+%             \fi
+%             \lst@bnext}%
+%            \@empty}\end{verbatim}
+% You got it?
+%
+%
+% \part{Implementation}
+%
+%
+% \CheckSum{10861}
+%^^A
+%^^A Don't index TeX-primitives.
+%^^A
+% \DoNotIndex{\advance,\afterassignment,\aftergroup,\batchmode,\begingroup}
+% \DoNotIndex{\box,\catcode,\char,\chardef,\closeout,\copy,\count,\csname,\def}
+% \DoNotIndex{\dimen,\discretionary,\divide,\dp,\edef,\else,\end,\endcsname}
+% \DoNotIndex{\endgroup,\endinput,\endlinechar,\escapechar,\everypar}
+% \DoNotIndex{\expandafter,\fi,\gdef,\global,\globaldefs,\hbadness,\hbox}
+% \DoNotIndex{\hrulefill,\hss,\ht}
+% \DoNotIndex{\if,\ifdim,\iffalse,\ifhmode,\ifinner,\ifnum,\ifodd,\iftrue}
+% \DoNotIndex{\ifvoid,\ifx,\ignorespaces,\immediate,\input,\jobname,\kern}
+% \DoNotIndex{\lccode,\leftskip,\let,\long,\lower,\lowercase,\meaning,\message}
+% \DoNotIndex{\multiply,\muskip,\noexpand,\noindent,\openout,\par,\parfillskip}
+% \DoNotIndex{\parshape,\parskip,\raise,\read,\relax,\rightskip,\setbox,\skip}
+% \DoNotIndex{\string,\the,\toks,\uppercase,\vbox,\vcenter,\vrule,\vtop,\wd}
+% \DoNotIndex{\write,\xdef}
+%
+%^^A
+%^^A Don't index LaTeX's private definitions.
+%^^A
+% \DoNotIndex{\@@end,\@@par,\@M,\@arabic,\@circlefnt,\@currentlabel}
+% \DoNotIndex{\@currenvir,\@depth,\@doendpe,\@dottedtocline,\@eha,\@ehc}
+% \DoNotIndex{\@empty,\@firstofone,\@firstoftwo,\@float,\@for,\@getcirc}
+% \DoNotIndex{\@gobble,\@gobbletwo,\@halfwidth,\@height,\@ifnextchar}
+% \DoNotIndex{\@ifundefined,\@ignoretrue,\@makecaption,\@makeother,\@namedef}
+% \DoNotIndex{\@ne,\@noligs,\@notprerr,\@onlypreamble,\@secondoftwo,\@spaces}
+% \DoNotIndex{\@starttoc,\@totalleftmargin,\@undefined,\@whilenum}
+% \DoNotIndex{\@wholewidth,\@width}
+% \DoNotIndex{\c@chapter,\c@figure,\c@page,\end@float,\f@family,\filename@area}
+% \DoNotIndex{\filename@base,\filename@ext,\filename@parse,\if@twoside}
+% \DoNotIndex{\l@ngrel@x,\m@ne,\new@command,\nfss@catcodes,\tw@,\thr@@}
+% \DoNotIndex{\z@,\zap@space}
+%
+%^^A
+%^^A Don't index LaTeX's package definitions.
+%^^A
+% \DoNotIndex{\AtEndOfPackage}
+% \DoNotIndex{\CurrentOption,\DeclareOption,\IfFileExists,\InputIfFileExists}
+% \DoNotIndex{\MessageBreak,\NeedsTeXFormat,\PackageError,\PackageWarning}
+% \DoNotIndex{\ProcessOptions,\ProvidesFile,\ProvidesPackage,\RequirePackage}
+%
+%^^A
+%^^A Don't index LaTeX's public definitions.
+%^^A
+% \DoNotIndex{\abovecaptionskip,\active,\addcontentsline,\addtocounter,\begin}
+% \DoNotIndex{\belowcaptionskip,\bfseries,\bgroup,\bigbreak,\chapter}
+% \DoNotIndex{\contentsname,\do,\egroup,\footnotesize,\index,\itshape}
+% \DoNotIndex{\linewidth,\llap,\makeatletter,\newbox,\newcommand,\newcount}
+% \DoNotIndex{\newcounter,\newdimen,\newtoks,\newwrite,\nointerlineskip}
+% \DoNotIndex{\normalbaselines,\normalfont,\numberline,\pretolerance,\protect}
+% \DoNotIndex{\qquad,\refstepcounter,\removelastskip,\renewcommand,\rlap}
+% \DoNotIndex{\small,\smallbreak,\smallskipamount,\smash,\space,\strut}
+% \DoNotIndex{\strutbox,\tableofcontents,\textasciicircum,\textasciitilde}
+% \DoNotIndex{\textasteriskcentered,\textbackslash,\textbar,\textbraceleft}
+% \DoNotIndex{\textbraceright,\textdollar,\textendash,\textgreater,\textless}
+% \DoNotIndex{\textunderscore,\textvisiblespace,\thechapter,\ttdefault}
+% \DoNotIndex{\ttfamily,\typeout,\value,\vphantom}
+%
+%^^A
+%^^A Don't index definitions from other packages.
+%^^A
+% \DoNotIndex{\MakePercentComment,\MakePercentIgnore}
+%
+%^^A
+%^^A Don't index 0.19 definitions.
+%^^A
+% \DoNotIndex{\listlistingsname,\listoflistings,\lstbox,\lstbox@}
+% \DoNotIndex{\lstlanguage@}
+%
+%^^A
+%^^A Don't index 0.20 subdefinitions.
+%^^A
+% \DoNotIndex{\lst@ATH@,\lst@BOLGobble@,\lst@BOLGobble@@,\lst@CArg@,\lst@CArg@@}
+% \DoNotIndex{\lst@CBC@,\lst@CBC@@,\lst@CCECUse@,\lst@CCPutMacro@,\lst@DefLang@}
+% \DoNotIndex{\lst@DefLang@@,\lst@DefOther@,\lst@DeleteKeysIn@,\lst@Escape@}
+% \DoNotIndex{\lstframe@,\lst@frameH@,\lst@frameL@,\lst@frameR@}
+% \DoNotIndex{\lst@FillFixed@,\lst@FindAlias@,\lst@FVConvert@}
+% \DoNotIndex{\lst@IfNextChars@,\lst@IfNextChars@@,\lst@InsideConvert@}
+% \DoNotIndex{\lst@InstallKeywords@,\lst@Key@,\lst@KeywordTestI@}
+% \DoNotIndex{\lst@MakeActive@,\lst@MakeMoreKeywords@}
+% \DoNotIndex{\lst@RC@,\lst@RC@@,\lst@ReplaceIn@,\lst@ReplaceInput@}
+% \DoNotIndex{\lst@ReportAllocs@,\lst@SKS@,\lst@SKS@@,\lst@UBC@}
+% \DoNotIndex{\lst@WorkingTestI@,\lstalias@,\lstalias@@,\lstalso@}
+% \DoNotIndex{\lstdefinestyle@,\lstenv@BOLGobble@@}
+% \DoNotIndex{\lstenv@ProcessJ@,\lstinline@,\lstKV@OptArg@,\lstKV@SetIf@}
+% \DoNotIndex{\lstlang@,\lstnewenvironment@,\lst@outputpos,\lstset@}
+%
+%
+% \section{Overture}
+%
+% \paragraph{Registers}
+% For each aspect, the required numbers of registers are listed in section
+% \lstref{dPackageLoading}. Furthermore, the \packagename{keyval} package
+% allocates one token register. The macros, boxes and counters
+% |\@temp|\ldots|a|/|b|, the dimensions |\@tempdim|\ldots, and the macro
+% |\@gtempa| are also used, see the index.
+%
+% \paragraph{Naming conventions}
+% Let's begin with definitions for the user. All these public macros have
+% lower case letters and contain |lst|. Private macros and variables use the
+% following prefixes (not up-to-date?):
+% \begin{itemize}
+% \item |\lst@| for a general macro or variable,
+% \item |\lstenv@| if it is defined for the listing environment,
+% \item |\lsts@| for |s|aved character meanings,
+% \item |\lsthk@|\meta{name of hook} holds hook material,
+% \item |\lst|\meta{prefix}|@| for various kinds of keywords and working
+%       identifiers.
+% \item |\lstlang@|\meta{language}|@|\meta{dialect} contains a language and
+% \item |\lststy@|\meta{the style} contains style definition,
+% \item |\lstpatch@|\meta{aspect} to patch an aspect,
+%
+% \item |\lsta@|\meta{language}|$|\meta{dialect} contains alias,
+% \item |\lsta@|\meta{language} contains alias for all dialects of a language,
+% \item |\lstdd@|\meta{language} contains default dialect of a language
+%       (if present).
+% \end{itemize}
+% To distinguish procedure-like macros from data-macros, the name of procedure
+% macros use upper case letters with each beginning word, e.g.~|\lst@AddTo|.
+% A macro with suffix |@| is the main working-procedure for another definition,
+% for example |\lstinputlisting@| does the main work for |\lstinputlisting|.
+%
+% \paragraph{Preamble}
+% All files generated from this \texttt{listings.dtx} will get a header.
+%    \begin{macrocode}
+%% Please read the software license in listings.dtx or listings.dvi.
+%%
+%% (w)(c) 1996 -- 2002 Carsten Heinz and/or any other author
+%% listed elsewhere in this file.
+%%
+%% This file is distributed under the terms of the LaTeX Project Public
+%% License from CTAN archives in directory  macros/latex/base/lppl.txt.
+%% Either version 1.0 or, at your option, any later version.
+%%
+%% Permission is granted to modify the listings package as well as
+%% lstdrvrs.dtx. You are not allowed to distribute a modified version
+%% of the package or lstdrvrs.dtx unless you change the file names and
+%% provide the original files. In any case it is better to contact the
+%% address below; other users will welcome removed bugs, new features,
+%% and additional programming languages.
+%%
+%% The listings package is free software.
+%%
+%% However, if you distribute the package as part of a commercial
+%% product or if you use the package to prepare a commercial document
+%% (books, journals, and so on), I'd like to encourage you to make a
+%% donation to the LaTeX3 fund. The size of this `license fee' should
+%% depend on the value of the package for your product. For more
+%% information about LaTeX see http://www.latex-project.org
+%%
+%% No matter whether you use the package for a commercial or
+%% non-commercial document, please send me a copy of the document (.dvi,
+%% .ps, .pdf, hardcopy, etc.) to support further development---it is
+%% easier to introduce new features or simplify things if I see how the
+%% package is used by other people.
+%%
+%% Send comments and ideas on the package, error reports and additional
+%% programming languages to <[email protected]>.
+%%
+%    \end{macrocode}
+%
+% \paragraph{Identification}
+% All files will have same date and version.
+%    \begin{macrocode}
+\def\filedate{2002/04/01}
+\def\fileversion{1.0}
+%    \end{macrocode}
+% What we need and who we are.
+%    \begin{macrocode}
+%<*kernel>
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesPackage{listings}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+%    \end{macrocode}
+% \begin{macro}{\lst@CheckVersion}
+% can be used by the various driver files to guarantee the correct version.
+%    \begin{macrocode}
+\def\lst@CheckVersion#1{\edef\reserved@a{#1}%
+    \ifx\lst@version\reserved@a \expandafter\@gobble
+                          \else \expandafter\@firstofone \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\let\lst@version\fileversion
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+% For example by the miscellaneous file
+%    \begin{macrocode}
+%<*misc>
+\ProvidesFile{lstmisc.sty}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+\lst@CheckVersion\fileversion
+    {\typeout{^^J%
+     ***^^J%
+     *** This file requires `listings.sty' version \fileversion.^^J%
+     *** You have a serious problem, so I'm exiting ...^^J%
+     ***^^J}%
+     \batchmode \@@end}
+%</misc>
+%    \end{macrocode}
+% or by the dummy patch.
+%    \begin{macrocode}
+%<*patch>
+\ProvidesFile{lstpatch.sty}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+\lst@CheckVersion\lst@version{}
+%</patch>
+%    \end{macrocode}
+%    \begin{macrocode}
+%<*doc>
+\ProvidesPackage{lstdoc}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+%</doc>
+%    \end{macrocode}
+%
+% \paragraph{Category codes}
+% We define two macros to ensure correct catcodes when we input other files of
+% the \packagename{listings} package.
+%
+% \begin{macro}{\lst@InputCatcodes}
+% |@| and |"| become letters. Tabulators and EOLs are ignored; this avoids
+% unwanted spaces---in the case I've forgotten a comment character.
+%    \begin{macrocode}
+%<*kernel>
+\def\lst@InputCatcodes{%
+    \makeatletter \catcode`\"12%
+    \catcode`\^^@\active
+    \catcode`\^^I9%
+    \catcode`\^^L9%
+    \catcode`\^^M9%
+    \catcode`\%14%
+    \catcode`\~\active}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@RestoreCatcodes}
+% To load the kernel, we will change some catcodes and lccodes. We restore them
+% at the end of package loading. \lsthelper{Dr.~Jobst~Hoffmann}{2000/11/17}
+% {incompatibility with typehtml package} reported an incompatibility with the
+% \packagename{typehtml} package, which is resolved by |\lccode`\/`\/| below.
+%    \begin{macrocode}
+\def\lst@RestoreCatcodes#1{%
+    \ifx\relax#1\else
+        \noexpand\catcode`\noexpand#1\the\catcode`#1\relax
+        \expandafter\lst@RestoreCatcodes
+    \fi}
+\edef\lst@RestoreCatcodes{%
+    \noexpand\lccode`\noexpand\/`\noexpand\/%
+    \lst@RestoreCatcodes\"\^^I\^^M\~\^^@\relax}
+%    \end{macrocode}
+% Now we are ready for
+%    \begin{macrocode}
+\lst@InputCatcodes
+\AtEndOfPackage{\lst@RestoreCatcodes}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+% \paragraph{Statistics}
+% \begin{macro}{\lst@GetAllocs}
+% \begin{macro}{\lst@ReportAllocs}
+% are used to show the allocated registers.
+%    \begin{macrocode}
+%<*info>
+\def\lst@GetAllocs{%
+    \edef\lst@allocs{%
+        0\noexpand\count\the\count10,1\noexpand\dimen\the\count11,%
+        2\noexpand\skip\the\count12,3\noexpand\muskip\the\count13,%
+        4\noexpand\box\the\count14,5\noexpand\toks\the\count15,%
+        6\noexpand\read\the\count16,7\noexpand\write\the\count17}}
+\def\lst@ReportAllocs{%
+    \message{^^JAllocs:}\def\lst@temp{none}%
+    \expandafter\lst@ReportAllocs@\lst@allocs,\z@\relax\z@,}
+\def\lst@ReportAllocs@#1#2#3,{%
+    \ifx#2\relax \message{\lst@temp^^J}\else
+        \@tempcnta\count1#1\relax \advance\@tempcnta -#3\relax
+        \ifnum\@tempcnta=\z@\else
+            \let\lst@temp\@empty
+            \message{\the\@tempcnta \string#2,}%
+        \fi
+        \expandafter\lst@ReportAllocs@
+    \fi}
+\lst@GetAllocs
+%    \end{macrocode}
+% \end{macro}\end{macro}
+% \begingroup
+%    \begin{macrocode}
+%</info>
+%    \end{macrocode}
+% \endgroup
+%
+% \paragraph{Miscellaneous}
+% \begin{macro}{\@lst}
+% Just a definition to save memory space.
+%    \begin{macrocode}
+%<*kernel>
+\def\@lst{lst}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{General problems}
+%
+% All definitions in this section belong to the kernel.
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+%
+%^^A \subsection{Quick `if parameter empty'}
+%^^A
+%^^A There are many situations where you have to look whether a macro parameter is empty.
+%^^A We have at least two possibilities to test |#1|, for example:
+%^^A \begin{center}
+%^^A \begin{minipage}{0.35\linewidth}
+%^^A \begin{verbatim}
+%^^A\def\test{#1}%
+%^^A\ifx \test\empty
+%^^A        % #1 is empty
+%^^A\else
+%^^A        % #1 is not empty
+%^^A\fi\end{verbatim}
+%^^A \end{minipage}
+%^^A \hskip2em\vrule\hskip2em
+%^^A \begin{minipage}{0.35\linewidth}
+%^^A \begin{verbatim}
+%^^A\ifx \empty#1\empty
+%^^A        % #1 is empty
+%^^A\else
+%^^A        % #1 is not empty
+%^^A\fi\end{verbatim}
+%^^A \end{minipage}
+%^^A \end{center}
+%^^A where |\empty| is defined by |\def\empty{}|, of course.
+%^^A The left variant should be clear and works in any case.
+%^^A The right-hand side works correct if and only if the first token of |#1| is
+%^^A not equivalent to |\empty|.
+%^^A This granted, the |\ifx| is true if and only if |#1| is empty (since |\empty|
+%^^A left from |#1| is (not) compared with |\empty| on the right).
+%^^A The two |\empty|s might be replaced by any other macro, which is not
+%^^A equivalent to the first token of the argument.
+%^^A But the definition of that macro shouldn't be too complex since this would
+%^^A slow down the |\ifx|.
+%^^A The right example needs about $45\%$ of the left's time.
+%^^A Note that this \TeX{}nique lost its importance from version 0.18 on and that
+%^^A other packages use |!| or |\relax| instead of |\empty|, for example.
+%^^A
+%^^A This \TeX nique is described in ``The \TeX book'' on page 376.
+%
+%
+% \subsection{Substring tests}\label{iSubstringTests}
+%
+% \lstset{language=TeX,gobble=4,xleftmargin=20pt,columns=[l]fullflexible,mathescape,keywordstyle=\ttfamily,texcsstyle=\bfseries}
+% \let\texverb\lstinline
+% \lstnewenvironment{texcode}[1][]{\lstset{#1}}{}
+% \lstset{keywords={def,key}}
+%
+% It's easy to decide whether a given character sequence is a substring of
+% another string. For example, for the substring \texverb|def| we could say
+% \begin{texcode}
+%   \def \lst@temp#1def#2\relax{%
+%       \ifx \@empty#2\@empty
+%               % "def" is not a substring
+%       \else
+%               % "def" is a substring
+%       \fi}
+%
+%   \lst@temp $\meta{another\ string}$def\relax
+% \end{texcode}
+% When \TeX\ passes the arguments |#1| and |#2|, the second is empty if
+% and only if \texverb|def| is not a substring. Without the additional
+% \texverb|def\relax|, one would get a ``runaway argument'' error if
+% \meta{another string} doesn't contain \texverb|def|.
+%
+% We use substring tests mainly in the special case of an identifier and a
+% comma separated list of keys or keywords:
+% \begin{texcode}[keywords=key]
+%   \def \lst@temp#1,key,#2\relax{%
+%       \ifx \@empty#2\@empty
+%               % `key' is not a keyword
+%       \else
+%               % `key' is a keyword
+%       \fi}
+%
+%   \lst@temp,$\meta{list\ of\ keywords}$,key,\relax
+% \end{texcode}
+% This works very well and is quite fast. But we can reduce run time in the
+% case that \texttt{key} is a keyword. Then |#2| takes the rest of the string,
+% namely all keywords after \texttt{key}.
+% Since \TeX\ inserts |#2| between the \texverb|\@empty|s, it must drop all of
+% |#2| except the first character---which is compared with \texverb|\@empty|.
+% We can redirect this rest to a third parameter:
+% \begin{texcode}[keywords=key]
+%   \def \lst@temp#1,key,#2#3\relax{%
+%       \ifx \@empty#2%
+%               % "key" is not a keyword
+%       \else
+%               % "key" is a keyword
+%       \fi}
+%
+%   \lst@temp,$\meta{list\ of\ keywords}$,key,\@empty\relax
+% \end{texcode}
+% That's a bit faster and an improvement for version 0.20.
+%
+% \begin{macro}{\lst@IfSubstring}
+% The implementation should be clear from the discussion above.
+%    \begin{macrocode}
+\def\lst@IfSubstring#1#2{%
+    \def\lst@temp##1#1##2##3\relax{%
+        \ifx \@empty##2\expandafter\@secondoftwo
+                 \else \expandafter\@firstoftwo \fi}%
+    \expandafter\lst@temp#2#1\@empty\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfOneOf}
+% Ditto.
+%    \begin{macrocode}
+\def\lst@IfOneOf#1\relax#2{%
+    \def\lst@temp##1,#1,##2##3\relax{%
+        \ifx \@empty##2\expandafter\@secondoftwo
+                 \else \expandafter\@firstoftwo \fi}%
+    \expandafter\lst@temp\expandafter,#2,#1,\@empty\relax}
+%    \end{macrocode}
+% \end{macro}
+% \begin{REMOVED}
+% One day, if there is need for a case insensitive key(word) test again, we
+% can use two |\uppercase|s to normalize the first parameter:
+%    \begin{verbatim}
+%\def\lst@IfOneOfInsensitive#1\relax#2{%
+%    \uppercase{\def\lst@temp##1,#1},##2##3\relax{%
+%        \ifx \@empty##2\expandafter\@secondoftwo
+%                 \else \expandafter\@firstoftwo \fi}%
+%    \uppercase{%
+%        \expandafter\lst@temp\expandafter,#2,#1},\@empty\relax}\end{verbatim}
+% Here we assume that macro |#2| already contains capital characters only, see
+% the definition of |\lst@MakeMacroUppercase| at the very end of section
+% \ref{iMakingTests}. If we \emph{must not} assume that, we could simply
+% insert an |\expandafter| between the second |\uppercase| and the following
+% brace. But this slows down the tests!
+% \end{REMOVED}
+%
+% \begin{macro}{\lst@DeleteKeysIn}
+% The submacro does the main work; we only need to expand the second
+% macro---the list of keys to remove---and append the terminator |\relax|.
+%    \begin{macrocode}
+\def\lst@DeleteKeysIn#1#2{%
+    \expandafter\lst@DeleteKeysIn@\expandafter#1#2,\relax,}
+%    \end{macrocode}
+% `Replacing' the very last |\lst@DeleteKeysIn@| by |\lst@RemoveCommas|
+% terminates the loop here. Note: The |\@empty| after |#2| ensures that this
+% macro also works if |#2| is empty.
+%    \begin{macrocode}
+\def\lst@DeleteKeysIn@#1#2,{%
+    \ifx\relax#2\@empty
+        \expandafter\@firstoftwo\expandafter\lst@RemoveCommas
+    \else
+        \ifx\@empty#2\@empty\else
+%    \end{macrocode}
+% If we haven't reached the end of the list and if the key is not empty, we
+% define a temporary macro which removes all appearances.
+%    \begin{macrocode}
+            \def\lst@temp##1,#2,##2{%
+                ##1%
+                \ifx\@empty##2\@empty\else
+                    \expandafter\lst@temp\expandafter,%
+                \fi ##2}%
+            \edef#1{\expandafter\lst@temp\expandafter,#1,#2,\@empty}%
+        \fi
+    \fi
+    \lst@DeleteKeysIn@#1}
+%    \end{macrocode}
+% \end{macro}
+% \begin{OLDDEF}
+% The following modification needs about $50\%$ more run time.
+% It doesn't use |\edef| and thus also works with |\{| inside |#1|.
+% However, we don't need that at the moment.
+%    \begin{verbatim}
+%            \def\lst@temp##1,#2,##2{%
+%                \ifx\@empty##2%
+%                    \lst@lAddTo#1{##1}%
+%                \else
+%                    \lst@lAddTo#1{,##1}%
+%                    \expandafter\lst@temp\expandafter,%
+%                \fi ##2}%
+%            \let\@tempa#1\let#1\@empty
+%            \expandafter\lst@temp\expandafter,\@tempa,#2,\@empty\end{verbatim}
+% \end{OLDDEF}
+%
+% \begin{macro}{\lst@RemoveCommas}
+% The macro drops commas at the beginning and assigns the new value to |#1|.
+%    \begin{macrocode}
+\def\lst@RemoveCommas#1{\edef#1{\expandafter\lst@RC@#1\@empty}}
+\def\lst@RC@#1{\ifx,#1\expandafter\lst@RC@ \else #1\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{OLDDEF}
+% The following version works with |\{| inside the macro |#1|.
+%    \begin{verbatim}
+%\def\lst@RemoveCommas#1{\expandafter\lst@RC@#1\@empty #1}
+%\def\lst@RC@#1{%
+%    \ifx,#1\expandafter\lst@RC@
+%      \else\expandafter\lst@RC@@\expandafter#1\fi}
+%\def\lst@RC@@#1\@empty#2{\def#2{#1}}\end{verbatim}
+% \end{OLDDEF}
+%
+% \begin{macro}{\lst@ReplaceIn}
+% \begin{macro}{\lst@ReplaceInArg}
+% These macros are similar to |\lst@DeleteKeysIn|, except that \ldots
+%    \begin{macrocode}
+\def\lst@ReplaceIn#1#2{%
+    \expandafter\lst@ReplaceIn@\expandafter#1#2\@empty\@empty}
+\def\lst@ReplaceInArg#1#2{\lst@ReplaceIn@#1#2\@empty\@empty}
+%    \end{macrocode}
+% \ldots\space we replace |#2| by |#3| instead of |,#2,| by a single comma
+% (which removed the key |#2| above).
+%    \begin{macrocode}
+\def\lst@ReplaceIn@#1#2#3{%
+    \ifx\@empty#3\relax\else
+        \def\lst@temp##1#2##2{%
+            \ifx\@empty##2%
+                \lst@lAddTo#1{##1}%
+            \else
+                \lst@lAddTo#1{##1#3}\expandafter\lst@temp
+            \fi ##2}%
+        \let\@tempa#1\let#1\@empty
+        \expandafter\lst@temp\@tempa#2\@empty
+        \expandafter\lst@ReplaceIn@\expandafter#1%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Flow of control}
+%
+% \begin{macro}{\@gobblethree}
+% is defined if and only if undefined.
+%    \begin{macrocode}
+\providecommand*\@gobblethree[3]{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GobbleNil}
+%    \begin{macrocode}
+\def\lst@GobbleNil#1\@nil{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Swap}
+% is just this:
+%    \begin{macrocode}
+\def\lst@Swap#1#2{#2#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@if}
+% \begin{macro}{\lst@true}
+% \begin{macro}{\lst@false}
+% A general |\if| for temporary use.
+%    \begin{macrocode}
+\def\lst@true{\let\lst@if\iftrue}
+\def\lst@false{\let\lst@if\iffalse}
+\lst@false
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextCharsArg}
+% is quite easy: We define a macro and call |\lst@IfNextChars|.
+%    \begin{macrocode}
+\def\lst@IfNextCharsArg#1{%
+    \def\lst@tofind{#1}\lst@IfNextChars\lst@tofind}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextChars}
+% We save the arguments and start a loop.
+%    \begin{macrocode}
+\def\lst@IfNextChars#1#2#3{%
+    \let\lst@tofind#1\def\@tempa{#2}\def\@tempb{#3}%
+    \let\lst@eaten\@empty \lst@IfNextChars@}
+%    \end{macrocode}
+% Expand the characters we are looking for.
+%    \begin{macrocode}
+\def\lst@IfNextChars@{\expandafter\lst@IfNextChars@@\lst@tofind\relax}
+%    \end{macrocode}
+% Now we can refine |\lst@tofind| and append the input character |#3| to
+% |\lst@eaten|.
+%    \begin{macrocode}
+\def\lst@IfNextChars@@#1#2\relax#3{%
+    \def\lst@tofind{#2}\lst@lAddTo\lst@eaten{#3}%
+    \ifx#1#3%
+%    \end{macrocode}
+% If characters are the same, we either call |\@tempa| or continue the test.
+%    \begin{macrocode}
+        \ifx\lst@tofind\@empty
+            \let\lst@next\@tempa
+        \else
+            \let\lst@next\lst@IfNextChars@
+        \fi
+        \expandafter\lst@next
+    \else
+%    \end{macrocode}
+% If the characters are different, we call |\@tempb|.
+%    \begin{macrocode}
+        \expandafter\@tempb
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextCharActive}
+% We compare the character |#3| with its active version |\lowercase{~}|.
+% Note that the right brace between |\ifx~| and |#3| ends the |\lowercase|.
+% The |\endgroup| restores the |\lccode|.
+%    \begin{macrocode}
+\def\lst@IfNextCharActive#1#2#3{%
+    \begingroup \lccode`\~=`#3\lowercase{\endgroup
+    \ifx~}#3%
+        \def\lst@next{#1}%
+    \else
+        \def\lst@next{#2}%
+    \fi \lst@next #3}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@for}
+% A for-loop with expansion of the loop-variable.
+%    \begin{macrocode}
+\def\lst@for#1\do#2{%
+    \def\lst@forbody##1{#2}%
+    \@for\lst@forvar:=#1\do
+	    {\expandafter\lst@forbody\expandafter{\lst@forvar}}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Catcode changes}\label{iCatcodeChanges}
+%
+% A character gets its catcode right after reading it and \TeX\ has no 
+% primitive command to change attached catcodes. However, we can replace these
+% characters by characters with same ASCII codes and different catcodes.
+% It's not the same but suffices since the result is the same.
+% Here we treat the very special case that all characters become active.
+% If we want \texverb|\lst@arg| to contain an active version of the character
+% |#1|, a prototype macro could be
+% \begin{texcode}
+%   \def\lst@MakeActive#1{\lccode`\~=`#1\lowercase{\def\lst@arg{~}}}
+% \end{texcode}
+% The |\lowercase| changes the ASCII code of |~| to the one of |#1| since we
+% have said that |~| is the lower case version of |#1|.
+% Fortunately the |\lowercase| doesn't change the catcode, so we have an active
+% version of |#1|.
+% Note that |~| is usually active.
+%
+% \begin{macro}{\lst@MakeActive}
+% We won't do this character by character.
+% To increase speed we change nine characters at the same time (if nine
+% characters are left).
+% \begin{TODO}
+% This was introduced when the delimiters were converted each listings. Now
+% this conversion is done only each language selection. So we might want to
+% implement a character by character conversion again to decrease the memory
+% usage.
+% \end{TODO}
+% We get the argument, empty |\lst@arg| and begin a loop.
+%    \begin{macrocode}
+\def\lst@MakeActive#1{%
+    \let\lst@temp\@empty \lst@MakeActive@#1%
+    \relax\relax\relax\relax\relax\relax\relax\relax\relax}
+%    \end{macrocode}
+% There are nine |\relax|es since |\lst@MakeActive@| has nine parameters and we
+% don't want any problems in the case that |#1| is empty.
+% We need nine active characters now instead of a single |~|.
+% We make these catcode changes local and define the coming macro |\global|.
+%    \begin{macrocode}
+\begingroup
+\catcode`\^^@=\active \catcode`\^^A=\active \catcode`\^^B=\active
+\catcode`\^^C=\active \catcode`\^^D=\active \catcode`\^^E=\active
+\catcode`\^^F=\active \catcode`\^^G=\active \catcode`\^^H=\active
+%    \end{macrocode}
+% First we |\let| the next operation be |\relax|.
+% This aborts our loop for processing all characters (default and possibly
+% changed later).
+% Then we look if we have at least one character.
+% If this is not the case, the loop terminates and all is done.
+%    \begin{macrocode}
+\gdef\lst@MakeActive@#1#2#3#4#5#6#7#8#9{\let\lst@next\relax
+    \ifx#1\relax
+    \else \lccode`\^^@=`#1%
+%    \end{macrocode}
+% Otherwise we say that |^^@|=chr(0) is the lower case version of the first
+% character.
+% Then we test the second character.
+% If there is none, we append the lower case |^^@| to |\lst@temp|.
+% Otherwise we say that |^^A|=chr(1) is the lower case version of the second
+% character and we test the next argument, and so on.
+%    \begin{macrocode}
+    \ifx#2\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@}}%
+    \else \lccode`\^^A=`#2%
+    \ifx#3\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A}}%
+    \else \lccode`\^^B=`#3%
+    \ifx#4\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B}}%
+    \else \lccode`\^^C=`#4%
+    \ifx#5\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C}}%
+    \else \lccode`\^^D=`#5%
+    \ifx#6\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D}}%
+    \else \lccode`\^^E=`#6%
+    \ifx#7\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E}}%
+    \else \lccode`\^^F=`#7%
+    \ifx#8\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E^^F}}%
+    \else \lccode`\^^G=`#8%
+    \ifx#9\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E^^F^^G}}%
+%    \end{macrocode}
+% If nine characters are present, we append (lower case versions of) nine
+% active characters and call this macro again via redefining |\lst@next|.
+%    \begin{macrocode}
+    \else \lccode`\^^H=`#9%
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E^^F^^G^^H}}%
+        \let\lst@next\lst@MakeActive@
+    \fi \fi \fi \fi \fi \fi \fi \fi \fi
+    \lst@next}
+\endgroup
+%    \end{macrocode}
+% This |\endgroup| restores the catcodes of chr(0)--chr(8), but not the
+% catcodes of the characters inside |\lst@MakeActive@| since they are already
+% read.
+%
+% Note: A conversion from an arbitrary `catcode--character code' table back to
+% \TeX's catcodes is possible if we test against the character codes (either
+% via |\ifnum| or |\ifcase|).
+% But control sequences and begin and end group characters definitely need
+% some special treatment.
+% However I haven't checked the details.
+% So just ignore this and don't bother me for this note. :\,--\,)
+% \end{macro}
+%
+% \begin{macro}{\lst@DefActive}
+% An easy application of |\lst@MakeActive|.
+%    \begin{macrocode}
+\def\lst@DefActive#1#2{\lst@MakeActive{#2}\let#1\lst@temp}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefOther}
+% We use the fact that |\meaning| produces catcode 12 characters except spaces
+% stay spaces. |\escapechar| is modified locally to suppress the output of an
+% escape character. Finally we remove spaces via \LaTeX's |\zap@space|, which
+% was proposed by \lsthelper{Rolf~Niepraschk}{1997/04/24}{use \zap@space}---not
+% in this context, but that doesn't matter.
+%    \begin{macrocode}
+\def\lst@DefOther#1#2{%
+    \begingroup \def#1{#2}\escapechar\m@ne \expandafter\endgroup
+    \expandafter\lst@DefOther@\meaning#1\relax#1}
+\def\lst@DefOther@#1>#2\relax#3{\edef#3{\zap@space#2 \@empty}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+%\ifhyper
+% \subsection{Applications to \ref*{iCatcodeChanges}}\label{iApplicationsTo}
+%\else
+% \subsection{Applications to \ref{iCatcodeChanges}}\label{iApplicationsTo}
+%\fi
+%
+% If an environment is used inside an argument, the listing is already read and
+% we can do nothing to preserve the catcodes.
+% However, under certain circumstances the environment can be used inside an
+% argument---that's at least what I've said in the User's guide.
+% And now I have to work for it coming true.
+% Moreover we define an analogous conversion macro for the
+% \packagename{fancyvrb} mode.
+% \begin{syntax}
+% \item[0.19] |\lst@InsideConvert{|\meta{\TeX\ material \textup(already read\textup)}|}|
+%
+%       \emph{appends} a verbatim version of the argument to |\lst@arg|, but all
+%       appended characters are active. Since it's not a character to character
+%       conversion, `verbatim' needs to be explained. All characters can be
+%       typed in as they are except |\|, |{|, |}| and |%|. If you want one of
+%       these, you must write |\\|, |\{|, |\}| and |\%| instead.
+%       If two spaces should follow each other, the second (third, fourth,
+%       \ldots) space must be entered with a preceding backslash.
+%
+% \item[0.19] |\lst@XConvert{|\meta{\TeX\ material \textup(already read\textup)}|}|
+%
+%       \emph{appends} a `verbatim' version of the argument to |\lst@arg|.
+%       Here \TeX\ material is allowed to be put inside argument braces like
+%       |{(*}{*)}|. The contents of these arguments are converted, the braces
+%       stay as curly braces.
+%
+%       If |\lst@if| is true, each second argument is treated differently.
+%       Only the first character (of the delimiter) becomes active.
+% \end{syntax}
+%
+% \begin{macro}{\lst@InsideConvert}
+% We call a submacro (similar to |\zap@space|) to preserve single spaces which
+% are replaced by active spaces.
+%    \begin{macrocode}
+\def\lst@InsideConvert#1{\lst@InsideConvert@#1 \@empty}
+\begingroup \lccode`\~=`\ \relax \lowercase{%
+%    \end{macrocode}
+% We make |#1| active and append these characters (plus an active space) to
+% |\lst@arg|.
+% If we haven't found the end |\@empty| of the input, we continue the process.
+%    \begin{macrocode}
+\gdef\lst@InsideConvert@#1 #2{%
+    \lst@MakeActive{#1}%
+    \ifx\@empty#2%
+        \lst@lExtend\lst@arg{\lst@temp}%
+    \else
+        \lst@lExtend\lst@arg{\lst@temp~}%
+        \expandafter\lst@InsideConvert@
+    \fi #2}
+%    \end{macrocode}
+% Finally we end the |\lowercase| and close a group.
+%    \begin{macrocode}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@XConvert}
+% Check for an argument \ldots
+%    \begin{macrocode}
+\def\lst@XConvert{\@ifnextchar\bgroup \lst@XConvertArg\lst@XConvert@}
+%    \end{macrocode}
+% \ldots, convert the argument, add it together with group delimiters to
+% |\lst@arg|, and we continue the conversion.
+%    \begin{macrocode}
+\def\lst@XConvertArg#1{%
+    {\lst@false \let\lst@arg\@empty
+     \lst@XConvert#1\@nil
+     \global\let\@gtempa\lst@arg}%
+    \lst@lExtend\lst@arg{\expandafter{\@gtempa}}%
+    \lst@XConvertNext}
+%    \end{macrocode}
+% Having no |\bgroup|, we look whether we've found the end of the input, and
+% convert one token ((non)active character or control sequence) and continue.
+%    \begin{macrocode}
+\def\lst@XConvert@#1{%
+    \ifx\@nil#1\else
+        \begingroup\lccode`\~=`#1\lowercase{\endgroup
+        \lst@lAddTo\lst@arg~}%
+        \expandafter\lst@XConvertNext
+    \fi}
+\def\lst@XConvertNext{%
+    \lst@if \expandafter\lst@XConvertX
+      \else \expandafter\lst@XConvert \fi}
+%    \end{macrocode}
+% Now we make only the first character active.
+%    \begin{macrocode}
+\def\lst@XConvertX#1{%
+    \ifx\@nil#1\else
+        \lst@XConvertX@#1\relax
+        \expandafter\lst@XConvert
+    \fi}
+\def\lst@XConvertX@#1#2\relax{%
+    \begingroup\lccode`\~=`#1\lowercase{\endgroup
+    \lst@XCConvertX@@~}{#2}}
+\def\lst@XCConvertX@@#1#2{\lst@lAddTo\lst@arg{{#1#2}}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Driver file handling*}
+%
+% The \packagename{listings} package is split into several driver files,
+% miscellaneous (= aspect) files, and one kernel file.
+% All these files can be loaded partially and on demand---except the kernel
+% which provides this functionality.
+% \begin{syntax}
+% \item[0.21] |\lst@Require|\marg{name}\marg{prefix}\marg{feature list}\meta{alias}\meta{file list macro}
+%
+%       tries to load all items of \meta{feature list} from the files
+%       listed in \meta{file list macro}.
+%       Each item has the form [\oarg{sub}]\meta{feature}.
+%       |\lst@if| equals |\iftrue| if and only if all items were loadable.
+%
+%       The macro \meta{alias} gets an item as argument and must define
+%       appropriate versions of |\lst@oalias| and |\lst@malias|. In fact
+%       the feature associated with these definitions is loaded. You can
+%       use \meta{alias}=|\lst@NoAlias| for no substitution.
+%
+%       \meta{prefix} identifies the type internally and \meta{name} is used
+%       for messages.
+%
+%       For example, |\lstloadaspects| uses the following arguments where |#1|
+%       is the list of aspects: |{aspects}|\allowbreak|a|\allowbreak
+%       |{#1}|\allowbreak|\lst@NoAlias|\allowbreak|\lstaspectfiles|.
+%
+% \item[0.20] |\lst@DefDriver|\marg{name}\marg{prefix}\meta{interface macro}|\if|\alternative{true,false}
+%
+%       
+%
+% \item[0.21] |\lst@IfRequired|\oarg{sub}\marg{feature}\marg{then}\marg{else}
+%
+%       is used inside a driver file by the aspect, language, or whatever
+%       else defining commands. \meta{then} is executed if and only if
+%       \oarg{sub}\marg{feature} has been requested via |\lst@Require|.
+%       Otherwise \meta{else} is executed---which is also the case for
+%       subsequent calls with the same \oarg{sub}\marg{feature}.
+%
+%       \meta{then} and \meta{else} may use |\lst@prefix| (read access only).
+%
+%       |\lst@BeginAspect| in section \ref{iAspectCommands} and |\lst@DefDriver|
+%       serve as examples.
+% \end{syntax}
+%
+% \begin{macro}{\lst@Require}
+% Initialize variables (if required items aren't empty), \ldots
+%    \begin{macrocode}
+\def\lst@Require#1#2#3#4#5{%
+    \begingroup
+    \aftergroup\lst@true
+    \ifx\@empty#3\@empty\else
+        \def\lst@prefix{#2}\let\lst@require\@empty
+%    \end{macrocode}
+% \ldots\space and for each nonempty item: determine alias and add it to
+% |\lst@require| if it isn't loaded.
+%    \begin{macrocode}
+        \edef\lst@temp{\expandafter\zap@space#3 \@empty}%
+        \lst@for\lst@temp\do{%
+          \ifx\@empty##1\@empty\else \lstKV@OptArg[]{##1}{%
+            #4[####1]{####2}%
+            \@ifundefined{\@lst\lst@prefix @\lst@malias $\lst@oalias}%
+            {\edef\lst@require{\lst@require,\lst@malias $\lst@oalias}}%
+            {}}%
+          \fi}%
+%    \end{macrocode}
+% Init things and input files if and as long as it is necessary.
+%    \begin{macrocode}
+        \global\let\lst@loadaspects\@empty
+        \lst@InputCatcodes
+        \ifx\lst@require\@empty\else
+            \lst@for{#5}\do{%
+                \ifx\lst@require\@empty\else
+                    \InputIfFileExists{##1}{}{}%
+                \fi}%
+        \fi
+%    \end{macrocode}
+% Issue error and call |\lst@false| (after closing the local group) if some
+% items weren't loadable.
+%    \begin{macrocode}
+        \ifx\lst@require\@empty\else
+            \PackageError{Listings}{Couldn't load requested #1}%
+            {The following #1s weren't loadable:^^J\@spaces
+             \lst@require^^JThis may cause errors in the sequel.}%
+            \aftergroup\lst@false
+        \fi
+%    \end{macrocode}
+% Request aspects.
+%    \begin{macrocode}
+        \ifx\lst@loadaspects\@empty\else
+            \lst@RequireAspects\lst@loadaspects
+        \fi
+    \fi
+    \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfRequired}
+% uses |\lst@IfOneOf| and adds some code to \meta{then} part:
+% delete the now loaded item from the list and define
+% |\lst|\meta{prefix}|@|\meta{feature}|$|\meta{sub}.
+%    \begin{macrocode}
+\def\lst@IfRequired[#1]#2{%
+    \lst@NormedDef\lst@temp{[#1]#2}%
+    \expandafter\lst@IfRequired@\lst@temp\relax}
+\def\lst@IfRequired@[#1]#2\relax#3{%
+    \lst@IfOneOf #2$#1\relax\lst@require
+        {\lst@DeleteKeysIn@\lst@require#2$#1,\relax,%
+         \global\expandafter\let
+             \csname\@lst\lst@prefix @#2$#1\endcsname\@empty
+         #3}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@require}
+%    \begin{macrocode}
+\let\lst@require\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NoAlias}
+% just defines |\lst@oalias| and |\lst@malias|.
+%    \begin{macrocode}
+\def\lst@NoAlias[#1]#2{%
+    \lst@NormedDef\lst@oalias{#1}\lst@NormedDef\lst@malias{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LAS}
+%    \begin{macrocode}
+\gdef\lst@LAS#1#2#3#4#5#6#7{%
+    \lst@Require{#1}{#2}{#3}#4#5%
+    #4#3%
+    \@ifundefined{lst#2@\lst@malias$\lst@oalias}%
+        {\PackageError{Listings}%
+         {#1 \ifx\@empty\lst@oalias\else \lst@oalias\space of \fi
+          \lst@malias\space undefined}%
+         {The #1 is not loadable. \@ehc}}%
+        {#6\csname\@lst#2@\lst@malias $\lst@oalias\endcsname #7}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@RequireAspects}
+% \begin{macro}{\lstloadaspects}
+% make use of the just developped definitions.
+%    \begin{macrocode}
+\def\lst@RequireAspects#1{%
+    \lst@Require{aspect}{asp}{#1}\lst@NoAlias\lstaspectfiles}
+\let\lstloadaspects\lst@RequireAspects
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lstaspectfiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lstaspectfiles}
+    {\newcommand\lstaspectfiles{lstmisc0.sty,lstmisc.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDriver}
+% Test the next character and reinsert the arguments.
+%    \begin{macrocode}
+\gdef\lst@DefDriver#1#2#3#4{%
+    \@ifnextchar[{\lst@DefDriver@{#1}{#2}#3#4}%
+                 {\lst@DefDriver@{#1}{#2}#3#4[]}}
+%    \end{macrocode}
+% We set |\lst@if| locally true if the item has been requested.
+%    \begin{macrocode}
+\gdef\lst@DefDriver@#1#2#3#4[#5]#6{%
+    \def\lst@name{#1}\let\lst@if#4%
+    \lst@NormedDef\lst@driver{\@lst#2@#6$#5}%
+    \lst@IfRequired[#5]{#6}{\begingroup \lst@true}%
+                           {\begingroup}%
+    \lst@setcatcodes
+    \@ifnextchar[{\lst@XDefDriver{#1}#3}{\lst@DefDriver@@#3}}
+%    \end{macrocode}
+% Note that |\lst@XDefDriver| takes optional `base' arguments, but eventually
+% calls |\lst@DefDriver@@|. We define the item (in case of need), and
+% |\endgroup| resets some catcodes and |\lst@if|, i.e.~|\lst@XXDefDriver| knows
+% whether called by a public or internal command.
+%    \begin{macrocode}
+\gdef\lst@DefDriver@@#1#2{%
+    \lst@if
+        \global\@namedef{\lst@driver}{#1{#2}}%
+    \fi
+    \endgroup
+    \@ifnextchar[\lst@XXDefDriver\@empty}
+%    \end{macrocode}
+% We get the aspect argument, and (if not empty) load the aspects immediately
+% if called by a public command or extend the list of required aspects or
+% simply ignore the argument if the item leaves undefined.
+%    \begin{macrocode}
+\gdef\lst@XXDefDriver[#1]{%
+    \ifx\@empty#1\@empty\else
+        \lst@if
+            \lstloadaspects{#1}%
+        \else
+            \@ifundefined{\lst@driver}{}%
+            {\xdef\lst@loadaspects{\lst@loadaspects,#1}}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% We insert an additional `also'key=value pair.
+%    \begin{macrocode}
+\gdef\lst@XDefDriver#1#2[#3]#4#5{\lst@DefDriver@@#2{also#1=[#3]#4,#5}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Aspect commands}\label{iAspectCommands}
+%
+% This section contains commands used in defining `\lst-aspects'.
+% \begin{macro}{\lst@UserCommand}
+% is mainly equivalent to |\gdef|.
+%    \begin{macrocode}
+%<!info>\let\lst@UserCommand\gdef
+%<info>\def\lst@UserCommand#1{\message{\string#1,}\gdef#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginAspect}
+% A straight-forward implementation:
+%    \begin{macrocode}
+\newcommand*\lst@BeginAspect[2][]{%
+    \def\lst@curraspect{#2}%
+    \ifx \lst@curraspect\@empty
+        \expandafter\lst@GobbleAspect
+    \else
+%    \end{macrocode}
+% If \meta{aspect name} is not empty, there are certain other conditions not to
+% define the aspect (as described in section \ref{dHowToDefineLstAspects}).
+%    \begin{macrocode}
+%<!info>        \let\lst@next\@empty
+%<info>        \def\lst@next{%
+%<info>            \message{^^JDefine lst-aspect `#2':}\lst@GetAllocs}%
+        \lst@IfRequired[]{#2}%
+            {\lst@RequireAspects{#1}%
+             \lst@if\else \let\lst@next\lst@GobbleAspect \fi}%
+            {\let\lst@next\lst@GobbleAspect}%
+        \expandafter\lst@next
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndAspect}
+% finishes an aspect definition.
+%    \begin{macrocode}
+\def\lst@EndAspect{%
+    \csname\@lst patch@\lst@curraspect\endcsname
+%<info>    \lst@ReportAllocs
+    \let\lst@curraspect\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GobbleAspect}
+% drops all code up to the next |\lst@EndAspect|.
+%    \begin{macrocode}
+\long\def\lst@GobbleAspect#1\lst@EndAspect{\let\lst@curraspect\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Key}
+% The command simply defines the key. But we must take care of an optional
+% parameter and the initialization argument |#2|.
+%    \begin{macrocode}
+\def\lst@Key#1#2{%
+%<info>    \message{#1,}%
+    \@ifnextchar[{\lstKV@def{#1}{#2}}%
+                 {\def\lst@temp{\lst@Key@{#1}{#2}}
+                  \afterassignment\lst@temp
+                  \global\@namedef{KV@\@lst @#1}####1}}
+%    \end{macrocode}
+% Now comes a renamed and modified copy from a \packagename{keyval} macro:
+% We need global key definitions.
+%    \begin{macrocode}
+\def\lstKV@def#1#2[#3]{%
+    \global\@namedef{KV@\@lst @#1@default\expandafter}\expandafter
+        {\csname KV@\@lst @#1\endcsname{#3}}%
+    \def\lst@temp{\lst@Key@{#1}{#2}}\afterassignment\lst@temp
+    \global\@namedef{KV@\@lst @#1}##1}
+%    \end{macrocode}
+% We initialize the key if the first token of |#2| is not |\relax|.
+%    \begin{macrocode}
+\def\lst@Key@#1#2{%
+    \ifx\relax#2\@empty\else
+        \begingroup \globaldefs\@ne
+        \csname KV@\@lst @#1\endcsname{#2}%
+        \endgroup
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@UseHook}
+% is very, very, \ldots, very (hundreds of times) easy.
+%    \begin{macrocode}
+\def\lst@UseHook#1{\csname\@lst hk@#1\endcsname}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AddToHook}
+% \begin{macro}{\lst@AddToHookExe}
+% \begin{macro}{\lst@AddToHookAtTop}
+% All use the same submacro.
+%    \begin{macrocode}
+\def\lst@AddToHook{\lst@ATH@\iffalse\lst@AddTo}
+\def\lst@AddToHookExe{\lst@ATH@\iftrue\lst@AddTo}
+\def\lst@AddToHookAtTop{\lst@ATH@\iffalse\lst@AddToAtTop}
+%    \end{macrocode}
+% If and only if the boolean value is true, the hook material is executed
+% globally.
+%    \begin{macrocode}
+\long\def\lst@ATH@#1#2#3#4{%
+    \@ifundefined{\@lst hk@#3}{%
+%<info>        \message{^^Jnew hook `#3',^^J}%
+        \expandafter\gdef\csname\@lst hk@#3\endcsname{}}{}%
+    \expandafter#2\csname\@lst hk@#3\endcsname{#4}%
+    \def\lst@temp{#4}%
+    #1% \iftrue|false
+        \begingroup \globaldefs\@ne \lst@temp \endgroup
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@AddTo}
+% Note that the definition is global!
+%    \begin{macrocode}
+\long\def\lst@AddTo#1#2{%
+    \expandafter\gdef\expandafter#1\expandafter{#1#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AddToAtTop}
+% We need a couple of |\expandafter|s now. Simply note that we have\\
+%   {\small\hspace*{2em}|\expandafter\gdef\expandafter#1\expandafter{\lst@temp|
+%    $\langle$\textit{contents of }|#1|$\rangle$|}|}\\
+% after the `first phase' of expansion.
+%    \begin{macrocode}
+\def\lst@AddToAtTop#1#2{\def\lst@temp{#2}%
+    \expandafter\expandafter\expandafter\gdef
+    \expandafter\expandafter\expandafter#1%
+    \expandafter\expandafter\expandafter{\expandafter\lst@temp#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@lAddTo}
+% A local version of |\lst@AddTo| \ldots
+%    \begin{macrocode}
+\def\lst@lAddTo#1#2{\expandafter\def\expandafter#1\expandafter{#1#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Extend}
+% \begin{macro}{\lst@lExtend}
+% \ldots\space and here we expand the first token of the second argument first.
+%    \begin{macrocode}
+\def\lst@Extend#1#2{%
+    \expandafter\lst@AddTo\expandafter#1\expandafter{#2}}
+\def\lst@lExtend#1#2{%
+    \expandafter\lst@lAddTo\expandafter#1\expandafter{#2}}
+%    \end{macrocode}
+% \begin{TODO}
+% This should never be changed to
+%    \begin{verbatim}
+%    \def\lst@Extend#1{%
+%        \expandafter\lst@AddTo\expandafter#1\expandafter}
+%    \def\lst@lExtend#1{%
+%        \expandafter\lst@lAddTo\expandafter#1}\end{verbatim}
+% The first is not equivalent in case that the second argument is a single
+% (= non-braced) control sequence, and the second isn't in case of a braced
+% second argument.
+% \end{TODO}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Interfacing with \textsf{keyval}}
+%
+% The \packagename{keyval} package passes the value via the one and only
+% paramater |#1| to the definition part of the key macro. The following
+% commands may be used to analyse the value. Note that we need at least version
+% 1.10 of the \packagename{keyval} package. Note also that the package removes
+% a naming conflict with AMS classes---reported by \lsthelper{Ralf~Quast}
+% {1998/01/08}{\keywords conflicts with AMS classes}.
+% \begingroup
+%    \begin{macrocode}
+\RequirePackage{keyval}[1997/11/10]
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lstKV@TwoArg}
+% \begin{macro}{\lstKV@ThreeArg}
+% \begin{macro}{\lstKV@FourArg}
+% Define temporary macros and call with given arguments |#1|. We add empty
+% arguments for the case that the user doesn't provide enough.
+%    \begin{macrocode}
+\def\lstKV@TwoArg#1#2{\gdef\@gtempa##1##2{#2}\@gtempa#1{}{}}
+\def\lstKV@ThreeArg#1#2{\gdef\@gtempa##1##2##3{#2}\@gtempa#1{}{}{}}
+\def\lstKV@FourArg#1#2{\gdef\@gtempa##1##2##3##4{#2}\@gtempa#1{}{}{}{}}
+%    \end{macrocode}
+% There's one question: What are the global definitions good for? |\lst@Key|
+% might set |\globaldefs| to one and possibly calls this macro. That's the
+% reason why we use global definitions here and below.
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@OptArg}
+% We define the temporary macro |\@gtempa| and insert default argument if
+% necessary.
+%    \begin{macrocode}
+\def\lstKV@OptArg[#1]#2#3{%
+    \gdef\@gtempa[##1]##2{#3}\lstKV@OptArg@{#1}#2\@}
+\def\lstKV@OptArg@#1{\@ifnextchar[\lstKV@OptArg@@{\lstKV@OptArg@@[#1]}}
+\def\lstKV@OptArg@@[#1]#2\@{\@gtempa[#1]{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@XOptArg}
+% Here |#3| is already a definition with at least two parameters whose first
+% is enclosed in brackets.
+%    \begin{macrocode}
+\def\lstKV@XOptArg[#1]#2#3{%
+    \global\let\@gtempa#3\lstKV@OptArg@{#1}#2\@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@CSTwoArg}
+% Just define temporary macro and call it.
+%    \begin{macrocode}
+\def\lstKV@CSTwoArg#1#2{%
+    \gdef\@gtempa##1,##2,##3\relax{#2}%
+    \@gtempa#1,,\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@SetIf}
+% We simply test the lower case first character of |#1|.
+%    \begin{macrocode}
+\def\lstKV@SetIf#1{\lstKV@SetIf@#1\relax}
+\def\lstKV@SetIf@#1#2\relax#3{\lowercase{%
+    \expandafter\let\expandafter#3%
+        \csname if\ifx #1t}true\else false\fi\endcsname}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@SwitchCases}
+% is implemented as a substring test.
+%    \begin{macrocode}
+\def\lstKV@SwitchCases#1#2#3{%
+    \def\lst@temp##1\\#1&##2\\##3##4\@nil{%
+        \ifx\@empty##3%
+            #3%
+        \else
+            ##2%
+        \fi
+    }%
+    \lst@temp\\#2\\#1&\\\@empty\@nil}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstset}
+% Finally this main user interface macro.
+% We change catcodes for reading the argument.
+%    \begin{macrocode}
+\lst@UserCommand\lstset{\begingroup \lst@setcatcodes \lstset@}
+\def\lstset@#1{\endgroup \ifx\@empty#1\@empty\else\setkeys{lst}{#1}\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@setcatcodes}
+% contains all catcode changes for |\lstset|.
+%    \begin{macrocode}
+\def\lst@setcatcodes{\makeatletter \catcode`\"=12\relax}
+%    \end{macrocode}
+% \begin{TODO}
+% Change more catcodes?
+% \end{TODO}
+% \end{macro}
+%
+%
+% \subsection{Internal modes}
+%
+% \begin{macro}{\lst@NewMode}
+% We simply use |\chardef| for a mode definition. The counter |\lst@mode|
+% mainly keeps the current mode number. But it is also used to advance the
+% number in the macro |\lst@newmode|---we don't waste another counter.
+%    \begin{macrocode}
+\def\lst@NewMode#1{%
+    \ifx\@undefined#1%
+        \lst@mode\lst@newmode\relax \advance\lst@mode\@ne
+        \xdef\lst@newmode{\the\lst@mode}%
+        \global\chardef#1=\lst@mode
+        \lst@mode\lst@nomode
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@mode}
+% \begin{macro}{\lst@nomode}
+% We allocate the counter and the first mode.
+%    \begin{macrocode}
+\newcount\lst@mode
+\def\lst@newmode{\m@ne}% init
+\lst@NewMode\lst@nomode % init (of \lst@mode :-)
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@UseDynamicMode}
+% For dynamic modes we must not use the counter |\lst@mode| (since possibly
+% already valued). |\lst@dynamicmode| substitutes |\lst@newmode| and is a local
+% definition here, \ldots
+%    \begin{macrocode}
+\def\lst@UseDynamicMode{%
+    \@tempcnta\lst@dynamicmode\relax \advance\@tempcnta\@ne
+    \edef\lst@dynamicmode{\the\@tempcnta}%
+    \expandafter\lst@Swap\expandafter{\expandafter{\lst@dynamicmode}}}
+%    \end{macrocode}
+% \ldots\ initialized each listing with the current `value' of |\lst@newmode|.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\let\lst@dynamicmode\lst@newmode}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EnterMode}
+% Each mode opens a group level, stores the mode number and execute mode
+% specific tokens. Moreover we keep all these changes in mind (locally) and
+% adjust internal variables if the user wants it.
+%    \begin{macrocode}
+\def\lst@EnterMode#1#2{%
+    \bgroup \lst@mode=#1\relax #2%
+    \lst@FontAdjust
+    \lst@lAddTo\lst@entermodes{\lst@EnterMode{#1}{#2}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\let\lst@entermodes\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LeaveMode}
+% We simply close the group and call |\lsthk@EndGroup| if and only if the
+% current mode is not |\lst@nomode|.
+%    \begin{macrocode}
+\def\lst@LeaveMode{%
+    \ifnum\lst@mode=\lst@nomode\else
+        \egroup \expandafter\lsthk@EndGroup
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{EndGroup}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InterruptModes}
+% We put the current mode sequence on a stack and leave all modes.
+%    \begin{macrocode}
+\def\lst@InterruptModes{%
+    \lst@Extend\lst@modestack{\expandafter{\lst@entermodes}}%
+    \lst@LeaveAllModes}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\global\let\lst@modestack\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ReenterModes}
+% If the stack is not empty, we leave all modes and pop the topmost element
+% (which is the last element of |\lst@modestack|).
+%    \begin{macrocode}
+\def\lst@ReenterModes{%
+    \ifx\lst@modestack\@empty\else
+        \lst@LeaveAllModes
+        \global\let\@gtempa\lst@modestack
+        \global\let\lst@modestack\@empty
+        \expandafter\lst@ReenterModes@\@gtempa\relax
+    \fi}
+\def\lst@ReenterModes@#1#2{%
+    \ifx\relax#2\@empty
+%    \end{macrocode}
+% If we've reached |\relax|, we've also found the last element: we execute |#1|
+% and gobble |{#2}|=|{\relax}| after |\fi|.
+%    \begin{macrocode}
+        \gdef\@gtempa##1{#1}%
+        \expandafter\@gtempa
+    \else
+%    \end{macrocode}
+% Otherwise we just add the element to |\lst@modestack| and continue the loop.
+%    \begin{macrocode}
+        \lst@AddTo\lst@modestack{{#1}}%
+        \expandafter\lst@ReenterModes@
+    \fi
+    {#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LeaveAllModes}
+% Leaving all modes means closing groups until the mode equals |\lst@nomode|.
+%    \begin{macrocode}
+\def\lst@LeaveAllModes{%
+    \ifnum\lst@mode=\lst@nomode
+        \expandafter\lsthk@EndGroup
+    \else
+        \expandafter\egroup\expandafter\lst@LeaveAllModes
+    \fi}
+%    \end{macrocode}
+% We need that macro to end a listing correctly.
+%    \begin{macrocode}
+\lst@AddToHook{ExitVars}{\lst@LeaveAllModes}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Pmode}
+% \begin{macro}{\lst@GPmode}
+% The `processing' and the general purpose mode.
+%    \begin{macrocode}
+\lst@NewMode\lst@Pmode
+\lst@NewMode\lst@GPmode
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@modetrue}
+% The usual macro to value a boolean except that we also execute a hook.
+%    \begin{macrocode}
+\def\lst@modetrue{\let\lst@ifmode\iftrue \lsthk@ModeTrue}
+\let\lst@ifmode\iffalse % init
+\lst@AddToHook{ModeTrue}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifLmode}
+% Comment lines use a static mode. It terminates at end of line.
+%    \begin{macrocode}
+\def\lst@Lmodetrue{\let\lst@ifLmode\iftrue}
+\let\lst@ifLmode\iffalse % init
+\lst@AddToHook{EOL}{\@whilesw \lst@ifLmode\fi \lst@LeaveMode}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Divers helpers}
+%
+% \begin{macro}{\lst@NormedDef}
+% works like |\def| (without any parameters!) but normalizes the replacement
+% text by making all characters lower case and stripping off spaces.
+%    \begin{macrocode}
+\def\lst@NormedDef#1#2{\lowercase{\edef#1{\zap@space#2 \@empty}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NormedNameDef}
+% works like |\global\@namedef| (again without any parameters!) but normalizes
+% both the macro name and the replacement text.
+%    \begin{macrocode}
+\def\lst@NormedNameDef#1#2{%
+    \lowercase{\edef\lst@temp{\zap@space#1 \@empty}%
+    \expandafter\xdef\csname\lst@temp\endcsname{\zap@space#2 \@empty}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GetFreeMacro}
+% Initialize |\@tempcnta| and |\lst@freemacro|, \ldots
+%    \begin{macrocode}
+\def\lst@GetFreeMacro#1{%
+    \@tempcnta\z@ \def\lst@freemacro{#1\the\@tempcnta}%
+    \lst@GFM@}
+%    \end{macrocode}
+% \ldots\space and either build the control sequence or advance the counter and
+% continue.
+%    \begin{macrocode}
+\def\lst@GFM@{%
+    \expandafter\ifx \csname\lst@freemacro\endcsname \relax
+        \edef\lst@freemacro{\csname\lst@freemacro\endcsname}%
+    \else
+        \advance\@tempcnta\@ne
+        \expandafter\lst@GFM@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@gtempboxa}
+%    \begin{macrocode}
+\newbox\lst@gtempboxa
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{Doing output}
+%
+%
+% \subsection{Basic registers and keys}
+%
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+% \paragraph{The current character string}
+% is kept in a token register and a counter holds its length.
+% Here we define the macros to put characters into the output queue.
+%
+% \begin{macro}{\lst@token}
+% \begin{macro}{\lst@length}
+% are allocated here. Quite a useful comment, isn't it?
+%    \begin{macrocode}
+\newtoks\lst@token \newcount\lst@length
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@ResetToken}
+% \begin{macro}{\lst@lastother}
+% The two registers get empty respectively zero at the beginning of each line.
+% After receiving a report from \lsthelper{Claus~Atzenbeck}{1999/11/24}{HTML:
+% output unit repeated after >}---I removed such a bug many times---I decided
+% to reset these registers in the \hookname{EndGroup} hook, too.
+%    \begin{macrocode}
+\def\lst@ResetToken{\lst@token{}\lst@length\z@}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVarsBOL}{\lst@ResetToken \let\lst@lastother\@empty}
+\lst@AddToHook{EndGroup}{\lst@ResetToken \let\lst@lastother\@empty}
+%    \end{macrocode}
+% The macro |\lst@lastother| will be equivalent to the last `other' character,
+% which leads us to |\lst@ifletter|.
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifletter}
+% indicates whether the token contains an identifier or other characters.
+%    \begin{macrocode}
+\def\lst@lettertrue{\let\lst@ifletter\iftrue}
+\def\lst@letterfalse{\let\lst@ifletter\iffalse}
+\lst@AddToHook{InitVars}{\lst@letterfalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Append}
+% puts the argument into the output queue.
+%    \begin{macrocode}
+\def\lst@Append#1{\advance\lst@length\@ne
+                  \lst@token=\expandafter{\the\lst@token#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AppendOther}
+% Depending on the current state, we first output the character string as an
+% identifier. Then we save the `argument' via |\futurelet| and call the macro
+% |\lst@Append| to do the rest.
+%    \begin{macrocode}
+\def\lst@AppendOther{%
+    \lst@ifletter \lst@Output\lst@letterfalse \fi
+    \futurelet\lst@lastother\lst@Append}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AppendLetter}
+% We output a non-identifier string if necessary and call |\lst@Append|.
+%    \begin{macrocode}
+\def\lst@AppendLetter{%
+    \lst@ifletter\else \lst@OutputOther\lst@lettertrue \fi
+    \lst@Append}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SaveToken}
+% \begin{macro}{\lst@RestoreToken}
+% If a group end appears and ruins the character string, we can use these
+% macros to save and restore the contents. |\lst@thestyle| is the current
+% printing style and must be saved and restored, too.
+%    \begin{macrocode}
+\def\lst@SaveToken{%
+    \global\let\lst@gthestyle\lst@thestyle
+    \xdef\lst@RestoreToken{\noexpand\lst@token{\the\lst@token}%
+                           \noexpand\lst@length\the\lst@length\relax
+                           \noexpand\let\noexpand\lst@thestyle
+                                        \noexpand\lst@gthestyle}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \paragraph{The current position}
+% is either the dimension |\lst@currlwidth|, which is the horizontal position
+% without taking the current character string into account, or it's the current
+% column starting with number 0. This is |\lst@column| $-$ |\lst@pos| $+$
+% |\lst@length|. Moreover we have |\lst@lostspace| which is the difference
+% between the current and the desired line width. We define macros to insert
+% this lost space.
+%
+% \begin{macro}{\lst@currlwidth}
+% \begin{macro}{\lst@column}
+% \begin{macro}{\lst@pos}
+% the current line width and two counters.
+%    \begin{macrocode}
+\newdimen\lst@currlwidth % \global
+\newcount\lst@column \newcount\lst@pos % \global
+\lst@AddToHook{InitVarsBOL}
+    {\global\lst@currlwidth\z@ \global\lst@pos\z@ \global\lst@column\z@}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@CalcColumn}
+% sets |\@tempcnta| to the current column. 
+% Note that |\lst@pos| will be nonpositive.
+%    \begin{macrocode}
+\def\lst@CalcColumn{%
+            \@tempcnta\lst@column
+    \advance\@tempcnta\lst@length
+    \advance\@tempcnta-\lst@pos}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@lostspace}
+% Whenever this dimension is positive we can insert space. A negative `lost
+% space' means that the printed line is wider than expected.
+%    \begin{macrocode}
+\newdimen\lst@lostspace % \global
+\lst@AddToHook{InitVarsBOL}{\global\lst@lostspace\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@UseLostSpace}
+% We insert space and reset it if and only if |\lst@lostspace| is positive.
+%    \begin{macrocode}
+\def\lst@UseLostSpace{\ifdim\lst@lostspace>\z@ \lst@InsertLostSpace \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InsertLostSpace}
+% \begin{macro}{\lst@InsertHalfLostSpace}
+% Ditto, but insert even if negative. |\lst@Kern| will be defined very soon.
+%    \begin{macrocode}
+\def\lst@InsertLostSpace{%
+    \lst@Kern\lst@lostspace \global\lst@lostspace\z@}
+\def\lst@InsertHalfLostSpace{%
+    \global\[email protected]\lst@lostspace \lst@Kern\lst@lostspace}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \paragraph{Column widths}
+% Here we deal with the width of a single column, which equals the width of a
+% single character box. Keep in mind that there are fixed and flexible column
+% formats.
+%
+% \begin{macro}{\lst@width}
+% \begin{lstkey}{basewidth}
+% \keyname{basewidth} assigns the values to macros and tests whether they are
+% negative.
+%    \begin{macrocode}
+\newdimen\lst@width
+\lst@Key{basewidth}{0.6em,0.45em}{\lstKV@CSTwoArg{#1}%
+    {\def\lst@widthfixed{##1}\def\lst@widthflexible{##2}%
+     \ifx\lst@widthflexible\@empty
+         \let\lst@widthflexible\lst@widthfixed
+     \fi
+     \def\lst@temp{\PackageError{Listings}%
+                                {Negative value(s) treated as zero}%
+                                \@ehc}%
+     \let\lst@error\@empty
+     \ifdim \lst@widthfixed<\z@
+         \let\lst@error\lst@temp \let\lst@widthfixed\z@
+     \fi
+     \ifdim \lst@widthflexible<\z@
+         \let\lst@error\lst@temp \let\lst@widthflexible\z@
+     \fi
+     \lst@error}}
+%    \end{macrocode}
+% We set the dimension in a special hook.
+%    \begin{macrocode}
+\lst@AddToHook{FontAdjust}
+    {\lst@width=\lst@ifflexible\lst@widthflexible
+                          \else\lst@widthfixed\fi \relax}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{macro}
+%
+% \begin{lstkey}{fontadjust}
+% \begin{macro}{\lst@FontAdjust}
+% This hook is controlled by a switch and is always executed at
+% \hookname{InitVars}.
+%    \begin{macrocode}
+\lst@Key{fontadjust}{false}[t]{\lstKV@SetIf{#1}\lst@iffontadjust}
+\def\lst@FontAdjust{\lst@iffontadjust \lsthk@FontAdjust \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\lsthk@FontAdjust}
+%    \end{macrocode}
+% \end{macro}
+% \end{lstkey}
+%
+%
+% \subsection{Low- and mid-level output}
+%
+% \paragraph{Doing the output}
+% means putting the character string into a box register, updating all internal
+% data, and eventually giving the box to \TeX.
+%
+% \begin{macro}{\lst@OutputBox}
+% \begin{macro}{\lst@alloverstyle}
+% The lowest level is the output of a box register.
+% Here we use |\box#1| as argument to |\lst@alloverstyle|.
+%    \begin{macrocode}
+\def\lst@OutputBox#1{\lst@alloverstyle{\box#1}}
+%    \end{macrocode}
+% \begin{ALTERNATIVE}
+% Instead of |\global\advance\lst@currlwidth| |\wd|\meta{box number} in
+% both definitions |\lst@Kern| and |\lst@CalcLostSpaceAndOutput|, we could
+% also advance the dimension here. But I decided not to do so since it
+% simplifies possible redefinitions of |\lst@OutputBox|: we need not to care
+% about |\lst@currlwidth|.
+% \end{ALTERNATIVE}
+%    \begin{macrocode}
+\def\lst@alloverstyle#1{#1}% init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@Kern}
+% has been used to insert `lost space'.
+% It must not use |\@tempboxa| since that \ldots
+%    \begin{macrocode}
+\def\lst@Kern#1{%
+    \setbox\z@\hbox{{\lst@currstyle{\kern#1}}}%
+    \global\advance\lst@currlwidth \wd\z@
+    \lst@OutputBox\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CalcLostSpaceAndOutput}
+% \ldots\space is used here.
+% We keep track of |\lst@lostspace|, |\lst@currlwidth| and |\lst@pos|.
+%    \begin{macrocode}
+\def\lst@CalcLostSpaceAndOutput{%
+    \global\advance\lst@lostspace \lst@length\lst@width
+    \global\advance\lst@lostspace-\wd\@tempboxa
+    \global\advance\lst@currlwidth \wd\@tempboxa
+    \global\advance\lst@pos -\lst@length
+%    \end{macrocode}
+% Before |\@tempboxa| is output, we insert space if there is enough lost space.
+% This possibly invokes |\lst@Kern| via `insert half lost space', which is the
+% reason for why we mustn't use |\@tempboxa| above. By redefinition we prevent
+% |\lst@OutputBox| from using any special style in |\lst@Kern|.
+%    \begin{macrocode}
+    \setbox\@tempboxa\hbox{\let\lst@OutputBox\box
+        \ifdim\lst@lostspace>\z@ \lst@leftinsert \fi
+        \box\@tempboxa
+        \ifdim\lst@lostspace>\z@ \lst@rightinsert \fi}%
+%    \end{macrocode}
+% Finally we can output the new box.
+%    \begin{macrocode}
+    \lst@OutputBox\@tempboxa \lsthk@PostOutput}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{PostOutput}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@OutputToken}
+% Now comes a mid-level definition.
+% Here we use |\lst@token| to set |\@tempboxa| and eventually output the box.
+% We take care of font adjustment and special output styles.
+% Yet unknown macros are defined in the following subsections.
+%    \begin{macrocode}
+\def\lst@OutputToken{%
+    \lst@TrackNewLines \lst@OutputLostSpace
+    \lst@CheckMerge
+    {\lst@thestyle{\lst@FontAdjust
+     \setbox\@tempboxa\lst@hbox
+        {\lsthk@OutputBox
+         \lst@lefthss
+         \expandafter\lst@FillOutputBox\the\lst@token\@empty
+         \lst@righthss}%
+     \lst@CalcLostSpaceAndOutput}}%
+    \lst@ResetToken}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{OutputBox}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Delaying the output}
+% means saving the character string somewhere and pushing it back when
+% neccessary. We may also attach the string to the next output box without
+% affecting style detection: both will be printed in the style of the upcoming
+% output. We will call this `merging'.
+%
+% \begin{macro}{\lst@Delay}
+% \begin{macro}{\lst@Merge}
+% To delay or merge |#1|, we process it as usual and simply save the state
+% in macros. For delayed characters we also need the currently `active'
+% output routine. Both definitions first check whether there are already
+% delayed or `merged' characters.
+%    \begin{macrocode}
+\def\lst@Delay#1{%
+    \lst@CheckDelay
+    #1%
+    \lst@GetOutputMacro\lst@delayedoutput
+    \edef\lst@delayed{\the\lst@token}%
+    \edef\lst@delayedlength{\the\lst@length}%
+    \lst@ResetToken}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@Merge#1{%
+    \lst@CheckMerge
+    #1%
+    \edef\lst@merged{\the\lst@token}%
+    \edef\lst@mergedlength{\the\lst@length}%
+    \lst@ResetToken}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@MergeToken}
+% Here we put the things together again.
+%    \begin{macrocode}
+\def\lst@MergeToken#1#2{%
+    \advance\lst@length#2%
+    \lst@lExtend#1{\the\lst@token}%
+    \expandafter\lst@token\expandafter{#1}%
+    \let#1\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CheckDelay}
+% We need to print delayed characters. The mode depends on the current output
+% macro. If it equals the saved definition, we put the delayed characters in
+% front of the character string (we merge them) since there has been no
+% letter-to-other or other-to-letter leap. Otherwise we locally reset the
+% current character string, merge this empty string with the delayed one,
+% and output it.
+%    \begin{macrocode}
+\def\lst@CheckDelay{%
+    \ifx\lst@delayed\@empty\else
+        \lst@GetOutputMacro\@gtempa
+        \ifx\lst@delayedoutput\@gtempa
+            \lst@MergeToken\lst@delayed\lst@delayedlength
+        \else
+            {\lst@ResetToken
+             \lst@MergeToken\lst@delayed\lst@delayedlength
+             \lst@delayedoutput}%
+            \let\lst@delayed\@empty
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CheckMerge}
+% All this is easier for |\lst@merged|.
+%    \begin{macrocode}
+\def\lst@CheckMerge{%
+    \ifx\lst@merged\@empty\else
+        \lst@MergeToken\lst@merged\lst@mergedlength
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\let\lst@delayed\@empty % init
+\let\lst@merged\@empty % init
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Column formats}
+%
+% It's time to deal with fixed and flexible column modes.
+% A couple of open definitions are now filled in.
+%
+% \begin{macro}{\lst@column@fixed}
+% switches to the fixed column format. The definitions here control how the
+% output of the above definitions looks like.
+%    \begin{macrocode}
+\def\lst@column@fixed{%
+    \lst@flexiblefalse
+    \lst@width\lst@widthfixed\relax
+    \let\lst@OutputLostSpace\lst@UseLostSpace
+    \let\lst@FillOutputBox\lst@FillFixed
+    \let\lst@hss\hss
+    \def\lst@hbox{\hbox to\lst@length\lst@width}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@FillFixed}
+% Filling up a fixed mode box is easy.
+%    \begin{macrocode}
+\def\lst@FillFixed#1{#1\lst@FillFixed@}
+%    \end{macrocode}
+% While not reaching the end (|\@empty| from above), we insert dynamic space,
+% output the argument and call the submacro again.
+%    \begin{macrocode}
+\def\lst@FillFixed@#1{%
+    \ifx\@empty#1\else \lst@hss#1\expandafter\lst@FillFixed@ \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@column@flexible}
+% The first flexible format.
+%    \begin{macrocode}
+\def\lst@column@flexible{%
+    \lst@flexibletrue
+    \lst@width\lst@widthflexible\relax
+    \let\lst@OutputLostSpace\lst@UseLostSpace
+    \let\lst@FillOutputBox\@empty
+    \let\lst@hss\@empty
+    \let\lst@hbox\hbox}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@column@fullflexible}
+% This column format inserts no lost space except at the beginning of a line.
+%    \begin{macrocode}
+\def\lst@column@fullflexible{%
+    \lst@column@flexible
+    \def\lst@OutputLostSpace{\lst@ifnewline \lst@UseLostSpace\fi}%
+    \let\lst@leftinsert\@empty
+    \let\lst@rightinsert\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% So far the column formats. Now we define macros to use them.
+%
+% \begin{macro}{\lst@outputpos}
+% This macro sets the `output-box-positioning' parameter (the old key
+% \keyname{outputpos}). We test for |l|, |c| and |r|. 
+% The fixed formats use |\lst@lefthss| and |\lst@righthss|, whereas the
+% flexibles need |\lst@leftinsert| and |\lst@rightinsert|.
+%    \begin{macrocode}
+\def\lst@outputpos#1#2\relax{%
+    \def\lst@lefthss{\lst@hss}\let\lst@righthss\lst@lefthss
+    \let\lst@rightinsert\lst@InsertLostSpace
+    \ifx #1c%
+        \let\lst@leftinsert\lst@InsertHalfLostSpace
+    \else\ifx #1r%
+        \let\lst@righthss\@empty
+        \let\lst@leftinsert\lst@InsertLostSpace
+        \let\lst@rightinsert\@empty
+    \else
+        \let\lst@lefthss\@empty
+        \let\lst@leftinsert\@empty
+        \ifx #1l\else \PackageWarning{Listings}%
+            {Unknown positioning for output boxes}%
+        \fi
+    \fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifflexible}
+% indicates the column mode but does not distinguish between different fixed
+% or flexible modes.
+%    \begin{macrocode}
+\def\lst@flexibletrue{\let\lst@ifflexible\iftrue}
+\def\lst@flexiblefalse{\let\lst@ifflexible\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{columns}
+% This is done here: check optional parameter and then build the control
+% sequence of the column format.
+%    \begin{macrocode}
+\lst@Key{columns}{[c]fixed}{\lstKV@OptArg[]{#1}{%
+    \ifx\@empty##1\@empty\else \lst@outputpos##1\relax\relax \fi
+    \expandafter\let\expandafter\lst@arg
+                                \csname\@lst @column@##2\endcsname
+%    \end{macrocode}
+% We issue a warning or save the definition for later.
+%    \begin{macrocode}
+    \lst@arg
+    \ifx\lst@arg\relax
+        \PackageWarning{Listings}{Unknown column format `##2'}%
+    \else
+        \lst@ifflexible
+            \let\lst@columnsflexible\lst@arg
+        \else
+            \let\lst@columnsfixed\lst@arg
+        \fi
+    \fi}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\let\lst@columnsfixed\lst@column@fixed % init
+\let\lst@columnsflexible\lst@column@flexible % init
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{flexiblecolumns}
+% Nothing else but a key to switch between the last flexible and fixed mode.
+%    \begin{macrocode}
+\lst@Key{flexiblecolumns}\relax[t]{%
+    \lstKV@SetIf{#1}\lst@ifflexible
+    \lst@ifflexible \lst@columnsflexible
+              \else \lst@columnsfixed \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+%
+% \subsection{New lines}
+%
+% \begin{macro}{\lst@newlines}
+% This counter holds the number of `new lines' (cr+lf) we have to perform.
+%    \begin{macrocode}
+\newcount\lst@newlines
+\lst@AddToHook{InitVars}{\global\lst@newlines\z@}
+\lst@AddToHook{InitVarsBOL}{\global\advance\lst@newlines\@ne}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NewLine}
+% This is how we start a new line: begin new paragraph and output an empty
+% box. If low-level definition |\lst@OutputBox| just gobbles the box , we
+% don't start a new line. This is used to drop the whole output.
+%    \begin{macrocode}
+\def\lst@NewLine{%
+    \ifx\lst@OutputBox\@gobble\else
+        \par\noindent \hbox{}%
+    \fi
+    \global\advance\lst@newlines\m@ne
+    \lst@newlinetrue}
+%    \end{macrocode}
+% Define |\lst@newlinetrue| and reset if after output.
+%    \begin{macrocode}
+\def\lst@newlinetrue{\global\let\lst@ifnewline\iftrue}
+\lst@AddToHookExe{PostOutput}{\global\let\lst@ifnewline\iffalse}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TrackNewLines}
+% If |\lst@newlines| is positive, we execute the hook and insert the
+% new lines.
+%    \begin{macrocode}
+\def\lst@TrackNewLines{%
+    \ifnum\lst@newlines>\z@
+        \lsthk@OnNewLine
+        \lst@DoNewLines
+    \fi}
+\lst@AddToHook{OnNewLine}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{emptylines}
+% \lsthelper{Adam~Prugel-Bennett}{2001/02/19}{spacing of empty lines} asked for
+% such a key---if I didn't misunderstood him. We check for the optional star
+% and set |\lst@maxempty| and switch.
+%    \begin{macrocode}
+\lst@Key{emptylines}\maxdimen{%
+    \@ifstar{\lst@true\@tempcnta\@gobble#1\relax\lst@GobbleNil}%
+            {\lst@false\@tempcnta#1\relax\lst@GobbleNil}#1\@nil
+    \advance\@tempcnta\@ne
+    \edef\lst@maxempty{\the\@tempcnta\relax}%
+    \let\lst@ifpreservenumber\lst@if}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DoNewLines}
+% First we take care of |\lst@maxempty| and then of the remaining empty lines.
+%    \begin{macrocode}
+\def\lst@DoNewLines{
+    \@whilenum\lst@newlines>\lst@maxempty \do
+        {\lst@ifpreservenumber
+            \lsthk@OnEmptyLine
+            \global\advance\c@lstnumber\lst@advancelstnum
+         \fi
+         \global\advance\lst@newlines\m@ne}%
+    \@whilenum \lst@newlines>\@ne \do
+        {\lsthk@OnEmptyLine \lst@NewLine}%
+    \ifnum\lst@newlines>\z@ \lst@NewLine \fi}
+\lst@AddToHook{OnEmptyLine}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{High-level output}
+%
+% \begin{lstkey}{identifierstyle}
+% A simple key.
+%    \begin{macrocode}
+\lst@Key{identifierstyle}{}{\def\lst@identifierstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@identifierstyle\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@GotoTabStop}
+% Here we look whether the line already contains printed characters.
+% If true, we output a box with the width of a blank space.
+%    \begin{macrocode}
+\def\lst@GotoTabStop{%
+    \ifnum\lst@newlines=\z@
+        \setbox\@tempboxa\hbox{\lst@outputspace}%
+        \setbox\@tempboxa\hbox to\wd\@tempboxa{{\lst@currstyle{\hss}}}%
+        \lst@CalcLostSpaceAndOutput
+%    \end{macrocode}
+% It's probably not clear why it is sufficient to output a single space to go
+% to the next tabulator stop. Just note that the space lost by this process is
+% `lost space' in the sense above and therefore will be inserted before the
+% next characters are output.
+%    \begin{macrocode}
+    \else
+%    \end{macrocode}
+% Otherwise (no printed characters) we only need to advance |\lst@lostspace|,
+% which is inserted by |\lst@OutputToken| above, and update the column.
+%    \begin{macrocode}
+        \global\advance\lst@lostspace \lst@length\lst@width
+        \global\advance\lst@column\lst@length \lst@length\z@
+    \fi}
+%    \end{macrocode}
+% Note that this version works also in flexible column mode.
+% In fact, it's mainly the flexible version of \packagename{listings} 0.20.
+% \begin{TODO}
+% Use |\lst@ifnewline| instead of |\ifnum\lst@newlines=\z@|?
+% \end{TODO}
+% \end{macro}
+%
+% \begin{macro}{\lst@OutputOther}
+% becomes easy with the previous definitions.
+%    \begin{macrocode}
+\def\lst@OutputOther{%
+    \lst@CheckDelay
+    \ifnum\lst@length=\z@\else
+        \let\lst@thestyle\lst@currstyle
+        \lsthk@OutputOther
+        \lst@OutputToken
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{OutputOther}{}% init
+\let\lst@currstyle\relax % init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Output}
+% We might use identifier style as default.
+%    \begin{macrocode}
+\def\lst@Output{%
+    \lst@CheckDelay
+    \ifnum\lst@length=\z@\else
+        \ifx\lst@currstyle\relax
+            \let\lst@thestyle\lst@identifierstyle
+        \else
+            \let\lst@thestyle\lst@currstyle
+        \fi
+        \lsthk@Output
+        \lst@OutputToken
+    \fi
+    \let\lst@lastother\relax}
+%    \end{macrocode}
+% Note that |\lst@lastother| becomes equivalent to |\relax| and not equivalent
+% to |\@empty| as everywhere else. I don't know whether this will be important
+% in the future or not.
+%    \begin{macrocode}
+\lst@AddToHook{Output}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GetOutputMacro}
+% Just saves the output macro to be used.
+%    \begin{macrocode}
+\def\lst@GetOutputMacro#1{%
+    \lst@ifletter \global\let#1\lst@Output
+            \else \global\let#1\lst@OutputOther\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@PrintToken}
+% outputs the current character string in letter or nonletter mode.
+%    \begin{macrocode}
+\def\lst@PrintToken{%
+    \lst@ifletter \lst@Output \lst@letterfalse
+            \else \lst@OutputOther \let\lst@lastother\@empty \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@XPrintToken}
+% is a special definition to print also merged characters.
+%    \begin{macrocode}
+\def\lst@XPrintToken{%
+    \lst@PrintToken \lst@CheckMerge
+    \ifnum\lst@length=\z@\else \lst@PrintToken \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Dropping the whole output}
+%
+% \begin{macro}{\lst@BeginDropOutput}
+% It's sometimes useful to process a part of a listing as usual, but to drop
+% the output. This macro does the main work and gets one argument, namely the
+% internal mode it enters. We save |\lst@newlines|, restore it |\aftergroup|
+% and redefine one macro, namely |\lst@OutputBox|. After a bug report from
+% \lsthelper{Gunther~Schmidl}{2002/02/27}{collapsing empty lines don't work
+% with printpod=false}
+%    \begin{macrocode}
+\def\lst@BeginDropOutput#1{%
+    \xdef\lst@BDOnewlines{\the\lst@newlines}%
+    \global\let\lst@BDOifnewline\lst@ifnewline
+    \lst@EnterMode{#1}%
+        {\lst@modetrue
+         \let\lst@OutputBox\@gobble
+         \aftergroup\lst@BDORestore}}
+%    \end{macrocode}
+% Restoring the date is quite easy:
+%    \begin{macrocode}
+\def\lst@BDORestore{%
+    \global\lst@newlines\lst@BDOnewlines
+    \global\let\lst@ifnewline\lst@BDOifnewline}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndDropOutput}
+% is equivalent to |\lst@LeaveMode|.
+%    \begin{macrocode}
+\let\lst@EndDropOutput\lst@LeaveMode
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Writing to an external file}
+%
+% \begin{aspect}{writefile}
+% Now it would be good to know something about character classes since we need
+% to access the true input characters, for example a tabulator and not the
+% spaces it `expands' to.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{writefile}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@WF}
+% \begin{macro}{\lst@WFtoken}
+% The contents of the token will be written to file.
+%    \begin{macrocode}
+\newtoks\lst@WFtoken % global
+\lst@AddToHook{InitVarsBOL}{\global\lst@WFtoken{}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newwrite\lst@WF
+\global\let\lst@WFifopen\iffalse % init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFWriteToFile}
+% To do this, we have to expand the contents and then expand this via |\edef|.
+% Empty |\lst@UM| ensures that special characters (underscore, dollar, etc.)
+% are written correctly.
+%    \begin{macrocode}
+\gdef\lst@WFWriteToFile{%
+  \begingroup
+   \let\lst@UM\@empty
+   \expandafter\edef\expandafter\lst@temp\expandafter{\the\lst@WFtoken}%
+   \immediate\write\lst@WF{\lst@temp}%
+  \endgroup
+  \global\lst@WFtoken{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFAppend}
+% Similar to |\lst@Append| but uses |\lst@WFtoken|.
+%    \begin{macrocode}
+\gdef\lst@WFAppend#1{%
+    \global\lst@WFtoken=\expandafter{\the\lst@WFtoken#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginWriteFile}
+% \begin{macro}{\lst@BeginAlsoWriteFile}
+% use different macros for |\lst@OutputBox| (not) to drop the output.
+%    \begin{macrocode}
+\gdef\lst@BeginWriteFile{\lst@WFBegin\@gobble}
+\gdef\lst@BeginAlsoWriteFile{\lst@WFBegin\lst@OutputBox}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFBegin}
+% Here \ldots
+%    \begin{macrocode}
+\begingroup \catcode`\^^I=11
+\gdef\lst@WFBegin#1#2{%
+    \begingroup
+    \let\lst@OutputBox#1%
+%    \end{macrocode}
+% \ldots\space we have to update |\lst@WFtoken| and \ldots
+%    \begin{macrocode}
+    \def\lst@Append##1{%
+        \advance\lst@length\@ne
+        \expandafter\lst@token\expandafter{\the\lst@token##1}%
+        \ifx ##1\lst@outputspace \else
+            \lst@WFAppend##1%
+        \fi}%
+    \lst@lAddTo\lst@PreGotoTabStop{\lst@WFAppend{^^I}}%
+    \lst@lAddTo\lst@ProcessSpace{\lst@WFAppend{ }}%
+%    \end{macrocode}
+% \ldots\space need different `EOL' and `DeInit' definitions to write the
+% token register to file.
+%    \begin{macrocode}
+    \let\lst@DeInit\lst@WFDeInit
+    \let\lst@MProcessListing\lst@WFMProcessListing
+%    \end{macrocode}
+% Finally we open the file if necessary.
+%    \begin{macrocode}
+    \lst@WFifopen\else
+        \immediate\openout\lst@WF=#2\relax
+        \global\let\lst@WFifopen\iftrue
+        \@gobbletwo\fi\fi
+    \fi}
+\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndWriteFile}
+% closes the file and restores original definitions.
+%    \begin{macrocode}
+\gdef\lst@EndWriteFile{%
+    \immediate\closeout\lst@WF \endgroup
+    \global\let\lst@WFifopen\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFMProcessListing}
+% \begin{macro}{\lst@WFDeInit}
+% write additionally |\lst@WFtoken| to external file.
+%    \begin{macrocode}
+\global\let\lst@WFMProcessListing\lst@MProcessListing
+\global\let\lst@WFDeInit\lst@DeInit
+\lst@AddToAtTop\lst@WFMProcessListing{\lst@WFWriteToFile}
+\lst@AddToAtTop\lst@WFDeInit{%
+    \ifnum\lst@length=\z@\else \lst@WFWriteToFile \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Character classes}\label{iCharacterClasses}
+%
+% In this section, we define how the basic character classes do behave, before
+% turning over to the selection of character tables and how to specialize
+% characters.
+%
+%
+% \subsection{Letters, digits and others}
+%
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@ProcessLetter}
+% We put the letter, which is not a whitespace, into the output queue.
+%    \begin{macrocode}
+\def\lst@ProcessLetter{\lst@whitespacefalse \lst@AppendLetter}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProcessOther}
+% Ditto.
+%    \begin{macrocode}
+\def\lst@ProcessOther{\lst@whitespacefalse \lst@AppendOther}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProcessDigit}
+% A digit appends the character to the current character string. But we must
+% use the right macro. This allows digits to be part of an identifier or
+% a numerical constant.
+%    \begin{macrocode}
+\def\lst@ProcessDigit{%
+    \lst@whitespacefalse
+    \lst@ifletter \expandafter\lst@AppendLetter
+            \else \expandafter\lst@AppendOther\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifwhitespace}
+% indicates whether the last processed character has been white space.
+%    \begin{macrocode}
+\def\lst@whitespacetrue{\global\let\lst@ifwhitespace\iftrue}
+\def\lst@whitespacefalse{\global\let\lst@ifwhitespace\iffalse}
+\lst@AddToHook{InitVarsBOL}{\lst@whitespacetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Whitespaces}
+%
+% Here we have to take care of two things: dropping empty lines at the end of
+% a listing and the different column formats. Both use |\lst@lostspace|. Lines
+% containing only tabulators and spaces should be viewed as empty. In order to
+% achieve this, tabulators and spaces at the beginning of a line don't output
+% any characters but advance |\lst@lostspace|. Whenever this dimension is
+% positive we insert that space before the character string is output. Thus,
+% if there are only tabulators and spaces, the line is `empty' since we
+% haven't done any output.
+%
+% We have to do more for flexible columns. Whitespaces can fix the column
+% alignment: if the real line is wider than expected, a tabulator is at least
+% one space wide; all remaining space fixes the alignment. If there are two or
+% more space characters, at least one is printed; the others fix the column
+% alignment.
+%
+%
+% \paragraph{Tabulators}
+% are processed in three stages. You have already seen the last stage
+% |\lst@GotoTabStop|. The other two calculate the necessary width and take care
+% of visible tabulators and spaces.
+%
+% \begin{lstkey}{tabsize}
+% We check for a legal argument before saving it. Default tabsize is 8 as
+% proposed by \lsthelper{Rolf~Niepraschk}{1997/04/24}{tabsize=8}.
+%    \begin{macrocode}
+\lst@Key{tabsize}{8}
+    {\ifnum#1>\z@ \def\lst@tabsize{#1}\else
+         \PackageError{Listings}{Strict positive integer expected}%
+         {You can't use `#1' as tabsize. \@ehc}%
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{showtabs}
+% \begin{lstkey}{tab}
+% Two more user keys for tab control.
+%    \begin{macrocode}
+\lst@Key{showtabs}f[t]{\lstKV@SetIf{#1}\lst@ifshowtabs}
+\lst@Key{tab}{\kern.06em\hbox{\vrule\@height.3ex}%
+              \hrulefill\hbox{\vrule\@height.3ex}}
+    {\def\lst@tab{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ProcessTabulator}
+% A tabulator outputs the preceding characters, which decrements |\lst@pos| by
+% the number of printed characters.
+%    \begin{macrocode}
+\def\lst@ProcessTabulator{%
+    \lst@XPrintToken \lst@whitespacetrue
+%    \end{macrocode}
+% Then we calculate how many columns we need to reach the next tabulator stop:
+% we add |\lst@tabsize| until |\lst@pos| is strict positive. In other words,
+% |\lst@pos| is the column modulo |tabsize| and we're looking for a positive
+% representative. We assign it to |\lst@length| and reset |\lst@pos| in the
+% submacro.
+%    \begin{macrocode}
+    \global\advance\lst@column -\lst@pos
+    \@whilenum \lst@pos<\@ne \do
+        {\global\advance\lst@pos\lst@tabsize}%
+    \lst@length\lst@pos
+    \lst@PreGotoTabStop}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@PreGotoTabStop}
+% Visible tabs print |\lst@tab|.
+%    \begin{macrocode}
+\def\lst@PreGotoTabStop{%
+    \lst@ifshowtabs
+        \lst@TrackNewLines
+        \setbox\@tempboxa\hbox to\lst@length\lst@width
+            {{\lst@currstyle{\hss\lst@tab}}}%
+        \lst@CalcLostSpaceAndOutput
+    \else
+%    \end{macrocode}
+% If we are advised to keep spaces, we insert the correct number of them.
+%    \begin{macrocode}
+        \lst@ifkeepspaces
+            \@tempcnta\lst@length \lst@length\z@
+            \@whilenum \@tempcnta>\z@ \do
+                {\lst@AppendOther\lst@outputspace
+                 \advance\@tempcnta\m@ne}%
+            \lst@OutputOther
+        \else
+            \lst@GotoTabStop
+        \fi
+    \fi
+    \lst@length\z@ \global\lst@pos\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Spaces}
+% are implemented as described at the beginning of this subsection. But first
+% we define some user keys.
+%
+% \begin{macro}{\lst@outputspace}
+% \begin{macro}{\lst@visiblespace}
+% The first macro is a default definition, \ldots
+%    \begin{macrocode}
+\def\lst@outputspace{\ }
+\def\lst@visiblespace{\lst@ttfamily{\char32}\textvisiblespace}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{showspaces}
+% \begin{lstkey}{keepspaces}
+% \ldots\space which is modified on user's request.
+%    \begin{macrocode}
+\lst@Key{showspaces}{false}[t]{\lstKV@SetIf{#1}\lst@ifshowspaces}
+\lst@Key{keepspaces}{false}[t]{\lstKV@SetIf{#1}\lst@ifkeepspaces}
+\lst@AddToHook{Init}
+    {\lst@ifshowspaces
+         \let\lst@outputspace\lst@visiblespace
+         \lst@keepspacestrue
+     \fi}
+\def\lst@keepspacestrue{\let\lst@ifkeepspaces\iftrue}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ProcessSpace}
+% We look whether spaces fix the column alignment or not. In the latter case
+% we append a space; otherwise \ldots
+%    \begin{macrocode}
+\def\lst@ProcessSpace{%
+    \lst@ifkeepspaces
+        \lst@AppendOther\lst@outputspace
+    \else \ifnum\lst@newlines=\z@
+%    \end{macrocode}
+% \ldots\space we append a `special space' if the line isn't empty.
+%    \begin{macrocode}
+        \lst@AppendSpecialSpace
+    \else \ifnum\lst@length=\z@
+%    \end{macrocode}
+% If the line is empty, we check whether there are characters in the output
+% queue. If there are no characters we just advance |\lst@lostspace|.
+% Otherwise we append the space.
+%    \begin{macrocode}
+            \global\advance\lst@lostspace\lst@width
+            \global\advance\lst@pos\m@ne
+        \else
+            \lst@AppendSpecialSpace
+        \fi
+    \fi \fi
+    \lst@whitespacetrue}
+%    \end{macrocode}
+% Note that this version works for fixed and flexible column output.
+% \end{macro}
+%
+% \begin{macro}{\lst@AppendSpecialSpace}
+% If there are at least two white spaces, we output preceding characters and
+% advance |\lst@lostspace| to avoid alignment problems. Otherwise we append
+% a space to the current character string.
+%    \begin{macrocode}
+\def\lst@AppendSpecialSpace{%
+    \lst@ifwhitespace
+        \lst@PrintToken
+        \global\advance\lst@lostspace\lst@width
+        \global\advance\lst@pos\m@ne
+    \else
+        \lst@AppendOther\lst@outputspace
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Form feeds}
+% has been introduced after communication with
+% \lsthelper{Jan~Braun}{1998/04/27}{formfeed}.
+%
+% \begin{lstkey}{formfeed}
+% let the user make adjustments.
+%    \begin{macrocode}
+\lst@Key{formfeed}{\bigbreak}{\def\lst@formfeed{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ProcessFormFeed}
+% Here we execute some macros according to whether a new line has already
+% begun or not. No |\lst@EOLUpdate| is used in the else branch
+% anymore---\lsthelper{Kalle~Tuulos}{2001/01/14}{form feed gobbles following
+% output unit} sent the bug report.
+%    \begin{macrocode}
+\def\lst@ProcessFormFeed{%
+    \lst@XPrintToken
+    \ifnum\lst@newlines=\z@
+        \lst@EOLUpdate \lsthk@InitVarsBOL
+    \fi
+    \lst@formfeed
+    \lst@whitespacetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Character tables}\label{iCharacterTables}
+%
+%
+% \subsubsection{The standard table}
+%
+% The standard character table is selected by |\lst@SelectStdCharTable|, which
+% expands to a token sequence 
+%    \ldots|\def| |A{\lst@ProcessLetter| |A}|\ldots\space
+% where the first A is active and the second has catcode 12. We use the
+% following macros to build the character table.
+% \begin{syntax}
+% \item[0.19] |\lst@CCPut|\meta{class macro}\meta{$c_1$}\ldots\meta{$c_k$}|\z@|
+%
+%       extends the standard character table by the characters with codes
+%       \meta{$c_1$}\ldots\meta{$c_k$} making each character use
+%       \meta{class macro}. All these characters must be printable via
+%       |\char|\meta{$c_i$}.
+%
+% \item[0.20] |\lst@CCPutMacro|\meta{class$_1$}\meta{$c_1$}\meta{definition$_1$}\ldots|\@empty\z@\@empty|
+%
+%       also extends the standard character table: the character \meta{$c_i$}
+%       will use \meta{class$_i$} and is printed via \meta{definition$_i$}.
+%       These definitions must be \meta{spec. token}s in the sense of section
+%       \ref{dCharacterTables}.
+% \end{syntax}
+%
+% \begin{macro}{\lst@Def}
+% \begin{macro}{\lst@Let}
+% For speed we won't use these helpers too often.
+%    \begin{macrocode}
+\def\lst@Def#1{\lccode`\~=#1\lowercase{\def~}}
+\def\lst@Let#1{\lccode`\~=#1\lowercase{\let~}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begingroup
+% The definition of the space below doesn't hurt anything. But other aspects,
+% for example \aspectname{lineshape} and \aspectname{formats}, redefine also
+% the macro |\space|. Now, if \LaTeX\ calls |\try@load@fontshape|, the |.log|
+% messages would show some strange things since \LaTeX\ uses |\space| in these
+% messages. The following addition ensures that |\space| expands to a space
+% and not to something different. This was one more bug reported by
+% \lsthelper{Denis~Girou}{1999/09/16}{bad font info message with breaklines}.
+%    \begin{macrocode}
+\lst@AddToAtTop{\try@load@fontshape}{\def\space{ }}
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@SelectStdCharTable}
+% The first three standard characters. |\lst@Let| has been replaced by
+% |\lst@Def| after a bug report from \lsthelper{Chris~Edwards}{2002/02/15}
+% {tabulators show up with firstline>1}.
+%    \begin{macrocode}
+\def\lst@SelectStdCharTable{%
+    \lst@Def{9}{\lst@ProcessTabulator}%
+    \lst@Def{12}{\lst@ProcessFormFeed}%
+    \lst@Def{32}{\lst@ProcessSpace}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CCPut}
+% The first argument gives the character class, then follow the codes.
+%    \begin{macrocode}
+\def\lst@CCPut#1#2{%
+    \ifnum#2=\z@
+        \expandafter\@gobbletwo
+    \else
+        \lccode`\~=#2\lccode`\/=#2\lowercase{\lst@CCPut@~{#1/}}%
+    \fi
+    \lst@CCPut#1}
+\def\lst@CCPut@#1#2{\lst@lAddTo\lst@SelectStdCharTable{\def#1{#2}}}
+%    \end{macrocode}
+% Now we insert more standard characters.
+%    \begin{macrocode}
+\lst@CCPut \lst@ProcessOther
+    {"21}{"22}{"27}{"28}{"29}{"2B}{"2C}{"2E}{"2F}
+    {"3A}{"3B}{"3D}{"3F}{"5B}{"5D}{"60}
+    \z@
+\lst@CCPut \lst@ProcessDigit
+    {"30}{"31}{"32}{"33}{"34}{"35}{"36}{"37}{"38}{"39}
+    \z@
+\lst@CCPut \lst@ProcessLetter
+    {"40}{"41}{"42}{"43}{"44}{"45}{"46}{"47}
+    {"48}{"49}{"4A}{"4B}{"4C}{"4D}{"4E}{"4F}
+    {"50}{"51}{"52}{"53}{"54}{"55}{"56}{"57}
+    {"58}{"59}{"5A}
+         {"61}{"62}{"63}{"64}{"65}{"66}{"67}
+    {"68}{"69}{"6A}{"6B}{"6C}{"6D}{"6E}{"6F}
+    {"70}{"71}{"72}{"73}{"74}{"75}{"76}{"77}
+    {"78}{"79}{"7A}
+    \z@
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CCPutMacro}
+% Now we come to a delicate point. The characters not inserted yet aren't
+% printable (|_|, |$|, \ldots) or aren't printed well (|*|, |-|, \ldots) if we
+% enter these characters. Thus we use proper macros to print the characters.
+% Works perfectly. The problem is that the current character string is
+% printable for speed, for example |_| is already replaced by a macro version,
+% but the new keyword tests need the original characters.
+%
+% The solution: We define |\def _{\lst@ProcessLetter\lst@um_}| where the first
+% underscore is active and the second belongs to the control sequence.
+% Moreover we have |\def\lst@um_{\lst@UM _}| where the second underscore has
+% the usual meaning. Now the keyword tests can access the original character
+% simply by making |\lst@UM| empty. The default definition gets the following
+% token and builds the control sequence |\lst@um_@|, which we'll define to
+% print the character. Easy, isn't it?^^A ;-)
+%
+% The following definition does all this for us. The first parameter gives the
+% character class, the second the character code, and the last the definition
+% which actually prints the character. We build the names |\lst@um_| and
+% |\lst@um_@| and give them to a submacro.
+%    \begin{macrocode}
+\def\lst@CCPutMacro#1#2#3{%
+    \ifnum#2=\z@ \else
+        \begingroup\lccode`\~=#2\relax \lccode`\/=#2\relax
+        \lowercase{\endgroup\expandafter\lst@CCPutMacro@
+            \csname\@lst @um/\expandafter\endcsname
+            \csname\@lst @um/@\endcsname /~}#1{#3}%
+        \expandafter\lst@CCPutMacro
+    \fi}
+%    \end{macrocode}
+% The arguments are now |\lst@um_|, |\lst@um_@|, nonactive character, active
+% character, character class and printing definition. We add |\def _{|
+% |\lst@ProcessLetter| |\lst@um_}| to |\lst@SelectStdCharTable| (and similarly
+% other special characters), define |\def\lst@um_{\lst@UM _}| and |\lst@um_@|.
+%    \begin{macrocode}
+\def\lst@CCPutMacro@#1#2#3#4#5#6{%
+    \lst@lAddTo\lst@SelectStdCharTable{\def#4{#5#1}}%
+    \def#1{\lst@UM#3}%
+    \def#2{#6}}
+%    \end{macrocode}
+% The default definition of |\lst@UM|:
+%    \begin{macrocode}
+\def\lst@UM#1{\csname\@lst @um#1@\endcsname}
+%    \end{macrocode}
+% And all remaining standard characters.
+%    \begin{macrocode}
+\lst@CCPutMacro
+    \lst@ProcessOther {"23}\#
+    \lst@ProcessLetter{"24}\textdollar
+    \lst@ProcessOther {"25}\%
+    \lst@ProcessOther {"26}\&
+    \lst@ProcessOther {"2A}{\lst@ttfamily*\textasteriskcentered}
+    \lst@ProcessOther {"2D}{\lst@ttfamily{-{}}{$-$}}
+    \lst@ProcessOther {"3C}{\lst@ttfamily<\textless}
+    \lst@ProcessOther {"3E}{\lst@ttfamily>\textgreater}
+    \lst@ProcessOther {"5C}{\lst@ttfamily{\char92}\textbackslash}
+    \lst@ProcessOther {"5E}\textasciicircum
+    \lst@ProcessLetter{"5F}{\lst@ttfamily{\char95}\textunderscore}
+    \lst@ProcessOther {"7B}{\lst@ttfamily{\char123}\textbraceleft}
+    \lst@ProcessOther {"7C}{\lst@ttfamily|\textbar}
+    \lst@ProcessOther {"7D}{\lst@ttfamily{\char125}\textbraceright}
+    \lst@ProcessOther {"7E}\textasciitilde
+    \lst@ProcessOther {"7F}-
+    \@empty\z@\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ttfamily}
+% What is this ominous macro? It prints either the first or the second
+% argument. In |\ttfamily| it ensures that |----| is typeset |----| and not
+% $-$$-$$-$$-$ as in version 0.17. Bug encountered by
+% \lsthelper{Dr.~Jobst~Hoffmann}{1998/03/30}{|\lst@minus| and |\ttfamily|}.
+% Furthermore I added |\relax| after receiving an error report from
+% \lsthelper{Magnus~Lewis-Smith}{1999/08/06}{! Bad character code (920).}
+%    \begin{macrocode}
+\def\lst@ttfamily#1#2{\ifx\f@family\ttdefault#1\relax\else#2\fi}
+%    \end{macrocode}
+% |\ttdefault| is defined |\long|, so the |\ifx| doesn't work since |\f@family|
+% isn't |\long|! We go around this problem by redefining |\ttdefault| locally:
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\edef\ttdefault{\ttdefault}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifactivechars}
+% A simple switch.
+%    \begin{macrocode}
+\def\lst@activecharstrue{\let\lst@ifactivechars\iftrue}
+\def\lst@activecharsfalse{\let\lst@ifactivechars\iffalse}
+\lst@activecharstrue
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SelectCharTable}
+% We select the standard character table and switch to active catcodes.
+%    \begin{macrocode}
+\def\lst@SelectCharTable{%
+    \lst@SelectStdCharTable
+    \lst@ifactivechars
+        \catcode9\active \catcode12\active \catcode13\active
+        \@tempcnta=32\relax
+        \@whilenum\@tempcnta<128\do
+            {\catcode\@tempcnta\active\advance\@tempcnta\@ne}%
+    \fi
+    \lst@ifec \lst@DefEC \fi
+%    \end{macrocode}
+% The following line and the according macros below have been added after a
+% bug report from \lsthelper{Fr\'ed\'eric~Boulanger}{2001/02/27}{ligatures}.
+%    \begin{macrocode}
+    \let\do@noligs\lst@do@noligs \verbatim@nolig@list
+%    \end{macrocode}
+% There are two ways to adjust the standard table: inside the hook or with
+% |\lst@DeveloperSCT|. We use these macros and initialize the backslash if
+% necessary. 
+%    \begin{macrocode}
+    \lsthk@SelectCharTable
+    \lst@DeveloperSCT
+    \ifx\lst@Backslash\relax\else
+        \lst@LetSaveDef{"5C}\lsts@backslash\lst@Backslash
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{SelectCharTable}
+% \begin{lstkey}{MoreSelectCharTable}
+% The keys to adjust |\lst@DeveloperSCT|.
+%    \begin{macrocode}
+\lst@Key{SelectCharTable}{}{\def\lst@DeveloperSCT{#1}}
+\lst@Key{MoreSelectCharTable}\relax{\lst@lAddTo\lst@DeveloperSCT{#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetLanguage}{\let\lst@DeveloperSCT\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@do@noligs}
+% To prevent ligatures, this macro inserts the token |\lst@NoLig| in front of
+% |\lst@Process|\meta{whatever}\meta{spec.~token}. This is done by
+% |\verbatim@nolig@list| for certain characters. Note that the submacro is
+% a special kind of a local |\lst@AddToAtTop|.
+%    \begin{macrocode}
+\def\lst@do@noligs#1{%
+    \begingroup \lccode`\~=`#1\lowercase{\endgroup
+    \lst@do@noligs@~}}
+\def\lst@do@noligs#1#2{%
+    \expandafter\expandafter\expandafter\def
+    \expandafter\expandafter\expandafter#1%
+    \expandafter\expandafter\expandafter{\expandafter\lst@NoLig#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NoLig}
+% When this extra macro is processed, it adds |\lst@nolig| to the output queue
+% without increasing its length. For keyword detection this must expand to
+% nothing if |\lst@UM| is empty.
+%    \begin{macrocode}
+\def\lst@NoLig{\advance\lst@length\m@ne \lst@Append\lst@nolig}
+\def\lst@nolig{\lst@UM\@empty}%
+%    \end{macrocode}
+% But the usual meaning of |\lst@UM| builds the following control sequence,
+% which prevents ligatures in the manner of \LaTeX's |\do@noligs|.
+%    \begin{macrocode}
+\@namedef{\@lst @um@}{\leavevmode\kern\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SaveOutputDef}
+% To get the \meta{spec.~token} meaning of character |#1|, we look for |\def|
+% `active character |#1|' in |\lst@SelectStdCharTable|, get the replacement
+% text, strip off the character class via |\@gobble|, and assign the meaning.
+% Note that you get a ``runaway argument'' error if an illegal \meta{character
+% code}=|#1| is used.
+%    \begin{macrocode}
+\def\lst@SaveOutputDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup
+    \def\lst@temp##1\def~##2##3\relax}{%
+        \global\expandafter\let\expandafter#2\@gobble##2\relax}%
+    \expandafter\lst@temp\lst@SelectStdCharTable\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstum@backslash}
+% A commonly used character.
+%    \begin{macrocode}
+\lst@SaveOutputDef{"5C}\lstum@backslash
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{National characters}
+%
+% \begin{lstkey}{extendedchars}
+% The user key to activate extended characters 128--255.
+%    \begin{macrocode}
+\lst@Key{extendedchars}{false}[t]{\lstKV@SetIf{#1}\lst@ifec}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DefEC}
+% Currently each character in the range 128--255 is treated as a letter.
+%    \begin{macrocode}
+\def\lst@DefEC{%
+    \lst@CCECUse \lst@ProcessLetter
+      ^^80^^81^^82^^83^^84^^85^^86^^87^^88^^89^^8a^^8b^^8c^^8d^^8e^^8f%
+      ^^90^^91^^92^^93^^94^^95^^96^^97^^98^^99^^9a^^9b^^9c^^9d^^9e^^9f%
+      ^^a0^^a1^^a2^^a3^^a4^^a5^^a6^^a7^^a8^^a9^^aa^^ab^^ac^^ad^^ae^^af%
+      ^^b0^^b1^^b2^^b3^^b4^^b5^^b6^^b7^^b8^^b9^^ba^^bb^^bc^^bd^^be^^bf%
+      ^^c0^^c1^^c2^^c3^^c4^^c5^^c6^^c7^^c8^^c9^^ca^^cb^^cc^^cd^^ce^^cf%
+      ^^d0^^d1^^d2^^d3^^d4^^d5^^d6^^d7^^d8^^d9^^da^^db^^dc^^dd^^de^^df%
+      ^^e0^^e1^^e2^^e3^^e4^^e5^^e6^^e7^^e8^^e9^^ea^^eb^^ec^^ed^^ee^^ef%
+      ^^f0^^f1^^f2^^f3^^f4^^f5^^f6^^f7^^f8^^f9^^fa^^fb^^fc^^fd^^fe^^ff%
+      ^^00}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CCECUse}
+% Reaching end of list (|^^00|) we terminate the loop.
+% Otherwise we do the same as in |\lst@CCPut| if the character is not active.
+% But if the character is active, we save the meaning before redefinition.
+%    \begin{macrocode}
+\def\lst@CCECUse#1#2{%
+    \ifnum`#2=\z@
+        \expandafter\@gobbletwo
+    \else
+        \ifnum\catcode`#2=\active
+            \lccode`\~=`#2\lccode`\/=`#2\lowercase{\lst@CCECUse@#1~/}%
+        \else
+            \lst@ifactivechars \catcode`#2=\active \fi
+            \lccode`\~=`#2\lccode`\/=`#2\lowercase{\def~{#1/}}%
+        \fi
+    \fi
+    \lst@CCECUse#1}
+%    \end{macrocode}
+% We save the meaning as mentioned. Here we must also use the `|\lst@UM|
+% construction' since extended characters could often appear in words =
+% identifiers. Bug reported by \lsthelper{Denis~Girou}{1999/07/26}
+% {incompatibility with inputenc}.
+%    \begin{macrocode}
+\def\lst@CCECUse@#1#2#3{%
+    \expandafter\def\csname\@lst @EC#3\endcsname{\lst@UM#3}%
+    \expandafter\let\csname\@lst @um#3@\endcsname #2%
+    \edef#2{\noexpand#1%
+            \expandafter\noexpand\csname\@lst @EC#3\endcsname}}
+%    \end{macrocode}
+% \lsthelper{Daniel~Gerigk}{2001/10/25}{extendedchars do not work} and
+% \lsthelper{Heiko~Oberdiek}{2001/10/26}{extendedchars do not work: um@\#3@
+% must be @um\#3@} reported an error and a solution, respectively.
+% \end{macro}
+%
+%
+% \subsubsection{Catcode problems}
+%
+% \begin{macro}{\lst@nfss@catcodes}
+% \lsthelper{Anders~Edenbrandt}{1997/04/22}{preload of .fd files} found a bug
+% with \texttt{.fd}-files. Since we change catcodes and these files are read
+% on demand, we must reset the catcodes before the files are input. We use a
+% local redefinition of |\nfss@catcodes|.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\let\lsts@nfss@catcodes\nfss@catcodes
+     \let\nfss@catcodes\lst@nfss@catcodes}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@nfss@catcodes{%
+    \lst@makeletter
+        ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\relax
+    \@makeother 0\@makeother 1\@makeother 2\@makeother 3\@makeother 4%
+    \@makeother 5\@makeother 6\@makeother 7\@makeother 8\@makeother 9%
+    \@makeother =\lsts@nfss@catcodes}
+%    \end{macrocode}
+% The investigation of a bug reported by \lsthelper{Christian~Gudrian}
+% {2000/11/16}{problems with mathpple} showed that the equal sign needs
+% to have `other' catcode, as assigned above.
+%
+% The name of |\lst@makeletter| is an imitation of \LaTeX's |\@makeother|.
+%    \begin{macrocode}
+\def\lst@makeletter#1{%
+    \ifx\relax#1\else\catcode`#111\relax \expandafter\lst@makeletter\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\output}
+% Another problem was first reported by \lsthelper{Marcin~Kasperski}
+% {1999/04/28}{listings spoil toc}. It is also catcode related and
+% \lsthelper{Donald~Arseneau}{1999/05/13}{comp.text.tex Re: delayed write and
+% catcode changes} let me understand it. The point is that \TeX\ seems to use
+% the \emph{currently} active catcode table when it writes non-|\immediate|
+% |\write|s to file and not the catcodes involved when \emph{reading} the
+% characters.
+% So a section heading |\L a| was written |\La| if a listing was split on two
+% pages since a non-standard catcode table was in use when writing |\La| to
+% file, the previously attached catcodes do not matter. One more bug was that
+% accents in page headings or footers were lost when a listing was split on
+% two pages. \lsthelper{Denis~Girou}{1999/08/03}{Accents lost in heading if
+% listing split on two pages} found this latter bug. A similar problem with
+% the tilde was reported by \lsthelper{Thorsten~Vitt}{2001/06/25}{fancyhdr +
+% listings crossing pages ==> ~ in header, not space}.
+%
+% The solution is a local redefinition of the output routine. We interrupt the
+% current modes---in particular |\lst@Pmode| with modified catcode table---,
+% call the original output routine and reenter the mode. This must be done
+% with a little care. First we have to close the group which \TeX\ opens at
+% the beginning of the output routine. A single |\egroup| gives an `unbalanced
+% output routine' error. But |\expandafter\egroup| works. Again it was
+% \lsthelper{Donald~Arseneau}{2001/01/10}{comp.text.tex Re: \output puzzle}
+% who gave the explaination: The |\expandafter| set the token type of |\bgroup|
+% to |backed_up|, which prevents \TeX's from recovering from an unbalanced
+% output routine. \lsthelper{Heiko~Oberdiek}{2001/01/05}{comp.text.tex Re:
+% \output puzzle} reported that |\csname| |egroup||\endcsname| does the trick,
+% too.
+%
+% However, since \TeX\ checks the contents of |\box| 255 when we close the
+% group (`output routine didn't use all of |\box| 255'), we have to save it
+% temporaryly.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+{\edef\lst@OrgOutput{\the\output}%
+ \output{\global\setbox\lst@gtempboxa\box\@cclv
+         \expandafter\egroup
+%    \end{macrocode}
+% Now we can interrupt the mode, but we have to save the current character
+% string and the current style.
+%    \begin{macrocode}
+         \lst@SaveToken
+     \lst@InterruptModes
+%    \end{macrocode}
+% We restore the contents, use the original output routine, and \ldots
+%    \begin{macrocode}
+     \setbox\@cclv\box\lst@gtempboxa
+     \bgroup\lst@OrgOutput\egroup
+%    \end{macrocode}
+% \ldots\space open a group matching the |}| which \TeX\ inserts at the end of
+% the output routine. We reenter modes and restore the character string and
+% style |\aftergroup|. Moreover we need to reset |\pagegoal|---added after a
+% bug report by \lsthelper{Jochen~Schneider}{2002/03/09}{de.comp.text.tex:
+% Problem mit Listings-Paket 1.0-Beta; unmotivated pagebreak with preceding
+% float}.
+%    \begin{macrocode}
+     \bgroup
+     \aftergroup\pagegoal\aftergroup\vsize
+     \aftergroup\lst@ReenterModes\aftergroup\lst@RestoreToken}}
+%    \end{macrocode}
+% Note that this output routine isn't used too often. It is executed only if
+% it's possible that a listing is split on two pages: if a listing ends at
+% the bottom or begins at the top of a page, or if a listing is really split.
+% \end{macro}
+%
+%
+% \subsubsection{Adjusting the table}
+%
+% We begin with modifiers for the basic character classes.
+%
+% \begin{lstkey}{alsoletter}
+% \begin{lstkey}{alsodigit}
+% \begin{lstkey}{alsoother}
+% The macros |\lst@also|\ldots\space will hold |\def|\meta{char}|{|\ldots|}|
+% sequences, which adjusts the standard character table.
+%    \begin{macrocode}
+\lst@Key{alsoletter}\relax{%
+    \lst@DoAlso{#1}\lst@alsoletter\lst@ProcessLetter}
+\lst@Key{alsodigit}\relax{%
+    \lst@DoAlso{#1}\lst@alsodigit\lst@ProcessDigit}
+\lst@Key{alsoother}\relax{%
+    \lst@DoAlso{#1}\lst@alsoother\lst@ProcessOther}
+%    \end{macrocode}
+% This is done at \hookname{SelectCharTable} and every language selection
+% the macros get empty.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\lst@alsoother \lst@alsodigit \lst@alsoletter}
+\lst@AddToHookExe{SetLanguage}% init
+    {\let\lst@alsoletter\@empty
+     \let\lst@alsodigit\@empty
+     \let\lst@alsoother\@empty}
+%    \end{macrocode}
+% The service macro starts a loop and \ldots
+%    \begin{macrocode}
+\def\lst@DoAlso#1#2#3{%
+    \lst@DefOther\lst@arg{#1}\let#2\@empty
+    \expandafter\lst@DoAlso@\expandafter#2\expandafter#3\lst@arg\relax}
+\def\lst@DoAlso@#1#2#3{%
+    \ifx\relax#3\expandafter\@gobblethree \else
+%    \end{macrocode}
+% \ldots\space while not reaching |\relax| we use the \TeX nique from
+% |\lst@SaveOutputDef| to replace the class by |#2|. Eventually we append
+% the new definition to |#1|.
+%    \begin{macrocode}
+        \begingroup \lccode`\~=`#3\relax \lowercase{\endgroup
+        \def\lst@temp##1\def~##2##3\relax{%
+            \edef\lst@arg{\def\noexpand~{\noexpand#2\expandafter
+                                         \noexpand\@gobble##2}}}}%
+        \expandafter\lst@temp\lst@SelectStdCharTable\relax
+        \lst@lExtend#1{\lst@arg}%
+    \fi
+    \lst@DoAlso@#1#2}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@SaveDef}
+% \begin{macro}{\lst@DefSaveDef}
+% \begin{macro}{\lst@LetSaveDef}
+% These macros can be used in language definitions to make special changes.
+% They save the definition and define or assign a new one.
+%    \begin{macrocode}
+\def\lst@SaveDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup\let#2~}}
+\def\lst@DefSaveDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup\let#2~\def~}}
+\def\lst@LetSaveDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup\let#2~\let~}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% Now we get to the more powerful definitions.
+%
+% \begin{macro}{\lst@CDef}
+% Here we unfold the first parameter \meta{1st}\marg{2nd}\marg{rest} and say
+% that this input string is `replaced' by \meta{save 1st}\marg{2nd}^^A
+% \marg{rest}---plus \meta{execute}, \meta{pre}, and \meta{post}. This main
+% work is done by |\lst@CDefIt|.
+%    \begin{macrocode}
+\def\lst@CDef#1{\lst@CDef@#1}
+\def\lst@CDef@#1#2#3#4{\lst@CDefIt#1{#2}{#3}{#4#2#3}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CDefX}
+% drops the input string.
+%    \begin{macrocode}
+\def\lst@CDefX#1{\lst@CDefX@#1}
+\def\lst@CDefX@#1#2#3{\lst@CDefIt#1{#2}{#3}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CDefIt}
+% is the main working procedure for the previous macros. It redefines the
+% sequence |#1#2#3| of characters. At least |#1| must be active; the other two
+% arguments might be empty, not equivalent to empty!
+%    \begin{macrocode}
+\def\lst@CDefIt#1#2#3#4#5#6#7#8{%
+    \ifx\@empty#2\@empty
+%    \end{macrocode}
+% For a single character we just execute the arguments in the correct order.
+% You might want to go back to section \ref{dCharacterTablesManipulated} to
+% look them up.
+%    \begin{macrocode}
+        \def#1{#6\def\lst@next{#7#4#8}\lst@next}%
+    \else \ifx\@empty#3\@empty
+%    \end{macrocode}
+% For a two character sequence we test whether \meta{pre} and \meta{post}
+% must be executed.
+%    \begin{macrocode}
+        \def#1##1{%
+            #6%
+            \ifx##1#2\def\lst@next{#7#4#8}\else
+                     \def\lst@next{#5##1}\fi
+            \lst@next}%
+    \else
+%    \end{macrocode}
+% We do the same for an arbitrary character sequence---except that we have to
+% use |\lst@IfNextCharsArg| instead of |\ifx|\ldots|\fi|.
+%    \begin{macrocode}
+        \def#1{%
+            #6%
+            \lst@IfNextCharsArg{#2#3}{#7#4#8}%
+                                     {\expandafter#5\lst@eaten}}%
+    \fi \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CArgX}
+% We make |#1#2| active and call |\lst@CArg|.
+%    \begin{macrocode}
+\def\lst@CArgX#1#2\relax{%
+    \lst@DefActive\lst@arg{#1#2}%
+    \expandafter\lst@CArg\lst@arg\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CArg}
+% arranges the first two arguments for |\lst@CDef|[|X|]. We get an undefined
+% macro and use |\@empty\@empty\relax| as delimiter for the submacro.
+%    \begin{macrocode}
+\def\lst@CArg#1#2\relax{%
+    \lccode`\/=`#1\lowercase{\def\lst@temp{/}}%
+    \lst@GetFreeMacro{lst@c\lst@temp}%
+    \expandafter\lst@CArg@\lst@freemacro#1#2\@empty\@empty\relax}
+%    \end{macrocode}
+% Save meaning of \meta{1st}=|#2| in \meta{save 1st}=|#1| and call the macro
+% |#6| with correct arguments. From version 1.0 on, |#2|, |#3| and |#4|
+% (respectively empty arguments) are tied together with group braces.
+% This allows us to save two arguments in other definitions, for example in
+% |\lst@DefDelimB|.
+%    \begin{macrocode}
+\def\lst@CArg@#1#2#3#4\@empty#5\relax#6{%
+    \let#1#2%
+    \ifx\@empty#3\@empty
+        \def\lst@next{#6{#2{}{}}}%
+    \else
+        \def\lst@next{#6{#2#3{#4}}}%
+    \fi
+    \lst@next #1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CArgEmpty}
+% `executes' an |\@empty|-delimited argument. We will use it for the delimiters.
+%    \begin{macrocode}
+\def\lst@CArgEmpty#1\@empty{#1}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Delimiters}
+%
+% Here we start with general definitions common to all delimiters.
+%
+% \begin{lstkey}{excludedelims}
+% controls which delimiters are not printed in \meta{whatever}style. We just
+% define |\lst@ifex|\meta{whatever} to be true. Such switches are set false
+% in the \hookname{ExcludeDelims} hook and are handled by the individual
+% delimiters.
+%    \begin{macrocode}
+\lst@Key{excludedelims}\relax
+    {\lsthk@ExcludeDelims \lst@NormedDef\lst@temp{#1}%
+     \expandafter\lst@for\lst@temp\do
+     {\expandafter\let\csname\@lst @ifex##1\endcsname\iftrue}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DelimPrint}
+% And this macro might help in doing so. |#1| is |\lst@ifex|\meta{whatever}
+% (plus |\else|) or just |\iffalse|, and |#2| will be the delimiter. The
+% temporary mode change ensures that the characters can't end the current
+% delimiter or start a new one.
+%    \begin{macrocode}
+\def\lst@DelimPrint#1#2{%
+    #1%
+      \begingroup
+        \lst@mode\lst@nomode \lst@modetrue
+        #2\lst@XPrintToken
+      \endgroup
+      \lst@ResetToken
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DelimOpen}
+% We print preceding characters and the delimiter, enter the appropriate mode,
+% print the delimiter again, and execute |#3|. In fact, the arguments |#1| and
+% |#2| will ensure that the delimiter is printed only once.
+%    \begin{macrocode}
+\def\lst@DelimOpen#1#2#3#4#5#6\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+    \lst@DelimPrint#1{#6}%
+    \lst@EnterMode{#4}{\def\lst@currstyle#5}%
+    \lst@DelimPrint{#1#2}{#6}%
+    #3}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DelimClose}
+% is the same in reverse order.
+%    \begin{macrocode}
+\def\lst@DelimClose#1#2#3\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+    \lst@DelimPrint{#1#2}{#3}%
+    \lst@LeaveMode
+    \lst@DelimPrint{#1}{#3}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginDelim}
+% \begin{macro}{\lst@EndDelim}
+% These definitions are applications of |\lst@DelimOpen| and |\lst@DelimClose|:
+% the delimiters have the same style as the delimited text.
+%    \begin{macrocode}
+\def\lst@BeginDelim{\lst@DelimOpen\iffalse\else{}}
+\def\lst@EndDelim{\lst@DelimClose\iffalse\else}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginIDelim}
+% \begin{macro}{\lst@EndIDelim}
+% Another application: no delimiter is printed.
+%    \begin{macrocode}
+\def\lst@BeginIDelim{\lst@DelimOpen\iffalse{}{}}
+\def\lst@EndIDelim{\lst@DelimClose\iffalse{}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelims}
+% This macro defines all delimiters and is therefore reset every language
+% selection.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@DefDelims}
+\lst@AddToHookExe{SetLanguage}{\let\lst@DefDelims\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim}
+% First we set default values: no |\lst@modetrue|, cumulative style, and no
+% argument to |\lst@Delim|[|DM|]|@|\meta{type}.
+%    \begin{macrocode}
+\def\lst@Delim#1{%
+    \lst@false \let\lst@cumulative\@empty \let\lst@arg\@empty
+%    \end{macrocode}
+% These are the correct settings for the double-star-form, so we immediately
+% call the submacro in this case. Otherwise we either just suppress cumulative
+% style, or even indicate the usage of |\lst@modetrue| with |\lst@true|.
+%    \begin{macrocode}
+    \@ifstar{\@ifstar{\lst@Delim@{#1}}%
+                     {\let\lst@cumulative\relax
+                      \lst@Delim@{#1}}}%
+            {\lst@true\lst@Delim@{#1}}}
+%    \end{macrocode}
+% The type argument is saved for later use. We check against the optional
+% \meta{style} argument using |#1| as default, define |\lst@delimstyle| and
+% look for the optional \meta{type option}, which is just saved in |\lst@arg|.
+%    \begin{macrocode}
+\def\lst@Delim@#1[#2]{%
+    \gdef\lst@delimtype{#2}%
+    \@ifnextchar[\lst@Delim@sty
+                 {\lst@Delim@sty[#1]}}
+\def\lst@Delim@sty[#1]{%
+    \def\lst@delimstyle{#1}%
+    \ifx\@empty#1\@empty\else
+        \lst@Delim@sty@ #1\@nil
+    \fi
+    \@ifnextchar[\lst@Delim@option
+                 \lst@Delim@delim}
+\def\lst@Delim@option[#1]{\def\lst@arg{#1}\lst@Delim@delim}
+%    \end{macrocode}
+% The definition of |\lst@delimstyle| depends on whether the first token is a
+% control sequence. Here we possibly build |\lst@|\meta{style}.
+%    \begin{macrocode}
+\def\lst@Delim@sty@#1#2\@nil{%
+    \if\relax\noexpand#1\else
+        \edef\lst@delimstyle{\expandafter\noexpand
+                             \csname\@lst @\lst@delimstyle\endcsname}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@delim}
+% Eventually this macro is called. First we might need to delete a bunch of
+% delimiters. If there is no delimiter, we might delete a subclass.
+%    \begin{macrocode}
+\def\lst@Delim@delim#1\relax#2#3#4#5#6#7#8{%
+    \ifx #4\@empty \lst@Delim@delall{#2}\fi
+    \ifx\@empty#1\@empty
+        \ifx #4\@nil
+            \@ifundefined{\@lst @#2DM@\lst@delimtype}%
+                {\lst@Delim@delall{#2@\lst@delimtype}}%
+                {\lst@Delim@delall{#2DM@\lst@delimtype}}%
+        \fi
+    \else
+%    \end{macrocode}
+% If the delimiter is not empty, we convert the delimiter and append it to
+% |\lst@arg|. Ditto |\lst@Begin|\ldots, |\lst@End|\ldots, and the style and
+% mode selection.
+%    \begin{macrocode}
+        \expandafter\lst@Delim@args\expandafter
+            {\lst@delimtype}{#1}{#5}#6{#7}{#8}#4%
+%    \end{macrocode}
+% If the type is known, we either choose dynamic or static mode and use the
+% contents of |\lst@arg| as arguments. All this is put into |\lst@delim|.
+%    \begin{macrocode}
+        \let\lst@delim\@empty
+        \expandafter\lst@IfOneOf\lst@delimtype\relax#3%
+        {\@ifundefined{\@lst @#2DM@\lst@delimtype}%
+             {\lst@lExtend\lst@delim{\csname\@lst @#2@\lst@delimtype
+                                     \expandafter\endcsname\lst@arg}}%
+             {\lst@lExtend\lst@delim{\expandafter\lst@UseDynamicMode
+                                     \csname\@lst @#2DM@\lst@delimtype
+                                     \expandafter\endcsname\lst@arg}}%
+%    \end{macrocode}
+% Now, depending on the mode |#4| we either remove this particular delimiter or
+% append it to all current ones.
+%    \begin{macrocode}
+         \ifx #4\@nil
+             \let\lst@temp\lst@DefDelims \let\lst@DefDelims\@empty
+             \expandafter\lst@Delim@del\lst@temp\@empty\@nil\@nil\@nil
+         \else
+             \lst@lExtend\lst@DefDelims\lst@delim
+         \fi}%
+%    \end{macrocode}
+% An unknown type issues an error.
+%    \begin{macrocode}
+        {\PackageError{Listings}{Illegal type `\lst@delimtype'}%
+                                {#2 types are #3.}}%
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@args}
+% Now let's look how we add the arguments to |\lst@arg|. First we initialize
+% the conversion just to make all characters active. But if the first character
+% of the type equals |#4|, \ldots
+%    \begin{macrocode}
+\def\lst@Delim@args#1#2#3#4#5#6#7{%
+    \begingroup
+    \lst@false \let\lst@next\lst@XConvert
+%    \end{macrocode}
+% \ldots\ we remove that character from |\lst@delimtype|, and |#5| might select
+% a different conversion setting or macro.
+%    \begin{macrocode}
+    \@ifnextchar #4{\xdef\lst@delimtype{\expandafter\@gobble
+                                        \lst@delimtype}%
+                    #5\lst@next#2\@nil
+                    \lst@lAddTo\lst@arg{\@empty#6}%
+                    \lst@GobbleNil}%
+%    \end{macrocode}
+% Since we are in the `special' case above, we've also added the special
+% |\lst@Begin|\ldots\space and |\lst@End|\ldots\space macros to |\lst@arg|
+% (and |\@empty| as a brake for the delimiter). No special task must be done
+% if the characters are not equal.
+%    \begin{macrocode}
+                   {\lst@next#2\@nil
+                    \lst@lAddTo\lst@arg{\@empty#3}%
+                    \lst@GobbleNil}%
+                 #1\@nil
+%    \end{macrocode}
+% We always transfer the arguments to the outside of the group and append the
+% style and mode selection if and only if we're not deleting a delimiter.
+% Therefor we expand the delimiter style.
+%    \begin{macrocode}
+    \global\let\@gtempa\lst@arg
+    \endgroup
+    \let\lst@arg\@gtempa
+    \ifx #7\@nil\else
+        \expandafter\lst@Delim@args@\expandafter{\lst@delimstyle}%
+    \fi}
+%    \end{macrocode}
+% Recall that the style is `selected' by |\def\lst@currstyle#5|, and this
+% `argument' |#5| is to be added now. Depending on the settings at the very
+% beginning, we use either |{\meta{style}}\lst@modetrue|---which selects the
+% style and deactivates keyword detection---, or |{}\meta{style}|---which
+% defines an empty style macro and executes the style for cumulative styles---,
+% or |{\meta{style}|---which just defines the style macro. Note that we have to
+% use two extra group levels below: one is discarded directly by |\lst@lAddTo|
+% and the other by |\lst@Delim|[|DM|]|@|\meta{type}.
+%    \begin{macrocode}
+\def\lst@Delim@args@#1{%
+    \lst@if
+        \lst@lAddTo\lst@arg{{{#1}\lst@modetrue}}%
+    \else
+        \ifx\lst@cumulative\@empty
+            \lst@lAddTo\lst@arg{{{}#1}}%
+        \else
+            \lst@lAddTo\lst@arg{{{#1}}}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@del}
+% To delete a particular delimiter, we iterate down the list of delimiters and
+% compare the current item with the user supplied.
+%    \begin{macrocode}
+\def\lst@Delim@del#1\@empty#2#3#4{%
+    \ifx #2\@nil\else
+        \def\lst@temp{#1\@empty#2#3}%
+        \ifx\lst@temp\lst@delim\else
+            \lst@lAddTo\lst@DefDelims{#1\@empty#2#3{#4}}%
+        \fi
+        \expandafter\lst@Delim@del
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@delall}
+% To delete a whole class of delimiters, we first expand the control sequence
+% name, init some other data, and call a submacro to do the work.
+%    \begin{macrocode}
+\def\lst@Delim@delall#1{%
+    \begingroup
+    \edef\lst@delim{\expandafter\string\csname\@lst @#1\endcsname}%
+    \lst@false \global\let\@gtempa\@empty
+    \expandafter\lst@Delim@delall@\lst@DefDelims\@empty
+    \endgroup
+    \let\lst@DefDelims\@gtempa}
+%    \end{macrocode}
+% We first discard a preceding |\lst@UseDynamicMode|.
+%    \begin{macrocode}
+\def\lst@Delim@delall@#1{%
+    \ifx #1\@empty\else
+        \ifx #1\lst@UseDynamicMode
+            \lst@true
+            \let\lst@next\lst@Delim@delall@do
+        \else
+            \def\lst@next{\lst@Delim@delall@do#1}%
+        \fi
+        \expandafter\lst@next
+    \fi}
+%    \end{macrocode}
+% Then we can check whether (the following) |\lst@|\meta{delimiter name}\ldots\ 
+% matches the delimiter class given by |\lst@delim|.
+%    \begin{macrocode}
+\def\lst@Delim@delall@do#1#2\@empty#3#4#5{%
+    \expandafter\lst@IfSubstring\expandafter{\lst@delim}{\string#1}%
+      {}%
+      {\lst@if \lst@AddTo\@gtempa\lst@UseDynamicMode \fi
+       \lst@AddTo\@gtempa{#1#2\@empty#3#4{#5}}}%
+    \lst@false \lst@Delim@delall@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelimB}
+% Here we put the arguments together to fit |\lst@CDef|. Note that the very
+% last argument |\@empty| to |\lst@CDef| is a brake for |\lst@CArgEmpty|
+% and |\lst@DelimOpen|.
+%    \begin{macrocode}
+\gdef\lst@DefDelimB#1#2#3#4#5#6#7#8{%
+    \lst@CDef{#1}#2%
+        {#3}%
+        {\let\lst@bnext\lst@CArgEmpty
+         \lst@ifmode #4\else
+             #5%
+             \def\lst@bnext{#6{#7}{#8}}%
+         \fi
+         \lst@bnext}%
+        \@empty}
+%    \end{macrocode}
+% After a bug report from \lsthelper{Vespe~Savikko}{2000/11/06}{bad output of
+% doc-strings if HTML and Python are loaded} I added braces around |#7|.
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelimE}
+% The  |\ifnum #7=\lst@mode| in the 5th line ensures that the delimiters
+% match each other.
+%    \begin{macrocode}
+\gdef\lst@DefDelimE#1#2#3#4#5#6#7{%
+    \lst@CDef{#1}#2%
+        {#3}%
+        {\let\lst@enext\lst@CArgEmpty
+         \ifnum #7=\lst@mode%
+             #4%
+             \let\lst@enext#6%
+         \else
+             #5%
+         \fi
+         \lst@enext}%
+        \@empty}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\let\lst@bnext\relax \let\lst@enext\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelimBE}
+% This service macro will actually define all string delimiters.
+%    \begin{macrocode}
+\gdef\lst@DefDelimBE#1#2#3#4#5#6#7#8#9{%
+    \lst@CDef{#1}#2%
+        {#3}%
+        {\let\lst@bnext\lst@CArgEmpty
+         \ifnum #7=\lst@mode
+             #4%
+             \let\lst@bnext#9%
+         \else
+             \lst@ifmode\else
+                 #5%
+                 \def\lst@bnext{#6{#7}{#8}}%
+             \fi
+         \fi
+         \lst@bnext}%
+        \@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@delimtypes}
+% is the list of general delimiter types.
+%    \begin{macrocode}
+\gdef\lst@delimtypes{s,l}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringKey}
+% We just put together the arguments for |\lst@Delim|.
+%    \begin{macrocode}
+\gdef\lst@DelimKey#1#2{%
+    \lst@Delim{}#2\relax
+        {Delim}\lst@delimtypes #1%
+                {\lst@BeginDelim\lst@EndDelim}
+        i\@empty{\lst@BeginIDelim\lst@EndIDelim}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{delim}
+% \begin{lstkey}{moredelim}
+% \begin{lstkey}{deletedelim}
+% all use |\lst@DelimKey|.
+%    \begin{macrocode}
+\lst@Key{delim}\relax{\lst@DelimKey\@empty{#1}}
+\lst@Key{moredelim}\relax{\lst@DelimKey\relax{#1}}
+\lst@Key{deletedelim}\relax{\lst@DelimKey\@nil{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DelimDM@l}
+% \begin{macro}{\lst@DelimDM@s}
+% Nohting special here.
+%    \begin{macrocode}
+\gdef\lst@DelimDM@l#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@DelimDM@s#1#2#3\@empty#4#5#6{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+    \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsubsection{Strings}
+%
+% \begin{aspect}{strings}
+% Just starting a new aspect.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{strings}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@stringtypes}
+% is the list of \ldots\space string types?
+%    \begin{macrocode}
+\gdef\lst@stringtypes{d,b,m,bd,db}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringKey}
+% We just put together the arguments for |\lst@Delim|.
+%    \begin{macrocode}
+\gdef\lst@StringKey#1#2{%
+    \lst@Delim\lst@stringstyle #2\relax
+        {String}\lst@stringtypes #1%
+                     {\lst@BeginString\lst@EndString}%
+        \@@end\@empty{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{string}
+% \begin{lstkey}{morestring}
+% \begin{lstkey}{deletestring}
+% all use |\lst@StringKey|.
+%    \begin{macrocode}
+\lst@Key{string}\relax{\lst@StringKey\@empty{#1}}
+\lst@Key{morestring}\relax{\lst@StringKey\relax{#1}}
+\lst@Key{deletestring}\relax{\lst@StringKey\@nil{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{stringstyle}
+% You shouldn't need comments on the following two lines, do you?
+%    \begin{macrocode}
+\lst@Key{stringstyle}{}{\def\lst@stringstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@stringstyle\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{showstringspaces}
+% Thanks to \lsthelper{Knut~M\"uller}{1997/04/28}{\blankstringtrue} for
+% reporting problems with |\blankstringtrue| (now |showstringspaces=false|).
+% The problem has gone.
+%    \begin{macrocode}
+\lst@Key{showstringspaces}t[t]{\lstKV@SetIf{#1}\lst@ifshowstringspaces}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginString}
+% Note that the tokens after |\lst@DelimOpen| are arguments! The only special
+% here is that we switch to `keepspaces' after starting a string, if necessary.
+% A bug reported by \lsthelper{Vespe~Savikko}{2000/09/27}{stringstyle used also
+% on previous other characters} has gone due to the use of |\lst@DelimOpen|.
+%    \begin{macrocode}
+\gdef\lst@BeginString{%
+    \lst@DelimOpen
+        \lst@ifexstrings\else
+        {\lst@ifshowstringspaces
+             \lst@keepspacestrue
+             \let\lst@outputspace\lst@visiblespace
+         \fi}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHookExe{ExcludeDelims}{\let\lst@ifexstrings\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndString}
+% Again the two tokens following |\lst@DelimClose| are arguments.
+%    \begin{macrocode}
+\gdef\lst@EndString{\lst@DelimClose\lst@ifexstrings\else}
+%    \end{macrocode}
+% \end{macro}
+%
+% And now all the |\lst@StringDM@|\meta{type} definitions.
+%
+% \begin{macro}{\lst@StringDM@d}
+% `d' means no extra work.; the first three arguments after |\lst@DefDelimBE|
+% are left empty. The others are used to start and end the string.
+%    \begin{macrocode}
+\gdef\lst@StringDM@d#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimBE{}{}{}#3{#1}{#5}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringDM@b}
+% The |\lst@ifletter|\ldots|\fi| has been inserted after bug reports by
+% \lsthelper{Daniel~Gerigk}{2001/10/25}{improper strings in C++} and
+% \lsthelper{Peter~Bartke}{2001/11/01}{improper strings in C++}. If the last
+% other character is a backslash (4th line), we gobble the `end string' token
+% sequence.
+%    \begin{macrocode}
+\gdef\lst@StringDM@b#1#2\@empty#3#4#5{%
+    \let\lst@ifbstring\iftrue
+    \lst@CArg #2\relax\lst@DefDelimBE
+       {\lst@ifletter \lst@Output \lst@letterfalse \fi}%
+       {\ifx\lst@lastother\lstum@backslash
+            \expandafter\@gobblethree
+        \fi}{}#3{#1}{#5}#4}
+%    \end{macrocode}
+%    \begin{macrocode}
+\global\let\lst@ifbstring\iffalse % init
+%    \end{macrocode}
+% \lsthelper{Heiko~Heil}{2002/02/08}{string '\\' does not finish after the
+% delimiter} reported problems with double backslashes. So:
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{%
+    \lst@ifbstring
+        \lst@CArgX \\\\\relax \lst@CDefX{}%
+           {\lst@ProcessOther\lstum@backslash
+            \lst@ProcessOther\lstum@backslash}%
+           {}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringDM@bd}
+% \begin{macro}{\lst@StringDM@db}
+% are just the same and the same as |\lst@StringDM@b|.
+%    \begin{macrocode}
+\global\let\lst@StringDM@bd\lst@StringDM@b
+\global\let\lst@StringDM@db\lst@StringDM@bd
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@StringDM@m}
+% `M'atlabed is designed for programming languages where string delimiters are
+% are also used for other purposes, like Matlab or Ada. Here we enter string
+% mode only if the last character has not been a letter and has not been a
+% right parenthesis or right bracket. The test for the latter one has been
+% added after bug report from \lsthelper{Christian~Kindinger}{2002/03/??}
+% {]' starts a string in Matlab}.
+%    \begin{macrocode}
+\gdef\lst@StringDM@m#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimBE{}{}%
+        {\let\lst@next\@gobblethree
+         \lst@ifletter\else
+         \ifx\lst@lastother)\else \ifx\lst@lastother]\else
+             \let\lst@next\@empty
+         \fi \fi \fi
+         \lst@next}#3{#1}{#5}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsubsection{Comments}
+%
+% \begin{aspect}{comments}
+% That's what we are working on.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{comments}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@commenttypes}
+% Via \keyname{comment} available comment types: \textbf line, \textbf fixed
+% column, \textbf single, and \textbf nested and all with
+% preceding \textbf i for invisible comments.
+%    \begin{macrocode}
+\gdef\lst@commenttypes{l,f,s,n}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentKey}
+% We just put together the arguments for |\lst@Delim|.
+%    \begin{macrocode}
+\gdef\lst@CommentKey#1#2{%
+    \lst@Delim\lst@commentstyle #2\relax
+        {Comment}\lst@commenttypes #1%
+                {\lst@BeginComment\lst@EndComment}%
+        i\@empty{\lst@BeginInvisible\lst@EndInvisible}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{comment}
+% \begin{lstkey}{morecomment}
+% \begin{lstkey}{deletecomment}
+% The keys are easy since defined in terms of |\lst@CommentKey|.
+%    \begin{macrocode}
+\lst@Key{comment}\relax{\lst@CommentKey\@empty{#1}}
+\lst@Key{morecomment}\relax{\lst@CommentKey\relax{#1}}
+\lst@Key{deletecomment}\relax{\lst@CommentKey\@nil{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{commentstyle}
+% Any hints necessary?
+%    \begin{macrocode}
+\lst@Key{commentstyle}{}{\def\lst@commentstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@commentstyle\itshape}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginComment}
+% \begin{macro}{\lst@EndComment}
+% Once more the three tokens following |\lst@DelimOpen| are arguments.
+%    \begin{macrocode}
+\gdef\lst@BeginComment{%
+    \lst@DelimOpen
+        \lst@ifexcomments\else
+        \lsthk@AfterBeginComment}
+%    \end{macrocode}
+% Ditto.
+%    \begin{macrocode}
+\gdef\lst@EndComment{\lst@DelimClose\lst@ifexcomments\else}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{AfterBeginComment}{}
+\lst@AddToHookExe{ExcludeDelims}{\let\lst@ifexcomments\iffalse}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginInvisible}
+% \begin{macro}{\lst@EndInvisible}
+% Print preceding characters and begin dropping the output.
+%    \begin{macrocode}
+\gdef\lst@BeginInvisible#1#2#3\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+    \lst@BeginDropOutput{#1}}
+%    \end{macrocode}
+% Don't print the delimiter and end dropping the output.
+%    \begin{macrocode}
+\gdef\lst@EndInvisible#1\@empty{\lst@EndDropOutput}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% Now we provide all |\lst@Comment|[|DM|]|@|\meta{type} macros.
+%
+% \begin{macro}{\lst@Comment@l}
+% is easy---thanks to |\lst@CArg| and |\lst@DefDelimB|. Note that the
+% `end comment' argument |#4| is not used here.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@l#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentDM@f}
+% is slightly more work. First we provide the number of preceding columns.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@f#1{%
+    \@ifnextchar[{\lst@Comment@@f{#1}}%
+                 {\lst@Comment@@f{#1}[0]}}
+%    \end{macrocode}
+% We define the comment in the same way as above, but we enter comment mode
+% if and only if the character is in column |#2| (counting from zero).
+%    \begin{macrocode}
+\gdef\lst@Comment@@f#1[#2]#3\@empty#4#5#6{%
+    \lst@CArg #3\relax\lst@DefDelimB{}{}%
+        {\lst@CalcColumn
+         \ifnum #2=\@tempcnta\else
+             \expandafter\@gobblethree
+         \fi}%
+        #4{#1}{#6\lst@Lmodetrue}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentDM@s}
+% Nothing special here.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@s#1#2#3\@empty#4#5#6{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+    \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentDM@n}
+% We either give an error message or define the nested comment.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@n#1#2#3\@empty#4#5#6{%
+    \ifx\@empty#3\@empty\else
+        \def\@tempa{#2}\def\@tempb{#3}%
+        \ifx\@tempa\@tempb
+            \PackageError{Listings}{Identical delimiters}%
+            {These delimiters make no sense with nested comments.}%
+        \else
+            \lst@CArg #2\relax\lst@DefDelimB
+                {}%
+%    \end{macrocode}
+% Note that the following |\@gobble| eats an |\else| from |\lst@DefDelimB|.
+%    \begin{macrocode}
+                {\ifnum\lst@mode=#1\relax \expandafter\@gobble \fi}%
+                {}#4{#1}{#6}%
+            \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsubsection{PODs}
+%
+% \begin{aspect}{pod}
+% PODs are defined as a separate aspect.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{pod}
+%    \end{macrocode}
+%
+% \begin{lstkey}{printpod}
+% \begin{lstkey}{podcomment}
+% We begin with the user keys, which I introduced after communication with
+% \lsthelper{Michael~Piotrowski}{1997/11/11}{printpod}.
+%    \begin{macrocode}
+\lst@Key{printpod}{false}[t]{\lstKV@SetIf{#1}\lst@ifprintpod}
+\lst@Key{podcomment}{false}[t]{\lstKV@SetIf{#1}\lst@ifpodcomment}
+\lst@AddToHookExe{SetLanguage}{\let\lst@ifpodcomment\iffalse}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@PODmode}
+% is the static mode for PODs.
+%    \begin{macrocode}
+\lst@NewMode\lst@PODmode
+%    \end{macrocode}
+% \end{macro}
+%
+% We adjust some characters if the user has selected |podcomment=true|.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\lst@ifpodcomment
+         \lst@CArgX =\relax\lst@DefDelimB{}{}%
+%    \end{macrocode}
+% The following code is executed if we've found an equality sign and haven't
+% entered a mode (in fact if mode changes are allowed): We `begin drop output'
+% and gobble the usual begin of comment sequence (via |\@gobblethree|) if PODs
+% aren't be printed. Moreover we gobble it if the current column number is not
+% zero---|\@tempcnta| is valued below.
+%    \begin{macrocode}
+           {\ifnum\@tempcnta=\z@
+                \lst@ifprintpod\else
+                    \def\lst@bnext{\lst@BeginDropOutput\lst@PODmode}%
+                    \expandafter\expandafter\expandafter\@gobblethree
+                \fi
+            \else
+               \expandafter\@gobblethree
+            \fi}%
+           \lst@BeginComment\lst@PODmode\lst@commentstyle
+%    \end{macrocode}
+% If we come to |=|, we calculate the current column number (zero based).
+%    \begin{macrocode}
+         \lst@CArgX =cut\^^M\relax\lst@DefDelimE
+           {\lst@CalcColumn}%
+%    \end{macrocode}
+% If there is additionally |cut|+EOL and if we are in |\lst@PODmode| but not in
+% column one, we must gobble the `end comment sequence'.
+%    \begin{macrocode}
+           {\ifnum\@tempcnta=\z@\else
+                \expandafter\@gobblethree
+            \fi}%
+           {}%
+           \lst@EndComment\lst@PODmode
+	 \fi}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Replacing input}
+%
+% \begingroup
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@ReplaceInput}
+% is defined in terms of |\lst@CArgX| and |\lst@CDefX|.
+%    \begin{macrocode}
+\def\lst@ReplaceInput#1{\lst@CArgX #1\relax\lst@CDefX{}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{literate}
+% \lsthelper{Jason~Alexander}{1999/03/10}{literate programming} asked for
+% something like that. The key simply saves the argument.
+%    \begin{macrocode}
+\lst@Key{literate}{}{\def\lst@literate{#1}}
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@literate\@empty\else
+         \expandafter\lst@Literate\lst@literate{}\relax\z@
+     \fi}
+%    \end{macrocode}
+% Internally we make use of the `replace input' feature.
+% We print the preceding text, assign token and length, and output it.
+%    \begin{macrocode}
+\def\lst@Literate#1#2#3{%
+    \ifx\relax#2\@empty\else
+        \lst@ReplaceInput{#1}%
+            {\lst@XPrintToken \lst@letterfalse
+             \lst@token{#2}\lst@length#3\relax
+             \lst@XPrintToken}%
+        \expandafter\lst@Literate
+    \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginDropInput}
+% We deactivate all `process' macros. |\lst@modetrue| does this for all
+% up-coming string delimiters, comments, and so on.
+%    \begin{macrocode}
+\def\lst@BeginDropInput#1{%
+    \lst@EnterMode{#1}%
+    {\lst@modetrue
+     \let\lst@ifdropinput\iftrue
+     \let\lst@ProcessLetter\@gobble
+     \let\lst@ProcessDigit\@gobble
+     \let\lst@ProcessOther\@gobble
+     \let\lst@ProcessSpace\@empty
+     \let\lst@ProcessTabulator\@empty
+     \let\lst@ProcessFormFeed\@empty}}
+\let\lst@ifdropinput\iffalse % init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begingroup
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \endgroup
+%
+%
+% \subsection{Escaping to \LaTeX}
+%
+% \begin{aspect}{escape}
+% We now define the \ldots\ damned \ldots\ the aspect has escaped!
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{escape}
+%    \end{macrocode}
+%
+% \begin{lstkey}{texcl}
+% Communication with \lsthelper{J\"orn~Wilms}{1997/07/07}{\TeX\ comments} is
+% responsible for this key. The definition and the first hooks are easy.
+%    \begin{macrocode}
+\lst@Key{texcl}{false}[t]{\lstKV@SetIf{#1}\lst@iftexcl}
+\lst@AddToHook{TextStyle}{\let\lst@iftexcl\iffalse}
+\lst@AddToHook{EOL}
+    {\ifnum\lst@mode=\lst@TeXLmode
+         \expandafter\lst@escapeend
+         \expandafter\lst@LeaveAllModes
+         \expandafter\lst@ReenterModes
+     \fi}
+%    \end{macrocode}
+% If the user wants \TeX\ comment lines, we print the comment separator and
+% interrupt the normal processing.
+%    \begin{macrocode}
+\lst@AddToHook{AfterBeginComment}
+    {\lst@iftexcl \lst@ifLmode \lst@ifdropinput\else
+         \lst@PrintToken
+         \lst@LeaveMode \lst@InterruptModes
+         \lst@EnterMode{\lst@TeXLmode}{\lst@modetrue\lst@commentstyle}%
+         \expandafter\expandafter\expandafter\lst@escapebegin
+     \fi \fi \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@NewMode\lst@TeXLmode
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ActiveCDefX}
+% Same as |\lst@CDefX| but we both make |#1| active and assign a new catcode.
+%    \begin{macrocode}
+\gdef\lst@ActiveCDefX#1{\lst@ActiveCDefX@#1}
+\gdef\lst@ActiveCDefX@#1#2#3{
+    \catcode`#1\active\lccode`\~=`#1%
+    \lowercase{\lst@CDefIt~}{#2}{#3}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Escape}
+% gets four arguments all in all. The first and second are the `begin' and
+% `end' escape sequences, the third is executed when the escape starts, and the
+% fourth right before ending it. We use the same mechanism as for \TeX\ comment
+% lines. The |\lst@ifdropinput| test has been added after a bug report by
+% \lsthelper{Michael~Weber}{2002/03/26}{escape on lines < firstline corrupts
+% output}.
+%    \begin{macrocode}
+\gdef\lst@Escape#1#2#3#4{%
+    \lst@CArgX #1\relax\lst@CDefX
+        {}%
+        {\lst@ifdropinput\else
+         \lst@TrackNewLines\lst@OutputLostSpace \lst@XPrintToken
+         \lst@InterruptModes
+         \lst@EnterMode{\lst@TeXmode}{\lst@modetrue}%
+%    \end{macrocode}
+% Now we must define the character sequence to end the escape.
+%    \begin{macrocode}
+         \ifx\^^M#2%
+             \lst@CArg #2\relax\lst@ActiveCDefX
+                 {}%
+                 {\lst@escapeend #4\lst@LeaveAllModes\lst@ReenterModes}%
+                 {\lst@MProcessListing}%
+         \else
+             \lst@CArg #2\relax\lst@ActiveCDefX
+                 {}%
+                 {\lst@escapeend #4\lst@LeaveAllModes\lst@ReenterModes
+                  \lst@whitespacefalse}%
+                 {}%
+         \fi
+         #3\lst@escapebegin
+         \fi}%
+        {}}
+%    \end{macrocode}
+% The |\lst@whitespacefalse| above was added after a bug report from
+% \lsthelper{Martin~Steffen}{2001/04/07}{mathescape drops subsequent space}.
+%    \begin{macrocode}
+\lst@NewMode\lst@TeXmode
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{escapebegin}
+% \begin{lstkey}{escapeend}
+% The keys simply store the arguments.
+%    \begin{macrocode}
+\lst@Key{escapebegin}{}{\def\lst@escapebegin{#1}}
+\lst@Key{escapeend}{}{\def\lst@escapeend{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{escapechar}
+% The introduction of this key is due to a communication with \lsthelper
+% {Rui~Oliveira}{1998/06/05}{escape characters}. We define |\lst@DefEsc| and
+% execute it after selecting the standard character table.
+%    \begin{macrocode}
+\lst@Key{escapechar}{}
+    {\ifx\@empty#1\@empty
+         \let\lst@DefEsc\relax
+     \else
+         \def\lst@DefEsc{\lst@Escape{#1}{#1}{}{}}%
+     \fi}
+\lst@AddToHook{TextStyle}{\let\lst@DefEsc\@empty}
+\lst@AddToHook{SelectCharTable}{\lst@DefEsc}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{escapeinside}
+% Nearly the same.
+%    \begin{macrocode}
+\lst@Key{escapeinside}{}{\lstKV@TwoArg{#1}%
+    {\let\lst@DefEsc\@empty
+     \ifx\@empty##1@empty\else \ifx\@empty##2\@empty\else
+         \def\lst@DefEsc{\lst@Escape{##1}{##2}{}{}}%
+     \fi\fi}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{mathescape}
+% This is a switch and checked after character table selection. We use
+% |\lst@Escape| with math shifts as arguments, but all inside |\hbox|
+% to determine the correct width.
+%    \begin{macrocode}
+\lst@Key{mathescape}{false}[t]{\lstKV@SetIf{#1}\lst@ifmathescape}
+\lst@AddToHook{SelectCharTable}
+    {\lst@ifmathescape \lst@Escape{\$}{\$}%
+        {\setbox\@tempboxa=\hbox\bgroup$}%
+        {$\egroup \lst@CalcLostSpaceAndOutput}\fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Keywords}
+%
+%
+% \subsection{Making tests}\label{iMakingTests}
+%
+% \begin{aspect}{keywords}
+% We begin a new and very important aspect.
+% First of all we need to initialize some variables in order to work around a
+% bug reported by \lsthelper{Beat~Birkhofer}{2001/06/15}{savemem doesn't work}.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{keywords}
+%    \end{macrocode}
+%    \begin{macrocode}
+\global\let\lst@ifsensitive\iftrue % init
+\global\let\lst@ifsensitivedefed\iffalse % init % \global
+%    \end{macrocode}
+% All keyword tests take the following three arguments.
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name}|@list| (a list of macros which contain the keywords)
+% \item |\lst@g|\meta{name}|@sty| (global style macro)
+% \end{macroargs}
+% We begin with non memory-saving tests.
+% \begingroup
+%    \begin{macrocode}
+\lst@ifsavemem\else
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@KeywordTest}
+% Fast keyword tests take advance of the |\lst@UM| construction in section
+% \ref{iCharacterTables}. If |\lst@UM| is empty, all `use macro' characters
+% expand to their original characters. Since |\lst|\meta{prefix}|@|\meta{keyword}
+% will be equivalent to the appropriate style, we only need to build the control
+% sequence |\lst|\meta{prefix}|@|\meta{current token} and assign it to
+% |\lst@thestyle|.
+%    \begin{macrocode}
+\gdef\lst@KeywordTest#1#2#3{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#1@\the\lst@token\endcsname
+    \endgroup
+    \ifx\@gtempa\relax\else
+        \let\lst@thestyle\@gtempa
+    \fi}
+%    \end{macrocode}
+% Note that we need neither |#2| nor |#3| here.
+% \end{macro}
+%
+% \begin{macro}{\lst@KEYWORDTEST}
+% Case insensitive tests make the current character string upper case and give
+% it to a submacro similar to |\lst@KeywordTest|.
+%    \begin{macrocode}
+\gdef\lst@KEYWORDTEST{%
+    \uppercase\expandafter{\expandafter
+        \lst@KEYWORDTEST@\the\lst@token}\relax}
+\gdef\lst@KEYWORDTEST@#1\relax#2#3#4{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#2@#1\endcsname
+    \endgroup
+    \ifx\@gtempa\relax\else
+        \let\lst@thestyle\@gtempa
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@WorkingTest}
+% \begin{macro}{\lst@WORKINGTEST}
+% The same except that |\lst|\meta{prefix}|@|\meta{current token} might be
+% a working procedure; it is executed.
+%    \begin{macrocode}
+\gdef\lst@WorkingTest#1#2#3{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#1@\the\lst@token\endcsname
+    \endgroup
+    \@gtempa}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@WORKINGTEST{%
+    \uppercase\expandafter{\expandafter
+        \lst@WORKINGTEST@\the\lst@token}\relax}
+\gdef\lst@WORKINGTEST@#1\relax#2#3#4{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#2@#1\endcsname
+    \endgroup
+    \@gtempa}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefineKeywords}
+% Eventually we need macros which define and undefine
+% |\lst|\meta{prefix}|@|\meta{keyword}. Here the arguments are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name} (a keyword list)
+% \item |\lst@g|\meta{name}|@sty|
+% \end{macroargs}
+% We make the keywords upper case if necessary, \ldots
+%    \begin{macrocode}
+\gdef\lst@DefineKeywords#1#2#3{%
+    \lst@ifsensitive
+        \def\lst@next{\lst@for#2}%
+    \else
+        \def\lst@next{\uppercase\expandafter{\expandafter\lst@for#2}}%
+    \fi
+    \lst@next\do
+%    \end{macrocode}
+% \ldots\space iterate through the list, and make
+% |\lst|\meta{prefix}|@|\meta{keyword} (if undefined) equivalent to
+% |\lst@g|\meta{name}|@sty| which is possibly a working macro.
+%    \begin{macrocode}
+    {\expandafter\ifx\csname\@lst#1@##1\endcsname\relax
+        \global\expandafter\let\csname\@lst#1@##1\endcsname#3%
+     \fi}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@UndefineKeywords}
+% We make the keywords upper case if necessary, \ldots
+%    \begin{macrocode}
+\gdef\lst@UndefineKeywords#1#2#3{%
+    \lst@ifsensitivedefed
+        \def\lst@next{\lst@for#2}%
+    \else
+        \def\lst@next{\uppercase\expandafter{\expandafter\lst@for#2}}%
+    \fi
+    \lst@next\do
+%    \end{macrocode}
+% \ldots\space iterate through the list, and `undefine'
+% |\lst|\meta{prefix}|@|\meta{keyword} if it's equivalent to
+% |\lst@g|\meta{name}|@sty|.
+%    \begin{macrocode}
+    {\expandafter\ifx\csname\@lst#1@##1\endcsname#3%
+        \global\expandafter\let\csname\@lst#1@##1\endcsname\relax
+     \fi}}
+%    \end{macrocode}
+% Thanks to \lsthelper{Magnus~Lewis-Smith}{1999/09/08}{keywords do not
+% undefine} a wrong |#2| in the replacement text could be changed to |#3|.
+% \end{macro}
+%
+% \begingroup
+% And now memory-saving tests.
+%    \begin{macrocode}
+\fi
+\lst@ifsavemem
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@IfOneOutOf}
+% The definition here is similar to |\lst@IfOneOf|, but its second argument
+% is a |\lst@|\meta{name}|@list|. Therefore we test a list of macros here.
+%    \begin{macrocode}
+\gdef\lst@IfOneOutOf#1\relax#2{%
+    \def\lst@temp##1,#1,##2##3\relax{%
+        \ifx\@empty##2\else \expandafter\lst@IOOOfirst \fi}%
+    \def\lst@next{\lst@IfOneOutOf@#1\relax}%
+    \expandafter\lst@next#2\relax\relax}
+%    \end{macrocode}
+% We either execute the \meta{else} part or make the next test.
+%    \begin{macrocode}
+\gdef\lst@IfOneOutOf@#1\relax#2#3{%
+    \ifx#2\relax
+        \expandafter\@secondoftwo
+    \else
+        \expandafter\lst@temp\expandafter,#2,#1,\@empty\relax
+        \expandafter\lst@next
+    \fi}
+\ifx\iffalse\else\fi
+\gdef\lst@IOOOfirst#1\relax#2#3{\fi#2}
+%    \end{macrocode}
+% The line |\ifx\iffalse\else\fi| balances the |\fi| inside |\lst@IOOOfirst|.
+% \end{macro}
+%
+% \begin{macro}{\lst@IFONEOUTOF}
+% As in |\lst@IFONEOF| we need two |\uppercase|s here.
+%    \begin{macrocode}
+\gdef\lst@IFONEOUTOF#1\relax#2{%
+    \uppercase{\def\lst@temp##1,#1},##2##3\relax{%
+        \ifx\@empty##2\else \expandafter\lst@IOOOfirst \fi}%
+    \def\lst@next{\lst@IFONEOUTOF@#1\relax}%
+    \expandafter\lst@next#2\relax}
+\gdef\lst@IFONEOUTOF@#1\relax#2#3{%
+    \ifx#2\relax
+        \expandafter\@secondoftwo
+    \else
+        \uppercase
+            {\expandafter\lst@temp\expandafter,#2,#1,\@empty\relax}%
+        \expandafter\lst@next
+    \fi}
+%    \end{macrocode}
+% Note: The third last line uses the fact that keyword lists (not the list
+% of keyword lists) are already made upper case if keywords are insensitive.
+% \end{macro}
+%
+% \begin{macro}{\lst@KWTest}
+% is a helper for the keyword and working identifier tests. We expand the
+% token and call |\lst@IfOneOf|. The tests below will append appropriate
+% \meta{then} and \meta{else} arguments.
+%    \begin{macrocode}
+\gdef\lst@KWTest{%
+    \begingroup \let\lst@UM\@empty
+    \expandafter\xdef\expandafter\@gtempa\expandafter{\the\lst@token}%
+    \endgroup
+    \expandafter\lst@IfOneOutOf\@gtempa\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@KeywordTest}
+% \begin{macro}{\lst@KEYWORDTEST}
+% are fairly easy now. Note that we don't need |#1|=\meta{prefix} here.
+%    \begin{macrocode}
+\gdef\lst@KeywordTest#1#2#3{\lst@KWTest #2{\let\lst@thestyle#3}{}}
+\global\let\lst@KEYWORDTEST\lst@KeywordTest
+%    \end{macrocode}
+% For case insensitive tests we assign the insensitive version to
+% |\lst@IfOneOutOf|. Thus we need no extra definition here.
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@WorkingTest}
+% \begin{macro}{\lst@WORKINGTEST}
+% Ditto.
+%    \begin{macrocode}
+\gdef\lst@WorkingTest#1#2#3{\lst@KWTest #2#3{}}
+\global\let\lst@WORKINGTEST\lst@WorkingTest
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begingroup
+%    \begin{macrocode}
+\fi
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{lstkey}{sensitive}
+% is a switch, preset \texttt{true} every language selection.
+%    \begin{macrocode}
+\lst@Key{sensitive}\relax[t]{\lstKV@SetIf{#1}\lst@ifsensitive}
+\lst@AddToHook{SetLanguage}{\let\lst@ifsensitive\iftrue}
+%    \end{macrocode}
+% We select case insensitive definitions if necessary.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifsensitive\else
+         \let\lst@KeywordTest\lst@KEYWORDTEST
+         \let\lst@WorkingTest\lst@WORKINGTEST
+         \let\lst@IfOneOutOf\lst@IFONEOUTOF
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@MakeMacroUppercase}
+% makes the contents of |#1| (if defined) upper case.
+%    \begin{macrocode}
+\gdef\lst@MakeMacroUppercase#1{%
+    \ifx\@undefined#1\else \uppercase\expandafter
+        {\expandafter\def\expandafter#1\expandafter{#1}}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Installing tests}
+%
+% \begin{macro}{\lst@InstallTest}
+% The arguments are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@|\meta{name}
+% \item |\lst@g|\meta{name}|@list|
+% \item |\lst@g|\meta{name}
+% \item |\lst@g|\meta{name}|@sty|
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% We just insert hook material. The tests will be inserted on demand.
+%    \begin{macrocode}
+\gdef\lst@InstallTest#1#2#3#4#5#6#7#8{%
+    \lst@AddToHook{TrackKeywords}{\lst@TrackKeywords{#1}#2#4#6#7#8}%
+    \lst@AddToHook{PostTrackKeywords}{\lst@PostTrackKeywords#2#3#4#5}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\lsthk@TrackKeywords\lsthk@PostTrackKeywords}
+\lst@AddToHook{TrackKeywords}{}% init
+\lst@AddToHook{PostTrackKeywords}{}% init
+%    \end{macrocode}
+% We have to detect the keywords somewhere.
+%    \begin{macrocode}
+\lst@AddToHook{Output}{\lst@ifkeywords \lsthk@DetectKeywords \fi}
+\lst@AddToHook{DetectKeywords}{}% init
+\lst@AddToHook{ModeTrue}{\let\lst@ifkeywords\iffalse}
+\lst@AddToHook{Init}{\let\lst@ifkeywords\iftrue}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InstallTestNow}
+% actually inserts a test.
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@g|\meta{name}|@sty|
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% For example, |#4#5|=|sd| will add
+%    |\lst@KeywordTest{|\meta{prefix}|}|
+%       |\lst@|\meta{name}|@list| |\lst@g|\meta{name}|@sty|
+% to the \hookname{DetectKeywords} hook.
+%    \begin{macrocode}
+\gdef\lst@InstallTestNow#1#2#3#4#5{%
+    \@ifundefined{\string#2#1}%
+    {\global\@namedef{\string#2#1}{}%
+     \edef\@tempa{%
+         \noexpand\lst@AddToHook{\ifx#5dDetectKeywords\else Output\fi}%
+         {\ifx #4w\noexpand\lst@WorkingTest
+             \else\noexpand\lst@KeywordTest \fi
+          {#1}\noexpand#2\noexpand#3}}%
+%    \end{macrocode}
+% If we are advised to save memory, we insert a test for each \meta{name}.
+% Otherwise we install the tests according to \meta{prefix}.
+%    \begin{macrocode}
+     \lst@ifsavemem
+         \@tempa
+     \else
+         \@ifundefined{\@lst#1@if@ins}%
+             {\@tempa \global\@namedef{\@lst#1@if@ins}{}}%
+             {}%
+     \fi}
+    {}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TrackKeywords}
+% Now it gets a bit tricky. We expand the class list |\lst@|\meta{name}|@list|
+% behind |\lst@TK@{|\meta{prefix}|}||\lst@g|\meta{name}|@sty| and use two
+% |\relax|es as terminators. This will define the keywords of all the classes
+% as keywords of type \meta{prefix}. More details come soon.
+%    \begin{macrocode}
+\gdef\lst@TrackKeywords#1#2#3#4#5#6{%
+    \lst@false
+    \def\lst@arg{{#1}#4}%
+    \expandafter\expandafter\expandafter\lst@TK@
+        \expandafter\lst@arg#2\relax\relax
+%    \end{macrocode}
+% And nearly the same to undefine all out-dated keywords, which is necessary
+% only if we don't save memory.
+%    \begin{macrocode}
+    \lst@ifsavemem\else
+        \def\lst@arg{{#1}#4#2}%
+        \expandafter\expandafter\expandafter\lst@TK@@
+            \expandafter\lst@arg#3\relax\relax
+    \fi
+%    \end{macrocode}
+% Finally we install the keyword test if keywords changed, in particular if
+% they are defined the first time. Note that |\lst@InstallTestNow| inserts a
+% test only once.
+%    \begin{macrocode}
+    \lst@if \lst@InstallTestNow{#1}#2#4#5#6\fi}
+%    \end{macrocode}
+% Back to the current keywords. Global macros |\lst@g|\meta{id} contain
+% globally defined keywords, whereas |\lst@|\meta{id} conatin the true
+% keywords. This way we can keep track of the keywords: If keywords or
+% \keyname{sensitive} changed, we undefine the old (= globally defined)
+% keywords and define the true ones. The arguments of |\lst@TK@| are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@g|\meta{name}|@sty|
+% \item |\lst@|\meta{id}
+% \item |\lst@g|\meta{id}
+% \end{macroargs}
+%    \begin{macrocode}
+\gdef\lst@TK@#1#2#3#4{%
+    \ifx\lst@ifsensitive\lst@ifsensitivedefed
+        \ifx#3#4\else
+            \lst@true
+            \lst@ifsavemem\else
+                \lst@UndefineKeywords{#1}#4#2%
+                \lst@DefineKeywords{#1}#3#2%
+            \fi
+        \fi
+    \else
+        \ifx#3\relax\else
+            \lst@true
+            \lst@ifsavemem\else
+                \lst@UndefineKeywords{#1}#4#2%
+                \lst@DefineKeywords{#1}#3#2%
+            \fi
+        \fi
+    \fi
+%    \end{macrocode}
+% We don't define and undefine keywords if we try to save memory. But we
+% possibly need to make them upper case, which again wastes some memory.
+%    \begin{macrocode}
+    \lst@ifsavemem \ifx#3\relax\else
+        \lst@ifsensitive\else \lst@MakeMacroUppercase#3\fi
+    \fi \fi
+%    \end{macrocode}
+% Reaching the end of the class list, we end the loop.
+%    \begin{macrocode}
+    \ifx#3\relax
+        \expandafter\@gobblethree
+    \fi
+    \lst@TK@{#1}#2}
+%    \end{macrocode}
+% Here now we undefine the out-dated keywords. While not reaching the end of
+% the global list, we look whether the keyword class |#4#5| is still in use or
+% needs to be undefined. Our arguments are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@g|\meta{name}|@sty|
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@|\meta{id}
+% \item |\lst@g|\meta{id}
+% \end{macroargs}
+%    \begin{macrocode}
+\gdef\lst@TK@@#1#2#3#4#5{%
+    \ifx#4\relax
+        \expandafter\@gobblefour
+    \else
+        \lst@IfSubstring{#4#5}#3{}{\lst@UndefineKeywords{#1}#5#2}%
+    \fi
+    \lst@TK@@{#1}#2#3}
+%    \end{macrocode}
+% Keywords are up-to-date after \hookname{InitVars}.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}
+    {\global\let\lst@ifsensitivedefed\lst@ifsensitive}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@PostTrackKeywords}
+% After updating all the keywords, the global keywords and the global list
+% become equivalent to the local ones.
+%    \begin{macrocode}
+\gdef\lst@PostTrackKeywords#1#2#3#4{%
+    \lst@ifsavemem\else
+        \global\let#3#1%
+        \global\let#4#2%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Classes and families}
+%
+% \begin{lstkey}{classoffset}
+% just stores the argument in a macro.
+%    \begin{macrocode}
+\lst@Key{classoffset}\z@{\def\lst@classoffset{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@InstallFamily}
+% Recall the parameters
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item \meta{name}
+% \item \meta{style name}
+% \item \meta{style init}
+% \item \meta{default style name}
+% \item \meta{working procedure}
+% \item \alternative{l,o} (language or other key)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% First we define the keys and the style key \meta{style name} if and only if
+% the name is not empty.
+%    \begin{macrocode}
+\gdef\lst@InstallFamily#1#2#3#4#5{%
+    \lst@Key{#2}\relax{\lst@UseFamily{#2}##1\relax\lst@MakeKeywords}%
+    \lst@Key{more#2}\relax
+        {\lst@UseFamily{#2}##1\relax\lst@MakeMoreKeywords}%
+    \lst@Key{delete#2}\relax
+        {\lst@UseFamily{#2}##1\relax\lst@DeleteKeywords}%
+    \ifx\@empty#3\@empty\else
+        \lst@Key{#3}{#4}{\lstKV@OptArg[\@ne]{##1}%
+            {\@tempcnta\lst@classoffset \advance\@tempcnta####1\relax
+             \@namedef{lst@#3\ifnum\@tempcnta=\@ne\else \the\@tempcnta
+                             \fi}{####2}}}%
+    \fi
+    \expandafter\lst@InstallFamily@
+        \csname\@lst @#2@data\expandafter\endcsname
+        \csname\@lst @#5\endcsname {#1}{#2}{#3}}
+%    \end{macrocode}
+% Now we check whether \meta{working procedure} is empty. Accordingly we use
+% \texttt working procedure or \texttt style in the `data' definition.
+% The working procedure is defined right here if necessary.
+%    \begin{macrocode}
+\gdef\lst@InstallFamily@#1#2#3#4#5#6#7#8{%
+    \gdef#1{{#3}{#4}{#5}#2#7}%
+    \long\def\lst@temp##1{#6}%
+    \ifx\lst@temp\@gobble
+        \lst@AddTo#1{s#8}%
+    \else
+        \lst@AddTo#1{w#8}%
+        \global\@namedef{lst@g#4@wp}##1{#6}%
+    \fi}
+%    \end{macrocode}
+% Nothing else is defined here, all the rest is done on demand.
+% \end{macro}
+%
+% \begin{macro}{\lst@UseFamily}
+% We look for the optional class number, provide this member, \ldots
+%    \begin{macrocode}
+\gdef\lst@UseFamily#1{%
+    \def\lst@family{#1}%
+    \@ifnextchar[\lst@UseFamily@{\lst@UseFamily@[\@ne]}}
+\gdef\lst@UseFamily@[#1]{%
+    \@tempcnta\lst@classoffset \advance\@tempcnta#1\relax
+    \lst@ProvideFamily\lst@family
+%    \end{macrocode}
+% \ldots\space and build the control sequences \ldots
+%    \begin{macrocode}
+    \lst@UseFamily@a
+        {\lst@family\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}}
+\gdef\lst@UseFamily@a#1{%
+    \expandafter\lst@UseFamily@b
+       \csname\@lst @#1@list\expandafter\endcsname
+       \csname\@lst @#1\expandafter\endcsname
+       \csname\@lst @#1@also\expandafter\endcsname
+       \csname\@lst @g#1\endcsname}
+%    \end{macrocode}
+% \ldots\space required for |\lst@MakeKeywords| and |#6|.
+%    \begin{macrocode}
+\gdef\lst@UseFamily@b#1#2#3#4#5\relax#6{\lstKV@XOptArg[]{#5}#6#1#2#3#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProvideFamily}
+% provides the member `|\the\@tempcnta|' of the family |#1|. We do nothing if
+% the member already exists. Otherwise we expand the data macro defined above.
+% Note that we don't use the counter if it equals one.
+%    \begin{macrocode}
+\gdef\lst@ProvideFamily#1{%
+    \@ifundefined{lst@#1\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}%
+    {\expandafter\expandafter\expandafter\lst@ProvideFamily@
+         \csname\@lst @#1@data\endcsname
+         {\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}}%
+    {}}
+%    \end{macrocode}
+% Now we have the following arguments
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item \meta{name}
+% \item \meta{style name}
+% \item \meta{default style name}
+% \item \alternative{l,o} (language or other key)
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \item |\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi|
+% \end{macroargs}
+% We define |\lst@g|\meta{name}\meta{number}|@sty| to call either
+% |\lst@g|\meta{name}|@wp| with the number as argument or
+% |\lst@|\meta{style name}\meta{number} where the number belongs to the control
+% sequence.
+%    \begin{macrocode}
+\gdef\lst@ProvideFamily@#1#2#3#4#5#6#7#8{%
+    \expandafter\xdef\csname\@lst @g#2#8@sty\endcsname
+    {\if #6w%
+         \expandafter\noexpand\csname\@lst @g#2@wp\endcsname{#8}%
+     \else
+         \expandafter\noexpand\csname\@lst @#3#8\endcsname
+     \fi}%
+%    \end{macrocode}
+% We ensure the existence of the style macro. This is done in the
+% \hookname{Init} hook by assigning the default style if necessary.
+%    \begin{macrocode}
+    \ifx\@empty#3\@empty\else
+        \edef\lst@temp{\noexpand\lst@AddToHook{Init}{%
+            \noexpand\lst@ProvideStyle\expandafter\noexpand
+                \csname\@lst @#3#8\endcsname\noexpand#4}}%
+        \lst@temp
+    \fi
+%    \end{macrocode}
+% We call a submacro to do the rest. It requires some control sequences.
+%    \begin{macrocode}
+    \expandafter\lst@ProvideFamily@@
+         \csname\@lst @#2#8@list\expandafter\endcsname
+         \csname\@lst @#2#8\expandafter\endcsname
+         \csname\@lst @#2#8@also\expandafter\endcsname
+         \csname\@lst @g#2#8@list\expandafter\endcsname
+         \csname\@lst @g#2#8\expandafter\endcsname
+         \csname\@lst @g#2#8@sty\expandafter\endcsname
+         {#1}#5#6#7}
+%    \end{macrocode}
+% Now we have (except that \meta{number} is possibly always missing)
+% \begin{macroargs}
+% \item |\lst@|\meta{name}\meta{number}|@list|
+% \item |\lst@|\meta{name}\meta{number}
+% \item |\lst@|\meta{name}\meta{number}|@also|
+% \item |\lst@g|\meta{name}\meta{number}|@list|
+% \item |\lst@g|\meta{name}\meta{number}
+% \item |\lst@g|\meta{name}\meta{number}|@sty|
+% \item \meta{prefix}
+% \item \alternative{l,o} (language or other key)
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% Note that |#9| and `|#10|' are read by |\lst@InstallTest|. We initialize all
+% required `variables' (at \hookname{SetLanguage}) and install the test (which
+% definition is in fact also delayed).
+%    \begin{macrocode}
+\gdef\lst@ProvideFamily@@#1#2#3#4#5#6#7#8{%
+    \gdef#1{#2#5}\global\let#2\@empty \global\let#3\@empty % init
+    \gdef#4{#2#5}\global\let#5\@empty % init
+    \if #8l\relax
+        \lst@AddToHook{SetLanguage}{\def#1{#2#5}\let#2\@empty}%
+    \fi
+    \lst@InstallTest{#7}#1#2#4#5#6}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InstallKeywords}
+% Now we take advance of the optional argument construction above. Thus, we
+% just insert |[\@ne]| as \meta{number} in the definitions of the keys.
+%    \begin{macrocode}
+\gdef\lst@InstallKeywords#1#2#3#4#5{%
+    \lst@Key{#2}\relax
+        {\lst@UseFamily{#2}[\@ne]##1\relax\lst@MakeKeywords}%
+    \lst@Key{more#2}\relax
+        {\lst@UseFamily{#2}[\@ne]##1\relax\lst@MakeMoreKeywords}%
+    \lst@Key{delete#2}\relax
+        {\lst@UseFamily{#2}[\@ne]##1\relax\lst@DeleteKeywords}%
+    \ifx\@empty#3\@empty\else
+        \lst@Key{#3}{#4}{\@namedef{lst@#3}{##1}}%
+    \fi
+    \expandafter\lst@InstallFamily@
+        \csname\@lst @#2@data\expandafter\endcsname
+        \csname\@lst @#5\endcsname {#1}{#2}{#3}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProvideStyle}
+% If the style macro |#1| is not defined, it becomes equivalent to |#2|.
+%    \begin{macrocode}
+\gdef\lst@ProvideStyle#1#2{%
+    \ifx#1\@undefined \let#1#2%
+    \else\ifx#1\relax \let#1#2\fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% Finally we define |\lst@MakeKeywords|, \ldots, |\lst@DeleteKeywords|.
+% We begin with two helper.
+%
+% \begin{macro}{\lst@BuildClassList}
+% After |#1| follows a comma separated list of keyword classes terminated by
+% |,\relax,|, e.g.~|keywords2,emph1,\relax,|. For each \meta{item} in this
+% list we \emph{append} the two macros |\lst@|\meta{item}|\lst@g|\meta{item}
+% to |#1|.
+%    \begin{macrocode}
+\gdef\lst@BuildClassList#1#2,{%
+    \ifx\relax#2\@empty\else
+        \ifx\@empty#2\@empty\else
+            \lst@lExtend#1{\csname\@lst @#2\expandafter\endcsname
+                           \csname\@lst @g#2\endcsname}%
+        \fi
+        \expandafter\lst@BuildClassList\expandafter#1
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DeleteClassesIn}
+% deletes pairs of tokens, namely the arguments |#2#3| to the submacro.
+%    \begin{macrocode}
+\gdef\lst@DeleteClassesIn#1#2{%
+    \expandafter\lst@DCI@\expandafter#1#2\relax\relax}
+\gdef\lst@DCI@#1#2#3{%
+    \ifx#2\relax
+        \expandafter\@gobbletwo
+    \else
+%    \end{macrocode}
+% If we haven't reached the end of the class list, we define a temporary macro
+% which removes all appearances.
+%    \begin{macrocode}
+        \def\lst@temp##1#2#3##2{%
+            \lst@lAddTo#1{##1}%
+            \ifx ##2\relax\else
+                \expandafter\lst@temp
+            \fi ##2}%
+        \let\@tempa#1\let#1\@empty
+        \expandafter\lst@temp\@tempa#2#3\relax
+    \fi
+    \lst@DCI@#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MakeKeywords}
+% We empty some macros and make use of |\lst@MakeMoreKeywords|.
+% Note that this and the next two definitions have the following arguments:
+% \begin{macroargs}
+% \item class list (in brackets)
+% \item keyword list
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@|\meta{name}
+% \item |\lst@|\meta{name}|@also|
+% \item |\lst@g|\meta{name}
+% \end{macroargs}
+%    \begin{macrocode}
+\gdef\lst@MakeKeywords[#1]#2#3#4#5#6{%
+    \def#3{#4#6}\let#4\@empty \let#5\@empty
+    \lst@MakeMoreKeywords[#1]{#2}#3#4#5#6}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MakeMoreKeywords}
+% We append classes and keywords.
+%    \begin{macrocode}
+\gdef\lst@MakeMoreKeywords[#1]#2#3#4#5#6{%
+    \lst@BuildClassList#3#1,\relax,%
+    \lst@DefOther\lst@temp{,#2}\lst@lExtend#4\lst@temp}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DeleteKeywords}
+% We convert the keyword arguments via |\lst@MakeKeywords| and remove the
+% classes and keywords.
+%    \begin{macrocode}
+\gdef\lst@DeleteKeywords[#1]#2#3#4#5#6{%
+    \lst@MakeKeywords[#1]{#2}\@tempa\@tempb#5#6%
+    \lst@DeleteClassesIn#3\@tempa
+    \lst@DeleteKeysIn#4\@tempb}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Main families and classes}
+%
+%
+% \paragraph{Keywords}
+%
+% \begin{lstkey}{keywords}
+% Defining the keyword family gets very, very easy.
+%    \begin{macrocode}
+\lst@InstallFamily k{keywords}{keywordstyle}\bfseries{keywordstyle}{}ld
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{ndkeywords}
+% Second order keywords use the same trick as |\lst@InstallKeywords|.
+%    \begin{macrocode}
+\lst@Key{ndkeywords}\relax
+    {\lst@UseFamily{keywords}[\tw@]#1\relax\lst@MakeKeywords}%
+\lst@Key{morendkeywords}\relax
+    {\lst@UseFamily{keywords}[\tw@]#1\relax\lst@MakeMoreKeywords}%
+\lst@Key{deletendkeywords}\relax
+    {\lst@UseFamily{keywords}[\tw@]#1\relax\lst@DeleteKeywords}%
+\lst@Key{ndkeywordstyle}\relax{\@namedef{lst@keywordstyle2}{#1}}%
+%    \end{macrocode}
+% \lsthelper{Dr.~Peter~Leibner}{1999/11/05}{undefined \lst@UseKeywords,
+% Illegal parameter number (##1)} reported two bugs: |\lst@UseKeywords| and
+% |##1| became |\lst@UseFamily| and |#1|.
+% \end{lstkey}
+%
+% \begin{lstkey}{keywordsprefix}
+% is implemented experimentally. The one and only prefix indicates its
+% presence by making |\lst@prefixkeyword| empty. We can catch this information
+% in the \keyname{Output} hook.
+%    \begin{macrocode}
+\lst@Key{keywordsprefix}\relax{\lst@DefActive\lst@keywordsprefix{#1}}
+\global\let\lst@keywordsprefix\@empty
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@keywordsprefix\@empty\else
+         \expandafter\lst@CArg\lst@keywordsprefix\relax
+             \lst@CDef{}%
+                      {\lst@ifletter\else
+                           \global\let\lst@prefixkeyword\@empty
+                       \fi}%
+                      {}%
+     \fi}
+\lst@AddToHook{Init}{\global\let\lst@prefixkeyword\relax}
+\lst@AddToHook{Output}
+    {\ifx\lst@prefixkeyword\@empty
+         \let\lst@thestyle\lst@gkeywords@sty
+         \global\let\lst@prefixkeyword\relax
+     \fi}%
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{otherkeywords}
+% Thanks to \lsthelper{Bradford~Chamberlain}{2001/07/07}{otherkeywords={@,@^}
+% does not work} we now iterate down the list of `other keywords' and make each
+% active---instead of making the whole argument active. We append the active
+% token sequence to |\lst@otherkeywords| to define each `other' keyword.
+%    \begin{macrocode}
+\lst@Key{otherkeywords}{}{%
+    \let\lst@otherkeywords\@empty
+    \lst@for{#1}\do{%
+      \lst@MakeActive{##1}%
+      \lst@lExtend\lst@otherkeywords{%
+          \expandafter\lst@CArg\lst@temp\relax\lst@CDef
+              {}\lst@PrintOtherKeyword\@empty}}}
+\lst@AddToHook{SelectCharTable}{\lst@otherkeywords}
+%    \end{macrocode}
+% |\lst@PrintOtherkeyword| has been changed to |\lst@PrintOtherKeyword| after a
+% bug report by \lsthelper{Peter~Bartke}{2001/11/06}{undefined control sequence
+% \lst@PrintOtherkeyword}.
+% \end{lstkey}
+%
+% \begin{macro}{\lst@PrintOtherKeyword}
+% print preceding characters, prepare the output and typeset the argument in
+% keyword style.
+%    \begin{macrocode}
+\gdef\lst@PrintOtherKeyword#1\@empty{%
+    \lst@XPrintToken
+    \begingroup
+      \lst@modetrue \lsthk@TextStyle
+      \let\lst@ProcessDigit\lst@ProcessLetter
+      \let\lst@ProcessOther\lst@ProcessLetter
+      \lst@lettertrue
+      \lst@gkeywords@sty{#1\lst@XPrintToken}%
+    \endgroup}
+%    \end{macrocode}
+% \begin{TODO}
+% Which part of \hookname{TextStyle} hook is required?
+% \end{TODO}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \paragraph{The emphasize family}
+%
+% \begin{aspect}{emph}
+% is just one macro call here.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{emph}
+\lst@InstallFamily e{emph}{emphstyle}{}{emphstyle}{}od
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \paragraph{\TeX\ control sequences}
+%
+% \begin{aspect}{tex}
+% Here we check the last `other' processed token.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{tex}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@InstallKeywords{cs}{texcs}{texcsstyle}\relax{keywordstyle}
+    {\ifx\lst@lastother\lstum@backslash
+         \let\lst@thestyle\lst@texcsstyle
+     \fi}
+    ld
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \paragraph{Compiler directives}
+%
+% \begin{aspect}{directives}
+% \begin{lstkey}{directives}
+% First some usual stuff.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{directives}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@NewMode\lst@CDmode
+\lst@AddToHook{EOL}{\ifnum\lst@mode=\lst@CDmode \lst@LeaveMode \fi}
+\lst@InstallKeywords{d}{directives}{directivestyle}\relax{keywordstyle}
+    {\ifnum\lst@mode=\lst@CDmode
+         \let\lst@thestyle\lst@directivestyle
+     \fi}
+    ld
+%    \end{macrocode}
+% If the user has defined directives, we redefine the character |#|.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@directives\@empty\else
+         \lst@DefSaveDef{`\#}\lsts@CCD
+         {\lst@CalcColumn
+          \lst@ifmode\else
+%    \end{macrocode}
+% We enter `directive mode' (without setting |\lst@ifmode| true) only in the
+% first column.
+%    \begin{macrocode}
+              \ifnum\@tempcnta=\z@
+                  \lst@EnterMode{\lst@CDmode}{}%
+              \fi
+          \fi
+          \ifnum\lst@mode=\lst@CDmode
+%    \end{macrocode}
+% We print |#| in directive style if and only if we are in the first column.
+%    \begin{macrocode}
+              \ifnum\@tempcnta=\z@
+                  \lst@XPrintToken
+%    \end{macrocode}
+% \begin{TODO}
+% Is this |\lst@XPrintToken| necessary? First column should imply that the
+% current character string is empty and that there are no delayed characters.
+% \end{TODO}
+%    \begin{macrocode}
+                  {\let\lst@currstyle\lst@directivestyle
+                   \lsts@CCD\lst@PrintToken}%
+              \else \lsts@CCD
+              \fi
+          \else \lsts@CCD
+          \fi}%
+     \fi}
+%    \end{macrocode}
+% We introduce a new string type (thanks to \lsthelper{R.~Isernhagen}
+% {1999/11/12}{float isn't keyword in #include <float>}), which \ldots
+%    \begin{macrocode}
+\lst@AddTo\lst@stringtypes{,directive}
+\gdef\lst@StringDM@directive#1#2#3\@empty{%
+    \lst@CArg #2\relax\lst@CDef
+        {}%
+%    \end{macrocode}
+% \ldots\space is active only in |\lst@CDmode|:
+%    \begin{macrocode}
+        {\let\lst@bnext\lst@CArgEmpty
+         \ifnum\lst@mode=\lst@CDmode
+             \def\lst@bnext{\lst@BeginString{#1}}%
+         \fi
+         \lst@bnext}%
+        \@empty
+    \lst@CArg #3\relax\lst@CDef
+        {}%
+        {\let\lst@enext\lst@CArgEmpty
+         \ifnum #1=\lst@mode
+             \let\lst@bnext\lst@EndString
+         \fi
+         \lst@bnext}%
+        \@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Restricted keywords}
+%
+% \begin{aspect}{html}
+% Support HTML and others.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{html}
+%    \end{macrocode}
+%
+% \begin{lstkey}{keywordsinside}
+% Allocate a new mode and start the key.
+%    \begin{macrocode}
+\lst@NewMode\lst@insidemode
+\lst@Key{keywordsinside}{}{\lstKV@TwoArg{#1}
+    {\let\lst@DefInside\@empty
+     \ifx\@empty##1\@empty\else \ifx\@empty##2\@empty\else
+         \def\lst@DefInside{%
+%    \end{macrocode}
+% The redefinitions of the characters enter respectively leave the mode and
+% execute the old meanings.
+%    \begin{macrocode}
+             \lst@DefSaveDef{`##1}\lsts@insideb
+                 {\lst@ifmode\else \ifnum\lst@mode=\lst@insidemode\else
+                      \lst@XPrintToken
+                      \lst@EnterMode\lst@insidemode{}%
+                  \fi\fi
+                  \lsts@insideb}%
+             \lst@DefSaveDef{`##2}\lsts@insidee
+                  {\ifnum\lst@mode=\lst@insidemode
+                       \lsts@insidee \lst@XPrintToken\lst@LeaveMode
+                   \else
+                       \expandafter\lsts@insidee
+                   \fi}}%
+     \fi\fi}}
+%    \end{macrocode}
+% The redefinition is done via \hookname{SelectCharTable}. It is reset in
+% \hookname{SetLanguage} since a bug report from \lsthelper{Richard~Hoefter}
+% {2000/11/03}{no keyword detection in case of language=HTML,language=Java}.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@DefInside}
+\lst@AddToHook{SetLanguage}{\let\lst@DefInside\@empty}
+%    \end{macrocode}
+% We reset |\lst@thestyle| if necessary.
+%    \begin{macrocode}
+\lst@AddToHook{Output}
+    {\ifx\lst@DefInside\@empty\else \ifx\lst@thestyle\lst@gkeywords@sty
+         \ifnum\lst@mode=\lst@insidemode\else
+             \let\lst@thestyle\@empty
+         \fi
+     \fi\fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{usekeywordsinside}
+% Here we set |\lst@thestyle| to keyword style if necessary.
+%    \begin{macrocode}
+\lst@Key{usekeywordsinside}t[t]{\lstKV@SetIf{#1}\lst@ifusekeysinside}
+\lst@AddToHook{Output}
+    {\ifnum\lst@mode=\lst@insidemode \lst@ifusekeysinside\else
+         \let\lst@thestyle\lst@gkeywords@sty
+     \fi\fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginCDATA}
+% This macro is used by the XML language definition.
+%    \begin{macrocode}
+\gdef\lst@BeginCDATA#1\@empty{%
+    \lst@TrackNewLines \lst@PrintToken
+    \lst@EnterMode\lst@GPmode{}\let\lst@ifmode\iffalse
+    \lst@mode\lst@insidemode #1\lst@mode\lst@GPmode\relax\lst@modetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Keyword comments}
+%
+% \begin{aspect}{keywordcomments}
+% includes both comment types and is possibly split into this and |dkcs|.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords,comments]{keywordcomments}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@BeginKC}
+% \begin{macro}{\lst@BeginKCS}
+% Starting a keyword comment is easy, but \ldots
+%    \begin{macrocode}
+\lst@NewMode\lst@KCmode \lst@NewMode\lst@KCSmode
+\gdef\lst@BeginKC{%
+    \lst@ResetToken
+    \lst@BeginComment\lst@KCmode\lst@commentstyle\@empty}
+\gdef\lst@BeginKCS{%
+    \lst@ResetToken
+    \lst@BeginComment\lst@KCSmode\lst@commentstyle\@empty}
+%    \end{macrocode}
+% \ldots\space we must ensure that the comment starts after printing the
+% comment delimiter since it could be a keyword. We assign |\lst@BeginKC|[|S|]
+% to |\lst@KCpost|, which is executed and reset in \hookname{PostOutput}.
+%    \begin{macrocode}
+\lst@AddToHook{PostOutput}{\lst@KCpost \global\let\lst@KCpost\@empty}
+\global\let\lst@KCpost\@empty % init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndKC}
+% leaves the comment mode before the (temporaryly saved) comment delimiter is
+% printed.
+%    \begin{macrocode}
+\gdef\lst@EndKC{\lst@SaveToken \lst@LeaveMode \lst@RestoreToken}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{keywordcomment}
+% The delimiters must be identical here, thus we use |\lst@KCmatch|. Note the
+% last argument |o| to |\lst@InstallKeywords|: The working test is installed
+% in the \hookname{Output} hook and not in \hookname{DetectKeywords}.
+% Otherwise we couldn't detect the ending delimiter since keyword detection is
+% done if and only if mode changes are allowed.
+%    \begin{macrocode}
+\lst@InstallKeywords{kc}{keywordcomment}{}\relax{}
+    {\ifnum\lst@mode=\lst@KCmode
+         \edef\lst@temp{\the\lst@token}%
+         \ifx\lst@temp\lst@KCmatch
+             \lst@EndKC
+         \fi
+     \else
+         \lst@ifmode\else
+             \xdef\lst@KCmatch{\the\lst@token}%
+             \global\let\lst@KCpost\lst@BeginKC
+         \fi
+     \fi}
+    lo
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{keywordcommentsemicolon}
+% The key simply stores the keywords.
+%    \begin{macrocode}
+\lst@Key{keywordcommentsemicolon}{}{\lstKV@ThreeArg{#1}%
+    {\def\lst@KCAkeywordsB{##1}%
+     \def\lst@KCAkeywordsE{##2}%
+     \def\lst@KCBkeywordsB{##3}%
+     \def\lst@KCkeywords{##1##2##3}}}
+%    \end{macrocode}
+% We define an appropriate semicolon if this keyword comment type is defined.
+% Appropriate means that we leave any keyword comment mode if active.
+% \lsthelper{Oldrich~Jedlicka}{2001/12/12}{keywordcomment(semicolon) fails}
+% reported a bug and provided the fix, the two |\@empty|s.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@KCkeywords\@empty\else
+        \lst@DefSaveDef{`\;}\lsts@EKC
+            {\lst@XPrintToken
+             \ifnum\lst@mode=\lst@KCmode \lst@EndComment\@empty \else
+             \ifnum\lst@mode=\lst@KCSmode \lst@EndComment\@empty
+             \fi \fi
+             \lsts@EKC}%
+     \fi}
+%    \end{macrocode}
+% The `working identifier' macros enter respectively leave comment mode.
+%    \begin{macrocode}
+\gdef\lst@KCAWorkB{%
+    \lst@ifmode\else \global\let\lst@KCpost\lst@BeginKC \fi}
+\gdef\lst@KCBWorkB{%
+    \lst@ifmode\else \global\let\lst@KCpost\lst@BeginKCS \fi}
+\gdef\lst@KCAWorkE{\ifnum\lst@mode=\lst@KCmode \lst@EndKC \fi}
+%    \end{macrocode}
+% Now we install the tests and initialize the given macros.
+%    \begin{macrocode}
+\lst@ProvideFamily@@
+    \lst@KCAkeywordsB@list\lst@KCAkeywordsB \lst@KC@also
+    \lst@gKCAkeywordsB@list\lst@gKCAkeywordsB \lst@KCAWorkB
+    {kcb}owo % prefix, other key, working procedure, Output hook
+\lst@ProvideFamily@@
+    \lst@KCAkeywordsE@list\lst@KCAkeywordsE \lst@KC@also
+    \lst@gKCAkeywordsE@list\lst@gKCAkeywordsE \lst@KCAWorkE
+    {kce}owo
+\lst@ProvideFamily@@
+    \lst@KCBkeywordsB@list\lst@KCBkeywordsB \lst@KC@also
+    \lst@gKCBkeywordsB@list\lst@gKCBkeywordsB \lst@KCBWorkB
+    {kcs}owo
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Export of identifiers}
+%
+% \begin{aspect}{index}
+% \begin{macro}{\lstindexmacro}
+% One more `keyword' class.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{index}
+\lst@InstallFamily w{index}{indexstyle}\lstindexmacro{indexstyle}
+    {\csname\@lst @indexstyle#1\expandafter\endcsname
+         \expandafter{\the\lst@token}}
+    od
+\lst@UserCommand\lstindexmacro#1{\index{{\ttfamily#1}}}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{macro}
+% \end{aspect}
+%
+% \begin{aspect}{procnames}
+% \begin{lstkey}{procnamestyle}
+% \begin{lstkey}{procnamekeys}
+% \begin{lstkey}{indexprocnames}
+% The `idea' here is the usage of a global |\lst@ifprocname|, indicating a
+% preceding `procedure keyword'. All the other is known stuff.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{procnames}
+\gdef\lst@procnametrue{\global\let\lst@ifprocname\iftrue}
+\gdef\lst@procnamefalse{\global\let\lst@ifprocname\iffalse}
+\lst@AddToHook{Init}{\lst@procnamefalse}
+\lst@AddToHook{DetectKeywords}
+    {\lst@ifprocname
+         \let\lst@thestyle\lst@procnamestyle
+         \lst@ifindexproc \csname\@lst @gindex@sty\endcsname \fi
+         \lst@procnamefalse
+     \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{procnamestyle}{}{\def\lst@procnamestyle{#1}}
+\lst@Key{indexprocnames}{false}[t]{\lstKV@SetIf{#1}\lst@ifindexproc}
+\lst@AddToHook{Init}{\lst@ifindexproc \lst@indexproc \fi}
+\gdef\lst@indexproc{%
+    \@ifundefined{lst@indexstyle1}%
+        {\@namedef{lst@indexstyle1}##1{}}%
+        {}}
+%    \end{macrocode}
+% The default definition of |\lst@indexstyle| above has been moved outside the
+% hook after a bug report from \lsthelper{Ulrich~G.~Wortmann}{2002/01/22}
+% {procnames doesn't work}.
+%    \begin{macrocode}
+\lst@InstallKeywords w{procnamekeys}{}\relax{}
+    {\global\let\lst@PNpost\lst@procnametrue}
+    od
+\lst@AddToHook{PostOutput}{\lst@PNpost\global\let\lst@PNpost\@empty}
+\global\let\lst@PNpost\@empty % init
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{aspect}
+%
+%
+% \section{More aspects and keys}
+%
+% \begin{lstkey}{basicstyle}
+% \begin{lstkey}{inputencoding}
+% There is no better place to define these keys, I think.
+%    \begin{macrocode}
+%<*kernel>
+\lst@Key{basicstyle}\relax{\def\lst@basicstyle{#1}}
+\lst@Key{inputencoding}\relax{\def\lst@inputenc{#1}}
+\lst@AddToHook{Init}
+    {\lst@basicstyle
+     \ifx\lst@inputenc\@empty\else
+         \@ifundefined{inputencoding}{}%
+            {\inputencoding\lst@inputenc}%
+     \fi}
+\lst@AddToHookExe{EmptyStyle}
+    {\let\lst@basicstyle\@empty
+     \let\lst@inputenc\@empty}
+%</kernel>
+%    \end{macrocode}
+% Michael Niedermair asked for a key like \keyname{inputencoding}.
+% \end{lstkey}
+% \end{lstkey}
+%
+%
+% \subsection{Styles and languages}
+%
+% \begin{aspect}{style}
+% We begin with style definition and selection.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{style}
+%    \end{macrocode}
+%
+% \begin{macro}{\lststylefiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lststylefiles}
+    {\lst@UserCommand\lststylefiles{lststy0.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstdefinestyle}
+% \begin{macro}{\lst@definestyle}
+% \begin{macro}{\lst@DefStyle}
+% are defined in terms of |\lst@DefStyle|, which is defined via
+% |\lst@DefDriver|.
+%    \begin{macrocode}
+\lst@UserCommand\lstdefinestyle{\lst@DefStyle\iftrue}
+\lst@UserCommand\lst@definestyle{\lst@DefStyle\iffalse}
+\gdef\lst@DefStyle{\lst@DefDriver{style}{sty}\lstset}
+%    \end{macrocode}
+% The `empty' style calls the initial empty hook \hookname{EmptyStyle}.
+%    \begin{macrocode}
+\global\@namedef{lststy@$}{\lsthk@EmptyStyle}
+\lst@AddToHook{EmptyStyle}{}% init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{style}
+% is an application of |\lst@LAS|. We just specify the hook and an empty
+% argument as `pre' and `post' code.
+%    \begin{macrocode}
+\lst@Key{style}\relax{%
+    \lst@LAS{style}{sty}{[]{#1}}\lst@NoAlias\lststylefiles
+        \lsthk@SetStyle
+        {}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetStyle}{}% init
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+% \begin{aspect}{language}
+% Now we deal with commands used in defining and selecting programming
+% languages, in particular with aliases.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{language}
+%    \end{macrocode}
+%
+% \begin{macro}{\lstlanguagefiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lstdriverfiles}
+    {\lst@UserCommand\lstlanguagefiles{lstlang0.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstdefinelanguage}
+% \begin{macro}{\lst@definelanguage}
+% \begin{macro}{\lst@DefLang}
+% are defined in terms of |\lst@DefLang|, which is defined via
+% |\lst@DefDriver|.
+%    \begin{macrocode}
+\lst@UserCommand\lstdefinelanguage{\lst@DefLang\iftrue}
+\lst@UserCommand\lst@definelanguage{\lst@DefLang\iffalse}
+\gdef\lst@DefLang{\lst@DefDriver{language}{lang}\lstset}
+%    \end{macrocode}
+% Now we can provide the `empty' language.
+%    \begin{macrocode}
+\lstdefinelanguage{}{}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{language}
+% \begin{lstkey}{alsolanguage}
+% is mainly an application of |\lst@LAS|.
+%    \begin{macrocode}
+\lst@Key{language}\relax{\lstKV@OptArg[]{#1}%
+    {\lst@LAS{language}{lang}{[##1]{##2}}\lst@FindAlias\lstlanguagefiles
+         \lsthk@SetLanguage
+         {\lst@FindAlias[##1]{##2}%
+          \let\lst@language\lst@malias
+          \let\lst@dialect\lst@oalias}}}
+%    \end{macrocode}
+% Ditto, we simply don't execute |\lsthk@SetLanguage|.
+%    \begin{macrocode}
+\lst@Key{alsolanguage}\relax{\lstKV@OptArg[]{#1}%
+    {\lst@LAS{language}{lang}{[##1]{##2}}\lst@FindAlias\lstlanguagefiles
+         {}%
+         {\lst@FindAlias[##1]{##2}%
+          \let\lst@language\lst@malias
+          \let\lst@dialect\lst@oalias}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetLanguage}{}% init
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lstalias}
+% Now we concentrate on aliases and default dialects.
+% |\lsta@|\meta{language}|$|\meta{dialect} and |\lsta@|\meta{language} contain
+% the aliases of a particular dialect respectively a complete language.
+% We'll use a |$|-character to separate a language name from its dialect.
+%    \begin{macrocode}
+\lst@UserCommand\lstalias{\@ifnextchar[\lstalias@\lstalias@@}
+\gdef\lstalias@[#1]#2[#3]#4{\lst@NormedNameDef{lsta@#2$#1}{#4$#3}}
+\gdef\lstalias@@#1#2{\lst@NormedNameDef{lsta@#1}{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{defaultdialect}
+% We simply store the dialect.
+%    \begin{macrocode}
+\lst@Key{defaultdialect}\relax
+    {\lstKV@OptArg[]{#1}{\lst@NormedNameDef{lstdd@##2}{##1}}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@FindAlias}
+% Now we have to find a language. First we test for a complete language alias,
+% then we set the default dialect if necessary.
+%    \begin{macrocode}
+\gdef\lst@FindAlias[#1]#2{%
+    \lst@NormedDef\lst@oalias{#1}%
+    \lst@NormedDef\lst@malias{#2}%
+    \@ifundefined{lsta@\lst@malias}{}%
+        {\edef\lst@malias{\csname\@lst a@\lst@malias\endcsname}}%
+%    \end{macrocode}
+%    \begin{macrocode}
+    \ifx\@empty\lst@oalias \@ifundefined{lstdd@\lst@malias}{}%
+        {\edef\lst@oalias{\csname\@lst dd@\lst@malias\endcsname}}%
+    \fi
+%    \end{macrocode}
+% Now we are ready for an alias of a single dialect.
+%    \begin{macrocode}
+    \edef\lst@temp{\lst@malias $\lst@oalias}%
+    \@ifundefined{lsta@\lst@temp}{}%
+        {\edef\lst@temp{\csname\@lst a@\lst@temp\endcsname}}%
+%    \end{macrocode}
+% Finally we again set the default dialect---for the case of a dialect alias.
+%    \begin{macrocode}
+    \expandafter\lst@FindAlias@\lst@temp $}
+\gdef\lst@FindAlias@#1$#2${%
+    \def\lst@malias{#1}\def\lst@oalias{#2}%
+    \ifx\@empty\lst@oalias \@ifundefined{lstdd@\lst@malias}{}%
+        {\edef\lst@oalias{\csname\@lst dd@\lst@malias\endcsname}}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@RequireLanguages}
+% This definition will be equivalent to |\lstloadlanguages|. We requested the
+% given list of languages and load additionally required aspects.
+%    \begin{macrocode}
+\gdef\lst@RequireLanguages#1{%
+    \lst@Require{language}{lang}{#1}\lst@FindAlias\lstlanguagefiles
+    \ifx\lst@loadaspects\@empty\else
+        \lst@RequireAspects\lst@loadaspects
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstloadlanguages}
+% is the same as |\lst@RequireLanguages|.
+%    \begin{macrocode}
+\global\let\lstloadlanguages\lst@RequireLanguages
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Format definitions*}
+%
+% \begin{aspect}{formats}
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{formats}
+%    \end{macrocode}
+%
+% \begin{macro}{\lstformatfiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lstformatfiles}
+    {\lst@UserCommand\lstformatfiles{lstfmt0.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstdefineformat}
+% \begin{macro}{\lst@defineformat}
+% \begin{macro}{\lst@DefFormat}
+% are defined in terms of |\lst@DefFormat|, which is defined via
+% |\lst@DefDriver|.
+%    \begin{macrocode}
+\lst@UserCommand\lstdefineformat{\lst@DefFormat\iftrue}
+\lst@UserCommand\lst@defineformat{\lst@DefFormat\iffalse}
+\gdef\lst@DefFormat{\lst@DefDriver{format}{fmt}\lst@UseFormat}
+%    \end{macrocode}
+% We provide the `empty' format.
+%    \begin{macrocode}
+\lstdefineformat{}{}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{format}
+% is an application of |\lst@LAS|. We just specify the hook as `pre' and an
+% empty argument as  `post' code.
+%    \begin{macrocode}
+\lst@Key{format}\relax{%
+    \lst@LAS{format}{fmt}{[]{#1}}\lst@NoAlias\lstformatfiles
+        \lsthk@SetFormat
+        {}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetFormat}{\let\lst@fmtformat\@empty}% init
+%    \end{macrocode}
+% \end{lstkey}
+%
+%
+% \paragraph{Helpers}
+% Our goal is to define the yet unkown |\lst@UseFormat|. This definition
+% will parse the user supplied format. We start with some general macros.
+%
+% \begin{macro}{\lst@fmtSplit}
+% splits the content of the macro |#1| at |#2| in the preceding characters
+% |\lst@fmta| and the following ones |\lst@fmtb|. |\lst@if| is false if and
+% only if |#1| doesn't contain |#2|.
+%    \begin{macrocode}
+\gdef\lst@fmtSplit#1#2{%
+    \def\lst@temp##1#2##2\relax##3{%
+        \ifnum##3=\z@
+            \ifx\@empty##2\@empty
+                \lst@false
+                \let\lst@fmta#1%
+                \let\lst@fmtb\@empty
+            \else
+                \expandafter\lst@temp#1\relax\@ne
+            \fi
+        \else
+            \def\lst@fmta{##1}\def\lst@fmtb{##2}%
+        \fi}%
+    \lst@true
+    \expandafter\lst@temp#1#2\relax\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextCharWhitespace}
+% is defined in terms of |\lst@IfSubstring|.
+%    \begin{macrocode}
+\gdef\lst@IfNextCharWhitespace#1#2#3{%
+    \lst@IfSubstring#3\lst@whitespaces{#1}{#2}#3}
+%    \end{macrocode}
+% And here come all white space characters.
+%    \begin{macrocode}
+\begingroup
+\catcode`\^^I=12\catcode`\^^J=12\catcode`\^^M=12\catcode`\^^L=12\relax%
+\lst@DefActive\lst@whitespaces{\ ^^I^^J^^M}% add ^^L
+\global\let\lst@whitespaces\lst@whitespaces%
+\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtIfIdentifier}
+% tests the first character of |#1|
+%    \begin{macrocode}
+\gdef\lst@fmtIfIdentifier#1{%
+    \ifx\relax#1\@empty
+        \expandafter\@secondoftwo
+    \else
+        \expandafter\lst@fmtIfIdentifier@\expandafter#1%
+    \fi}
+%    \end{macrocode}
+% against the `letters' |_|, |@|, |A|,\ldots,|Z| and |a|,\ldots,|z|.
+%    \begin{macrocode}
+\gdef\lst@fmtIfIdentifier@#1#2\relax{%
+    \let\lst@next\@secondoftwo
+    \ifnum`#1=`_\else
+    \ifnum`#1<64\else
+    \ifnum`#1<91\let\lst@next\@firstoftwo\else
+    \ifnum`#1<97\else
+    \ifnum`#1<123\let\lst@next\@firstoftwo\else
+    \fi \fi \fi \fi \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtIfNextCharIn}
+% is required for the optional \meta{exceptional characters}.
+% The implementation is easy---refer section \ref{iSubstringTests}.
+%    \begin{macrocode}
+\gdef\lst@fmtIfNextCharIn#1{%
+    \ifx\@empty#1\@empty \expandafter\@secondoftwo \else
+                         \def\lst@next{\lst@fmtIfNextCharIn@{#1}}%
+                         \expandafter\lst@next\fi}
+\gdef\lst@fmtIfNextCharIn@#1#2#3#4{%
+    \def\lst@temp##1#4##2##3\relax{%
+        \ifx \@empty##2\expandafter\@secondoftwo
+                 \else \expandafter\@firstoftwo \fi}%
+    \lst@temp#1#4\@empty\relax{#2}{#3}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtCDef}
+% We need derivations of |\lst@CDef| and |\lst@CDefX|: we have to test the
+% next character against the sequence |#5| of exceptional characters.
+% These tests are inserted here.
+%    \begin{macrocode}
+\gdef\lst@fmtCDef#1{\lst@fmtCDef@#1}
+\gdef\lst@fmtCDef@#1#2#3#4#5#6#7{%
+    \lst@CDefIt#1{#2}{#3}%
+               {\lst@fmtIfNextCharIn{#5}{#4#2#3}{#6#4#2#3#7}}%
+               #4%
+               {}{}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtCDefX}
+% The same but `drop input'.
+%    \begin{macrocode}
+\gdef\lst@fmtCDefX#1{\lst@fmtCDefX@#1}
+\gdef\lst@fmtCDefX@#1#2#3#4#5#6#7{%
+    \let#4#1%
+    \ifx\@empty#2\@empty
+        \def#1{\lst@fmtIfNextCharIn{#5}{#4}{#6#7}}%
+    \else \ifx\@empty#3\@empty
+        \def#1##1{%
+            \ifx##1#2%
+                \def\lst@next{\lst@fmtIfNextCharIn{#5}{#4##1}%
+                                                      {#6#7}}%
+            \else
+                 \def\lst@next{#4##1}%
+            \fi
+            \lst@next}%
+    \else
+        \def#1{%
+            \lst@IfNextCharsArg{#2#3}%
+                {\lst@fmtIfNextCharIn{#5}{\expandafter#4\lst@eaten}%
+                                         {#6#7}}%
+                {\expandafter#4\lst@eaten}}%
+    \fi \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{The parser}
+% applies |\lst@fmtSplit| to cut a format definition into items, items into
+% `input' and `output', and `output' into `pre' and 'post'. This should be
+% clear if you are in touch with format definitions.
+%
+% \begin{macro}{\lst@UseFormat}
+% Now we can start with the parser.
+%    \begin{macrocode}
+\gdef\lst@UseFormat#1{%
+    \def\lst@fmtwhole{#1}%
+    \lst@UseFormat@}
+\gdef\lst@UseFormat@{%
+    \lst@fmtSplit\lst@fmtwhole,%
+%    \end{macrocode}
+% We assign the rest of the format definition, \ldots
+%    \begin{macrocode}
+    \let\lst@fmtwhole\lst@fmtb
+    \ifx\lst@fmta\@empty\else
+%    \end{macrocode}
+% \ldots\space split the item at the equal sign, and work on the item.
+%    \begin{macrocode}
+        \lst@fmtSplit\lst@fmta=%
+        \ifx\@empty\lst@fmta\else
+%    \end{macrocode}
+% \begin{TODO}
+% Insert |\let\lst@arg\@empty| |\expandafter\lst@XConvert\lst@fmtb\@nil|
+% |\let\lst@fmtb\lst@arg|.
+% \end{TODO}
+%    \begin{macrocode}
+            \expandafter\lstKV@XOptArg\expandafter[\expandafter]%
+                \expandafter{\lst@fmtb}\lst@UseFormat@b
+        \fi
+    \fi
+%    \end{macrocode}
+% Finally we process the next item if the rest is not empty.
+%    \begin{macrocode}
+    \ifx\lst@fmtwhole\@empty\else
+        \expandafter\lst@UseFormat@
+    \fi}
+%    \end{macrocode}
+% We make |\lst@fmtc| contain the preceding characters as a braced argument.
+% To add more arguments, we first split the replacement tokens at the control
+% sequence |\string|.
+%    \begin{macrocode}
+\gdef\lst@UseFormat@b[#1]#2{%
+    \def\lst@fmtc{{#1}}\lst@lExtend\lst@fmtc{\expandafter{\lst@fmta}}%
+    \def\lst@fmtb{#2}%
+    \lst@fmtSplit\lst@fmtb\string
+%    \end{macrocode}
+% We append an empty argument or |\lst@fmtPre| with `|\string|-preceding'
+% tokens as argument. We do the same for the tokens after |\string|.
+%    \begin{macrocode}
+    \ifx\@empty\lst@fmta
+        \lst@lAddTo\lst@fmtc{{}}%
+    \else
+        \lst@lExtend\lst@fmtc{\expandafter
+            {\expandafter\lst@fmtPre\expandafter{\lst@fmta}}}%
+    \fi
+    \ifx\@empty\lst@fmtb
+        \lst@lAddTo\lst@fmtc{{}}%
+    \else
+        \lst@lExtend\lst@fmtc{\expandafter
+            {\expandafter\lst@fmtPost\expandafter{\lst@fmtb}}}%
+    \fi
+%    \end{macrocode}
+% Eventually we extend |\lst@fmtformat| appropriately. Note that |\lst@if|
+% still indicates whether the replacement tokens contain |\string|.
+%    \begin{macrocode}
+    \expandafter\lst@UseFormat@c\lst@fmtc}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@UseFormat@c#1#2#3#4{%
+    \lst@fmtIfIdentifier#2\relax
+    {\lst@fmtIdentifier{#2}%
+     \lst@if\else \PackageWarning{Listings}%
+         {Cannot drop identifier in format definition}%
+     \fi}%
+    {\lst@if
+         \lst@lAddTo\lst@fmtformat{\lst@CArgX#2\relax\lst@fmtCDef}%
+     \else
+         \lst@lAddTo\lst@fmtformat{\lst@CArgX#2\relax\lst@fmtCDefX}%
+     \fi
+     \lst@DefActive\lst@fmtc{#1}%
+     \lst@lExtend\lst@fmtformat{\expandafter{\lst@fmtc}{#3}{#4}}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@fmtformat}
+\global\let\lst@fmtformat\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{The formatting}
+%
+% \begin{macro}{\lst@fmtPre}
+%    \begin{macrocode}
+\gdef\lst@fmtPre#1{%
+    \lst@PrintToken
+    \begingroup
+    \let\newline\lst@fmtEnsureNewLine
+    \let\space\lst@fmtEnsureSpace
+    \let\indent\lst@fmtIndent
+    \let\noindent\lst@fmtNoindent
+    #1%
+    \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtPost}
+%    \begin{macrocode}
+\gdef\lst@fmtPost#1{%
+    \global\let\lst@fmtPostOutput\@empty
+    \begingroup
+    \def\newline{\lst@AddTo\lst@fmtPostOutput\lst@fmtEnsureNewLine}%
+    \def\space{\aftergroup\lst@fmtEnsurePostSpace}%
+    \def\indent{\lst@AddTo\lst@fmtPostOutput\lst@fmtIndent}%
+    \def\noindent{\lst@AddTo\lst@fmtPostOutput\lst@fmtNoindent}%
+    \aftergroup\lst@PrintToken
+    #1%
+    \endgroup}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\global\let\lst@fmtPostOutput\@empty}
+\lst@AddToHook{PostOutput}
+    {\lst@fmtPostOutput \global\let\lst@fmtPostOutput\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtEnsureSpace}
+% \begin{macro}{\lst@fmtEnsurePostSpace}
+%    \begin{macrocode}
+\gdef\lst@fmtEnsureSpace{%
+    \lst@ifwhitespace\else \expandafter\lst@ProcessSpace \fi}
+\gdef\lst@fmtEnsurePostSpace{%
+    \lst@IfNextCharWhitespace{}{\lst@ProcessSpace}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{fmtindent}
+% \begin{macro}{\lst@fmtIndent}
+% \begin{macro}{\lst@fmtNoindent}
+%    \begin{macrocode}
+\lst@Key{fmtindent}{20pt}{\def\lst@fmtindent{#1}}
+\newdimen\lst@fmtcurrindent
+\lst@AddToHook{InitVars}{\global\lst@fmtcurrindent\z@}
+\gdef\lst@fmtIndent{\global\advance\lst@fmtcurrindent\lst@fmtindent}
+\gdef\lst@fmtNoindent{\global\advance\lst@fmtcurrindent-\lst@fmtindent}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@fmtEnsureNewLine}
+%    \begin{macrocode}
+\gdef\lst@fmtEnsureNewLine{%
+    \global\advance\lst@newlines\@ne
+    \global\advance\lst@newlinesensured\@ne
+    \lst@fmtignoretrue}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToAtTop\lst@DoNewLines{%
+    \ifnum\lst@newlines>\lst@newlinesensured
+        \global\advance\lst@newlines-\lst@newlinesensured
+    \fi
+    \global\lst@newlinesensured\z@}
+\newcount\lst@newlinesensured % global
+\lst@AddToHook{Init}{\global\lst@newlinesensured\z@}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@fmtignoretrue{\let\lst@fmtifignore\iftrue}
+\gdef\lst@fmtignorefalse{\let\lst@fmtifignore\iffalse}
+\lst@AddToHook{InitVars}{\lst@fmtignorefalse}
+\lst@AddToHook{Output}{\lst@fmtignorefalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtUseLostSpace}
+%    \begin{macrocode}
+\gdef\lst@fmtUseLostSpace{%
+    \lst@ifnewline \kern\lst@fmtcurrindent \global\lst@lostspace\z@
+    \else
+        \lst@OldOLS
+    \fi}
+\lst@AddToHook{Init}
+    {\lst@true
+     \ifx\lst@fmtformat\@empty \ifx\lst@fmt\@empty \lst@false \fi\fi
+     \lst@if
+        \let\lst@OldOLS\lst@OutputLostSpace
+        \let\lst@OutputLostSpace\lst@fmtUseLostSpace
+        \let\lst@ProcessSpace\lst@fmtProcessSpace
+     \fi}
+%    \end{macrocode}
+% \begin{TODO}
+% This `lost space' doesn't use |\lst@alloverstyle| yet!
+% \end{TODO}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtProcessSpace}
+%    \begin{macrocode}
+\gdef\lst@fmtProcessSpace{%
+    \lst@ifletter
+        \lst@Output
+        \lst@fmtifignore\else
+            \lst@AppendOther\lst@outputspace
+        \fi
+    \else \lst@ifkeepspaces
+        \lst@AppendOther\lst@outputspace
+    \else \ifnum\lst@newlines=\z@
+        \lst@AppendSpecialSpace
+    \else \ifnum\lst@length=\z@
+            \global\advance\lst@lostspace\lst@width
+            \global\advance\lst@pos\m@ne
+        \else
+            \lst@AppendSpecialSpace
+        \fi
+    \fi \fi \fi
+    \lst@whitespacetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Formatting identifiers}
+%
+% \begin{macro}{\lst@fmtIdentifier}
+% We install a (keyword) test for the `format identifiers'.
+%    \begin{macrocode}
+\lst@InstallTest{f}
+    \lst@fmt@list\lst@fmt \lst@gfmt@list\lst@gfmt
+    \lst@gfmt@wp
+    wd
+\gdef\lst@fmt@list{\lst@fmt\lst@gfmt}\global\let\lst@fmt\@empty
+\gdef\lst@gfmt@list{\lst@fmt\lst@gfmt}\global\let\lst@gfmt\@empty
+%    \end{macrocode}
+% The working procedure expands |\lst@fmt$|\meta{string} (and defines
+% |\lst@PrintToken| to do nothing).
+%    \begin{macrocode}
+\gdef\lst@gfmt@wp{%
+    \begingroup \let\lst@UM\@empty
+    \let\lst@PrintToken\@empty
+    \csname\lst@ @fmt$\the\lst@token\endcsname
+    \endgroup}
+%    \end{macrocode}
+% This control sequence is probably defined as `working identifier'.
+%    \begin{macrocode}
+\gdef\lst@fmtIdentifier#1#2#3#4{%
+    \lst@DefOther\lst@fmta{#2}\edef\lst@fmt{\lst@fmt,\lst@fmta}%
+    \@namedef{\lst@ @fmt$\lst@fmta}{#3#4}}
+%    \end{macrocode}
+% |\lst@fmt$|\meta{identifier} expands to a |\lst@fmtPre|/|\lst@fmtPost|
+% sequence defined by |#2| and |#3|.
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+%
+% \subsection{Line numbers}
+%
+% \begin{aspect}{labels}
+% \lsthelper{Rolf~Niepraschk}{1997/04/24}{line numbers} asked for line numbers.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{labels}
+%    \end{macrocode}
+%
+% \begin{lstkey}{numbers}
+% Depending on the argument we define |\lst@PlaceNumber| to print the line
+% number.
+%    \begin{macrocode}
+\lst@Key{numbers}{none}{%
+    \let\lst@PlaceNumber\@empty
+    \lstKV@SwitchCases{#1}%
+    {none&\\%
+     left&\def\lst@PlaceNumber{\llap{\normalfont
+                \lst@numberstyle{\thelstnumber}\kern\lst@numbersep}}\\%
+     right&\def\lst@PlaceNumber{\rlap{\normalfont
+                \kern\linewidth \kern\lst@numbersep
+                \lst@numberstyle{\thelstnumber}}}%
+    }{\PackageError{Listings}{Numbers #1 unknown}\@ehc}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{numberstyle}
+% \begin{lstkey}{numbersep}
+% \begin{lstkey}{stepnumber}
+% \begin{lstkey}{numberblanklines}
+% Definition of the keys.
+%    \begin{macrocode}
+\lst@Key{numberstyle}{}{\def\lst@numberstyle{#1}}
+\lst@Key{numbersep}{10pt}{\def\lst@numbersep{#1}}
+\lst@Key{stepnumber}{1}{\def\lst@stepnumber{#1\relax}}
+\lst@AddToHook{EmptyStyle}{\let\lst@stepnumber\@ne}
+\lst@Key{numberblanklines}{true}[t]
+    {\lstKV@SetIf{#1}\lst@ifnumberblanklines}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{firstnumber}
+% We select the first number according to the argument.
+%    \begin{macrocode}
+\lst@Key{firstnumber}{auto}{%
+    \lstKV@SwitchCases{#1}%
+    {auto&\let\lst@firstnumber\@undefined\\%
+     last&\let\lst@firstnumber\c@lstnumber
+    }{\def\lst@firstnumber{#1\relax}}}
+\lst@AddToHook{PreSet}{\let\lst@advancenumber\z@}
+\lst@AddToHook{PreInit}
+    {\ifx\lst@firstnumber\@undefined
+         \let\lst@firstnumber\lst@firstline
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@SetFirstNumber}
+% \begin{macro}{\lst@SaveFirstNumber}
+% \lsthelper{Boris~Veytsman}{1998/03/25}{continue line numbering: a.c b.c a.c}
+% proposed to continue line numbers according to listing names. We define the
+% label number of the first printing line here. A bug reported by
+% \lsthelper{Jens~Schwarzer}{2001/05/29}{wrong line numbering of lstlisting
+% with first>1} has been removed by replacing |\@ne| by |\lst@firstline|.
+%    \begin{macrocode}
+\gdef\lst@SetFirstNumber{%
+    \ifx\lst@firstnumber\@undefined
+        \@tempcnta 0\csname\@lst no@\lst@intname\endcsname\relax
+        \ifnum\@tempcnta=\z@ \@tempcnta\lst@firstline
+                       \else \lst@nololtrue \fi
+        \advance\@tempcnta\lst@advancenumber
+        \edef\lst@firstnumber{\the\@tempcnta\relax}%
+    \fi}
+%    \end{macrocode}
+% The current label is stored in|\lstno@|\meta{name}. If the name is empty,
+% we use a space instead, which leaves |\lstno@| undefined.
+%    \begin{macrocode}
+\gdef\lst@SaveFirstNumber{%
+    \expandafter\xdef
+        \csname\@lst no\ifx\lst@intname\@empty @ \else @\lst@intname\fi
+        \endcsname{\the\c@lstnumber}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\c@lstnumber}
+% This counter keeps the current label number. We use it as current label to
+% make line numbers referenced by |\ref|. This was proposed by
+% \lsthelper{Boris~Veytsman}{1998/03/25}{make line numbers referenced via
+% \label and \ref}. We now use |\refstepcounter| to do the job---thanks to a
+% bug report from \lsthelper{Christian~Gudrian}{2000/11/13}{\ref{lst:line}
+% jumps to top of listing and not to the line}.
+%    \begin{macrocode}
+\newcounter{lstnumber}% \global
+\global\c@lstnumber\@ne % init
+\renewcommand*\thelstnumber{\@arabic\c@lstnumber}
+\lst@AddToHook{EveryPar}
+    {\global\advance\c@lstnumber\lst@advancelstnum
+     \global\advance\c@lstnumber\m@ne \refstepcounter{lstnumber}%
+     \lst@SkipOrPrintLabel}%
+\global\let\lst@advancelstnum\@ne
+%    \end{macrocode}
+% Note that the counter advances \emph{before} the label is printed and not
+% afterwards. Otherwise we have wrong references---reported by
+% \lsthelper{Gregory~Van~Vooren}{1999/06/04}{reference one unit too large}.
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\def\@currentlabel{\thelstnumber}}
+%    \end{macrocode}
+% The label number is initialized and we ensure correct line numbers for
+% continued listings.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}
+    {\global\c@lstnumber\lst@firstnumber
+     \global\advance\c@lstnumber\lst@advancenumber
+     \global\advance\c@lstnumber-\lst@advancelstnum
+     \ifx \lst@firstnumber\c@lstnumber
+         \global\advance\c@lstnumber-\lst@advancelstnum
+     \fi}
+\lst@AddToHook{ExitVars}
+    {\global\advance\c@lstnumber\lst@advancelstnum}
+%    \end{macrocode}
+% \lsthelper{Walter~E.~Brown}{2001/05/22}{pdftex 3.14159-14f warning:
+% destination with the same identifier} reported problems with pdftex and
+% \packagename{hyperref}. A bad default of |\theHlstlabel| was the reason.
+% \lsthelper{Heiko~Oberdiek}{2001/11/08}{pdftex warning: destination with
+% the same identifier} found another bug which was due to the localization
+% of |\lst@neglisting|. He also provided the following fix, replacing
+% |\thelstlisting| with the |\ifx| \ldots\ |\fi| construction.
+%    \begin{macrocode}
+\AtBeginDocument{%
+    \def\theHlstnumber{\ifx\lst@@caption\@empty \lst@neglisting
+                                          \else \thelstlisting \fi
+                       .\thelstnumber}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@skipnumbers}
+% There are more things to do. We calculate how many lines must skip their
+% label. The formula is
+%	$$|\lst@skipnumbers|=
+%		\textrm{\emph{first printing line}}\bmod|\lst@stepnumber|.$$
+% Note that we use a nonpositive representative for |\lst@skipnumbers|.
+%    \begin{macrocode}
+\newcount\lst@skipnumbers % \global
+\lst@AddToHook{Init}
+    {\ifnum \z@>\lst@stepnumber
+         \let\lst@advancelstnum\m@ne
+         \edef\lst@stepnumber{-\lst@stepnumber}%
+     \fi
+     \ifnum \z@<\lst@stepnumber
+         \global\lst@skipnumbers\lst@firstnumber
+         \global\divide\lst@skipnumbers\lst@stepnumber
+         \global\multiply\lst@skipnumbers-\lst@stepnumber
+         \global\advance\lst@skipnumbers\lst@firstnumber
+         \ifnum\lst@skipnumbers>\z@
+             \global\advance\lst@skipnumbers -\lst@stepnumber
+         \fi
+%    \end{macrocode}
+% If |\lst@stepnumber| is zero, no line numbers are printed:
+%    \begin{macrocode}
+     \else
+         \let\lst@SkipOrPrintLabel\relax
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SkipOrPrintLabel}
+% But default is this. We use the fact that |\lst@skipnumbers| is nonpositive.
+% The counter advances every line and if that counter is zero, we print a line
+% number and decrement the counter by |\lst@stepnumber|.
+%    \begin{macrocode}
+\gdef\lst@SkipOrPrintLabel{%
+    \ifnum\lst@skipnumbers=\z@
+        \global\advance\lst@skipnumbers-\lst@stepnumber\relax
+        \lst@PlaceNumber
+    \fi
+    \global\advance\lst@skipnumbers\@ne}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{OnEmptyLine}{%
+    \lst@ifnumberblanklines\else \ifnum\lst@skipnumbers=\z@
+        \global\advance\lst@skipnumbers-\lst@stepnumber\relax
+    \fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Line shape and line breaking}
+%
+% \begin{macro}{\lst@parshape}
+% We define a default version of |\lst@parshape| for the case that the
+% \aspectname{lineshape} aspect is not loaded. We use this parshape every line
+% (in fact every paragraph). Furthermore we must repeat the parshape if we
+% close a group level---or the shape is forgotten.
+%    \begin{macrocode}
+%<*kernel>
+\def\lst@parshape{\parshape\@ne \z@ \linewidth}
+\lst@AddToHookAtTop{EveryLine}{\lst@parshape}
+\lst@AddToHookAtTop{EndGroup}{\lst@parshape}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{aspect}{lineshape}
+% Our first aspect in this section.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{lineshape}
+%    \end{macrocode}
+%
+% \begin{lstkey}{xleftmargin}
+% \begin{lstkey}{xrightmargin}
+% \begin{lstkey}{resetmargins}
+% \begin{lstkey}{linewidth}
+% Usual stuff.
+%    \begin{macrocode}
+\lst@Key{xleftmargin}{\z@}{\def\lst@xleftmargin{#1}}
+\lst@Key{xrightmargin}{\z@}{\def\lst@xrightmargin{#1}}
+\lst@Key{resetmargins}{false}[t]{\lstKV@SetIf{#1}\lst@ifresetmargins}
+%    \end{macrocode}
+% The margins become zero if we make an exact box around the listing.
+%    \begin{macrocode}
+\lst@AddToHook{BoxUnsafe}{\let\lst@xleftmargin\z@
+                          \let\lst@xrightmargin\z@}
+\lst@AddToHook{TextStyle}{%
+    \let\lst@xleftmargin\z@ \let\lst@xrightmargin\z@
+    \let\lst@ifresetmargins\iftrue}
+%    \end{macrocode}
+% Added above hook after bug report from \lsthelper{Magnus~Lewis-Smith}
+%{1999/08/06}{|\lstinline| indented} and \lsthelper{Jos\'e~Romildo~Malaquias}
+%{2000/08/22}{|\lstinline| indented (resetmargins)} respectively.
+%    \begin{macrocode}
+\lst@Key{linewidth}\linewidth{\def\lst@linewidth{#1}}
+\lst@AddToHook{PreInit}{\linewidth\lst@linewidth\relax}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@parshape}
+% The definition itself is easy.
+%    \begin{macrocode}
+\gdef\lst@parshape{%
+    \parshape\@ne \@totalleftmargin \linewidth}
+%    \end{macrocode}
+% We calculate the line width and (inner/outer) indent for a listing.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifresetmargins
+         \advance\linewidth\@totalleftmargin
+         \advance\linewidth\rightmargin
+         \@totalleftmargin\z@
+     \fi
+     \advance\linewidth-\lst@xleftmargin
+     \advance\linewidth-\lst@xrightmargin
+     \advance\@totalleftmargin\lst@xleftmargin\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{lineskip}
+% The introduction of this key is due to communication with
+% \lsthelper{Andreas~Bartelt}{1997/09/11}{problem with redefed \parskip;
+% \lstlineskip introduced}. Version 1.0 implements this feature by
+% redefining |\baselinestretch|.
+%    \begin{macrocode}
+\lst@Key{lineskip}{\z@}{\def\lst@lineskip{#1\relax}}
+\lst@AddToHook{Init}
+    {\parskip\z@
+     \ifdim\z@=\lst@lineskip\else
+         \@tempdima\baselineskip
+         \advance\@tempdima\lst@lineskip
+         \divide\@tempdima\strip@pt\baselineskip\relax
+         \edef\baselinestretch{\strip@pt\@tempdima}%
+         \selectfont
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{breaklines}
+% \begin{lstkey}{breakindent}
+% \begin{lstkey}{breakautoindent}
+% \begin{lstkey}{prebreak}
+% \begin{lstkey}{postbreak}
+% As usual we have no problems in announcing more keys.
+%    \begin{macrocode}
+\lst@Key{breaklines}{false}[t]{\lstKV@SetIf{#1}\lst@ifbreaklines}
+\lst@Key{breakindent}{20pt}{\def\lst@breakindent{#1}}
+\lst@Key{breakautoindent}{t}[t]{\lstKV@SetIf{#1}\lst@ifbreakautoindent}
+\lst@Key{prebreak}{}{\def\lst@prebreak{#1}}
+\lst@Key{postbreak}{}{\def\lst@postbreak{#1}}
+%    \end{macrocode}
+% We assign some different macros and (if necessary) suppress ``underfull
+% |\hbox|'' messages (and use different pretolerance):
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifbreaklines
+         \hbadness\@M \pretolerance\@M
+%    \end{macrocode}
+% We use the normal parshape and the calculated |\lst@breakshape| (see below).
+%    \begin{macrocode}
+         \def\lst@parshape{\parshape\tw@ \@totalleftmargin\linewidth
+                           \lst@breakshape}%
+     \else
+         \let\lst@discretionary\@empty
+     \fi}
+\lst@AddToHook{OnNewLine}
+    {\lst@ifbreaklines \lst@breakNewLine \fi}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}\end{lstkey}\end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@discretionary}
+% \begin{macro}{\lst@spacekern}
+% Here comes the whole magic: We set a discretionary break after each `output
+% unit'. However we redefine |\space| to be used inside |\discretionary| and
+% use \hookname{EveryLine} hook.
+%    \begin{macrocode}
+\gdef\lst@discretionary{%
+    \discretionary{\let\space\lst@spacekern\lst@prebreak}%
+                  {\llap{\lsthk@EveryLine \kern\lst@breakcurrindent}%
+                   \let\space\lst@spacekern\lst@postbreak}{}}
+\lst@AddToHook{PostOutput}{\lst@discretionary}
+\gdef\lst@spacekern{\kern\lst@width}
+%    \end{macrocode}
+% \begin{ALTERNATIVE}
+% |\penalty\@M \hskip\z@ plus 1fil \penalty0\hskip\z@ plus-1fil| \emph{before}
+% each `output unit' (i.e.~before |\hbox{...}| in the output macros) also break
+% the lines as desired. But we wouldn't have |prebreak| and |postbreak|.
+% \end{ALTERNATIVE}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@breakNewLine}
+% We use \keyname{breakindent}, and additionally the current line indention
+% (coming from white spaces at the beginning of the line) if `auto indent' is
+% on.
+%    \begin{macrocode}
+\gdef\lst@breakNewLine{%
+    \@tempdima\lst@breakindent\relax
+    \lst@ifbreakautoindent \advance\@tempdima\lst@lostspace \fi
+%    \end{macrocode}
+% Now we calculate the margin and line width of the wrapped part \ldots
+%    \begin{macrocode}
+    \@tempdimc-\@tempdima \advance\@tempdimc\linewidth
+                          \advance\@tempdima\@totalleftmargin
+%    \end{macrocode}
+% \ldots\space and store it in |\lst@breakshape|.
+%    \begin{macrocode}
+    \xdef\lst@breakshape{\noexpand\lst@breakcurrindent \the\@tempdimc}%
+    \xdef\lst@breakcurrindent{\the\@tempdima}}
+%    \end{macrocode}
+% \begin{TODO}
+% We could speed this up by allocating two global dimensions.
+% \end{TODO}
+% \end{macro}
+%
+% \begin{macro}{\lst@breakshape}
+% \lsthelper{Andreas~Deininger}{2000/08/25}{`breaklines,first>1' leads to
+% ``undefined control sequence'' error} reported a problem which is resolved
+% by providing a default break shape.
+%    \begin{macrocode}
+\gdef\lst@breakshape{\@totalleftmargin \linewidth}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@breakProcessOther}
+% is the same as |\lst@ProcessOther| except that it also outputs the current
+% token string. This inserts a potential linebreak point.
+% Only the closing parenthesis uses this macro yet.
+%    \begin{macrocode}
+\gdef\lst@breakProcessOther#1{\lst@ProcessOther#1\lst@OutputOther}
+\lst@AddToHook{SelectCharTable}
+    {\lst@ifbreaklines \lst@Def{`)}{\lst@breakProcessOther)}\fi}
+%    \end{macrocode}
+% A bug reported by \lsthelper{Gabriel~Tauro}{2001/04/18}{unexpected `)' if
+% the character appears before first printed line} has been removed by using
+% |\lst@ProcessOther| instead of |\lst@AppendOther|.
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Frames}
+%
+% \begin{aspect}{frames}
+% Another aspect.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[lineshape]{frames}
+%    \end{macrocode}
+%
+% \begin{lstkey}{framexleftmargin}
+% \begin{lstkey}{framexrightmargin}
+% \begin{lstkey}{framextopmargin}
+% \begin{lstkey}{framexbottommargin}
+% These keys just save the argument.
+%    \begin{macrocode}
+\lst@Key{framexleftmargin}{\z@}{\def\lst@framexleftmargin{#1}}
+\lst@Key{framexrightmargin}{\z@}{\def\lst@framexrightmargin{#1}}
+\lst@Key{framextopmargin}{\z@}{\def\lst@framextopmargin{#1}}
+\lst@Key{framexbottommargin}{\z@}{\def\lst@framexbottommargin{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{backgroundcolor}
+% \lsthelper{Ralf~Imh\"auser}{2000/01/08}{coloured background} inspired the
+% key \keyname{backgroundcolor}. All keys save the argument, and \ldots
+%    \begin{macrocode}
+\lst@Key{backgroundcolor}{}{\def\lst@bkgcolor{#1}}
+\lst@Key{fillcolor}{}{\def\lst@fillcolor{#1}}
+\lst@Key{rulecolor}{}{\def\lst@rulecolor{#1}}
+\lst@Key{rulesepcolor}{}{\def\lst@rulesepcolor{#1}}
+%    \end{macrocode}
+% \ldots\space some have default settings if they are empty.
+%    \begin{macrocode}
+\lst@AddToHook{Init}{%
+    \ifx\lst@fillcolor\@empty
+        \let\lst@fillcolor\lst@bkgcolor
+    \fi
+    \ifx\lst@rulesepcolor\@empty
+        \let\lst@rulesepcolor\lst@fillcolor
+    \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{rulesep}
+% \begin{lstkey}{framerule}
+% \begin{lstkey}{framesep}
+% \begin{lstkey}{frameshape}
+% Another set of keys, which mainly save their respective argument.
+% \keyname{frameshape} capitalizes all letters, and checks whether at least one
+% round corner is specified. Eventually we define |\lst@frame| to be empty if
+% and only if there is no frameshape.
+%    \begin{macrocode}
+\lst@Key{rulesep}{2pt}{\def\lst@rulesep{#1}}
+\lst@Key{framerule}{.4pt}{\def\lst@framerulewidth{#1}}
+\lst@Key{framesep}{3pt}{\def\lst@frametextsep{#1}}
+\lst@Key{frameshape}{}{%
+    \let\lst@xrulecolor\@empty
+    \lstKV@FourArg{#1}%
+    {\uppercase{\def\lst@frametshape{##1}}%
+     \uppercase{\def\lst@framelshape{##2}}%
+     \uppercase{\def\lst@framershape{##3}}%
+     \uppercase{\def\lst@framebshape{##4}}%
+     \let\lst@ifframeround\iffalse
+     \lst@IfSubstring R\lst@frametshape{\let\lst@ifframeround\iftrue}{}%
+     \lst@IfSubstring R\lst@framebshape{\let\lst@ifframeround\iftrue}{}%
+     \def\lst@frame{##1##2##3##4}}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{frameround}
+% \begin{lstkey}{frame}
+% We have to do some conversion here.
+%    \begin{macrocode}
+\lst@Key{frameround}\relax
+    {\uppercase{\def\lst@frameround{#1}}%
+     \expandafter\lstframe@\lst@frameround ffff\relax}
+\global\let\lst@frameround\@empty
+%    \end{macrocode}
+% In case of an verbose argument, we use the |trbl|-subset replacement.
+%    \begin{macrocode}
+\lst@Key{frame}\relax{%
+    \let\lst@xrulecolor\@empty
+    \lstKV@SwitchCases{#1}%
+    {none&\let\lst@frame\@empty\\%
+     leftline&\def\lst@frame{l}\\%
+     topline&\def\lst@frame{t}\\%
+     bottomline&\def\lst@frame{b}\\%
+     lines&\def\lst@frame{tb}\\%
+     single&\def\lst@frame{trbl}\\%
+     shadowbox&\def\lst@frame{tRBl}%
+            \def\lst@xrulecolor{\lst@rulesepcolor}%
+            \def\lst@rulesep{\lst@frametextsep}%
+    }{\def\lst@frame{#1}}%
+    \expandafter\lstframe@\lst@frameround ffff\relax}
+%    \end{macrocode}
+% Adding |t|, |r|, |b|, and |l| in case of their upper case versions makes
+% later tests easier.
+%    \begin{macrocode}
+\gdef\lstframe@#1#2#3#4#5\relax{%
+    \lst@IfSubstring T\lst@frame{\edef\lst@frame{t\lst@frame}}{}%
+    \lst@IfSubstring R\lst@frame{\edef\lst@frame{r\lst@frame}}{}%
+    \lst@IfSubstring B\lst@frame{\edef\lst@frame{b\lst@frame}}{}%
+    \lst@IfSubstring L\lst@frame{\edef\lst@frame{l\lst@frame}}{}%
+%    \end{macrocode}
+% We now check top and bottom frame rules, \ldots
+%    \begin{macrocode}
+    \let\lst@frametshape\@empty \let\lst@framebshape\@empty
+    \lst@frameCheck
+        ltr\lst@framelshape\lst@frametshape\lst@framershape #4#1%
+    \lst@frameCheck
+        LTR\lst@framelshape\lst@frametshape\lst@framershape #4#1%
+    \lst@frameCheck
+        lbr\lst@framelshape\lst@framebshape\lst@framershape #3#2%
+    \lst@frameCheck
+        LBR\lst@framelshape\lst@framebshape\lst@framershape #3#2%
+%    \end{macrocode}
+% \ldots\space look for round corners \ldots
+%    \begin{macrocode}
+    \let\lst@ifframeround\iffalse
+    \lst@IfSubstring R\lst@frametshape{\let\lst@ifframeround\iftrue}{}%
+    \lst@IfSubstring R\lst@framebshape{\let\lst@ifframeround\iftrue}{}%
+%    \end{macrocode}
+% and define left and right frame shape.
+%    \begin{macrocode}
+    \let\lst@framelshape\@empty \let\lst@framershape\@empty
+    \lst@IfSubstring L\lst@frame
+        {\def\lst@framelshape{YY}}%
+        {\lst@IfSubstring l\lst@frame{\def\lst@framelshape{Y}}{}}%
+    \lst@IfSubstring R\lst@frame
+        {\def\lst@framershape{YY}}%
+        {\lst@IfSubstring r\lst@frame{\def\lst@framershape{Y}}{}}}
+%    \end{macrocode}
+% Now comes the macro used to define top and bottom frame shape.
+% It extends the macro |#5|.
+% The last two arguments show whether left and right corners are round.
+% |#4| and |#6| are temporary macros.
+% |#1#2#3| are the three characters we test for.
+%    \begin{macrocode}
+\gdef\lst@frameCheck#1#2#3#4#5#6#7#8{%
+    \lst@IfSubstring #1\lst@frame
+        {\if #7T\def#4{R}\else \def#4{Y}\fi}%
+        {\def#4{N}}%
+    \lst@IfSubstring #3\lst@frame
+        {\if #8T\def#6{R}\else \def#6{Y}\fi}%
+        {\def#6{N}}%
+    \lst@IfSubstring #2\lst@frame{\edef#5{#5#4Y#6}}{}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@frameMakeVBox}
+%    \begin{macrocode}
+\gdef\lst@frameMakeBoxV#1#2#3{%
+    \setbox#1\hbox{%
+      \color@begingroup \lst@rulecolor
+      \llap{\setbox\z@\hbox{\vrule\@width\z@\@height#2\@depth#3%
+                            \lst@frameL}%
+            \rlap{\lst@frameBlock\lst@rulesepcolor{\wd\z@}%
+                                                  {\ht\z@}{\dp\z@}}%
+            \box\z@
+            \ifx\lst@framelshape\@empty
+                \kern\lst@frametextsep\relax
+            \else
+                \lst@frameBlock\lst@fillcolor\lst@frametextsep{#2}{#3}%
+            \fi
+            \kern\lst@framexleftmargin}%
+      \rlap{\kern-\lst@framexleftmargin
+                    \@tempdima\linewidth
+            \advance\@tempdima\lst@framexleftmargin
+            \advance\@tempdima\lst@framexrightmargin
+            \lst@frameBlock\lst@bkgcolor\@tempdima{#2}{#3}%
+            \ifx\lst@framershape\@empty
+                \kern\lst@frametextsep\relax
+            \else
+                \lst@frameBlock\lst@fillcolor\lst@frametextsep{#2}{#3}%
+            \fi
+            \setbox\z@\hbox{\vrule\@width\z@\@height#2\@depth#3%
+                            \lst@frameR}%
+            \rlap{\lst@frameBlock\lst@rulesepcolor{\wd\z@}%
+                                                  {\ht\z@}{\dp\z@}}%
+            \box\z@}%
+      \color@endgroup}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameBlock}
+%    \begin{macrocode}
+\gdef\lst@frameBlock#1#2#3#4{%
+    \color@begingroup
+      #1%
+      \setbox\z@\hbox{\vrule\@height#3\@depth#4%
+                      \ifx#1\@empty \@width\z@ \kern#2\relax
+                              \else \@width#2\relax \fi}%
+      \box\z@
+    \color@endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameR}
+% typesets right rules.
+% We only need to iterate through |\lst@framershape|.
+%    \begin{macrocode}
+\gdef\lst@frameR{%
+    \expandafter\lst@frameR@\lst@framershape\relax
+    \kern-\lst@rulesep}
+\gdef\lst@frameR@#1{%
+    \ifx\relax#1\@empty\else
+        \if #1Y\lst@framevrule \else \kern\lst@framerulewidth \fi
+        \kern\lst@rulesep
+        \expandafter\lst@frameR@b
+    \fi}
+\gdef\lst@frameR@b#1{%
+    \ifx\relax#1\@empty
+    \else
+        \if #1Y\color@begingroup
+               \lst@xrulecolor
+               \lst@framevrule
+               \color@endgroup
+        \else
+               \kern\lst@framerulewidth
+        \fi
+        \kern\lst@rulesep
+        \expandafter\lst@frameR@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameL}
+% Ditto left rules.
+%    \begin{macrocode}
+\gdef\lst@frameL{%
+    \kern-\lst@rulesep
+    \expandafter\lst@frameL@\lst@framelshape\relax}
+\gdef\lst@frameL@#1{%
+    \ifx\relax#1\@empty\else
+        \kern\lst@rulesep
+        \if#1Y\lst@framevrule \else \kern\lst@framerulewidth \fi
+        \expandafter\lst@frameL@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameH}
+% This is the central macro used to draw top and bottom frame rules.
+% The first argument is either |T| or |B| and the second contains the shape.
+% We use |\@tempcntb| as size counter.
+%    \begin{macrocode}
+\gdef\lst@frameH#1#2{%
+    \global\let\lst@framediml\z@ \global\let\lst@framedimr\z@
+    \setbox\z@\hbox{}\@tempcntb\z@
+    \expandafter\lst@frameH@\expandafter#1#2\relax\relax\relax
+            \@tempdimb\lst@frametextsep\relax
+    \advance\@tempdimb\lst@framerulewidth\relax
+            \@tempdimc-\@tempdimb
+    \advance\@tempdimc\ht\z@
+    \advance\@tempdimc\dp\z@
+    \setbox\z@=\hbox{%
+      \lst@frameHBkg\lst@fillcolor\@tempdimb\@firstoftwo
+      \if#1T\rlap{\raise\dp\@tempboxa\box\@tempboxa}%
+       \else\rlap{\lower\ht\@tempboxa\box\@tempboxa}\fi
+      \lst@frameHBkg\lst@rulesepcolor\@tempdimc\@secondoftwo
+      \advance\@tempdimb\ht\@tempboxa
+      \if#1T\rlap{\raise\lst@frametextsep\box\@tempboxa}%
+       \else\rlap{\lower\@tempdimb\box\@tempboxa}\fi
+      \rlap{\box\z@}%
+    }}
+\gdef\lst@frameH@#1#2#3#4{%
+    \ifx\relax#4\@empty\else
+        \lst@frameh \@tempcntb#1#2#3#4%
+        \advance\@tempcntb\@ne
+        \expandafter\lst@frameH@\expandafter#1%
+    \fi}
+\gdef\lst@frameHBkg#1#2#3{%
+    \setbox\@tempboxa\hbox{%
+        \kern-\lst@framexleftmargin
+        #3{\kern-\lst@framediml\relax}{\@tempdima\z@}%
+        \ifdim\lst@framediml>\@tempdimb
+            #3{\@tempdima\lst@framediml \advance\@tempdima-\@tempdimb
+               \lst@frameBlock\lst@rulesepcolor\@tempdima\@tempdimb\z@}%
+              {\kern-\lst@framediml
+               \advance\@tempdima\lst@framediml\relax}%
+        \fi
+        #3{\@tempdima\z@
+           \ifx\lst@framelshape\@empty\else
+               \advance\@tempdima\@tempdimb
+           \fi
+           \ifx\lst@framershape\@empty\else
+               \advance\@tempdima\@tempdimb
+           \fi}%
+          {\ifdim\lst@framedimr>\@tempdimb
+              \advance\@tempdima\lst@framedimr\relax
+           \fi}%
+        \advance\@tempdima\linewidth
+        \advance\@tempdima\lst@framexleftmargin
+        \advance\@tempdima\lst@framexrightmargin
+        \lst@frameBlock#1\@tempdima#2\z@
+        #3{\ifdim\lst@framedimr>\@tempdimb
+               \@tempdima-\@tempdimb
+               \advance\@tempdima\lst@framedimr\relax
+               \lst@frameBlock\lst@rulesepcolor\@tempdima\@tempdimb\z@
+           \fi}{}%
+        }}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameh}
+% This is the low-level macro used to draw top and bottom frame rules.
+% It \emph{adds} one rule plus corners to box 0.
+% The first parameter gives the size of the corners and the second is either
+% |T| or |B|.
+% |#3#4#5| is a left-to-right description of the frame and is in
+% $\{$\texttt{Y,N,R}$\}\times\{$\texttt{Y,N}$\}\times\{$\texttt{Y,N,R}$\}$.
+% We move to the correct horizontal position, set the left corner, the
+% horizontal line, and the right corner.
+%    \begin{macrocode}
+\gdef\lst@frameh#1#2#3#4#5{%
+    \lst@frameCalcDimA#1%
+    \lst@ifframeround \@getcirc\@tempdima \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \setbox\z@\hbox{%
+      \begingroup
+      \setbox\z@\hbox{%
+        \kern-\lst@framexleftmargin
+        \color@begingroup
+        \ifnum#1=\z@ \lst@rulecolor \else \lst@xrulecolor \fi
+%    \end{macrocode}
+% |\lst@frameCorner| gets four arguments:
+% |\llap|, |TL| or |BL|, the corner type $\in\{$\texttt{Y,N,R}$\}$, and the
+% size |#1|.
+%    \begin{macrocode}
+        \lst@frameCornerX\llap{#2L}#3#1%
+        \ifdim\lst@framediml<\@tempdimb
+            \xdef\lst@framediml{\the\@tempdimb}%
+        \fi
+        \begingroup
+        \if#4Y\else \let\lst@framerulewidth\z@ \fi
+                \@tempdima\lst@framexleftmargin
+        \advance\@tempdima\lst@framexrightmargin
+        \advance\@tempdima\linewidth
+        \vrule\@width\@tempdima\@height\lst@framerulewidth \@depth\z@
+        \endgroup
+        \lst@frameCornerX\rlap{#2R}#5#1%
+        \ifdim\lst@framedimr<\@tempdimb
+            \xdef\lst@framedimr{\the\@tempdimb}%
+        \fi
+        \color@endgroup}%
+%    \end{macrocode}
+%    \begin{macrocode}
+      \if#2T\rlap{\raise\dp\z@\box\z@}%
+       \else\rlap{\lower\ht\z@\box\z@}\fi
+      \endgroup
+      \box\z@}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameCornerX}
+% typesets a single corner and returns |\@tempdimb|, the width of the corner.
+%    \begin{macrocode}
+\gdef\lst@frameCornerX#1#2#3#4{%
+    \setbox\@tempboxa\hbox{\csname\@lst @frame\if#3RR\fi #2\endcsname}%
+    \@tempdimb\wd\@tempboxa
+    \if #3R%
+        #1{\box\@tempboxa}%
+    \else
+        \if #3Y\expandafter#1\else
+               \@tempdimb\z@ \expandafter\vphantom \fi
+        {\box\@tempboxa}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameCalcDimA}
+% calculates an all over width; used by |\lst@frameh| and |\lst@frameInit|.
+%    \begin{macrocode}
+\gdef\lst@frameCalcDimA#1{%
+            \@tempdima\lst@rulesep
+    \advance\@tempdima\lst@framerulewidth
+    \multiply\@tempdima#1\relax
+    \advance\@tempdima\lst@frametextsep
+    \advance\@tempdima\lst@framerulewidth
+    \multiply\@tempdima\tw@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameInit}
+% First we look which frame types we have on the left and on the right.
+% We speed up things if there are no vertical rules.
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\lst@frameInit}
+\newbox\lst@framebox
+\gdef\lst@frameInit{%
+    \ifx\lst@framelshape\@empty \let\lst@frameL\@empty \fi
+    \ifx\lst@framershape\@empty \let\lst@frameR\@empty \fi
+    \def\lst@framevrule{\vrule\@width\lst@framerulewidth\relax}%
+%    \end{macrocode}
+% We adjust values to round corners if necessary.
+%    \begin{macrocode}
+    \lst@ifframeround
+        \lst@frameCalcDimA\z@ \@getcirc\@tempdima
+        \@tempdimb\@tempdima \divide\@tempdimb\tw@
+        \advance\@tempdimb -\@wholewidth
+        \edef\lst@frametextsep{\the\@tempdimb}%
+        \edef\lst@framerulewidth{\the\@wholewidth}%
+%    \end{macrocode}
+%    \begin{macrocode}
+        \lst@frameCalcDimA\@ne \@getcirc\@tempdima
+        \@tempdimb\@tempdima \divide\@tempdimb\tw@
+        \advance\@tempdimb -\tw@\@wholewidth
+        \advance\@tempdimb -\lst@frametextsep
+        \edef\lst@rulesep{\the\@tempdimb}%
+    \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \lst@frameMakeBoxV\lst@framebox{\ht\strutbox}{\dp\strutbox}%
+    \def\lst@framelr{\copy\lst@framebox}%
+%    \end{macrocode}
+% Finally we typeset the rules (+ corners).
+% We possibly need to insert negative |\vskip| to remove space between
+% preceding text and top rule.
+% \begin{TODO}
+% Use |\vspace| instead of |\vskip|?
+% \end{TODO}
+%    \begin{macrocode}
+    \ifx\lst@frametshape\@empty\else
+        \lst@frameH T\lst@frametshape
+        \ifvoid\z@\else
+            \par\lst@parshape
+            \@tempdima-\baselineskip \advance\@tempdima\ht\z@
+            \ifdim\prevdepth<\@cclvi\p@\else
+                \advance\@tempdima\prevdepth
+            \fi
+            \ifdim\@tempdima<\z@
+                \vskip\@tempdima\vskip\lineskip
+            \fi
+            \noindent\box\z@\par
+            \lineskiplimit\maxdimen \lineskip\z@
+        \fi
+        \lst@frameSpreadV\lst@framextopmargin
+    \fi}
+%    \end{macrocode}
+% |\parshape\lst@parshape| ensures that the top rules correctly indented.
+% The bug was reported by \lsthelper{Marcin~Kasperski}{1999/04/28}{top rules
+% indented right inside itemize}.
+%
+% We typeset left and right rules every line.
+%    \begin{macrocode}
+\lst@AddToHook{EveryLine}{\lst@framelr}
+\global\let\lst@framelr\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameExit}
+% The rules at the bottom.
+%    \begin{macrocode}
+\lst@AddToHook{DeInit}
+    {\ifx\lst@framebshape\@empty\else \lst@frameExit \fi}
+\gdef\lst@frameExit{%
+    \lst@frameSpreadV\lst@framexbottommargin
+    \lst@frameH B\lst@framebshape
+    \ifvoid\z@\else
+        \everypar{}\par\lst@parshape\nointerlineskip\noindent\box\z@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameSpreadV}
+% sets rules for vertical spread.
+%    \begin{macrocode}
+\gdef\lst@frameSpreadV#1{%
+    \ifdim\z@=#1\else
+        \everypar{}\par\lst@parshape\nointerlineskip\noindent
+        \lst@frameMakeBoxV\z@{#1}{\z@}%
+        \box\z@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameTR}
+% \begin{macro}{\lst@frameBR}
+% \begin{macro}{\lst@frameBL}
+% \begin{macro}{\lst@frameTL}
+% These macros make a vertical and horizontal rule.
+% The implicit argument |\@tempdima| gives the size of two corners and is
+% provided by |\lst@frameh|.
+%    \begin{macrocode}
+\gdef\lst@frameTR{%
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@
+    \kern-\lst@framerulewidth
+    \raise\lst@framerulewidth\hbox{%
+        \vrule\@width\lst@framerulewidth\@height\z@\@depth.5\@tempdima}}
+\gdef\lst@frameBR{%
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@
+    \kern-\lst@framerulewidth
+    \vrule\@width\lst@framerulewidth\@height.5\@tempdima\@depth\z@}
+\gdef\lst@frameBL{%
+    \vrule\@width\lst@framerulewidth\@height.5\@tempdima\@depth\z@
+    \kern-\lst@framerulewidth
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@}
+\gdef\lst@frameTL{%
+    \raise\lst@framerulewidth\hbox{%
+        \vrule\@width\lst@framerulewidth\@height\z@\@depth.5\@tempdima}%
+    \kern-\lst@framerulewidth
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}\end{macro}
+%
+% \begin{macro}{\lst@frameRoundT}
+% \begin{macro}{\lst@frameRoundB}
+% are helper macros to typeset round corners. We set height and depth to
+% the visible parts of the circle font.
+%    \begin{macrocode}
+\gdef\lst@frameRoundT{%
+    \setbox\@tempboxa\hbox{\@circlefnt\char\@tempcnta}%
+    \ht\@tempboxa\lst@framerulewidth
+    \box\@tempboxa}
+\gdef\lst@frameRoundB{%
+    \setbox\@tempboxa\hbox{\@circlefnt\char\@tempcnta}%
+    \dp\@tempboxa\z@
+    \box\@tempboxa}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameRTR}
+% \begin{macro}{\lst@frameRBR}
+% \begin{macro}{\lst@frameRBL}
+% \begin{macro}{\lst@frameRTL}
+% The round corners.
+%    \begin{macrocode}
+\gdef\lst@frameRTR{%
+    \hb@[email protected]\@tempdima{\kern-\lst@framerulewidth
+                           \kern.5\@tempdima \lst@frameRoundT \hss}}
+\gdef\lst@frameRBR{%
+    \hb@[email protected]\@tempdima{\kern-\lst@framerulewidth
+    \advance\@tempcnta\@ne \kern.5\@tempdima \lst@frameRoundB \hss}}
+\gdef\lst@frameRBL{%
+    \advance\@tempcnta\tw@ \lst@frameRoundB
+    \kern-.5\@tempdima}
+\gdef\lst@frameRTL{%
+    \advance\@tempcnta\thr@@\lst@frameRoundT
+    \kern-.5\@tempdima}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}\end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Macro use for make}
+%
+% \begin{aspect}{make}
+% \begin{macro}{\lst@makemode}
+% \begin{macro}{\lst@ifmakekey}
+% If we've entered the special mode for Make, we save whether the last
+% identifier has been a first order keyword.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{make}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@NewMode\lst@makemode
+\lst@AddToHook{Output}{%
+    \ifnum\lst@mode=\lst@makemode
+        \ifx\lst@thestyle\lst@gkeywords@sty
+            \lst@makekeytrue
+        \fi
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@makekeytrue{\let\lst@ifmakekey\iftrue}
+\gdef\lst@makekeyfalse{\let\lst@ifmakekey\iffalse}
+\global\lst@makekeyfalse % init
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{lstkey}{makemacrouse}
+% adjusts the character table if necessary
+%    \begin{macrocode}
+\lst@Key{makemacrouse}f[t]{\lstKV@SetIf{#1}\lst@ifmakemacrouse}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@MakeSCT}
+% If `macro use' is on, the opening |$(| prints preceding characters, enters
+% the special mode and merges the two characters with the following output.
+% 
+%    \begin{macrocode}
+\gdef\lst@MakeSCT{%
+    \lst@ifmakemacrouse
+        \lst@ReplaceInput{$(}{%
+            \lst@PrintToken
+            \lst@EnterMode\lst@makemode{\lst@makekeyfalse}%
+            \lst@Merge{\lst@ProcessOther\$\lst@ProcessOther(}}%
+%    \end{macrocode}
+% The closing parenthesis tests for the mode and either processes |)| as usual
+% or outputs it right here (in keyword style if a keyword was between |$(| and
+% |)|).
+%    \begin{macrocode}
+        \lst@ReplaceInput{)}{%
+            \ifnum\lst@mode=\lst@makemode
+                \lst@PrintToken
+                \begingroup
+                    \lst@ProcessOther)%
+                    \lst@ifmakekey
+                        \let\lst@currstyle\lst@gkeywords@sty
+                    \fi
+                    \lst@OutputOther
+                \endgroup
+                \lst@LeaveMode
+            \else
+                \expandafter\lst@ProcessOther\expandafter)%
+            \fi}%
+%    \end{macrocode}
+% If \keyname{makemacrouse} is off then both |$(| are just `others'.
+%    \begin{macrocode}
+    \else
+        \lst@ReplaceInput{$(}{\lst@ProcessOther\$\lst@ProcessOther(}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Typesetting a listing}
+%
+% \begingroup
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+% \endgroup
+% \begin{macro}{\lst@lineno}
+% \begin{lstkey}{print}
+% \begin{lstkey}{firstline}
+% \begin{lstkey}{lastline}
+% The `current line' counter and three keys.
+%    \begin{macrocode}
+\newcount\lst@lineno % \global
+\lst@AddToHook{InitVars}{\global\lst@lineno\@ne}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{print}{true}[t]{\lstKV@SetIf{#1}\lst@ifprint}
+\lst@Key{firstline}\relax{\def\lst@firstline{#1\relax}}
+\lst@Key{lastline}\relax{\def\lst@lastline{#1\relax}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{PreSet}
+    {\let\lst@firstline\@ne \def\lst@lastline{9999999\relax}}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}\end{lstkey}\end{macro}
+%
+% \begin{lstkey}{nolol}
+% is just a key here. We'll use it below, of course.
+%    \begin{macrocode}
+\lst@Key{nolol}{false}[t]{\lstKV@SetIf{#1}\lst@ifnolol}
+\def\lst@nololtrue{\let\lst@ifnolol\iftrue}
+\let\lst@ifnolol\iffalse % init
+%    \end{macrocode}
+% \end{lstkey}
+%
+%
+% \subsection{Floats, boxes and captions}
+%
+% \begin{lstkey}{captionpos}
+% \begin{lstkey}{abovecaptionskip}
+% \begin{lstkey}{belowcaptionskip}
+% \begin{lstkey}{label}
+% \begin{lstkey}{title}
+% \begin{lstkey}{caption}
+% Some keys and \ldots
+%    \begin{macrocode}
+\lst@Key{captionpos}{t}{\def\lst@captionpos{#1}}
+\lst@Key{abovecaptionskip}\smallskipamount{\def\lst@abovecaption{#1}}
+\lst@Key{belowcaptionskip}\smallskipamount{\def\lst@belowcaption{#1}}
+%    \end{macrocode}
+% \lsthelper{Rolf~Niepraschk}{2000/01/10}{key: title} proposed \keyname{title}.
+%    \begin{macrocode}
+\lst@Key{label}\relax{\def\lst@label{#1}}
+\lst@Key{title}\relax{\def\lst@title{#1}\let\lst@caption\relax}
+\lst@Key{caption}\relax{\lstKV@OptArg[{#1}]{#1}%
+    {\def\lst@caption{##2}\def\lst@@caption{##1}}%
+     \let\lst@title\@empty}
+\lst@AddToHookExe{TextStyle}
+    {\let\lst@caption\@empty \let\lst@@caption\@empty
+     \let\lst@title\@empty \let\lst@label\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\thelstlisting}
+% \begin{macro}{\lstlistingname}
+% \ldots\space and how the caption numbers look like. I switched to
+% |\@ifundefined| (instead of |\ifx| |\@undefined|) after an error report from
+% \lsthelper{Denis~Girou}{1999/07/26}{incompatible if hyperref loaded before
+% listings}.
+%    \begin{macrocode}
+\@ifundefined{thechapter}
+    {\newcounter{lstlisting}
+     \renewcommand\thelstlisting{\@arabic\c@lstlisting}}
+    {\newcounter{lstlisting}[chapter]
+     \renewcommand\thelstlisting
+         {\ifnum \c@chapter>\z@ \thechapter.\fi \@arabic\c@lstlisting}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@UserCommand\lstlistingname{Listing}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@MakeCaption}
+% Before defining this macro, we ensure that some other control sequences
+% exist---\lsthelper{Adam~Prugel-Bennett}{2001/02/19}{\abovecaptionskip
+% undefined in slides.cls} reported problems with the slides document class.
+% In particular we allocate above- and belowcaption skip registers and define
+% |\@makecaption|, which is an exact copy of the definition in the article
+% class. To respect the LPPL: you should have a copy of this class on your
+% \TeX\ system or you can obtain a copy from the CTAN, e.g.~from the ftp-server
+% \texttt{ftp.dante.de}.
+%    \begin{macrocode}
+\@ifundefined{abovecaptionskip}
+{\newskip\abovecaptionskip
+ \newskip\belowcaptionskip
+ \long\def\@makecaption#1#2{%
+   \vskip\abovecaptionskip
+   \sbox\@tempboxa{#1: #2}%
+   \ifdim \wd\@tempboxa >\hsize
+     #1: #2\par
+   \else
+     \global \@minipagefalse
+     \hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%
+   \fi
+   \vskip\belowcaptionskip}%
+}{}
+%    \end{macrocode}
+% We |\refstepcounter| the listing counter if and only if |\lst@@caption| is
+% not empty. Otherwise we ensure correct hyper-references,
+% see |\lst@HRefStepCounter| below. We do this once a listing, namely at the
+% top.
+%    \begin{macrocode}
+\def\lst@MakeCaption#1{%
+    \ifx #1t%
+        \ifx\lst@@caption\@empty\expandafter\lst@HRefStepCounter \else
+                                \expandafter\refstepcounter
+        \fi {lstlisting}%
+        \ifx\lst@label\@empty\else \label{\lst@label}\fi
+    \fi
+%    \end{macrocode}
+% We make a caption if and only if the caption is not empty and the user
+% requested a caption at |#1| $\in\{\mathtt t,\mathtt b\}$. To disallow
+% pagebreaks between caption (or title) and a listing, we redefine the
+% primitive |\vskip| locally to insert |\nobreak|s. Note that we allow
+% pagebreaks in front of a `top-caption' and after a `bottom-caption'.
+% \begin{TODO}
+% This redefinition is a brute force method. Is there a better one?
+% \end{TODO}
+%    \begin{macrocode}
+    \ifx\lst@caption\@empty\else
+        \lst@IfSubstring #1\lst@captionpos
+            {\begingroup \let\@@vskip\vskip
+             \def\vskip{\afterassignment\lst@vskip \@tempskipa}%
+             \def\lst@vskip{\nobreak\@@vskip\@tempskipa\nobreak}%
+             \par\normalsize\normalfont
+             \ifx #1t\allowbreak \fi
+             \ifx\lst@title\@empty
+                 \expandafter\@makecaption
+             \else
+                 \expandafter\lst@maketitle
+             \fi
+                {\noindent\lstlistingname
+                 \ifx\lst@@caption\@empty\else~\thelstlisting\fi}%
+                \lst@caption
+             \ifx #1b\allowbreak \fi
+             \endgroup}{}%
+    \fi}
+%    \end{macrocode}
+% I've inserted |\normalsize| after a bug report from
+% \lsthelper{Andreas~Matthias}{2000/01/04}{caption affected by basicstyle}
+% and moved it in front of |\@makecaption| after receiving another from
+% \lsthelper{Sonja~Weidmann}{2000/02/01}{listings and caption packages
+% not compatible}.
+% \end{macro}
+%
+% \begin{macro}{\lst@maketitle}
+% This definition depends on the existence of the \packagename{caption}
+% package. The default gobbles the delimiter and ignores spaces. Note that
+% this definition isn't compatible with all packages and classes.
+%    \begin{macrocode}
+\def\lst@maketitle#1#2{\@makecaption\lst@title@dropdelim\lst@title}
+\def\lst@title@dropdelim#1{\ignorespaces}
+%    \end{macrocode}
+% For \packagename{caption2} we modify the caption style locally and make this
+% style \ldots
+%    \begin{macrocode}
+\AtBeginDocument{%
+\@ifundefined{caption@make}{}{%
+\def\lst@maketitle#1#2{%
+    \begingroup
+    \captionstyle{lsttitle}\@makecaption{}\lst@title
+    \endgroup}
+%    \end{macrocode}
+% \ldots\space print only the title = caption text.
+%    \begin{macrocode}
+\newcaptionstyle{lsttitle}{\caption@make{lsttitle}}%
+\def\caption@@@lsttitle{\captiontext\par}%
+}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@HRefStepCounter}
+% This macro sets the listing number to a negative value since the user
+% shouldn't refer to such a listing. If the \packagename{hyperref} package
+% is present, we use `lstlisting' (argument from above) to hyperref to.
+% The groups have been added to prevent other packages (namely
+% \packagename{tabularx}) from reading the locally changed counter
+% and writing it back globally. Thanks to \lsthelper{Michael~Niedermair}
+% {2001/09/18}{strange numbering of listings} for the report. Unfortunately
+% this localization led to another bug, see |\theHlstnumber|.
+%    \begin{macrocode}
+\def\lst@HRefStepCounter#1{%
+    \begingroup
+    \c@lstlisting\lst@neglisting
+    \advance\c@lstlisting\m@ne \xdef\lst@neglisting{\the\c@lstlisting}%
+    \ifx\hyper@refstepcounter\@undefined\else
+        \hyper@refstepcounter{#1}%
+    \fi
+    \endgroup}
+\gdef\lst@neglisting{\z@}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{boxpos}
+% \begin{macro}{\lst@boxtrue}
+% sets the vertical alignment of the (possibly) used box respectively indicates
+% that a box is used.
+%    \begin{macrocode}
+\lst@Key{boxpos}{c}{\def\lst@boxpos{#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@boxtrue{\let\lst@ifbox\iftrue}
+\let\lst@ifbox\iffalse
+%    \end{macrocode}
+% \end{macro}\end{lstkey}
+%
+% \begin{lstkey}{float}
+% \begin{lstkey}{floatplacement}
+% Matthias Zenger asked for double-column floats, so I've inserted some code.
+% We first check for a star \ldots
+%    \begin{macrocode}
+\lst@Key{float}\relax[\lst@floatplacement]{%
+    \def\lst@next{\@ifstar{\let\lst@beginfloat\@dblfloat
+                           \let\lst@endfloat\end@dblfloat
+                           \lst@KFloat}%
+                          {\let\lst@beginfloat\@float
+                           \let\lst@endfloat\end@float
+                           \lst@KFloat}}
+    \edef\lst@float{#1}%
+    \expandafter\lst@next\lst@float\relax}
+%    \end{macrocode}
+% \ldots\ and define |\lst@float|.
+%    \begin{macrocode}
+\def\lst@KFloat#1\relax{%
+    \ifx\@empty#1\@empty
+        \let\lst@float\lst@floatplacement
+    \else
+        \def\lst@float{#1}%
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{floatplacement}{tbp}{\def\lst@floatplacement{#1}}
+\lst@AddToHook{PreSet}{\let\lst@float\relax}
+\lst@AddToHook{TextStyle}{\let\lst@float\relax}
+%    \end{macrocode}
+% The float type |\ftype@lstlisting| is set according to whether the
+% \packagename{float} package is loaded and whether \texttt{figure} and
+% \texttt{table} floats are defined. This is done at |\begin{document}| to
+% make the code independent of the order of package loading.
+%    \begin{macrocode}
+\AtBeginDocument{%
+\@ifundefined{c@float@type}%
+    {\edef\ftype@lstlisting{\ifx\c@figure\@undefined 1\else 4\fi}}
+    {\edef\ftype@lstlisting{\the\c@float@type}%
+     \addtocounter{float@type}{\value{float@type}}}%
+}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+%
+% \subsection{Init and EOL}
+%
+% \begin{lstkey}{aboveskip}
+% \begin{lstkey}{belowskip}
+% We define and initialize these keys and prevent extra spacing for `inline'
+% listings (in particular if \packagename{fancyvrb} interface is active,
+% problem reported by \lsthelper{Denis~Girou}{1999/08/03}{wrong spacing}).
+%    \begin{macrocode}
+\lst@Key{aboveskip}\medskipamount{\def\lst@aboveskip{#1}}
+\lst@Key{belowskip}\medskipamount{\def\lst@belowskip{#1}}
+\lst@AddToHook{TextStyle}
+    {\let\lst@aboveskip\z@ \let\lst@belowskip\z@}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}
+%
+% \begin{lstkey}{everydisplay}
+% \begin{macro}{\lst@ifdisplaystyle}
+% Some things depend on display-style listings.
+%    \begin{macrocode}
+\lst@Key{everydisplay}{}{\def\lst@EveryDisplay{#1}}
+\lst@AddToHook{TextStyle}{\let\lst@ifdisplaystyle\iffalse}
+\lst@AddToHook{DisplayStyle}{\let\lst@ifdisplaystyle\iftrue}
+\let\lst@ifdisplaystyle\iffalse
+%    \end{macrocode}
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@Init}
+% Begin a float if requested.
+%    \begin{macrocode}
+\def\lst@Init#1{%
+    \begingroup
+    \ifx\lst@float\relax\else
+        \edef\@tempa{\noexpand\lst@beginfloat{lstlisting}[\lst@float]}%
+        \expandafter\@tempa
+    \fi
+%    \end{macrocode}
+% In restricted horizontal \TeX\ mode we switch to |\lst@boxtrue|.
+% In that case we make appropriate box(es) around the listing.
+%    \begin{macrocode}
+    \ifhmode\ifinner \lst@boxtrue \fi\fi
+    \lst@ifbox
+        \lsthk@BoxUnsafe
+        \hbox to\z@\bgroup
+             $\if t\lst@boxpos \vtop
+        \else \if b\lst@boxpos \vbox
+        \else \vcenter \fi\fi
+        \bgroup \par\noindent
+    \else
+        \lst@ifdisplaystyle
+            \lst@EveryDisplay
+            \par\penalty-50\relax
+            \vspace\lst@aboveskip
+        \fi
+    \fi
+%    \end{macrocode}
+% Moved |\vspace| after |\par|---or we can get an empty line atop listings.
+% Bug reported by \lsthelper{Jim~Hefferon}{1999/08/27}{empty line before
+% listings with |\lstinputlisting|}.
+%
+% Now make the top caption.
+%    \begin{macrocode}
+    \normalbaselines
+    \abovecaptionskip\lst@abovecaption\relax
+    \belowcaptionskip\lst@belowcaption\relax
+    \lst@MakeCaption t%
+%    \end{macrocode}
+% Some initialization.
+% I removed |\par\nointerlineskip| |\normalbaselines| after bug report from
+% \lsthelper{Jim~Hefferon}{1999/08/23}{bad vertical space after lstlisting}.
+% He reported the same problem as Aidan Philip Heerdegen (see below), but I
+% immediately saw the bug here since Jim used |\parskip|$\,\neq0$.
+%    \begin{macrocode}
+    \lsthk@PreInit \lsthk@Init
+    \lst@ifdisplaystyle
+        \global\let\lst@ltxlabel\@empty
+        \if@inlabel
+            \lst@ifresetmargins
+                \leavevmode
+            \else
+                \xdef\lst@ltxlabel{\the\everypar}%
+                \lst@AddTo\lst@ltxlabel{%
+                    \global\let\lst@ltxlabel\@empty
+                    \everypar{\lsthk@EveryLine\lsthk@EveryPar}}%
+            \fi
+        \fi
+        \everypar\expandafter{\lst@ltxlabel
+                              \lsthk@EveryLine\lsthk@EveryPar}%
+    \else
+        \everypar{}\let\lst@NewLine\@empty
+    \fi
+    \lsthk@InitVars \lsthk@InitVarsBOL
+%    \end{macrocode}
+% The end of line character chr(13)=|^^M| controls the processing, see the
+% definition of |\lst@MProcessListing| below.
+% The argument |#1| is either |\relax| or |\lstenv@backslash|.
+%    \begin{macrocode}
+    \lst@Let{13}\lst@MProcessListing
+    \let\lst@Backslash#1%
+    \lst@EnterMode{\lst@Pmode}{\lst@SelectCharTable}}
+%    \end{macrocode}
+% Note: From version 0.19 on `listing processing' is implemented as an internal
+% mode, namely a mode with special character table.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}
+    {\rightskip\z@ \leftskip\z@ \parfillskip=\z@ plus 1fil
+     \let\par\@@par}
+\lst@AddToHook{EveryLine}{}% init
+\lst@AddToHook{EveryPar}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{showlines}
+% lets the user control whether empty lines at the end of a listing are
+% printed. But you know that if you've read the User's guide.
+%    \begin{macrocode}
+\lst@Key{showlines}f[t]{\lstKV@SetIf{#1}\lst@ifshowlines}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DeInit}
+% Output the remaining characters and update all things. First I missed to
+% to use |\lst@ifdisplaystyle| here, but then \lsthelper{KP~Gores}{2001/07/11}
+% {\csname{par} after each \lstinline} reported a problem.
+%    \begin{macrocode}
+\def\lst@DeInit{%
+    \lst@XPrintToken \lst@EOLUpdate
+    \global\advance\lst@newlines\m@ne
+    \lst@ifshowlines
+        \lst@DoNewLines
+    \else
+        \setbox\@tempboxa\vbox{\lst@DoNewLines}%
+    \fi
+    \lst@ifdisplaystyle \par\removelastskip \fi
+    \everypar{}\lsthk@ExitVars \lsthk@DeInit
+%    \end{macrocode}
+% Making the bottom caption.
+%    \begin{macrocode}
+    \lst@MakeCaption b%
+%    \end{macrocode}
+% Close the boxes if necessary and make a rule to get the right width.
+% I added the |\par\nointerlineskip| (and removed |\nointerlineskip| later
+% again) after receiving a bug report from \lsthelper{Aidan~Philip~Heerdegen}
+% {1999/07/23}{wrong vertical spacing}. |\everypar{}| is due to a bug report
+% from \lsthelper{Sonja~Weidmann}{2000/02/01}{listings and caption packages
+% not compatible}.
+%    \begin{macrocode}
+    \lst@ifbox
+        \egroup $\hss \egroup
+        \vrule\@width\lst@maxwidth\@height\z@\@depth\z@
+    \else
+        \lst@ifdisplaystyle
+            \par\penalty-50\vspace\lst@belowskip
+        \fi
+    \fi
+%    \end{macrocode}
+% End the float if necessary.
+%    \begin{macrocode}
+    \ifx\lst@float\relax\else
+        \expandafter\lst@endfloat
+    \fi
+    \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@maxwidth}
+% is to be allocated, initialized and updated.
+%    \begin{macrocode}
+\newdimen\lst@maxwidth % \global
+\lst@AddToHook{InitVars}{\global\lst@maxwidth\z@}
+\lst@AddToHook{InitVarsEOL}
+    {\ifdim\lst@currlwidth>\lst@maxwidth
+         \global\lst@maxwidth\lst@currlwidth
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EOLUpdate}
+% What do you think this macro does?
+%    \begin{macrocode}
+\def\lst@EOLUpdate{\lsthk@EOL \lsthk@InitVarsEOL}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MProcessListing}
+% This is what we have to do at EOL while processing a listing.
+% We output all remaining characters and update the variables.
+% We call |\lst@EndProcessListing| if the next line number is greater than the
+% last printing line.
+% Finally we gobble characters to come to the beginning of the next line.
+%    \begin{macrocode}
+\def\lst@MProcessListing{%
+    \lst@XPrintToken \lst@EOLUpdate \lsthk@InitVarsBOL
+    \global\advance\lst@lineno\@ne
+    \ifnum \lst@lineno>\lst@lastline
+        \expandafter\lst@EndProcessListing
+    \else
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndProcessListing}
+% Default definition is |\endinput|.
+% This works for |\lstinputlisting|.
+%    \begin{macrocode}
+\let\lst@EndProcessListing\endinput
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{gobble}
+% The key sets the number of characters to gobble each line.
+%    \begin{macrocode}
+\lst@Key{gobble}{0}{\def\lst@gobble{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BOLGobble}
+% If the number is positive, we set a temporary counter and start a loop.
+%    \begin{macrocode}
+\def\lst@BOLGobble{%
+    \ifnum\lst@gobble>\z@
+        \@tempcnta\lst@gobble\relax
+        \expandafter\lst@BOLGobble@
+	\fi}
+%    \end{macrocode}
+% A nonpositive number terminates the loop (by not continuing).
+% Note: This is not the macro just used in |\lst@BOLGobble|.
+%    \begin{macrocode}
+\def\lst@BOLGobble@@{%
+    \ifnum\@tempcnta>\z@
+        \expandafter\lst@BOLGobble@
+    \fi}
+%    \end{macrocode}
+% If we gobble a backslash, we have to look whether this backslash ends an
+% environment. Whether the coming characters equal e.g.~|end{lstlisting}|,
+% we either end the environment or insert all just eaten characters after the
+% `continue loop' macro.
+%    \begin{macrocode}
+\def\lstenv@BOLGobble@@{%
+    \lst@IfNextChars\lstenv@endstring{\lstenv@End}%
+    {\advance\@tempcnta\m@ne \expandafter\lst@BOLGobble@@\lst@eaten}}
+%    \end{macrocode}
+% Now comes the loop: if we read |\relax|, EOL or FF, the next operation is
+% exactly the same token.
+%    \begin{macrocode}
+\def\lst@BOLGobble@#1{%
+    \let\lst@next#1%
+    \ifx \lst@next\relax\else
+    \ifx \lst@next\lst@MProcessListing\else
+    \ifx \lst@next\lst@ProcessFormFeed\else
+%    \end{macrocode}
+% Otherwise we use one of the two submacros.
+%    \begin{macrocode}
+    \ifx \lst@next\lstenv@backslash
+        \let\lst@next\lstenv@BOLGobble@@
+    \else
+        \let\lst@next\lst@BOLGobble@@
+%    \end{macrocode}
+% Now we really gobble characters. A tabulator decreases the temporary counter
+% by |\lst@tabsize| (and deals with remaining amounts, if necessary), \ldots
+%    \begin{macrocode}
+        \ifx #1\lst@ProcessTabulator
+            \advance\@tempcnta-\lst@tabsize\relax
+            \ifnum\@tempcnta<\z@
+                \lst@length-\@tempcnta \lst@PreGotoTabStop
+            \fi
+%    \end{macrocode}
+% \ldots\space whereas any other character decreases the counter by one.
+%    \begin{macrocode}
+        \else
+            \advance\@tempcnta\m@ne
+        \fi
+    \fi \fi \fi \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{List of listings}
+%
+% \begin{lstkey}{name}
+% \begin{macro}{\lstname}
+% \begin{macro}{\lst@name}
+% \begin{macro}{\lst@intname}
+% Each pretty-printing command values |\lst@intname| before setting any keys.
+%    \begin{macrocode}
+\lst@Key{name}\relax{\def\lst@intname{#1}}
+\lst@AddToHookExe{PreSet}{\global\let\lst@intname\@empty}
+\lst@AddToHook{PreInit}{%
+    \let\lst@arg\lst@intname \lst@ReplaceIn\lst@arg\lst@filenamerpl
+    \global\let\lst@name\lst@arg \global\let\lstname\lst@name}
+%    \end{macrocode}
+% Use of |\lst@ReplaceIn| removes a bug first reported by
+% \lsthelper{Magne~Rudshaug}{1998/01/09}{_ and list of listings}.
+% Here is the replacement list.
+%    \begin{macrocode}
+\def\lst@filenamerpl{_\textunderscore $\textdollar -\textendash}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\l@lstlisting}
+% prints one `lol' line.
+%    \begin{macrocode}
+\def\l@lstlisting#1#2{\@dottedtocline{1}{1.5em}{2.3em}{#1}{#2}}
+%    \end{macrocode}
+% We make a `lol' entry if the name is neither empty nor a single space.
+% But we test |\lst@|(|@|)|caption| and |\lst@ifnolol| first.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifnolol\else
+         \ifx\lst@@caption\@empty
+             \ifx\lst@caption\@empty
+                 \ifx\lst@intname\@empty \else \def\lst@temp{ }%
+                 \ifx\lst@intname\lst@temp \else
+                     \addcontentsline{lol}{lstlisting}\lst@name
+                 \fi\fi
+             \fi
+        \else
+             \addcontentsline{lol}{lstlisting}%
+                 {\protect\numberline{\thelstlisting}\lst@@caption}%
+        \fi
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstlistlistingname}
+% contains simply the header name.
+%    \begin{macrocode}
+\lst@UserCommand\lstlistlistingname{Listings}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstlistoflistings}
+% We make local adjustments and call |\tableofcontents|. This way,
+% redefinitions of that macro (e.g.~without any |\MakeUppercase| inside)
+% also take effect on the list of listings.
+%    \begin{macrocode}
+\lst@UserCommand\lstlistoflistings{\bgroup
+    \let\contentsname\lstlistlistingname
+    \let\lst@temp\@starttoc \def\@starttoc##1{\lst@temp{lol}}%
+    \tableofcontents \egroup}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Inline listings}\label{iInlineListings}
+%
+% \begin{macro}{\lstinline}
+% In addition to |\lsthk@PreSet|, we use |boxpos=b| and flexiblecolumns.
+% I've inserted |\leavevmode| after bug report from \lsthelper{Michael~Weber}
+% {1999/12/16}{wrong spacing in list environments}. \lsthelper{Olivier~Lecarme}
+% {2001/07/30}{inconsistent `break' when \lstinline is used inside caption}
+% reported a problem which has gone after removing |\let| |\lst@newlines|
+% |\@empty| (now |\lst@newlines| is a counter!). Unfortunately I don't know
+% the reason for inserting this code some time ago! At the end of the macro we
+% check the delimiter.
+%    \begin{macrocode}
+\newcommand\lstinline[1][]{%
+    \leavevmode\bgroup % \hbox\bgroup --> \bgroup
+      \def\lst@boxpos{b}%
+      \lsthk@PreSet\lstset{flexiblecolumns,#1}%
+      \lsthk@TextStyle
+      \@ifnextchar\bgroup{\afterassignment\lst@InlineG \let\@let@token}%
+                         \lstinline@}
+\def\lstinline@#1{%
+    \lst@Init\relax
+    \lst@IfNextCharActive{\lst@InlineM#1}{\lst@InlineJ#1}}
+\lst@AddToHook{TextStyle}{}% init
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@inlinechars}
+\global\let\lst@inlinechars\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InlineM}
+% \begin{macro}{\lst@InlineJ}
+% treat the cases of `normal' inlines and inline listings inside an argument.
+% In the first case the given character ends the inline listing and EOL within
+% such a listing immediately ends it and produces an error message.
+%    \begin{macrocode}
+\def\lst@InlineM#1{\gdef\lst@inlinechars{%
+    \lst@Def{`#1}{\lst@DeInit\egroup\global\let\lst@inlinechars\@empty}%
+    \lst@Def{13}{\lst@DeInit\egroup \global\let\lst@inlinechars\@empty
+        \PackageError{Listings}{lstinline ended by EOL}\@ehc}}%
+    \lst@inlinechars}
+%    \end{macrocode}
+% In the other case we get all characters up to |#1|, make these characters
+% active, execute (typeset) them and end the listing (all via temporary macro).
+% That's all about it.
+%    \begin{macrocode}
+\def\lst@InlineJ#1{%
+    \def\lst@temp##1#1{%
+        \let\lst@arg\@empty \lst@InsideConvert{##1}\lst@arg
+        \lst@DeInit\egroup}%
+    \lst@temp}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@InlineG}
+% is experimental.
+%    \begin{macrocode}
+\def\lst@InlineG{%
+    \lst@Init\relax
+    \lst@IfNextCharActive{\lst@InlineM\}}%
+                         {\let\lst@arg\@empty \lst@InlineGJ}}
+\def\lst@InlineGJ{\futurelet\@let@token\lst@InlineGJTest}
+\def\lst@InlineGJTest{%
+    \ifx\@let@token\egroup
+        \afterassignment\lst@InlineGJEnd
+        \expandafter\let\expandafter\@let@token
+    \else
+        \ifx\@let@token\@sptoken
+            \let\lst@next\lst@InlineGJReadSp
+        \else
+            \let\lst@next\lst@InlineGJRead
+        \fi
+        \expandafter\lst@next
+    \fi}
+\def\lst@InlineGJEnd{\lst@arg\lst@DeInit\egroup}
+\def\lst@InlineGJRead#1{%
+    \lccode`\~=`#1\lowercase{\lst@lAddTo\lst@arg~}%
+    \lst@InlineGJ}
+\def\lst@InlineGJReadSp#1{%
+    \lccode`\~=`\ \lowercase{\lst@lAddTo\lst@arg~}%
+    \lst@InlineGJ#1}
+%    \end{macrocode}
+%    \begin{macrocode}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{The input command}\label{iTheInputCommand}
+%
+% \begin{macro}{\lstinputlisting}
+% inputs the listing or asks the user for a new file name.
+%    \begin{macrocode}
+\newcommand\lstinputlisting[2][]{%
+    \def\lst@set{#1}%
+    \IfFileExists{#2}%
+        {\lst@InputListing{#2}}%
+        {\filename@parse{#2}%
+         \edef\reserved@a{\noexpand\lst@MissingFileError
+             {\filename@area\filename@base}%
+             {\ifx\filename@ext\relax tex\else\filename@ext\fi}}%
+         \reserved@a}%
+    \@doendpe \@newlistfalse \ignorespaces}
+%    \end{macrocode}
+% We use |\@doendpe| to remove indention at the beginning of the next
+% line---except there is an empty line after |\lstinputlisting|. Bug was
+% reported by \lsthelper{David~John~Evans}{1999/06/08}{indention after
+% listings} and \lsthelper{David~Carlisle}{1999/06/08}{LaTeX `display
+% environment' code} pointed me to the solution.
+% \end{macro}
+%
+% \begin{macro}{\lst@MissingFileError}
+% is a derivation of \LaTeX's |\@missingfileerror|:
+%    \begin{macrocode}
+\def\lst@MissingFileError#1#2{%
+    \typeout{^^J! Package Listings Error: File `#1.#2' not found.^^J^^J%
+        Type X to quit or <RETURN> to proceed,^^J%
+        or enter new name. (Default extension: #2)^^J}%
+    \message{Enter file name: }%
+    {\endlinechar\m@ne \global\read\m@ne to\@gtempa}%
+%    \end{macrocode}
+% Typing |x| or |X| exits.
+%    \begin{macrocode}
+    \ifx\@gtempa\@empty \else
+        \def\reserved@a{x}\ifx\reserved@a\@gtempa\batchmode\@@end\fi
+        \def\reserved@a{X}\ifx\reserved@a\@gtempa\batchmode\@@end\fi
+%    \end{macrocode}
+% In all other cases we try the new file name.
+%    \begin{macrocode}
+        \filename@parse\@gtempa
+        \edef\filename@ext{%
+            \ifx\filename@ext\relax#2\else\filename@ext\fi}%
+        \edef\reserved@a{\noexpand\IfFileExists %
+                {\filename@area\filename@base.\filename@ext}%
+            {\noexpand\lst@InputListing %
+                {\filename@area\filename@base.\filename@ext}}%
+            {\noexpand\lst@MissingFileError
+                {\filename@area\filename@base}{\filename@ext}}}%
+        \expandafter\reserved@a %
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifdraft}
+% makes use of |\lst@ifprint|.
+%    \begin{macrocode}
+\let\lst@ifdraft\iffalse
+\DeclareOption{draft}{\let\lst@ifdraft\iftrue}
+\lst@AddToHook{PreSet}
+    {\lst@ifdraft
+         \let\lst@ifprint\iffalse
+         \@gobbletwo\fi\fi
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InputListing}
+% The one and only argument is the file name, but we have the `implicit'
+% argument |\lst@set|. Note that |\lst@Init| takes |\relax| as argument.
+%    \begin{macrocode}
+\def\lst@InputListing#1{%
+    \begingroup
+      \lsthk@PreSet \gdef\lst@intname{#1}%
+      \expandafter\lstset\expandafter{\lst@set}%
+      \lsthk@DisplayStyle
+      \lst@Init\relax \let\lst@gobble\z@
+      \lst@SkipToFirst
+      \lst@ifprint \def\lst@next{\input{#1}}%
+             \else \let\lst@next\@empty \fi
+      \lst@next
+      \lst@DeInit
+    \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SkipToFirst}
+% The end of line character either processes the listing or is responsible for
+% dropping lines up to first printing line.
+%    \begin{macrocode}
+\def\lst@SkipToFirst{%
+    \ifnum \lst@lineno<\lst@firstline
+%    \end{macrocode}
+% We drop the input and redefine the end of line characters.
+%    \begin{macrocode}
+        \lst@BeginDropInput\lst@Pmode
+        \lst@Let{13}\lst@MSkipToFirst
+        \lst@Let{10}\lst@MSkipToFirst
+    \else
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MSkipToFirst}
+% We just look whether to drop more lines or to leave the mode which restores
+% the definition of chr(13) and chr(10).
+%    \begin{macrocode}
+\def\lst@MSkipToFirst{%
+    \global\advance\lst@lineno\@ne
+    \ifnum \lst@lineno=\lst@firstline
+        \lst@LeaveMode \global\lst@newlines\z@
+        \lsthk@InitVarsBOL
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{The environment}
+%
+%
+% \subsubsection{Low-level processing}
+%
+% \begin{macro}{\lstenv@DroppedWarning}
+% gives a warning if characters have been dropped.
+%    \begin{macrocode}
+\def\lstenv@DroppedWarning{%
+    \ifx\lst@dropped\@undefined\else
+        \PackageWarning{Listings}{Text dropped after begin of listing}%
+    \fi}
+\let\lst@dropped\@undefined % init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@Process}
+% We execute `|\lstenv@ProcessM|' or |\lstenv@ProcessJ| according to whether we
+% find an active EOL or a nonactive |^^J|.
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\^^M\lowercase{%
+\gdef\lstenv@Process#1{%
+    \ifx~#1%
+%    \end{macrocode}
+% We make no extra |\lstenv@ProcessM| definition since there is nothing to do
+% at all if we've found an active EOL.
+%    \begin{macrocode}
+        \lstenv@DroppedWarning \let\lst@next\lst@SkipToFirst
+    \else\ifx^^J#1%
+        \lstenv@DroppedWarning \let\lst@next\lstenv@ProcessJ
+    \else
+        \let\lst@dropped#1\let\lst@next\lstenv@Process
+    \fi \fi
+    \lst@next}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@ProcessJ}
+% Now comes the horrible scenario: a listing inside an argument. We've
+% already worked in section \ref{iApplicationsTo} for this. Here we must get
+% all characters up to `end environment'. We distinguish the cases `command
+% fashion' and `true environment'.
+%    \begin{macrocode}
+\def\lstenv@ProcessJ{%
+    \let\lst@arg\@empty
+    \ifx\@currenvir\lstenv@name
+        \expandafter\lstenv@ProcessJEnv
+    \else
+%    \end{macrocode}
+% The first case is pretty simple: The code is terminated by
+% |\end|\meta{name of environment}. Thus we expand that control sequence
+% before defining a temporary macro, which gets the listing and does all
+% the rest. Back to the definition of |\lstenv@ProcessJ| we call the
+% temporary macro after expanding |\fi|.
+%    \begin{macrocode}
+        \expandafter\def\expandafter\lst@temp\expandafter##1%
+            \csname end\lstenv@name\endcsname
+                {\lst@InsideConvert{##1}\lstenv@ProcessJ@}%
+        \expandafter\lst@temp
+    \fi}
+%    \end{macrocode}
+% We must append an active backslash and the `end string' to |\lst@arg|. So all
+% (in fact most) other processing won't notice that the code has been inside
+% an argument. But the EOL character is chr(10)=|^^J| now and not chr(13).
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\\\lowercase{%
+\gdef\lstenv@ProcessJ@{%
+    \lst@lExtend\lst@arg
+        {\expandafter\ \expandafter~\lstenv@endstring}%
+    \catcode10=\active \lst@Let{10}\lst@MProcessListing
+%    \end{macrocode}
+% We execute |\lst@arg| to typeset the listing.
+%    \begin{macrocode}
+    \lst@SkipToFirst \lst@arg}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@ProcessJEnv}
+% The `true environment' case is more complicated. We get all characters up to
+% an |\end| and the following argument. If that equals |\lstenv@name|, we have
+% found the end of environment and start typesetting.
+%    \begin{macrocode}
+\def\lstenv@ProcessJEnv#1\end#2{\def\lst@temp{#2}%
+    \ifx\lstenv@name\lst@temp
+        \lst@InsideConvert{#1}%
+        \expandafter\lstenv@ProcessJ@
+    \else
+%    \end{macrocode}
+% Otherwise we append the characters including the eaten |\end| and the eaten
+% argument to current |\lst@arg|. And we look for the end of environment again.
+%    \begin{macrocode}
+        \lst@InsideConvert{#1\\end\{#2\}}%
+        \expandafter\lstenv@ProcessJEnv
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@backslash}
+% Coming to a backslash we either end the listing or process a backslash and
+% insert the eaten characters again.
+%    \begin{macrocode}
+\def\lstenv@backslash{%
+    \lst@IfNextChars\lstenv@endstring
+        {\lstenv@End}%
+        {\expandafter\lsts@backslash \lst@eaten}}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@End}
+% This macro has just been used and terminates a listing environment:
+% We call the `end environment' macro using |\end| or as a command.
+%    \begin{macrocode}
+\def\lstenv@End{%
+    \ifx\@currenvir\lstenv@name
+        \edef\lst@next{\noexpand\end{\lstenv@name}}%
+    \else
+        \def\lst@next{\csname end\lstenv@name\endcsname}%
+    \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{\cs{lstnewenvironment}}
+%
+% \begin{macro}{\lstnewenvironment}
+% Now comes the main command. We define undefined environments only. On the
+% parameter text |#1#2#| (in particular the last sharp) see the paragraph
+% following example 20.5 on page 204 of `The \TeX book'.
+%    \begin{macrocode}
+\lst@UserCommand\lstnewenvironment#1#2#{%
+    \@ifundefined{#1}%
+        {\let\lst@arg\@empty
+         \lst@XConvert{#1}\@nil
+         \expandafter\lstnewenvironment@\lst@arg{#1}{#2}}%
+        {\PackageError{Listings}{Environment `#1' already defined}\@eha
+         \@gobbletwo}}
+\def\@tempa#1#2#3{%
+\gdef\lstnewenvironment@##1##2##3##4##5{%
+    \begingroup
+%    \end{macrocode}
+% A lonely `end environment' produces an error.
+%    \begin{macrocode}
+    \global\@namedef{end##2}{\lstenv@Error{##2}}%
+%    \end{macrocode}
+% The `main' environment macro defines the environment name for later use and
+% calls a submacro getting all arguments. We open a group and make EOL active.
+% This ensures |\@ifnextchar[| not to read characters of the listing---it reads
+% the active EOL instead.
+%    \begin{macrocode}
+    \global\@namedef{##2}{\def\lstenv@name{##2}%
+        \begingroup \catcode\active=\active \csname##2@\endcsname}%
+%    \end{macrocode}
+% The submacro is defined via |\new@command|. We misuse |\l@ngrel@x| to make
+% the definition |\global| and refine \LaTeX's |\@xargdef|.
+%    \begin{macrocode}
+    \let\l@ngrel@x\global
+    \let\@xargdef\lstenv@xargdef
+    \expandafter\new@command\csname##2@\endcsname##3%
+%    \end{macrocode}
+% First we execute |##4|=\meta{begin code}. Then follows the definition of
+% the terminating string (|end{lstlisting}| or |endlstlisting|, for example):
+%    \begin{macrocode}
+        {\lsthk@PreSet ##4%
+         \ifx\@currenvir\lstenv@name
+             \def\lstenv@endstring{#1#2##1#3}%
+         \else
+             \def\lstenv@endstring{#1##1}%
+         \fi
+%    \end{macrocode}
+% We redefine (locally) `end environment' since ending is legal now.
+% Note that the redefinition also works inside a \TeX\ comment line.
+%    \begin{macrocode}
+         \@namedef{end##2}{\lst@DeInit ##5\endgroup
+                          \@doendpe \@ignoretrue}%
+%    \end{macrocode}
+% |\@doendpe| again removes the indention problem.
+% Finally we start the processing.
+%    \begin{macrocode}
+         \lsthk@DisplayStyle
+         \lst@Init\lstenv@backslash
+         \let\lst@EndProcessListing\lstenv@SkipToEnd
+         \lst@ifprint
+             \expandafter\expandafter\expandafter\lstenv@Process
+         \else
+             \expandafter\lstenv@SkipToEnd
+         \fi
+         \lst@insertargs}%
+    \endgroup}%
+}
+\let\lst@arg\@empty \lst@XConvert{end}\{\}\@nil
+\expandafter\@tempa\lst@arg
+\let\lst@insertargs\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@xargdef}
+% This is a derivation of \LaTeX's |\@xargdef|. We expand the submacro's name,
+% use |\gdef| instead of |\def|, and hard code a kind of |\@protected@testopt|.
+%    \begin{macrocode}
+\def\lstenv@xargdef#1{
+    \expandafter\lstenv@xargdef@\csname\string#1\endcsname#1}
+\def\lstenv@xargdef@#1#2[#3][#4]#5{%
+  \@ifdefinable#2{%
+       \gdef#2{%
+          \ifx\protect\@typeset@protect
+            \expandafter\lstenv@testopt
+          \else
+            \@x@protect#2%
+          \fi
+          #1%
+          {#4}}%
+       \@yargdef
+          #1%
+           \tw@
+           {#3}%
+           {#5}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@testopt}
+% The difference between this macro and |\@testopt| is that we temporaryly
+% reset the catcode of the EOL character |^^M| to read the optional argument.
+%    \begin{macrocode}
+\long\def\lstenv@testopt#1#2{%
+  \@ifnextchar[{\catcode\active5\relax \lstenv@testopt@#1}%
+               {#1[{#2}]}}
+\def\lstenv@testopt@#1[#2]{%
+    \catcode\active\active
+    #1[#2]}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@SkipToEnd}
+% We use the temporary definition
+% \begin{itemize}\item[]
+%    |\long\def\lst@temp##1\|\meta{content of \textup{\cs{lstenv@endstring}}}|{\lstenv@End}|
+% \end{itemize}
+% which gobbles all characters up to the end of environment and finishes it.
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\\\lowercase{%
+\gdef\lstenv@SkipToEnd{%
+    \long\expandafter\def\expandafter\lst@temp\expandafter##\expandafter
+        1\expandafter~\lstenv@endstring{\lstenv@End}%
+    \lst@temp}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@Error}
+% is called by a lonely `end environment'.
+%    \begin{macrocode}
+\def\lstenv@Error#1{\PackageError{Listings}{Extra \string\end#1}%
+    {I'm ignoring this, since I wasn't doing a \csname#1\endcsname.}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TestEOLChar}
+% Here we test for the two possible EOL characters.
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\^^M\lowercase{%
+\gdef\lst@TestEOLChar#1{%
+    \def\lst@insertargs{#1}%
+    \ifx ~#1\@empty \else
+    \ifx^^J#1\@empty \else
+        \global\let\lst@intname\lst@insertargs
+        \let\lst@insertargs\@empty
+    \fi \fi}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{environment}{lstlisting}
+% The awkward work is done, the definition is quite easy now. We test whether
+% the user has given the name argument, set the keys, and deal with
+% continued line numbering.
+%    \begin{macrocode}
+\lstnewenvironment{lstlisting}[2][]
+    {\lst@TestEOLChar{#2}%
+     \lstset{#1}%
+     \csname\@lst @SetFirstNumber\endcsname}
+    {\csname\@lst @SaveFirstNumber\endcsname}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{environment}
+%
+%
+% \section{Documentation support}
+%
+% \begin{syntax}
+% \item[0.19]
+%   |\begin{lstsample}|\marg{point list}\marg{left}\marg{right}
+%
+%   \leavevmode\hspace*{-\leftmargini}|\end{lstsample}|
+%
+%       Roughly speaking all material in between this environment is executed
+%       `on the left side' and typeset verbatim on the right. \meta{left} is
+%       executed before the left side is typeset, and similarly \meta{right}
+%       before the right-hand side.
+%
+%       \meta{point list} is used as argument to the \keyname{point} key.
+%       This is a special key used to highlight the keys in the examples.
+%
+% \item[1.0]
+%   |\begin{lstxsample}|\marg{point list}
+%
+%   \leavevmode\hspace*{-\leftmargini}|\end{lstxsample}|
+%
+%       The material in between is (a) added to the left side of the next
+%       \texttt{lstsample} environment and (b) typeset verbatim using the
+%       whole line width.
+%
+% \item[0.21] |\newdocenvironment|\marg{name}\marg{short name}\marg{begin code}\marg{end code}
+%
+%       The \meta{name} environment can be used in the same way as `macro'.
+%       The provided(!) definitions
+%           |\Print|\meta{short name}|Name|
+%       and |\SpecialMain|\meta{short name}|Index|
+%       control printing in the margin and indexing as the defaults
+%       |\PrintMacroName| and |\SpecialMainIndex| do.
+%
+%       This command is used to define the `aspect' and `lstkey' environments.
+%
+%\item[0.21] \texttt{macroargs} environment
+%
+%       This `enumerate' environment uses as labels `|#1| =', `|#2| =',
+%       and so on.
+%
+% \item \texttt{TODO} environment
+% \item \texttt{ALTERNATIVE} environment
+% \item \texttt{REMOVED} environment
+% \item \texttt{OLDDEF} environment
+%
+%       These environments enclose comments on `to do's', alternatives and
+%       removed or old definitions.
+%
+% \item[0.21] |\lstscanlanguages|\meta{list macro}\marg{input files}\marg{don't input}
+%
+%       scans \marg{input files}$\setminus$\marg{don't input} for language
+%       definitions. The available languages are stored in \meta{list macro}
+%       using the form \meta{language}|(|\meta{dialtect}|),|.
+%
+% \item[0.21] |\lstprintlanguages|\meta{list macro}
+%
+%       prints the languages in two column format.
+% \end{syntax}
+% and a lot of more simple commands.
+%
+%
+% \subsection{Required packages}
+%
+% Most of the `required' packages are optional.
+%    \begin{macrocode}
+%<*doc>
+\let\lstdoc@currversion\fileversion
+\RequirePackage[writefile]{listings}[2002/04/01]
+\newif\iffancyvrb \IfFileExists{fancyvrb.sty}{\fancyvrbtrue}{}
+\newif\ifcolor \IfFileExists{color.sty}{\colortrue}{}
+\newif\ifhyper \@ifundefined{pdfoutput}{}
+    {\IfFileExists{hyperref.sty}{\hypertrue}{}}
+\newif\ifalgorithmic \IfFileExists{algorithmic.sty}{\algorithmictrue}{}
+\iffancyvrb \RequirePackage{fancyvrb}\fi
+\ifhyper \RequirePackage[colorlinks]{hyperref}\else
+    \def\href#1{\texttt}\fi
+\ifcolor \RequirePackage{color}\fi
+\ifalgorithmic \RequirePackage{algorithmic}\fi
+\RequirePackage{nameref}
+\renewcommand\ref{\protect\T@ref}
+\renewcommand\pageref{\protect\T@pageref}
+%    \end{macrocode}
+%
+%
+% \subsection{Environments for notes}
+%
+% \begin{macro}{\lst@BeginRemark}
+% \begin{macro}{\lst@EndRemark}
+% We begin with two simple definitions \ldots
+%    \begin{macrocode}
+\def\lst@BeginRemark#1{%
+    \begin{quote}\topsep0pt\let\small\footnotesize\small#1:}
+\def\lst@EndRemark{\end{quote}}
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{environment}{TODO}
+% \begin{environment}{ALTERNATIVE}
+% \begin{environment}{REMOVED}
+% \begin{environment}{OLDDEF}
+% \ldots\space used to define some environments.
+%    \begin{macrocode}
+\newenvironment{TODO}
+    {\lst@BeginRemark{To do}}{\lst@EndRemark}
+\newenvironment{ALTERNATIVE}
+    {\lst@BeginRemark{Alternative}}{\lst@EndRemark}
+\newenvironment{REMOVED}
+    {\lst@BeginRemark{Removed}}{\lst@EndRemark}
+\newenvironment{OLDDEF}
+    {\lst@BeginRemark{Old definition}}{\lst@EndRemark}
+%    \end{macrocode}
+% \end{environment}\end{environment}\end{environment}\end{environment}
+%
+% \begin{environment}{advise}
+% \begin{macro}{\advisespace}
+% The environment uses |\@listi|.
+%    \begin{macrocode}
+\def\advise{\par\list\labeladvise
+    {\advance\linewidth\@totalleftmargin
+     \@totalleftmargin\z@
+     \@listi
+     \let\small\footnotesize \small\sffamily
+     \parsep \z@ \@plus\z@ \@minus\z@
+     \topsep6\p@ \@plus1\p@\@minus2\p@
+     \def\makelabel##1{\hss\llap{##1}}}}
+\let\endadvise\endlist
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\advisespace{\hbox{}\qquad}
+\def\labeladvise{$\to$}
+%    \end{macrocode}
+% \end{macro}
+% \end{environment}
+%
+% \begin{environment}{syntax}
+% \begin{macro}{\syntaxbreak}
+% \begin{macro}{\syntaxnewline}
+% \begin{macro}{\syntaxor}
+% This environment uses |\list| with a special |\makelabel|, \ldots
+%    \begin{macrocode}
+\newenvironment{syntax}
+   {\list{}{\itemindent-\leftmargin
+    \def\makelabel##1{\hss\lst@syntaxlabel##1,,,,\relax}}}
+   {\endlist}
+%    \end{macrocode}
+% \ldots\ which is defined here. The comma separated items are placed as
+% needed.
+%    \begin{macrocode}
+\def\lst@syntaxlabel#1,#2,#3,#4\relax{%
+    \llap{\scriptsize\itshape#3}%
+    \def\lst@temp{#2}%
+    \expandafter\lst@syntaxlabel@\meaning\lst@temp\relax
+    \rlap{\hskip-\itemindent\hskip\itemsep\hskip\linewidth
+          \llap{\ttfamily\lst@temp}\hskip\labelwidth
+          \def\lst@temp{#1}%
+          \ifx\lst@temp\lstdoc@currversion#1\fi}}
+\def\lst@syntaxlabel@#1>#2\relax
+    {\edef\lst@temp{\zap@space#2 \@empty}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newcommand*\syntaxnewline{\newline\hbox{}\kern\labelwidth}
+\newcommand*\syntaxor{\qquad or\qquad}
+\newcommand*\syntaxbreak
+    {\hfill\kern0pt\discretionary{}{\kern\labelwidth}{}}
+\let\syntaxfill\hfill
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{environment}
+%
+% \begin{macro}{\alternative}
+% iterates down the list and inserts vertical rule(s).
+%    \begin{macrocode}
+\def\alternative#1{\lst@true \alternative@#1,\relax,}
+\def\alternative@#1,{%
+    \ifx\relax#1\@empty
+        \expandafter\@gobble
+    \else
+        \ifx\@empty#1\@empty\else
+            \lst@if \lst@false \else $\vert$\fi
+            \textup{\texttt{#1}}%
+        \fi
+    \fi
+    \alternative@}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Extensions to \textsf{doc}}
+%
+% \begin{macro}{\m@cro@}
+% We need a slight modification of \packagename{doc}'s internal macro.
+% The former argument |#2| has become |#3|. This change is not marked below.
+% The second argument is now \meta{short name}.
+%    \begin{macrocode}
+\long\def\m@cro@#1#2#3{\endgroup \topsep\MacroTopsep \trivlist
+  \edef\saved@macroname{\string#3}%
+  \def\makelabel##1{\llap{##1}}%
+  \if@inlabel
+    \let\@tempa\@empty \count@\macro@cnt
+    \loop \ifnum\count@>\z@
+      \edef\@tempa{\@tempa\hbox{\strut}}\advance\count@\m@ne \repeat
+    \edef\makelabel##1{\llap{\vtop to\baselineskip
+                               {\@tempa\hbox{##1}\vss}}}%
+    \advance \macro@cnt \@ne
+  \else  \macro@cnt\@ne  \fi
+  \edef\@tempa{\noexpand\item[%
+     #1%
+       \noexpand\PrintMacroName
+     \else
+%    \end{macrocode}
+% The next line has been modified.
+%    \begin{macrocode}
+       \expandafter\noexpand\csname Print#2Name\endcsname % MODIFIED
+     \fi
+     {\string#3}]}%
+  \@tempa
+  \global\advance\c@CodelineNo\@ne
+   #1%
+      \SpecialMainIndex{#3}\nobreak
+      \DoNotIndex{#3}%
+   \else
+%    \end{macrocode}
+% Ditto.
+%    \begin{macrocode}
+      \csname SpecialMain#2Index\endcsname{#3}\nobreak % MODIFIED
+   \fi
+  \global\advance\c@CodelineNo\m@ne
+  \ignorespaces}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\macro}
+% \begin{macro}{\environment}
+% These two definitions need small adjustments due to the modified |\m@cro@|.
+%    \begin{macrocode}
+\def\macro{\begingroup
+   \catcode`\\12
+   \MakePrivateLetters \m@cro@ \iftrue {Macro}}% MODIFIED
+\def\environment{\begingroup
+   \catcode`\\12
+   \MakePrivateLetters \m@cro@ \iffalse {Env}}% MODIFIED
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\newdocenvironment}
+% This command simply makes definitions similar to `environment' and provides
+% the printing and indexing commands.
+%    \begin{macrocode}
+\def\newdocenvironment#1#2#3#4{%
+    \@namedef{#1}{#3\begingroup \catcode`\\12\relax
+                  \MakePrivateLetters \m@cro@ \iffalse {#2}}%
+    \@namedef{end#1}{#4\endmacro}%
+    \@ifundefined{Print#2Name}{\expandafter
+        \let\csname Print#2Name\endcsname\PrintMacroName}{}%
+    \@ifundefined{SpecialMain#2Index}{\expandafter
+        \let\csname SpecialMain#2Index\endcsname\SpecialMainIndex}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{environment}{aspect}
+% \begin{macro}{\PrintAspectName}
+% \begin{macro}{\SpecialMainAspectIndex}
+% The environment and its `print' and `index' commands.
+%    \begin{macrocode}
+\newdocenvironment{aspect}{Aspect}{}{}
+\def\PrintAspectName#1{}
+\def\SpecialMainAspectIndex#1{%
+    \@bsphack
+    \index{aspects:\levelchar\protect\aspectname{#1}\encapchar main}%
+    \@esphack}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{environment}
+%
+% \begin{environment}{lstkey}
+% \begin{macro}{\PrintKeyName}
+% \begin{macro}{\SpecialMainKeyIndex}
+% One more environment with its `print' and `index' commands.
+%    \begin{macrocode}
+\newdocenvironment{lstkey}{Key}{}{}
+\def\PrintKeyName#1{\strut\keyname{#1}\ }
+\def\SpecialMainKeyIndex#1{%
+    \@bsphack
+    \index{keys\levelchar\protect\keyname{#1}\encapchar main}%
+    \@esphack}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{environment}
+%
+% \begin{macro}{\labelargcount}
+% \begin{environment}{macroargs}
+% We just allocate a counter and use \LaTeX's |\list| to implement this
+% environment.
+%    \begin{macrocode}
+\newcounter{argcount}
+\def\labelargcount{\texttt{\#\arabic{argcount}}\hskip\labelsep$=$}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\macroargs{\list\labelargcount
+    {\usecounter{argcount}\leftmargin=2\leftmargin
+     \parsep \z@ \@plus\z@ \@minus\z@
+     \topsep4\p@ \@plus\p@ \@minus2\p@
+     \itemsep\z@ \@plus\z@ \@minus\z@
+     \def\makelabel##1{\hss\llap{##1}}}}
+\def\endmacroargs{\endlist\@endparenv}
+%    \end{macrocode}
+% \end{environment}\end{macro}
+%
+%
+% \subsection{The \texttt{lstsample} environment}
+%
+% \begin{environment}{lstsample}
+% We store the verbatim part and write the source code also to file.
+%    \begin{macrocode}
+\lst@RequireAspects{writefile}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newbox\lst@samplebox
+\lstnewenvironment{lstsample}[3][]
+    {\global\let\lst@intname\@empty
+     \gdef\lst@sample{#2}%
+     \setbox\lst@samplebox=\hbox\bgroup
+         \setkeys{lst}{language={},style={},tabsize=4,gobble=5,%
+             basicstyle=\small\ttfamily,basewidth=0.51em,point={#1}}
+         #3%
+         \lst@BeginAlsoWriteFile{\jobname.tmp}}
+    {\lst@EndWriteFile\egroup
+%    \end{macrocode}
+% Now |\lst@samplebox| contains the verbatim part.
+% If it's too wide, we use atop and below instead of left and right.
+%    \begin{macrocode}
+     \ifdim \wd\lst@samplebox>.5\linewidth
+         \begin{center}%
+             \hbox to\linewidth{\box\lst@samplebox\hss}%
+         \end{center}%
+         \lst@sampleInput
+     \else
+         \begin{center}%
+         \begin{minipage}{0.45\linewidth}\lst@sampleInput\end{minipage}%
+         \qquad
+         \begin{minipage}{0.45\linewidth}%
+             \hbox to\linewidth{\box\lst@samplebox\hss}%
+         \end{minipage}%
+         \end{center}%
+     \fi}
+%    \end{macrocode}
+% The new keyword class \keyname{point}.
+%    \begin{macrocode}
+\lst@InstallKeywords{p}{point}{pointstyle}\relax{keywordstyle}{}ld
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{environment}{lstxsample}
+% Omitting |\lst@EndWriteFile| leaves the file open.
+%    \begin{macrocode}
+\lstnewenvironment{lstxsample}[1][]
+    {\begingroup
+         \setkeys{lst}{belowskip=-\medskipamount,language={},style={},%
+             tabsize=4,gobble=5,basicstyle=\small\ttfamily,%
+             basewidth=0.51em,point={#1}}
+         \lst@BeginAlsoWriteFile{\jobname.tmp}}
+    {\endgroup
+     \endgroup}
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{macro}{\lst@sampleInput}
+% inputs the `left-hand' side.
+%    \begin{macrocode}
+\def\lst@sampleInput{%
+    \MakePercentComment\catcode`\^^M=10\relax
+    \small\lst@sample
+    {\setkeys{lst}{SelectCharTable=\lst@ReplaceInput{\^\^I}%
+                                  {\lst@ProcessTabulator}}%
+     \leavevmode \input{\jobname.tmp}}\MakePercentIgnore}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Miscellaneous}
+%
+% \paragraph{Sectioning and cross referencing}
+% We begin with a redefinition paragraph.
+%    \begin{macrocode}
+\renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
+                                      {1.25ex \@plus1ex \@minus.2ex}%
+                                      {-1em}%
+                                      {\normalfont\normalsize\bfseries}}
+%    \end{macrocode}
+% We introduce |\lstref| which prints section number together with its name.
+%    \begin{macrocode}
+\def\lstref#1{\emph{\ref{#1} \nameref{#1}}}
+%    \end{macrocode}
+% Moreover we adjust the table of contents.
+%    \begin{macrocode}
+\def\@part[#1]#2{\addcontentsline{toc}{part}{#1}%
+    {\parindent\z@ \raggedright \interlinepenalty\@M
+     \normalfont \huge \bfseries #2\markboth{}{}\par}%
+    \nobreak\vskip 3ex\@afterheading}
+\renewcommand*\l@section[2]{%
+    \addpenalty\@secpenalty
+    \addvspace{.25em \@plus\p@}%
+    \setlength\@tempdima{1.5em}%
+    \begingroup
+      \parindent \z@ \rightskip \@pnumwidth
+      \parfillskip -\@pnumwidth
+      \leavevmode
+      \advance\leftskip\@tempdima
+      \hskip -\leftskip
+      #1\nobreak\hfil \nobreak\hb@xt@\@pnumwidth{\hss #2}\par
+    \endgroup}
+\renewcommand*\l@subsection{\@dottedtocline{2}{0pt}{2.3em}}
+\renewcommand*\l@subsubsection{\@dottedtocline{3}{0pt}{3.2em}}
+%    \end{macrocode}
+%
+% \paragraph{Indexing}
+% The `user' commands. |\rstyle| is defined below.
+%    \begin{macrocode}
+\newcommand\ikeyname[1]{%
+    \lstkeyindex{#1}{}%
+    \lstaspectindex{#1}{}%
+    \keyname{#1}}
+\newcommand\ekeyname[1]{%
+    \@bsphack
+    \lstkeyindex{#1}{\encapchar usage}%
+    \lstaspectindex{#1}{\encapchar usage}%
+    \@esphack}
+\newcommand\rkeyname[1]{%
+    \@bsphack
+    \lstkeyindex{#1}{\encapchar main}%
+    \lstaspectindex{#1}{\encapchar main}%
+    \@esphack{\rstyle\keyname{#1}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newcommand\icmdname[1]{%
+    \@bsphack
+    \lstaspectindex{#1}{}%
+    \@esphack\texttt{\string#1}}
+\newcommand\rcmdname[1]{%
+    \@bsphack
+    \lstaspectindex{#1}{\encapchar main}%
+    \@esphack\texttt{\rstyle\string#1}}
+%    \end{macrocode}
+% One of the two yet unknown `index'-macros is empty, the other looks up
+% the aspect name for the given argument.
+%    \begin{macrocode}
+\def\lstaspectindex#1#2{%
+    \global\@namedef{lstkandc@\string#1}{}%
+    \@ifundefined{lstisaspect@\string#1}
+        {\index{unknown\levelchar
+                \protect\texttt{\protect\string\string#1}#2}}%
+        {\index{\@nameuse{lstisaspect@\string#1}\levelchar
+                \protect\texttt{\protect\string\string#1}#2}}%
+}
+\def\lstkeyindex#1#2{%
+%    \index{key\levelchar\protect\keyname{#1}#2}%
+}
+%    \end{macrocode}
+% The key/command to aspect relation is defined near the top of this file using
+% the following command. In future the package should read this information
+% from the aspect files.
+%    \begin{macrocode}
+\def\lstisaspect[#1]#2{%
+    \global\@namedef{lstaspect@#1}{#2}%
+    \lst@AddTo\lst@allkeysandcmds{,#2}%
+    \@for\lst@temp:=#2\do
+    {\ifx\@empty\lst@temp\else
+         \global\@namedef{lstisaspect@\lst@temp}{#1}%
+     \fi}}
+\gdef\lst@allkeysandcmds{}
+%    \end{macrocode}
+% This relation is also good to print all keys and commands of a particular
+% aspect \ldots
+%    \begin{macrocode}
+\def\lstprintaspectkeysandcmds#1{%
+    \lst@true
+    \expandafter\@for\expandafter\lst@temp
+    \expandafter:\expandafter=\csname lstaspect@#1\endcsname\do
+    {\lst@if\lst@false\else, \fi \texttt{\lst@temp}}}
+%    \end{macrocode}
+% \ldots\ or to check the reference. Note that we've defined
+% |\lstkandc@|\meta{name} in |\lstaspectindex|.
+%    \begin{macrocode}
+\def\lstcheckreference{%
+   \@for\lst@temp:=\lst@allkeysandcmds\do
+   {\ifx\lst@temp\@empty\else
+        \@ifundefined{lstkandc@\lst@temp}
+        {\typeout{\lst@temp\space not in reference guide?}}{}%
+    \fi}}
+%    \end{macrocode}
+%
+% \paragraph{Unique styles}
+%    \begin{macrocode}
+\newcommand*\lst{\texttt{lst}}
+\newcommand*\Cpp{C\texttt{++}}
+\let\keyname\texttt
+\let\keyvalue\texttt
+\let\hookname\texttt
+\newcommand*\aspectname[1]{{\normalfont\sffamily#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\DeclareRobustCommand\packagename[1]{%
+    {\leavevmode\text@command{#1}%
+     \switchfontfamily\sfdefault\rmdefault
+     \check@icl #1\check@icr
+     \expandafter}}%
+\def\switchfontfamily#1#2{%
+    \begingroup\xdef\@gtempa{#1}\endgroup
+    \ifx\f@family\@gtempa\fontfamily#2%
+                    \else\fontfamily#1\fi
+    \selectfont}
+%    \end{macrocode}
+% The color mainly for keys and commands in the reference guide.
+%    \begin{macrocode}
+\ifcolor
+    \definecolor{darkgreen}{rgb}{0,0.6,0}
+    \def\rstyle{\color{darkgreen}}
+\else
+    \let\rstyle\empty
+\fi
+%    \end{macrocode}
+%
+% \paragraph{Commands for credits and helpers}
+%    \begin{macrocode}
+\gdef\lst@emails{}
+\newcommand*\lstthanks[2]
+    {#1\lst@AddTo\lst@emails{,#1,<#2>}%
+     \ifx\@empty#2\@empty\typeout{Missing email for #1}\fi}
+\newcommand*\lsthelper[3]
+    {{\let~\ #1}%
+     \lst@IfOneOf#1\relax\lst@emails
+     {}{\typeout{^^JWarning: Unknown helper #1.^^J}}}
+%    \end{macrocode}
+%
+% \paragraph{Languages and styles}
+%    \begin{macrocode}
+\lstdefinelanguage[doc]{Pascal}{%
+  morekeywords={alfa,and,array,begin,boolean,byte,case,char,const,div,%
+     do,downto,else,end,false,file,for,function,get,goto,if,in,%
+     integer,label,maxint,mod,new,not,of,or,pack,packed,page,program,%
+     procedure,put,read,readln,real,record,repeat,reset,rewrite,set,%
+     text,then,to,true,type,unpack,until,var,while,with,write,writeln},%
+  sensitive=false,%
+  morecomment=[s]{(*}{*)},%
+  morecomment=[s]{\{}{\}},%
+  morestring=[d]{'}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lstdefinestyle{}
+    {basicstyle={},%
+     keywordstyle=\bfseries,identifierstyle={},%
+     commentstyle=\itshape,stringstyle={},%
+     numberstyle={},stepnumber=1,%
+     pointstyle=\pointstyle}
+\def\pointstyle{%
+    {\let\lst@um\@empty \xdef\@gtempa{\the\lst@token}}%
+    \expandafter\lstkeyindex\expandafter{\@gtempa}{}%
+    \expandafter\lstaspectindex\expandafter{\@gtempa}{}%
+    \rstyle}
+\lstset{defaultdialect=[doc]Pascal,language=Pascal,style={}}
+%    \end{macrocode}
+%
+%
+% \subsection{Scanning languages}
+%
+% \begin{macro}{\lstscanlanguages}
+% We modify some internal definitions and input the files.
+%    \begin{macrocode}
+\def\lstscanlanguages#1#2#3{%
+    \begingroup
+        \def\lst@DefDriver@##1##2##3##4[##5]##6{%
+           \lst@false
+           \lst@lAddTo\lst@scan{##6(##5),}%
+           \begingroup
+           \@ifnextchar[{\lst@XDefDriver{##1}##3}{\lst@DefDriver@@##3}}%
+        \def\lst@XXDefDriver[##1]{}%
+        \lst@InputCatcodes
+        \def\lst@dontinput{#3}%
+        \let\lst@scan\@empty
+        \lst@for{#2}\do{%
+            \lst@IfOneOf##1\relax\lst@dontinput
+                {}%
+                {\InputIfFileExists{##1}{}{}}}%
+        \global\let\@gtempa\lst@scan
+    \endgroup
+    \let#1\@gtempa}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstprintlanguages}
+% |\do| creates a box of width 0.5|\linewidth| or |\linewidth| depending
+% on how wide the argument is. This leads to `two column' output.
+% The other main thing is sorting the list and begin with the output.
+%    \begin{macrocode}
+\def\lstprintlanguages#1{%
+    \def\do##1{\setbox\@tempboxa\hbox{##1\space\space}%
+        \ifdim\wd\@tempboxa<.5\linewidth \wd\@tempboxa.5\linewidth
+                                   \else \wd\@tempboxa\linewidth \fi
+        \box\@tempboxa\allowbreak}%
+    \begin{quote}
+      \par\noindent
+      \hyphenpenalty=\@M \rightskip=\z@\@plus\linewidth\relax
+      \lst@BubbleSort#1%
+      \expandafter\lst@NextLanguage#1\relax(\relax),%
+    \end{quote}}
+%    \end{macrocode}
+% We get and define the current language and \ldots
+%    \begin{macrocode}
+\def\lst@NextLanguage#1(#2),{%
+    \ifx\relax#1\else
+        \def\lst@language{#1}\def\lst@dialects{(#2),}%
+        \expandafter\lst@NextLanguage@
+    \fi}
+%    \end{macrocode}
+% \ldots\space gather all available dialect of this language (note that the
+% list has been sorted)
+%    \begin{macrocode}
+\def\lst@NextLanguage@#1(#2),{%
+    \def\lst@temp{#1}%
+    \ifx\lst@temp\lst@language
+        \lst@lAddTo\lst@dialects{(#2),}%
+        \expandafter\lst@NextLanguage@
+    \else
+%    \end{macrocode}
+% or begin to print this language with all its dialects. Therefor we sort the
+% dialects
+%    \begin{macrocode}
+        \do{\lst@language
+        \ifx\lst@dialects\lst@emptydialect\else
+            \expandafter\lst@NormedDef\expandafter\lst@language
+                \expandafter{\lst@language}%
+            \space(%
+            \lst@BubbleSort\lst@dialects
+            \expandafter\lst@PrintDialects\lst@dialects(\relax),%
+            )%
+        \fi}%
+        \def\lst@next{\lst@NextLanguage#1(#2),}%
+        \expandafter\lst@next
+    \fi}
+\def\lst@emptydialect{(),}
+%    \end{macrocode}
+% and print the dialect with appropriate commas in between.
+%    \begin{macrocode}
+\def\lst@PrintDialects(#1),{%
+    \ifx\@empty#1\@empty empty\else
+        \lst@PrintDialect{#1}%
+    \fi
+    \lst@PrintDialects@}
+\def\lst@PrintDialects@(#1),{%
+    \ifx\relax#1\else
+        , \lst@PrintDialect{#1}%
+        \expandafter\lst@PrintDialects@
+    \fi}
+%    \end{macrocode}
+% Here we take care of default dialects.
+%    \begin{macrocode}
+\def\lst@PrintDialect#1{%
+    \lst@NormedDef\lst@temp{#1}%
+    \expandafter\ifx\csname\@lst dd@\lst@language\endcsname\lst@temp
+        \texttt{\underbar{#1}}%
+    \else
+        \texttt{#1}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Bubble sort}
+%
+% \begin{macro}{\lst@IfLE}
+% \meta{string 1}|\relax\@empty|\meta{string 2}|\relax\@empty|\marg{then}\meta{else}.
+% If \meta{string 1} $\leq$ \meta{string 2}, we execute \meta{then} and
+% \meta{else} otherwise.
+% Note that this comparision is case insensitive.
+%    \begin{macrocode}
+\def\lst@IfLE#1#2\@empty#3#4\@empty{%
+    \ifx #1\relax
+        \let\lst@next\@firstoftwo
+    \else \ifx #3\relax
+        \let\lst@next\@secondoftwo
+    \else
+        \lowercase{\ifx#1#3}%
+            \def\lst@next{\lst@IfLE#2\@empty#4\@empty}%
+        \else
+            \lowercase{\ifnum`#1<`#3}\relax
+                \let\lst@next\@firstoftwo
+            \else
+                \let\lst@next\@secondoftwo
+            \fi
+        \fi
+    \fi \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BubbleSort}
+% is in fact a derivation of bubble sort.
+%    \begin{macrocode}
+\def\lst@BubbleSort#1{%
+    \ifx\@empty#1\else
+        \lst@false
+%    \end{macrocode}
+% We `bubble sort' the first, second, \ldots\ elements and \ldots
+%    \begin{macrocode}
+        \expandafter\lst@BubbleSort@#1\relax,\relax,%
+%    \end{macrocode}
+% \ldots\space then the second, third, \ldots\ elements until no elemets have
+% been swapped.
+%    \begin{macrocode}
+        \expandafter\lst@BubbleSort@\expandafter,\lst@sorted
+                                      \relax,\relax,%
+        \let#1\lst@sorted
+        \lst@if
+            \def\lst@next{\lst@BubbleSort#1}%
+            \expandafter\expandafter\expandafter\lst@next
+        \fi
+    \fi}
+\def\lst@BubbleSort@#1,#2,{%
+    \ifx\@empty#1\@empty
+        \def\lst@sorted{#2,}%
+        \def\lst@next{\lst@BubbleSort@@}%
+    \else
+        \let\lst@sorted\@empty
+        \def\lst@next{\lst@BubbleSort@@#1,#2,}%
+    \fi
+    \lst@next}
+%    \end{macrocode}
+% But the bubbles rise only one step per call. Putting the elements at their
+% top most place would be inefficient (since \TeX\ had to read much more
+% parameters in this case).
+%    \begin{macrocode}
+\def\lst@BubbleSort@@#1,#2,{%
+    \ifx\relax#1\else
+        \ifx\relax#2%
+            \lst@lAddTo\lst@sorted{#1,}%
+            \expandafter\expandafter\expandafter\lst@BubbleSort@@@
+        \else
+            \lst@IfLE #1\relax\@empty #2\relax\@empty
+                          {\lst@lAddTo\lst@sorted{#1,#2,}}%
+                {\lst@true \lst@lAddTo\lst@sorted{#2,#1,}}%
+            \expandafter\expandafter\expandafter\lst@BubbleSort@@
+        \fi
+    \fi}
+\def\lst@BubbleSort@@@#1\relax,{}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</doc>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{Interfaces to other programs}
+%
+%
+% \subsection{0.21 compatibility}
+%
+% \begin{aspect}{0.21}
+% Some keys have just been renamed.
+%    \begin{macrocode}
+%<*0.21>
+\lst@BeginAspect{0.21}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@Key{labelstyle}{}{\def\lst@numberstyle{#1}}
+\lst@Key{labelsep}{10pt}{\def\lst@numbersep{#1}}
+\lst@Key{labelstep}{0}{%
+    \ifnum #1=\z@ \KV@lst@numbers{none}%
+            \else \KV@lst@numbers{left}\fi
+    \def\lst@stepnumber{#1\relax}}
+\lst@Key{firstlabel}\relax{\def\lst@firstnumber{#1\relax}}
+\lst@Key{advancelabel}\relax{\def\lst@advancenumber{#1\relax}}
+\let\c@lstlabel\c@lstnumber
+\lst@AddToHook{Init}{\let\thelstnumber\thelstlabel}
+\newcommand*\thelstlabel{\@arabic\c@lstlabel}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{first}\relax{\def\lst@firstline{#1\relax}}
+\lst@Key{last}\relax{\def\lst@lastline{#1\relax}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{framerulewidth}{.4pt}{\def\lst@framerulewidth{#1}}
+\lst@Key{framerulesep}{2pt}{\def\lst@rulesep{#1}}
+\lst@Key{frametextsep}{3pt}{\def\lst@frametextsep{#1}}
+\lst@Key{framerulecolor}{}{\lstKV@OptArg[]{#1}%
+    {\ifx\@empty##2\@empty
+         \let\lst@rulecolor\@empty
+     \else
+         \ifx\@empty##1\@empty
+             \def\lst@rulecolor{\color{##2}}%
+         \else
+             \def\lst@rulecolor{\color[##1]{##2}}%
+         \fi
+     \fi}}
+\lst@Key{backgroundcolor}{}{\lstKV@OptArg[]{#1}%
+    {\ifx\@empty##2\@empty
+         \let\lst@bkgcolor\@empty
+     \else
+         \ifx\@empty##1\@empty
+             \def\lst@bkgcolor{\color{##2}}%
+         \else
+             \def\lst@bkgcolor{\color[##1]{##2}}%
+         \fi
+     \fi}}
+\lst@Key{framespread}{\z@}{\def\lst@framespread{#1}}
+\lst@AddToHook{PreInit}
+    {\@tempdima\lst@framespread\relax \divide\@tempdima\tw@
+     \edef\lst@framextopmargin{\the\@tempdima}%
+     \let\lst@framexrightmargin\lst@framextopmargin
+     \let\lst@framexbottommargin\lst@framextopmargin
+     \advance\@tempdima\lst@xleftmargin\relax
+     \edef\lst@framexleftmargin{\the\@tempdima}}
+%    \end{macrocode}
+% \lsthelper{Harald~Harders}{1998/03/30}{inner- and outerspread} had the idea
+% of two spreads (inner and outer). We either divide the dimension by two or
+% assign the two dimensions to inner- and outerspread.
+%    \begin{macrocode}
+\newdimen\lst@innerspread \newdimen\lst@outerspread
+\lst@Key{spread}{\z@,\z@}{\lstKV@CSTwoArg{#1}%
+    {\lst@innerspread##1\relax
+     \ifx\@empty##2\@empty
+         \divide\lst@innerspread\tw@\relax
+         \lst@outerspread\lst@innerspread
+     \else
+         \lst@outerspread##2\relax
+     \fi}}
+\lst@AddToHook{BoxUnsafe}{\lst@outerspread\z@ \lst@innerspread\z@}
+\lst@Key{wholeline}{false}[t]{\lstKV@SetIf{#1}\lst@ifresetmargins}
+\lst@Key{indent}{\z@}{\def\lst@xleftmargin{#1}}
+\lst@AddToHook{PreInit}
+    {\lst@innerspread=-\lst@innerspread
+     \lst@outerspread=-\lst@outerspread
+     \ifodd\c@page \advance\lst@innerspread\lst@xleftmargin
+             \else \advance\lst@outerspread\lst@xleftmargin \fi
+     \ifodd\c@page
+         \edef\lst@xleftmargin{\the\lst@innerspread}%
+         \edef\lst@xrightmargin{\the\lst@outerspread}%
+     \else
+         \edef\lst@xleftmargin{\the\lst@outerspread}%
+         \edef\lst@xrightmargin{\the\lst@innerspread}%
+     \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{defaultclass}\relax{\def\lst@classoffset{#1}}
+\lst@Key{stringtest}\relax{}% dummy
+\lst@Key{outputpos}\relax{\lst@outputpos#1\relax\relax}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{stringspaces}\relax[t]{\lstKV@SetIf{#1}\lst@ifshowstringspaces}
+\lst@Key{visisblespaces}\relax[t]{\lstKV@SetIf{#1}\lst@ifshowspaces}
+\lst@Key{visibletabs}\relax[t]{\lstKV@SetIf{#1}\lst@ifshowtabs}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</0.21>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{\textsf{fancyvrb}}
+%
+% \lsthelper{Denis~Girou}{1998/07/26}{fancyvrb} asked whether
+% \packagename{fancyvrb} and \packagename{listings} could work together.
+% This is still the second attempt.
+%
+% \begin{lstkey}{fancyvrb}
+% We set the boolean and call a submacro.
+%    \begin{macrocode}
+%<*kernel>
+\lst@Key{fancyvrb}\relax[t]{%
+    \lstKV@SetIf{#1}\lst@iffancyvrb
+    \lstFV@fancyvrb}
+\ifx\lstFV@fancyvrb\@undefined
+    \gdef\lstFV@fancyvrb{\lst@RequireAspects{fancyvrb}\lstFV@fancyvrb}
+\fi
+%</kernel>
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{aspect}{fancyvrb}
+% We end the job if \packagename{fancyvrb} is not present.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{fancyvrb}
+%    \end{macrocode}
+%    \begin{macrocode}
+\@ifundefined{FancyVerbFormatLine}
+    {\typeout{^^J%
+     ***^^J%
+     *** `listings.sty' needs `fancyvrb.sty' right now.^^J%
+     *** Please ensure its availability and try again.^^J%
+     ***^^J}%
+     \batchmode \@@end}{}
+%    \end{macrocode}
+%
+% \begin{macro}{\lstFV@fancyvrb}
+% We assign the correct |\FancyVerbFormatLine| macro.
+%    \begin{macrocode}
+\gdef\lstFV@fancyvrb{%
+    \lst@iffancyvrb
+        \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine\else
+            \let\lstFV@FVFL\FancyVerbFormatLine
+            \let\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \fi
+    \else
+        \ifx\lstFV@FVFL\@undefined\else
+            \let\FancyVerbFormatLine\lstFV@FVFL
+            \let\lstFV@FVFL\@undefined
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstFV@VerbatimBegin}
+% We initialize things if necessary.
+%    \begin{macrocode}
+\gdef\lstFV@VerbatimBegin{%
+    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \lsthk@TextStyle \lsthk@BoxUnsafe
+        \lsthk@PreSet
+        \lst@activecharsfalse
+        \let\normalbaselines\relax
+%    \end{macrocode}
+% \begin{TODO}
+% Is this |\let| bad?
+% \end{TODO}
+% I inserted |\lst@ifresetmargins|\ldots|\fi| after a bug report from
+% \lsthelper{Peter~Bartke}{1999/11/18}{wrong fancyvrb frame}.
+%    \begin{macrocode}
+        \lst@Init\relax
+        \lst@ifresetmargins \advance\linewidth-\@totalleftmargin \fi
+        \everypar{}\global\lst@newlines\z@
+        \lst@mode\lst@nomode \let\lst@entermodes\@empty
+        \lst@InterruptModes
+%    \end{macrocode}
+% \lsthelper{Rolf~Niepraschk}{1998/11/25}{ligatures problem} reported a bug
+% concerning ligatures to \lsthelper{Denis~Girou}{1998/11/27}{use |\@noligs|}.
+%    \begin{macrocode}
+%% D.G. modification begin - Nov. 25, 1998
+        \let\@noligs\relax
+%% D.G. modification end
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstFV@VerbatimEnd}
+% A box and macro must exist after |\lst@DeInit|.
+% We store them globally.
+%    \begin{macrocode}
+\gdef\lstFV@VerbatimEnd{%
+    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \global\setbox\lstFV@gtempboxa\box\@tempboxa
+        \global\let\@gtempa\FV@ProcessLine
+        \lst@mode\lst@Pmode
+        \lst@DeInit
+        \let\FV@ProcessLine\@gtempa
+        \setbox\@tempboxa\box\lstFV@gtempboxa
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newbox\lstFV@gtempboxa
+%    \end{macrocode}
+% \end{macro}
+%
+% \noindent
+% We insert |\lstFV@VerbatimBegin| and |\lstFV@VerbatimEnd| where necessary.
+%    \begin{macrocode}
+\lst@AddTo\FV@VerbatimBegin\lstFV@VerbatimBegin
+\lst@AddToAtTop\FV@VerbatimEnd\lstFV@VerbatimEnd
+\lst@AddTo\FV@LVerbatimBegin\lstFV@VerbatimBegin
+\lst@AddToAtTop\FV@LVerbatimEnd\lstFV@VerbatimEnd
+\lst@AddTo\FV@BVerbatimBegin\lstFV@VerbatimBegin
+\lst@AddToAtTop\FV@BVerbatimEnd\lstFV@VerbatimEnd
+%    \end{macrocode}
+%
+% \begin{macro}{\lstFV@FancyVerbFormatLine}
+% `@' terminates the argument of |\lst@FVConvert|.
+% Moreover |\lst@ReenterModes| and |\lst@InterruptModes| encloses some code.
+% This ensures that we have same group level at the beginning and at the end of
+% the macro---even if the user begins but doesn't end a comment, which means
+% one open group.
+% Furthermore we use |\vtop| and reset |\lst@newlines| to allow line breaking.
+%    \begin{macrocode}
+\gdef\lstFV@FancyVerbFormatLine#1{%
+    \let\lst@arg\@empty \lst@FVConvert#1\@nil
+    \global\lst@newlines\z@
+    \vtop{\leavevmode\lst@parshape
+          \lst@ReenterModes
+          \lst@arg \lst@PrintToken\lst@EOLUpdate\lsthk@InitVarsBOL
+          \lst@InterruptModes}}
+%    \end{macrocode}
+% The |\lst@parshape| inside |\vtop| is due to a bug report from
+% \lsthelper{Peter~Bartke}{1999/11/18}{wrong par indention with fancyvrb}.
+% \end{macro}
+%
+% \begin{macro}{\lst@FVConvert}
+% Since |\@ifnextchar\bgroup| might fail, we have to use |\ifcat| here.
+% Bug reported by \lsthelper{Denis~Girou}{1999/07/26}{fancyvrb=true + `second
+% commandchar' other than \{ doesn't work}.
+% However we don't gobble space tokens as |\@ifnextchar| does.
+%    \begin{macrocode}
+\gdef\lst@FVConvert{\futurelet\@let@token\lst@FVConvert@@}
+\gdef\lst@FVConvert@@{%
+    \ifcat\noexpand\@let@token\bgroup \expandafter\lst@FVConvertArg
+                                \else \expandafter\lst@FVConvert@ \fi}
+%    \end{macrocode}
+% Coming to such a catcode${}={}$1 character we convert the argument and add
+% it together with group delimiters to |\lst@arg|.
+% We also add |\lst@PrintToken|, which prints all collected characters before
+% we forget them.
+% Finally we continue the conversion.
+%    \begin{macrocode}
+\gdef\lst@FVConvertArg#1{%
+    {\let\lst@arg\@empty
+     \lst@FVConvert#1\@nil
+     \global\let\@gtempa\lst@arg}%
+     \lst@lExtend\lst@arg{\expandafter{\@gtempa\lst@PrintToken}}%
+     \lst@FVConvert}
+%    \end{macrocode}
+% Having no |\bgroup|, we look whether we've found the end of the input, and
+% convert one token ((non)active character or control sequence) and continue.
+%    \begin{macrocode}
+\gdef\lst@FVConvert@#1{%
+    \ifx \@nil#1\else
+       \if\relax\noexpand#1%
+          \lst@lAddTo\lst@arg{\lst@OutputLostSpace\lst@PrintToken#1}%
+       \else
+          \lccode`\~=`#1\lowercase{\lst@lAddTo\lst@arg~}%
+       \fi
+       \expandafter\lst@FVConvert
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Omega support}
+%
+% \begingroup
+% $\Omega$ support looks easy---I hope it works at least in some cases.
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%    \begin{macrocode}
+\@ifundefined{ocp}{}
+    {\lst@AddToHook{OutputBox}%
+         {\let\lst@ProcessLetter\@firstofone
+          \let\lst@ProcessDigit\@firstofone
+          \let\lst@ProcessOther\@firstofone}}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \endgroup
+%
+%
+% \subsection{\textsf{LGrind}}
+%
+% \begin{aspect}{lgrind}
+% \begin{macro}{\lst@LGGetNames}
+% is used to extract the language names from |\lst@arg| (the
+% \packagename{LGrind} definition).
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords,comments,strings,language]{lgrind}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@LGGetNames#1:#2\relax{%
+    \lst@NormedDef\lstlang@{#1}\lst@ReplaceInArg\lstlang@{|,}%
+    \def\lst@arg{:#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGGetValue}
+% returns in |\lst@LGvalue| the value of capability |#1| given by the list
+% |\lst@arg|. If |#1| is not found, we have |\lst@if|=|\iffalse|.
+% Otherwise it is true and the ``cap=value'' pair is removed from the list.
+% First we test for |#1| and
+%    \begin{macrocode}
+\gdef\lst@LGGetValue#1{%
+    \lst@false
+    \def\lst@temp##1:#1##2##3\relax{%
+        \ifx\@empty##2\else \lst@LGGetValue@{#1}\fi}
+    \expandafter\lst@temp\lst@arg:#1\@empty\relax}
+%    \end{macrocode}
+% remove the pair if necessary.
+%    \begin{macrocode}
+\gdef\lst@LGGetValue@#1{%
+    \lst@true
+    \def\lst@temp##1:#1##2:##3\relax{%
+        \@ifnextchar=\lst@LGGetValue@@{\lst@LGGetValue@@=}##2\relax
+        \def\lst@arg{##1:##3}}%
+    \expandafter\lst@temp\lst@arg\relax}
+\gdef\lst@LGGetValue@@=#1\relax{\def\lst@LGvalue{#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGGetComment}
+% stores the comment delimiters (enclosed in braces) in |#2| if comment of type
+% |#1| is present and not a comment line. Otherwise |#2| is empty.
+%    \begin{macrocode}
+\gdef\lst@LGGetComment#1#2{%
+    \let#2\@empty
+    \lst@LGGetValue{#1b}%
+    \lst@if
+        \let#2\lst@LGvalue
+        \lst@LGGetValue{#1e}%
+        \ifx\lst@LGvalue\lst@LGEOL
+            \edef\lstlang@{\lstlang@,commentline={#2}}%
+            \let#2\@empty
+        \else
+            \edef#2{{#2}{\lst@LGvalue}}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGGetString}
+% does the same for string delimiters, but it doesn't `return' any value.
+%    \begin{macrocode}
+\gdef\lst@LGGetString#1#2{%
+    \lst@LGGetValue{#1b}%
+    \lst@if
+        \let#2\lst@LGvalue
+        \lst@LGGetValue{#1e}%
+        \ifx\lst@LGvalue\lst@LGEOL
+            \edef\lstlang@{\lstlang@,morestringizer=[l]{#2}}%
+        \else
+%    \end{macrocode}
+% we must check for |\e|, i.e.~whether we have to use \texttt doubled or
+% \texttt backslashed stringizer.
+%    \begin{macrocode}
+            \ifx #2\lst@LGvalue
+                \edef\lstlang@{\lstlang@,morestringizer=[d]{#2}}%
+            \else
+                \edef\lst@temp{\lst@LGe#2}%
+                \ifx \lst@temp\lst@LGvalue
+                    \edef\lstlang@{\lstlang@,morestringizer=[b]{#2}}%
+                \else
+                    \PackageWarning{Listings}%
+                    {String #2...\lst@LGvalue\space not supported}%
+                \fi
+            \fi
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGDefLang}
+% defines the language given by |\lst@arg|, the definition part, and
+% |\lst@language@|, the language name. First we remove unwanted stuff from
+% |\lst@arg|, e.g.~we replace |:\ :| by |:|.
+%    \begin{macrocode}
+\gdef\lst@LGDefLang{%
+    \lst@LGReplace
+    \let\lstlang@\empty
+%    \end{macrocode}
+% Get the keywords and values of friends.
+%    \begin{macrocode}
+    \lst@LGGetValue{kw}%
+    \lst@if
+        \lst@ReplaceInArg\lst@LGvalue{{ },}%
+        \edef\lstlang@{\lstlang@,keywords={\lst@LGvalue}}%
+    \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \lst@LGGetValue{oc}%
+    \lst@if
+        \edef\lstlang@{\lstlang@,sensitive=f}%
+    \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \lst@LGGetValue{id}%
+    \lst@if
+        \edef\lstlang@{\lstlang@,alsoletter=\lst@LGvalue}%
+    \fi
+%    \end{macrocode}
+% Now we get the comment delimiters and use them as single or double comments
+% according to whether there are two or four delimiters.
+% Note that |\lst@LGGetComment| takes care of comment lines.
+%    \begin{macrocode}
+    \lst@LGGetComment a\lst@LGa
+    \lst@LGGetComment c\lst@LGc
+    \ifx\lst@LGa\@empty
+        \ifx\lst@LGc\@empty\else
+            \edef\lstlang@{\lstlang@,singlecomment=\lst@LGc}%
+        \fi
+    \else
+        \ifx\lst@LGc\@empty
+            \edef\lstlang@{\lstlang@,singlecomment=\lst@LGa}%
+        \else
+            \edef\lstlang@{\lstlang@,doublecomment=\lst@LGc\lst@LGa}%
+        \fi
+    \fi
+%    \end{macrocode}
+% Now we parse the stringizers.
+%    \begin{macrocode}
+    \lst@LGGetString s\lst@LGa
+    \lst@LGGetString l\lst@LGa
+%    \end{macrocode}
+% We test for the continuation capability and
+%    \begin{macrocode}
+    \lst@LGGetValue{tc}%
+    \lst@if
+        \edef\lstlang@{\lstlang@,lgrindef=\lst@LGvalue}%
+    \fi
+%    \end{macrocode}
+% define the language.
+%    \begin{macrocode}
+    \expandafter\xdef\csname\@lst LGlang@\lst@language@\endcsname
+        {\noexpand\lstset{\lstlang@}}%
+%    \end{macrocode}
+% Finally we inform the user of all ignored capabilities.
+%    \begin{macrocode}
+    \lst@ReplaceInArg\lst@arg{{: :}:}\let\lst@LGvalue\@empty
+    \expandafter\lst@LGDroppedCaps\lst@arg\relax\relax
+    \ifx\lst@LGvalue\@empty\else
+        \PackageWarningNoLine{Listings}{Ignored capabilities for
+            \space `\lst@language@' are\MessageBreak\lst@LGvalue}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGDroppedCaps}
+% just drops a previous value and appends the next capabilty name to
+% |\lst@LGvalue|.
+%    \begin{macrocode}
+\gdef\lst@LGDroppedCaps#1:#2#3{%
+    \ifx#2\relax
+        \lst@RemoveCommas\lst@LGvalue
+    \else
+        \edef\lst@LGvalue{\lst@LGvalue,#2#3}%
+        \expandafter\lst@LGDroppedCaps
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGReplace}
+% \begin{macro}{\lst@LGe}
+% We replace `escaped \verb!:^$|!' by catcode 11 versions, and other strings
+% by some kind of short versions (which is necessary to get the above
+% definitions work).
+%    \begin{macrocode}
+\begingroup
+\catcode`\/=0
+\lccode`\z=`\:\lccode`\y=`\^\lccode`\x=`\$\lccode`\v=`\|
+\catcode`\\=12\relax
+/lowercase{%
+/gdef/lst@LGReplace{/lst@ReplaceInArg/lst@arg
+    {{\:}{z }{\^}{y}{\$}{x}{\|}{v}{ \ }{ }{:\ :}{:}{\ }{ }{\(}({\)})}}
+/gdef/lst@LGe{\e}
+}
+/endgroup
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@LGRead}
+% reads one language definition and defines the language if the correct one
+% is found.
+%    \begin{macrocode}
+\gdef\lst@LGRead#1\par{%
+    \lst@LGGetNames#1:\relax
+    \def\lst@temp{endoflanguagedefinitions}%
+    \ifx\lstlang@\lst@temp
+        \let\lst@next\endinput
+    \else
+        \expandafter\lst@IfOneOf\lst@language@\relax\lstlang@
+            {\lst@LGDefLang \let\lst@next\endinput}%
+            {\let\lst@next\lst@LGRead}%
+    \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{lgrindef}
+% We only have to request the language and
+%    \begin{macrocode}
+\lst@Key{lgrindef}\relax{%
+    \lst@NormedDef\lst@language@{#1}%
+    \begingroup
+    \@ifundefined{lstLGlang@\lst@language@}%
+        {\everypar{\lst@LGRead}%
+         \catcode`\\=12\catcode`\{=12\catcode`\}=12\catcode`\%=12%
+         \catcode`\#=14\catcode`\$=12\catcode`\^=12\catcode`\_=12\relax
+         \input{\lstlgrindeffile}%
+        }{}%
+    \endgroup
+%    \end{macrocode}
+% select it or issue an error message.
+%    \begin{macrocode}
+    \@ifundefined{lstLGlang@\lst@language@}%
+        {\PackageError{Listings}%
+         {LGrind language \lst@language@\space undefined}%
+         {The language is not loadable. \@ehc}}%
+        {\lsthk@SetLanguage
+         \csname\@lst LGlang@\lst@language@\endcsname}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lstlgrindeffile}
+% contains just the file name.
+%    \begin{macrocode}
+\@ifundefined{lstlgrindeffile}
+    {\lst@UserCommand\lstlgrindeffile{lgrindef.}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{\textsf{hyperref}}
+%
+% \begin{aspect}{hyper}
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{hyper}
+%    \end{macrocode}
+%
+% \begin{lstkey}{hyperanchor}
+% \begin{lstkey}{hyperlink}
+% determine the macro to set an anchor and a link, respectively.
+%    \begin{macrocode}
+\lst@Key{hyperanchor}\hyper@@anchor{\let\lst@hyperanchor#1}
+\lst@Key{hyperlink}\hyperlink{\let\lst@hyperlink#1}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}
+% Again, the main thing is a special working procedure. First we extract the
+% contents of |\lst@token| and get a free macro name for this current character
+% string (using prefix |lstHR@| and a number as suffix). Then we make this
+% free macro equivalent to |\@empty|, so it is not used the next time.
+%    \begin{macrocode}
+\lst@InstallKeywords{h}{hyperref}{}\relax{}
+    {\begingroup
+         \let\lst@UM\@empty \xdef\@gtempa{\the\lst@token}%
+     \endgroup
+     \lst@GetFreeMacro{lstHR@\@gtempa}%
+     \global\expandafter\let\lst@freemacro\@empty
+%    \end{macrocode}
+% |\@tempcnta| is the suffix of the free macro. We use it here to refer to
+% the last occurence of the same string. To do this, we redefine the output
+% macro |\lst@alloverstyle| to set an anchor \ldots
+%    \begin{macrocode}
+     \@tempcntb\@tempcnta \advance\@tempcntb\m@ne
+     \edef\lst@alloverstyle##1{%
+         \let\noexpand\lst@alloverstyle\noexpand\@empty
+         \noexpand\smash{\raise\baselineskip\hbox
+             {\noexpand\lst@hyperanchor{lst.\@gtempa\the\@tempcnta}%
+                                       {\relax}}}%
+%    \end{macrocode}
+% \ldots\space and a link to the last occurence (if there is any).
+%    \begin{macrocode}
+         \ifnum\@tempcnta=\z@ ##1\else
+             \noexpand\lst@hyperlink{lst.\@gtempa\the\@tempcntb}{##1}%
+         \fi}%
+    }
+    od
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Epilogue}
+%
+% \begingroup
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+% Each option adds the aspect name to |\lst@loadaspects| or removes it from that data macro.
+%    \begin{macrocode}
+\DeclareOption*{\expandafter\lst@ProcessOption\CurrentOption\relax}
+\def\lst@ProcessOption#1#2\relax{%
+    \ifx #1!%
+        \lst@DeleteKeysIn\lst@loadaspects{#2}%
+    \else
+        \lst@lAddTo\lst@loadaspects{,#1#2}%
+    \fi}
+%    \end{macrocode}
+% The following aspects are loaded by default.
+%    \begin{macrocode}
+\@ifundefined{lst@loadaspects}
+  {\def\lst@loadaspects{strings,comments,escape,style,language,%
+      keywords,labels,lineshape,frames,emph,index}%
+  }{}
+%    \end{macrocode}
+% We load the patch file, \ldots
+%    \begin{macrocode}
+\InputIfFileExists{lstpatch.sty}{}{}
+%    \end{macrocode}
+% \ldots\ process the options, \ldots
+%    \begin{macrocode}
+\let\lst@ifsavemem\iffalse
+\DeclareOption{savemem}{\let\lst@ifsavemem\iftrue}
+\DeclareOption{noaspects}{\let\lst@loadaspects\@empty}
+\ProcessOptions
+%    \end{macrocode}
+% \ldots\ and load the aspects.
+%    \begin{macrocode}
+\lst@RequireAspects\lst@loadaspects
+\let\lst@loadaspects\@empty
+%    \end{macrocode}
+% If present we select the empty style and language.
+%    \begin{macrocode}
+\lst@UseHook{SetStyle}\lst@UseHook{EmptyStyle}
+\lst@UseHook{SetLanguage}\lst@UseHook{EmptyLanguage}
+%    \end{macrocode}
+% Finally we load the configuration files.
+%    \begin{macrocode}
+\InputIfFileExists{listings.cfg}{}{}
+\InputIfFileExists{lstlocal.cfg}{}{}
+%<info>\lst@ReportAllocs
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \endgroup
+%
+%
+% \section{History}
+% \begingroup\small
+% Only major changes are listed here. Introductory version numbers of commands
+% and keys are in the sources of the guides, which makes this history fairly
+% short.
+% \renewcommand\labelitemi{--}
+% \begin{itemize}
+% \item[0.1] from 1996/03/09
+%   \item test version to look whether package is possible or not
+% \item[0.11] from 1996/08/19
+%\iffalse
+%   \item additional blank option (= language)
+%\fi
+%   \item improved alignment
+% \item[0.12] from 1997/01/16
+%   \item nearly `perfect' alignment
+% \item[0.13] from 1997/02/11
+%\iffalse
+%   \item additional languages: Eiffel, Fortran 90, Modula-2, Pascal XSC
+%\fi
+%   \item load on demand: language specific macros moved to driver files
+%   \item comments are declared now and not implemented for each language again
+%         (this makes the \TeX\ sources easier to read)
+% \item[0.14] from 1997/02/18
+%   \item User's guide rewritten, Implementation guide uses macro environment
+%   \item (non) case sensitivity implemented and multiple string types,
+%         i.e.~Modula-2 handles both string types: quotes and double quotes
+%\iffalse
+%   \item comment declaration is user-accessible
+%   \item package compatible to \verb!german.sty!
+%\fi
+% \item[0.15] from 1997/04/18
+%\iffalse
+%   \item additional languages: Java, Turbo Pascal
+%\fi
+%   \item package renamed from \packagename{listing} to \packagename{listings}
+%         since the first already exists
+% \item[0.16] from 1997/06/01
+%\iffalse
+%   \item changed `$<$' to `$>$' in |\lst@SkipToFirst|
+%   \item bug removed: |\lst@Init| must be placed before |\lst@SkipToFirst|
+%\fi
+%   \item listing environment rewritten
+% \item[0.17] from 1997/09/29
+%\iffalse
+%   \item |\spreadlisting| works correct now (e.g.~page numbers don't move right)
+%\fi
+%   \item speed up things (quick `if parameter empty', all |\long| except one
+%         removed, faster \verb!\lst@GotoNextTabStop!, etc.)
+%   \item improved alignment of wide other characters (e.g.~$==$)
+%\iffalse
+%   \item many new languages: Ada, Algol, Cobol, Comal 80, Elan, Fortran 77,
+%         Lisp, Logo, Matlab, Oberon, Perl, PL/I, Simula, SQL, \TeX
+%\fi
+% \item[pre-0.18] from 1998/03/24 (unpublished)
+%\iffalse
+%   \item bug concerning |\labelstyle| (becomes \keyname{numberstyle}) removed
+%         (now oldstylenum example works)
+%\fi
+%   \item experimental implementation of character classes
+% \item[0.19] from 1998/11/09
+%   \item character classes and new \lst-aspects seem to be good
+%   \item user interface uses \packagename{keyval} package
+%   \item \packagename{fancyvrb} support
+% \item[0.20] from 1999/07/12
+%   \item new keyword detection mechanism
+%   \item new aspects: \aspectname{writefile}, \aspectname{breaklines},
+%         captions, \aspectname{html}
+%\iffalse
+%   \item improved \packagename{fancyvrb} support
+%\fi
+%   \item all aspects reside in a single file and the language drivers in
+%         currently two files
+% \item[0.21] 2000/08/23
+%   \item completely new User's guide
+%   \item experimental format definitions
+%   \item keyword classes replaced by families
+%   \item dynamic modes
+% \item[1.0$\beta$] 2001/09/21
+%   \item keynames synchronized with \packagename{fancyvrb}
+%   \item \aspectname{frames} aspect extended
+%   \item new output concept (delaying and merging)
+% \item[1.0] 2002/04/01
+%   \item update of all documentation sections including Developer's guide
+%   \item delimiters unified
+% \end{itemize}
+% \endgroup
+%
+%
+% \Finale
+%
+\endinput

docs/packages/listings/listings.ins

@@ -1,77 +1,95 @@
 %%
-%% Installation file: Listings package for LaTeX2e
-%% (w)(c) 1996-1998 Carsten Heinz
+%% This file generates files required to use the listings package.
+%% At your command prompt write
 %%
-\def\batchfile{listings.ins}
-%
-% just do these things
-%
-\input{docstrip}
-\keepsilent
-\askforoverwritefalse
-
-
-%
-% define the preamble
-%
+%%     tex listings.ins
+%%
+%%
+%% (w)(c) 1996--1999,2002 Carsten Heinz
+%%
+%% This file is distributed under the terms of the LaTeX Project Public
+%% License from CTAN archives in directory  macros/latex/base/lppl.txt.
+%% Either version 1.0 or, at your option, any later version.
+%%
+%% This file is completely free and comes without any warranty.
+%%
+%% Permission is granted to change this file. You are not allowed to
+%% distribute any changed version of this file unless you rename it.
+%%
+\input docstrip
 \preamble
-
-(w)(c) 1996-1998 Carsten Heinz
-
-Please read the software license in listings.dtx or listings.dvi.
-
-This file is distributed freely. You are not allowed to take money for
-the distribution of this file, except for a nominal charge for copying
-etc..
-
-This file is free for any non-commercial use. Commercial use needs (i)
-explicit permission of the author of this package and (ii) the payment
-of a license fee. This fee is to be determined in each instance by the
-commercial user and the package author and is to be payed as donation
-to the LaTeX3 project.
-
-This file is distributed without any warranty, express or implied, as
-to merchantability or fitness for any particular purpose.
-
-Permission is granted to change this file. You are not allowed to
-distribute any changed version this file, neither under the same name
-nor under a different one.
-
 \endpreamble
 
+\usedir{tex/latex/listings}
+\keepsilent
+\askforoverwritefalse
+
 
 %
-% unpack the listings package
+% generate base package
 %
 \generate{
-    \file{listings.sty} {\from{listings.dtx}{kernel}}
-    \file{lst017.sty}  {\from{listings.dtx}{0.17}}
-    \file{lstfvrb.sty} {\from{listings.dtx}{fancyvrb}}
+    \file{listings.sty}{\from{listings.dtx}{kernel}}
+    \file{lstmisc.sty}{\from{listings.dtx}{misc,0.21}}
+    \file{lstdoc.sty}{\from{listings.dtx}{doc}}
+    \file{lstdrvrs.ins}{\from{lstdrvrs.dtx}{install}}
+    \file{listings.cfg}{\from{lstdrvrs.dtx}{config}}
 }
 
-
 %
-% create installation and configuration file if lstdrvrs.dtx exists
+% generate dummy patch if necessary
 %
-\IfFileExists{lstdrvrs.dtx}{\generate{
-    \file{lstdrvrs.ins}{\from{lstdrvrs.dtx}{install}}
-    \file{listings.cfg}{\from{lstdrvrs.dtx}{config}}
-}}
-
+\newif\ifdummypatch
+\def\lstinsIfFileExists#1#2#3{% <filename><pre-input><post-input>
+    \openin\inputcheck #1\relax
+    \ifeof\inputcheck\else
+        \closein\inputcheck
+        #2%
+        \@@input #1
+        #3%
+    \fi}
+\def\ProvidesFile#1[#2]{\def\lstpatch{#2}\endinput}
+\def\lstinsCheckVersion#1 #2{%
+    \ifx #2v\dummypatchtrue \expandafter\lstinsGobbleNil \fi
+    \afterassignment\lstinsCheckVersion@ \count\z@#2}
+\def\lstinsCheckVersion@.{%
+    \afterassignment\lstinsGobbleNil \count\tw@}
+\def\lstinsGobbleNil#1\@nil{%
+    \ifdummypatch\else
+        \edef\patchversion{\the\count\z@.\the\count\tw@}%
+        \ifx\lstversion\patchversion\else
+            \dummypatchtrue
+        \fi
+    \fi}
+
+\Msg{checking listings version ...}
+\lstinsIfFileExists{listings.sty}
+    {\def\NeedsTeXFormat#1{\endinput}}
+    {\let\lstversion\fileversion
+     \lstinsIfFileExists{lstpatch.sty}%
+         {\let\fileversion\@undefined}%
+         {\ifx\fileversion\@undefined
+              \expandafter\lstinsCheckVersion\lstpatch\@nil
+          \fi}%
+    }
+
+\ifdummypatch
+    \generate{\file{lstpatch.sty}{\from{listings.dtx}{patch}}}
+\fi
 
 %
-% unpack drivers if possible
+% generate language driver files
 %
-\InputIfFileExists{lstdrvrs.ins}{}{}
+\batchinput{lstdrvrs.ins}
 
 
-%
-% print user's advice
-%
 \Msg{*}
-\Msg{* Move all `.sty' and `.cfg' files into a folder searched by TeX.}
+\Msg{* You probably need to move all created `.sty' and `.cfg'}
+\Msg{* files into a directory searched by TeX.}
 \Msg{*}
-\Msg{* Run the `.dtx' file through LaTeX2e to get the documentation.}
+\Msg{* And don't forget to refresh your filename database}
+\Msg{* if your TeX distribution uses such a database.}
 \Msg{*}
 
-\endinput
+\endbatchfile
+

docs/packages/listings/lstdrvrs.ins

@@ -6,89 +6,45 @@
 %%
 %% lstdrvrs.dtx  (with options: `install')
 %% 
-%% (w)(c) 1996-1998 Carsten Heinz
-%% 
-%% Please read the software license in listings.dtx or listings.dvi.
-%% 
-%% This file is distributed freely. You are not allowed to take money for
-%% the distribution of this file, except for a nominal charge for copying
-%% etc..
-%% 
-%% This file is free for any non-commercial use. Commercial use needs (i)
-%% explicit permission of the author of this package and (ii) the payment
-%% of a license fee. This fee is to be determined in each instance by the
-%% commercial user and the package author and is to be payed as donation
-%% to the LaTeX3 project.
-%% 
-%% This file is distributed without any warranty, express or implied, as
-%% to merchantability or fitness for any particular purpose.
-%% 
-%% Permission is granted to change this file. You are not allowed to
-%% distribute any changed version this file, neither under the same name
-%% nor under a different one.
-%% 
-\ifx\keepsilent\undefined %
-    \input{docstrip}
-    \keepsilent
-    \askforoverwritefalse
-\fi
-\def\batchfile{lstdrvrs.ins}
-
+%% (w)(c) 1996/1997/1998/1999/2000/2001/2002 Carsten Heinz and/or any
+%% other author listed elsewhere in this file.
+%%
+%% This file is distributed under the terms of the LaTeX Project Public
+%% License from CTAN archives in directory  macros/latex/base/lppl.txt.
+%% Either version 1.0 or, at your option, any later version.
+%%
+%% This file is completely free and comes without any warranty.
+%%
+%% Send comments and ideas on the package, error reports and additional
+%% programming languages to <[email protected]>.
+%%
+\input docstrip
 \preamble
-
-(w)(c) 1996,1997,1998 Carsten Heinz and/or any other author mentioned
-elsewhere in this file.
-
-This file is distributed freely. You are not allowed to take money for
-the use or distribution of this file, except for a nominal charge for
-copying etc..
-
-This file is distributed without any warranty, express or implied, as
-to merchantability or fitness for any particular purpose.
-
-Permission is granted to change this file. You are not allowed to
-distribute any changed version this file, neither under the same name
-nor under a different one.
-
 \endpreamble
 
-\generate{
-    \file{lstalgol.sty}   {\from{listings.dtx}{keywordcomments}
-                           \from{lstdrvrs.dtx}{algol}}
-    \file{lstc.sty}       {\from{listings.dtx}{c}
-                           \from{lstdrvrs.dtx}{c,objective-c,c++}}
-    \file{lstperl.sty}    {\from{listings.dtx}{perl}
-                           \from{lstdrvrs.dtx}{perl}}
-    \file{lstsimula.sty}  {\from{listings.dtx}{keywordcomments}
-                           \from{lstdrvrs.dtx}{simula}}
-    \file{lsttex.sty}     {\from{listings.dtx}{tex}
-                           \from{lstdrvrs.dtx}{tex}}
-    \file{lstada.sty}     {\from{lstdrvrs.dtx}{ada}}
-    \file{lstcobol.sty}   {\from{lstdrvrs.dtx}{cobol}}
-    \file{lstedu.sty}     {\from{lstdrvrs.dtx}{comal,elan,logo}}
-    \file{lstcsh.sty}     {\from{lstdrvrs.dtx}{csh}}
-    \file{lstdelphi.sty}  {\from{lstdrvrs.dtx}{delphi}}
-    \file{lsteiffel.sty}  {\from{lstdrvrs.dtx}{eiffel}}
-    \file{lsteuphoria.sty}{\from{lstdrvrs.dtx}{euphoria}}
-    \file{lstfortran.sty} {\from{lstdrvrs.dtx}{fortran}}
-    \file{lsthtml.sty}    {\from{lstdrvrs.dtx}{html}}
-    \file{lstidl.sty}     {\from{lstdrvrs.dtx}{idl}}
-    \file{lstjava.sty}    {\from{lstdrvrs.dtx}{java}}
+\ifToplevel{
+\usedir{tex/latex/listings}
+\keepsilent
+\askonceonly
 }
 
 \generate{
-    \file{lstlisp.sty}    {\from{lstdrvrs.dtx}{lisp}}
-    \file{lstmatlab.sty}  {\from{lstdrvrs.dtx}{matlab}}
-    \file{lstmercury.sty} {\from{lstdrvrs.dtx}{mercury}}
-    \file{lstmodula.sty}  {\from{lstdrvrs.dtx}{modula}}
-    \file{lstoberon.sty}  {\from{lstdrvrs.dtx}{oberon}}
-    \file{lstpascal.sty}  {\from{lstdrvrs.dtx}{pascal}}
-    \file{lstpli.sty}     {\from{lstdrvrs.dtx}{pli}}
-    \file{lstprolog.sty}  {\from{lstdrvrs.dtx}{prolog}}
-    \file{lstsql.sty}     {\from{lstdrvrs.dtx}{sql}}
-    \file{lstvhdl.sty}    {\from{lstdrvrs.dtx}{vhdl}}
+    \file{lstlang1.sty}{\from{lstdrvrs.dtx}{lang1}}
+    \file{lstlang2.sty}{\from{lstdrvrs.dtx}{lang2}}
+    \file{lstlang3.sty}{\from{lstdrvrs.dtx}{lang3}}
 }
-\end
+
+\ifToplevel{
+\Msg{*}
+\Msg{* You probably need to move all created `.sty' and `.cfg'}
+\Msg{* files into a directory searched by TeX.}
+\Msg{*}
+\Msg{* Run `lstdrvrs.dtx' through LaTeX2e to get the documentation.}
+\Msg{*}
+}
+
+\endbatchfile
+    [2002/07/31 v1.0d listings language file]
 \endinput
 %%
 %% End of file `lstdrvrs.ins'.

docs/packages/listings/lstpatch.sty

@@ -1,69 +1,464 @@
-%%
-%% 1998/11/23: First patch for listings.sty
-%%
-%% (c) 1998 Carsten Heinz
-%%
-\def\lstlanguage@[#1]#2{%
-    \lst@LocateLanguage[#1]{#2}%
-    \@ifundefined{\lst@requested}%
-        {{\catcode`\^^M=9\catcode`\"=12\makeatletter %
-          \input{\[email protected]}}}{}%
-    \@ifundefined{\lst@requested}%
-        {\PackageError{Listings}%
-         {\ifx\@empty\lst@dialect@\else \lst@dialect@\space of \fi %
-          \lst@language@\space undefined}{The driver file is not
-          loadable or doesn't support the language.^^J%
-         Type <RETURN> to proceed without changing the language.}}%
-        {\lsthk@SetLanguage %
-         \csname\lst@requested\endcsname %
-%% modification of
-%         \def\lst@language{#1}\lst@Normalize\lst@language %
-%         \def\lst@dialect{#2}\lst@Normalize\lst@dialect}}
-         \def\lst@language{#2}\lst@Normalize\lst@language %
-         \def\lst@dialect{#1}\lst@Normalize\lst@dialect}}
-%% end modification
-%
-%% load .fd files
-\lst@AddToHook{BeforeSelectCharTable}
-    {\setbox\@tempboxa\hbox{\lst@labelstyle \lst@loadfd}}
-%% end load .fd files
-%
-%% move \let\lst@lastother\relax to end of macros
-\def\lst@Output{%
-    \ifnum\lst@length=\z@\else %
-        \lst@NewLine \lst@UseLostSpace %
-        \hbox to \lst@length\lst@width{%
-            \lst@lefthss %
-            \lsthk@Output \lst@thestyle{%
-                \expandafter\lst@FillOutputBox\the\lst@token\relax}%
-            \lst@righthss}%
-        \global\advance\lst@pos -\lst@length %
-        \lst@token{}\lst@length\z@ %
-    \fi %
-    \let\lst@lastother\relax}
-\def\lst@OutputFlexible{%
-    \ifnum\lst@length=\z@\else %
-        \lst@NewLine \lst@UseLostSpace %
-        \setbox\@tempboxa\hbox{%
-            \lsthk@Output \lst@thestyle{\the\lst@token}}%
-        \lst@CalcLostSpaceAndOutput %
-    \fi %
-    \let\lst@lastother\relax}
-%% end move \let\lst@lastother\relax to end of macros
-%
-%% correct bug of \lst@Aspect{texcs}{\def\lst@texcs{#1}}
-\let\lstS@Aspect\lst@Aspect
-\def\lst@Aspect#1{\def\@tempa{#1}\def\@tempb{texcs}%
-    \ifx\@tempa\@tempb %
-        \expandafter\lst@AspectTeX %
-    \fi %
-    \lstS@Aspect{#1}}
-\def\lst@AspectTeX#1#2#3{%
-    \@ifundefined{KV@lst@#2}%
-        {\let\lst@ifnew\iftrue}{\let\lst@ifnew\iffalse}%
-    \lst@ifnew %
-    \else %
-        \expandafter\@gobblefour %
-    \fi %
-    \lstdefine@key{lst}{#2}{\edef\lst@texcs{##1}}}
-%% end correct bug of \lst@Aspect{texcs}{\def\lst@texcs{#1}}
+%%
+%% This is file `lstpatch.sty', generated manually.
+%%
+%% Please read the software license in listings.dtx or listings.dvi.
+%%
+%% (w)(c) 2002 Carsten Heinz
+%%
+%% This file is distributed under the terms of the LaTeX Project Public
+%% License from CTAN archives in directory  macros/latex/base/lppl.txt.
+%% Either version 1.0 or, at your option, any later version.
+%%
+%% Send comments and ideas on the package, error reports and additional
+%% programming languages to <[email protected]>.
+%%
+%% This patch file will remove the following bugs from the listings package.
+%% Each item contains the bug finder with date of report and first bug fix
+%% version, a short description of the problem, and the reason for the bug
+%% in parenthesis.
+%%
+%%  1) Jochen Schneider, 2002/04/03, 1.0a (2002/04/05)
+%%
+%%     undefined control sequence \lst@CommentB with HTML, XML, tcl
+%%     (I didn't renamed them to \lst@DefDelimB|E)
+%%
+%%  2) Michael Niedermair, 2002/04/07, 1.0b
+%%
+%%     undefined control sequence \lst@commentmode with XML
+%%     (mode not defined any more)
+%%
+%%  3) Carsten Heinz, 2002/04/08, 1.0b
+%%
+%%     bad PODs (investigating bugs 1 and 2)
+%%     (definition doesn't use 1.0 style)
+%%
+%%  4) Peter Bartke, 2002/04/10, 1.0b
+%%
+%%     various problems with fancyvrb interface: string ".5" at beginning
+%%     of first line when using lineskip; ditto "perhaps a missing \item
+%%     error"; wrong placed characters , and - when using fancyvrb
+%%     (bad use of \strip@pt; TeX is not in vertical mode when leaving
+%%     Verbatim; bad `noligs' handling)
+%%
+%%  5) Rolf Niepraschk, 2002/04/12, 1.0b
+%%
+%%     \RequirePackage is missing keywordstyle when near the top of a page
+%%     (\lst@lastother not saved away across page breaks)
+%%
+%%  6) Peter Ruckdeschel, 2002/04/12, 1.0b
+%%     Timothy Van Zandt analyzed and fixed the bug
+%%
+%%     incompatibility with seminar class
+%%     (bad assignment of \lst@do@noligs in \lst@SelectCharTable)
+%%
+%%  7) Rene H. Larsen, 2002/04/12, 1.0b
+%%
+%%     \lstinputlistings and texcl conflict
+%%     (^^M not active to reenter modes)
+%%
+%%  8) Carsten Heinz, 2002/04/15, 1.0b (2002/04/15)
+%%
+%%     gobble doesn't always work (investigating problem with VTeX)
+%%     (\lst@BOLGobble@ must test against \lst@Process{FormFeed|Tabulator}X)
+%%
+%%  9) Peter Bartke, 2002/04/17, 1.0c
+%%
+%%     TeX capacity exceeded with fancyvrb
+%%     (\let\lst@entermodes\@empty must stay in \lstFV@VerbatimBegin)
+%%
+%% 10) Svend Tollak Munkejord, 2002/04/17, 1.0c
+%%     Heiko Oberdiek analyzed and fixed the bug
+%%
+%%     package incompatible with Lucida .fd files
+%%     (parentheses have active catcodes when reading the file)
+%%
+%% 11) Carsten Hamm, 2002/04/19, 1.0c (2002/04/24)
+%%
+%%     wrong frame rules with breaklines and xleftmargin>0pt
+%%     (missing \kern-\lst@xleftmargin in \lst@discretionary)
+%%
+%% 12) Michael Niedermair, 2002/05/14, 1.0d
+%%
+%%     backgroundcolor take effect on bottom captions
+%%     (wrong order of \everypar{} and \lsthk@ExitVars in \lst@DeInit)
+%%
+%% 13) Georg Rehm, 2002/05/14, 1.0d
+%%
+%%     bad baselineskip with captionpos=b
+%%     (missing \normalbaselines)
+%%
+%% 14) Herfried Karl Wagner, 2002/05/11, 1.0d
+%%
+%%     undefined control sequence \lst@entermodes
+%%     (\output called before first \lst@EnterMode)
+%%
+%% 15) Peter K\"oller, 2002/05/24, 1.0d
+%%
+%%     XML keywords don't have keywordstyle
+%%     (missing \ifx... in implementation of contentsstyle)
+%%
+%% 16) Stephen Reindl, 2002/05/28, 1.0d
+%%
+%%     \inaccessible using Cobol
+%%     (\lst@Delim@option didn't enclose option in [])
+%%
+%% 17) Stephen Reindl, 2002/06/04, 1.0d (2002/06/12)
+%%
+%%     frames not deactivated for text style listings
+%%
+%% 18) Carsten Heinz, 2002/07/27, 1.0e (2002/07/31)
+%%
+%%     broken keywordcomments
+%%     (\lst@KCpost inside group level 2; bad \lst@BeginComment call)
+%%
+%% 19) Kris Luyten, 2002/07/30, 1.0f (2002/08/03)
+%%
+%%     Undefined control sequence \lst@thestyle
+%%     (undefined \lst@directives after _loading_ C)
+%%
+%% 20) Kris Luyten, 2002/08/03, 1.0g (2002/08/06)
+%%
+%%     Undefined control sequence \lst@thestyle
+%%     (side effect of 19-bugfix on \lst@ProvideFamily)
+%%
+%% 21) Venkatesh Prasad Ranganath, 2002/08/31, 1.0h
+%%
+%%     Undefined control sequence \thelstnumber with 0.21-option
+%%     (\let must be changed to a \def inition)
+%%
+%% 22) Fermin Reig, 2002/09/04, 1.0h (2002/09/09)
+%%
+%%     Bad top frame inside figure+centering
+%%     (reset of leftskip, rightskip and parfillskip comes too late)
+%%
+%% 23) Hermann H\"uttler, 2002/10/05, 1.0i (2002/10/13)
+%%
+%%     C++-string "... \\" does not end with second double quote
+%%     (missing \let\lst@lastother\@empty in old fix)
+%%
+%%
+%% Moreover the following functionality is added.
+%%
+%%  a) option "final" (Rolf Niepraschk, Enrico Straube)
+%%
+%%  b) keys "fvcmdparams" and "morefvcmdparams" (Denis Girou)
+%%
+%%  c) key "contentstyle" (Peter K\"oller)
+%%
+%%  d) key "numberfirstline" (Georg Rehm)
+%%
+%%
+\ProvidesFile{lstpatch.sty}[2002/10/13 1.0i (Carsten Heinz)]
+\lst@CheckVersion{1.0}
+{\typeout{^^J%
+    ***^^J%
+    *** This is a patch for `listings.sty' version 1.0, but^^J%
+    *** you're using version \lst@version.^^J%
+    ***^^J
+    *** Patch file not loaded.^^J%
+    ***^^J}%
+    \endinput
+}
+%
+% 1) Define the missing control sequences. (Not needed any more.)
+\def\lstpatch@comments{%
+    \global\let\lst@CommentB\lst@DefDelimB
+    \global\let\lst@CommentE\lst@DefDelimE}
+%
+% 2) Define  \lst@commentmode.
+\lst@NewMode\lst@commentmode
+%
+% 3) Introduce \lst@ifxpodcomment as master-clause and define 1.0 style
+%    contents for SelectCharTable.
+\def\lstpatch@pod{%
+\lst@Key{podcomment}{false}[t]{\lstKV@SetIf{##1}\lst@ifxpodcomment}%
+\lst@AddToHookExe{SetLanguage}{\let\lst@ifxpodcomment\iffalse}%
+\lst@AddToHook{SelectCharTable}%
+    {\lst@ifxpodcomment
+         \lst@CArgX =\relax\lst@DefDelimB{}{}%
+           {\ifnum\@tempcnta=\z@
+                \lst@ifprintpod\else
+                    \def\lst@bnext{\lst@BeginDropOutput\lst@PODmode}%
+                    \expandafter\expandafter\expandafter\@gobblethree
+                \fi
+            \else
+               \expandafter\@gobblethree
+            \fi}%
+           \lst@BeginComment\lst@PODmode{{\lst@commentstyle}}% modified
+         \lst@CArgX =cut\^^M\relax\lst@DefDelimE
+           {\lst@CalcColumn}%
+           {\ifnum\@tempcnta=\z@\else
+                \expandafter\@gobblethree
+            \fi}%
+           {}%
+           \lst@EndComment\lst@PODmode
+	 \fi}%
+}
+%
+% 4) Redefine lineskip like podcomment above and don't use \strip@pt
+%    together with \divide.
+\def\lstpatch@lineshape{%
+\lst@Key{lineskip}{\z@}{\def\lst@xlineskip{##1\relax}}
+\lst@AddToHook{Init}
+    {\ifdim\z@=\lst@xlineskip\else
+         \@tempdima\baselineskip
+         \advance\@tempdima\lst@xlineskip
+         \multiply\@tempdima\@cclvi
+         \divide\@tempdima\baselineskip\relax
+         \multiply\@tempdima\@cclvi
+         \edef\baselinestretch{\strip@pt\@tempdima}%
+         \selectfont
+     \fi}%
+% 11) Add \kern-\lst@xleftmargin.
+\gdef\lst@discretionary{%
+    \discretionary{\let\space\lst@spacekern\lst@prebreak}%
+                  {\llap{\lsthk@EveryLine
+                   \kern\lst@breakcurrindent\kern-\lst@xleftmargin}%
+                   \let\space\lst@spacekern\lst@postbreak}{}}%
+}
+% Back to 4): Insert \par for vertical mode.
+\def\lstpatch@fancyvrb{%
+\gdef\lstFV@VerbatimEnd{%
+    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \global\setbox\lstFV@gtempboxa\box\@tempboxa
+        \global\let\@gtempa\FV@ProcessLine
+        \lst@mode\lst@Pmode
+        \lst@DeInit
+        \let\FV@ProcessLine\@gtempa
+        \setbox\@tempboxa\box\lstFV@gtempboxa
+        \par % modified
+    \fi}%
+% 9) Redefined \lstFV@VerbatimBegin removed.
+% b) Refine conversion definitions to either work as usual or to ...
+\gdef\lst@FVConvert{\@tempcnta\z@ \lst@FVConvertO@}%
+\gdef\lst@FVConvertO@{%
+    \ifcase\@tempcnta \expandafter
+        \futurelet\expandafter\@let@token\expandafter\lst@FVConvert@@
+    \else
+% append arguments as they are.
+        \expandafter\lst@FVConvertO@a
+    \fi}%
+\gdef\lst@FVConvertO@a##1{%
+    \lst@lAddTo\lst@arg{{##1}}\advance\@tempcnta\m@ne
+    \lst@FVConvertO@}%
+% Here, ...
+\gdef\lst@FVConvert@##1{%
+    \ifx \@nil##1\else
+       \if\relax\noexpand##1%
+          \lst@lAddTo\lst@arg{\lst@OutputLostSpace\lst@PrintToken##1}%
+% ... actually here, we check for commands with arguments and set the
+% value of \@tempcnta as required.
+          \def\lst@temp####1,##1####2,####3####4\relax{%
+              \ifx####3\@empty \else \@tempcnta####2\relax \fi}%
+          \expandafter\lst@temp\lst@FVcmdparams,##1\z@,\@empty\relax
+       \else
+          \lccode`\~=`##1\lowercase{\lst@lAddTo\lst@arg~}%
+       \fi
+       \expandafter\lst@FVConvertO@
+    \fi}
+% Eventually we define user keys to adjust \lst@FVcmdparams. The base
+% set of commands and parameter numbers was provided by Denis Girou.
+\lst@Key{fvcmdparams}%
+% D.G. suggestion begin - 2002/05/31
+    {\overlay\@ne}%
+% D.G. suggestion end
+    {\def\lst@FVcmdparams{,##1}}%
+\lst@Key{morefvcmdparams}\relax{\lst@lAddTo\lst@FVcmdparams{,##1}}%
+}
+%
+% 5) Extend \lst@SaveToken to save \lst@lastother.
+\def\lst@SaveToken{%
+    \global\let\lst@gthestyle\lst@thestyle
+    \global\let\lst@glastother\lst@lastother
+    \xdef\lst@RestoreToken{\noexpand\lst@token{\the\lst@token}%
+                           \noexpand\lst@length\the\lst@length\relax
+                           \noexpand\let\noexpand\lst@thestyle
+                                        \noexpand\lst@gthestyle
+                           \noexpand\let\noexpand\lst@lastother
+                                        \noexpand\lst@glastother}%
+}
+%
+% 6) Assign \lst@do@noligs to \do.
+\def\lst@SelectCharTable{%
+    \lst@SelectStdCharTable
+    \lst@ifactivechars
+        \catcode9\active \catcode12\active \catcode13\active
+        \@tempcnta=32\relax
+        \@whilenum\@tempcnta<128\do
+            {\catcode\@tempcnta\active\advance\@tempcnta\@ne}%
+    \fi
+    \lst@ifec \lst@DefEC \fi
+    \let\do\lst@do@noligs \verbatim@nolig@list % modified
+    \lsthk@SelectCharTable
+    \lst@DeveloperSCT
+    \ifx\lst@Backslash\relax\else
+        \lst@LetSaveDef{"5C}\lsts@backslash\lst@Backslash
+    \fi}
+% 4)+6) And we need correct versions of \lst@do@noligs[@].
+\def\lst@do@noligs#1{%
+    \begingroup \lccode`\~=`#1\lowercase{\endgroup
+    \lst@do@noligs@~}}
+\def\lst@do@noligs@#1{%
+    \expandafter\expandafter\expandafter\def
+    \expandafter\expandafter\expandafter#1%
+    \expandafter\expandafter\expandafter{\expandafter\lst@NoLig#1}}
+%
+% 7) Make ^^M active.
+\def\lst@InputListing#1{%
+    \begingroup
+      \lsthk@PreSet \gdef\lst@intname{#1}%
+      \expandafter\lstset\expandafter{\lst@set}%
+      \lsthk@DisplayStyle
+      \catcode\active=\active % added
+      \lst@Init\relax \let\lst@gobble\z@
+      \lst@SkipToFirst
+      \lst@ifprint \def\lst@next{\input{#1}}%
+             \else \let\lst@next\@empty \fi
+      \lst@next
+      \lst@DeInit
+    \endgroup}
+%
+% 8) Replace \lst@Process{FormFeed|Tabulator}.
+\def\lst@ProcessFormFeedX{\lst@ProcessFormFeed}
+\def\lst@ProcessTabulatorX{\lst@ProcessTabulator}
+\def\lst@BOLGobble@#1{%
+    \let\lst@next#1%
+    \ifx \lst@next\relax\else
+    \ifx \lst@next\lst@MProcessListing\else
+    \ifx \lst@next\lst@ProcessFormFeedX\else
+    \ifx \lst@next\lstenv@backslash
+        \let\lst@next\lstenv@BOLGobble@@
+    \else
+        \let\lst@next\lst@BOLGobble@@
+        \ifx #1\lst@ProcessTabulatorX
+            \advance\@tempcnta-\lst@tabsize\relax
+            \ifnum\@tempcnta<\z@
+                \lst@length-\@tempcnta \lst@PreGotoTabStop
+            \fi
+        \else
+            \advance\@tempcnta\m@ne
+        \fi
+    \fi \fi \fi \fi
+    \lst@next}
+%
+% 10) Add some \@makeother to \lst@nfss@catcodes.
+\def\lst@nfss@catcodes{%
+    \lst@makeletter
+        ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\relax
+    \@makeother (\@makeother )\@makeother ,\@makeother :\@makeother &%
+    \@makeother 0\@makeother 1\@makeother 2\@makeother 3\@makeother 4%
+    \@makeother 5\@makeother 6\@makeother 7\@makeother 8\@makeother 9%
+    \@makeother =\lsts@nfss@catcodes}
+%
+% 12) and 13) Deactivate \everypar and use normal baseline parameters.
+\lst@AddToHook{DeInit}{\everypar{}\normalbaselines}
+%
+% 14) Define \lst@entermodes.
+\let\lst@entermodes\@empty
+%
+% 16) Insert [ and ] in replacement text.
+\def\lst@Delim@option[#1]{\def\lst@arg{[#1]}\lst@Delim@delim}
+%
+% 17) Just empty `frame' and top, right, bottom, and left shape.
+\lst@AddToHook{TextStyle}
+   {\let\lst@frame\@empty
+    \let\lst@frametshape\@empty
+    \let\lst@framershape\@empty
+    \let\lst@framebshape\@empty
+    \let\lst@framelshape\@empty}
+%
+% 18) Execute \lst@BeginKC and \lst@BeginKCS outside the two groups.
+%     Modify third argument to \lst@BeginComment to work properly.
+\def\lstpatch@keywordcomments{%
+\gdef\lst@BeginKC{\aftergroup\aftergroup\aftergroup\lst@BeginKC@}%
+\gdef\lst@BeginKC@{%
+    \lst@ResetToken
+    \lst@BeginComment\lst@KCmode{{\lst@commentstyle}\lst@modetrue}\@empty}%
+\gdef\lst@BeginKCS{\aftergroup\aftergroup\aftergroup\lst@BeginKCS@}%
+\gdef\lst@BeginKCS@{%
+    \lst@ResetToken
+    \lst@BeginComment\lst@KCSmode{{\lst@commentstyle}\lst@modetrue}\@empty}%
+\gdef\lst@EndKC{\lst@SaveToken \lst@LeaveMode \lst@RestoreToken
+    \let\lst@thestyle\lst@identifierstyle \lsthk@Output}% renew style selection
+}
+%
+% 19) Init \lst@directives.
+\def\lstpatch@directives{%
+    \global\let\lst@directives\@empty}
+%
+% 20) Use new prefix for a family -- the now initialized \lst@directives
+%     clashes with the default.
+\def\lstpatch@keywords{%
+\gdef\lst@ProvideFamily##1{%
+    \@ifundefined{lstfam@##1\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}%
+    {\@namedef{lstfam@##1\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}{}%
+     \expandafter\expandafter\expandafter\lst@ProvideFamily@
+         \csname\@lst @##1@data\endcsname
+         {\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}}%
+    {}}%
+}
+% 21) Define \thelstnumber every listing via \def.
+\@namedef{lstpatch@021}{%
+    \lst@AddToHook{Init}{\def\thelstnumber{\thelstlabel}}%
+}
+% 22) Reset the registers in PreInit hook
+\lst@AddToHook{PreInit}
+  {\rightskip\z@ \leftskip\z@ \parfillskip\z@ plus 1fil}
+%
+% 23) Add \let\lst@lastother\@empty
+\lst@AddToHook{SelectCharTable}{%
+    \lst@ifbstring
+        \lst@CArgX \\\\\relax \lst@CDefX{}%
+           {\lst@ProcessOther\lstum@backslash
+            \lst@ProcessOther\lstum@backslash
+            \let\lst@lastother\@empty}%
+           {}%
+    \fi}
+%
+% a) Just declare the option.
+\DeclareOption{final}{\let\lst@ifdraft\iffalse}
+%
+% c) Define contentstyle and use it.
+\def\lstpatch@html{%
+\lst@Key{contentstyle}{}{\def\lst@contentstyle{##1}}%
+\lst@AddToHook{Init}%
+    {\ifx\lst@DefInside\@empty\else
+         \let\lst@tagstyle\lst@identifierstyle
+         \let\lst@identifierstyle\lst@contentstyle
+     \fi}%
+\lst@AddToHook{Output}%
+    {\ifnum\lst@mode=\lst@insidemode
+% 15) Check for keywordstyle.
+     \ifx\lst@thestyle\lst@gkeywords@sty\else
+         \lst@ifusekeysinside \let\lst@thestyle\lst@tagstyle
+                   \else \let\lst@thestyle\lst@gkeywords@sty \fi
+     \fi\fi}%
+\lst@AddToHook{OutputOther}%
+    {\lst@ifmode\else \ifnum\lst@mode=\lst@insidemode\else
+     \ifx\lst@DefInside\@empty\else
+         \let\lst@thestyle\lst@contentstyle
+     \fi
+     \fi\fi}%
+}
+%
+% d) Define key and adjust \lst@SkipOrPrintLabel.
+\def\lstpatch@labels{%
+\lst@Key{numberfirstline}{f}[t]{\lstKV@SetIf{##1}\lst@ifnumberfirstline}%
+\gdef\lst@numberfirstlinefalse{\let\lst@ifnumberfirstline\iffalse}
+\gdef\lst@SkipOrPrintLabel{%
+    \ifnum\lst@skipnumbers=\z@
+        \global\advance\lst@skipnumbers-\lst@stepnumber\relax
+        \lst@PlaceNumber
+        \lst@numberfirstlinefalse
+    \else
+        \lst@ifnumberfirstline
+            \lst@PlaceNumber
+            \lst@numberfirstlinefalse
+        \fi
+    \fi
+    \global\advance\lst@skipnumbers\@ne}%
+}
+%%
+\endinput
+%%
+%% End of file `lstpatch.sty'.