new conversion float->integer: conversion is valid only when

float has an exact representation as an integer

lauxlib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.c,v 1.264 2014/06/26 17:25:11 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.265 2014/07/16 14:51:36 roberto Exp roberto $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -396,8 +396,8 @@ LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) {
 
 
 static void interror (lua_State *L, int arg) {
-  if (lua_type(L, arg) == LUA_TNUMBER)
-    luaL_argerror(L, arg, "float value out of integer range");
+  if (lua_isnumber(L, arg))
+    luaL_argerror(L, arg, "number has no integer representation");
   else
     tag_error(L, arg, LUA_TNUMBER);
 }

ldebug.c

@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.97 2013/12/09 14:21:10 roberto Exp roberto $
+** $Id: ldebug.c,v 2.98 2014/07/15 21:26:50 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -534,18 +534,20 @@ l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
 
 l_noret luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
   lua_Number temp;
-  if (!tonumber(p1, &temp))
-    p2 = p1;  /* first operand is wrong */
+  if (!tonumber(p1, &temp))  /* first operand is wrong? */
+    p2 = p1;  /* now second is wrong */
   luaG_typeerror(L, p2, "perform arithmetic on");
 }
 
 
+/*
+** Error when both values are convertible to numbers, but not to integers
+*/
 l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
   lua_Integer temp;
   if (!tointeger(p1, &temp))
     p2 = p1;
-  luaG_runerror(L, "attempt to convert an out of range float%s to an integer",
-                   varinfo(L, p2));
+  luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
 }
 
 

lmathlib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lmathlib.c,v 1.105 2014/06/30 19:48:08 roberto Exp roberto $
+** $Id: lmathlib.c,v 1.106 2014/07/16 13:47:13 roberto Exp roberto $
 ** Standard mathematical library
 ** See Copyright Notice in lua.h
 */
@@ -76,39 +76,39 @@ static int math_atan (lua_State *L) {
 }
 
 
-static int math_ifloor (lua_State *L) {
+static int math_toint (lua_State *L) {
   int valid;
   lua_Integer n = lua_tointegerx(L, 1, &valid);
   if (valid)
-    lua_pushinteger(L, n);  /* floor computed by Lua */
+    lua_pushinteger(L, n);
   else {
-    luaL_checktype(L, 1, LUA_TNUMBER);  /* argument must be a number */
-    lua_pushnil(L);  /* number is not convertible to integer */
+    luaL_checkany(L, 1);
+    lua_pushnil(L);  /* value is not convertible to integer */
   }
   return 1;
 }
 
 
-static int math_floor (lua_State *L) {
-  int valid;
-  lua_Integer n = lua_tointegerx(L, 1, &valid);
-  if (valid)
-    lua_pushinteger(L, n);  /* floor computed by Lua */
-  else
-    lua_pushnumber(L, l_mathop(floor)(luaL_checknumber(L, 1)));
-  return 1;
-}
-
-
 static void pushnumint (lua_State *L, lua_Number d) {
   lua_Integer n;
-  if (lua_numtointeger(d, &n))  /* fits in an integer? */
+  if (lua_numtointeger(d, &n))  /* does 'd' fit in an integer? */
     lua_pushinteger(L, n);  /* result is integer */
   else
     lua_pushnumber(L, d);  /* result is float */
 }
 
 
+static int math_floor (lua_State *L) {
+  if (lua_isinteger(L, 1))
+    lua_settop(L, 1);  /* integer is its own floor */
+  else {
+    lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1));
+    pushnumint(L, d);
+  }
+  return 1;
+}
+
+
 static int math_ceil (lua_State *L) {
   if (lua_isinteger(L, 1))
     lua_settop(L, 1);  /* integer is its own ceil */
@@ -264,15 +264,16 @@ static int math_randomseed (lua_State *L) {
 
 
 static int math_type (lua_State *L) {
-  luaL_checkany(L, 1);
   if (lua_type(L, 1) == LUA_TNUMBER) {
       if (lua_isinteger(L, 1))
         lua_pushliteral(L, "integer"); 
       else
         lua_pushliteral(L, "float"); 
   }
-  else
+  else {
+    luaL_checkany(L, 1);
     lua_pushnil(L);
+  }
   return 1;
 }
 
@@ -339,7 +340,7 @@ static const luaL_Reg mathlib[] = {
   {"cos",   math_cos},
   {"deg",   math_deg},
   {"exp",   math_exp},
-  {"ifloor", math_ifloor},
+  {"tointeger", math_toint},
   {"floor", math_floor},
   {"fmod",   math_fmod},
   {"log",   math_log},

lvm.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.216 2014/06/19 18:27:20 roberto Exp roberto $
+** $Id: lvm.c,v 2.217 2014/06/30 19:48:08 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -80,15 +80,23 @@ int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
 
 
 /*
-** try to convert a value to an integer, rounding up if 'up' is true
+** try to convert a value to an integer, rounding according to 'mode':
+** mode == 0: accepts only integral values
+** mode < 0: takes the floor of the number
+** mode > 0: takes the ceil of the number
 */
-static int tointeger_aux (const TValue *obj, lua_Integer *p, int up) {
+static int tointeger_aux (const TValue *obj, lua_Integer *p, int mode) {
   TValue v;
  again:
   if (ttisfloat(obj)) {
     lua_Number n = fltvalue(obj);
-    n = (up ? -l_floor(-n) : l_floor(n));
-    return lua_numtointeger(n, p);
+    lua_Number f = l_floor(n);
+    if (n != f) {  /* not an integral value? */
+      if (mode == 0) return 0;  /* fails if mode demands integral value */
+      else if (mode > 0)  /* needs ceil? */
+        f += 1;  /* convert floor to ceil (remember: n != f) */
+    }
+    return lua_numtointeger(f, p);
   }
   else if (ttisinteger(obj)) {
     *p = ivalue(obj);
@@ -104,7 +112,7 @@ static int tointeger_aux (const TValue *obj, lua_Integer *p, int up) {
 
 
 /*
-** try to convert a non-integer value to an integer, rounding down
+** try to convert a value to an integer
 */
 int luaV_tointeger_ (const TValue *obj, lua_Integer *p) {
   return tointeger_aux(obj, p, 0);
@@ -155,7 +163,7 @@ int luaV_tostring (lua_State *L, StkId obj) {
 static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
                      int *stopnow) {
   *stopnow = 0;  /* usually, let loops run */
-  if (!tointeger_aux(obj, p, (step < 0))) {  /* does not fit in integer? */
+  if (!tointeger_aux(obj, p, (step < 0 ? 1 : -1))) {  /* not fit in integer? */
     lua_Number n;  /* try to convert to float */
     if (!tonumber(obj, &n)) /* cannot convert to float? */
       return 0;  /* not a number */