Lua : Hoist __static__ variable declarations

In Haxe, a __static__ method on a class has special behavior.  It
functions as a low level initialization for the class.  It's not
commonly used, but it's a necessary part of the language for many
purposes.

One of these purposes is the __static__ method on the Boot class which
initializes the base abstracts for Int, Bool, etc.  This works fine in
js, which can automatically hoist any variable declarations.  However,
in lua the local instances that carry type information are not
avaialable in any of the code prior to the __static__ declaration. They
won't work.

It's also not a good idea to move the __static__ declarations to the top
of the file... there is a lot of other implementations for String and
Array missing, so any code there would have crippling limitations.

So, the workaround here is to hoist *just* the local variable declarations in
__static__ blocks to the top.  Then, the Array/String/Class definitions
are provided, then the actual __static__ implementation, then the
individual static field generation, and finally the static main
invocation.

genlua.ml

@@ -316,6 +316,10 @@ let rec gen_call ctx e el in_value =
 		spr ctx "(";
 		concat ctx ", " (gen_value ctx) el;
 		spr ctx ")";
+	| TLocal { v_name = "__lua_table__" }, el ->
+		spr ctx "{";
+		concat ctx ", " (gen_value ctx) el;
+		spr ctx "}";
 	| TLocal { v_name = "__lua__" }, [{ eexpr = TConst (TString code) }] ->
 		spr ctx (String.concat "\n" (ExtString.String.nsplit code "\r\n"))
 	| TLocal { v_name = "__lua__" }, { eexpr = TConst (TString code); epos = p } :: tl ->
@@ -385,7 +389,7 @@ let rec gen_call ctx e el in_value =
 		spr ctx ")");
 	ctx.iife_assign <- false;
 
-and gen_expr ctx e =
+and gen_expr ?(local=true) ctx e =
 	match e.eexpr with
 	 TConst c ->
 		gen_constant ctx e.epos c;
@@ -488,7 +492,10 @@ and gen_expr ctx e =
 		ctx.in_loop <- snd old;
 		ctx.separator <- true
 	| TCall (e,el) ->
-		gen_call ctx e el false
+		begin
+		    spr ctx (debug_expression e);
+		    gen_call ctx e el false;
+		end;
 	| TArrayDecl el ->
 		spr ctx "lua.Boot.defArray({";
 		let count = ref 0 in
@@ -505,20 +512,23 @@ and gen_expr ctx e =
 	| TVar (v,eo) ->
 		begin match eo with
 			| None ->
-				spr ctx "local ";
+				if local then
+				    spr ctx "local ";
 				spr ctx (ident v.v_name);
 			| Some e ->
 				match e.eexpr with
 				| TBinop(OpAssign, e1, e2) ->
 				    gen_tbinop ctx OpAssign e1 e2;
-				    spr ctx "local ";
+				    if local then
+					spr ctx "local ";
 				    spr ctx (ident v.v_name);
 				    spr ctx " = ";
 				    gen_value ctx e1;
 				    spr ctx ";";
 
 				| _ ->
-				    spr ctx "local ";
+				    if local then
+					spr ctx "local ";
 				    spr ctx (ident v.v_name);
 				    spr ctx " = ";
 				    gen_value ctx e;
@@ -758,7 +768,49 @@ and gen_expr ctx e =
 		spr ctx ")"
 
 
-and gen_block_element ?(after=false) ctx e =
+
+and gen__static__hoist ctx e =
+    begin match e.eexpr with
+	| TVar (v,eo) ->
+		print ctx "local %s = {};" (ident v.v_name);
+	| TBlock el ->
+		List.iter (gen__static__hoist ctx) el
+	| TCall (e, el) ->
+		(match e.eexpr , el with
+		    | TLocal { v_name = "__feature__" }, { eexpr = TConst (TString f) } :: eif :: eelse ->
+			    (if has_feature ctx f then
+				    gen__static__hoist ctx eif
+			    else match eelse with
+				    | [] -> ()
+				    | e :: _ -> gen__static__hoist ctx e)
+		    |_->());
+	| _ -> ();
+    end
+
+and gen__static__impl ctx e =
+    begin match e.eexpr with
+	| TVar (v,eo) ->
+		gen_expr ~local:false ctx e
+	| TBlock el ->
+		List.iter (gen__static__impl ctx) el
+	| TCall (e, el) ->
+		(match e.eexpr , el with
+		    | TLocal { v_name = "__feature__" }, { eexpr = TConst (TString f) } :: eif :: eelse ->
+			    (if has_feature ctx f then
+				    gen__static__impl ctx eif
+			    else match eelse with
+				    | [] -> ()
+				    | e :: _ -> gen__static__impl ctx e)
+		    |_->
+			begin
+			    newline ctx;
+			    gen_call ctx e el false
+			end;
+		    	    );
+	| _ -> gen_block_element ctx e;
+    end
+
+and gen_block_element ?(after=false) ctx e  =
     newline ctx;
     begin match e.eexpr with
 	| TTypeExpr _ -> ()
@@ -807,7 +859,6 @@ and gen_block_element ?(after=false) ctx e =
 	| TMeta (_,e) ->
 		gen_block_element ctx e
 	| _ ->
-		(* spr ctx (debug_expression e); *)
 		gen_expr ctx e;
 		semicolon ctx;
 		if after then newline ctx;
@@ -844,11 +895,11 @@ and gen_value ctx e =
 	in
 	match e.eexpr with
 	| TBinop((OpAssignOp(_)|OpAssign),e1,e2) ->
-		spr ctx "((function()";
+		spr ctx "(function()";
 		gen_expr ctx e;
 		spr ctx ";return ";
 		gen_expr ctx e1;
-		spr ctx ";end)())";
+		spr ctx ";end)()";
 	| TConst _
 	| TLocal _
 	| TArray _
@@ -1384,6 +1435,10 @@ let generate_type ctx = function
 
 let generate_type_forward ctx = function
 	| TClassDecl c ->
+		(match c.cl_init with
+		| None -> ()
+		| Some e ->
+			ctx.inits <- e :: ctx.inits);
 		if not c.cl_extern then begin
 		    generate_package_create ctx c.cl_path;
 		    let p = s_path ctx c.cl_path in
@@ -1459,10 +1514,18 @@ let generate com =
 		newline ctx
 	);
 
+	spr ctx "--[[begin type forwards--]]"; newline ctx;
 	List.iter (generate_type_forward ctx) com.types;
 	newline ctx;
-	(* TODO: inline this at the end *)
-	spr ctx "_bind = lua.Boot.bind";
+	spr ctx "--[[end type forwards--]]"; newline ctx;
+
+	spr ctx "--[[begin __static__ hoist --]]"; newline ctx;
+	List.iter (gen__static__hoist ctx) (List.rev ctx.inits);
+	ctx.inits <- []; (* reset inits *)
+	newline ctx;
+	spr ctx "--[[end __static__ hoist --]]"; newline ctx;
+
+	spr ctx "local _bind = {}";
 	newline ctx;
 
 	List.iter (generate_type ctx) com.types;
@@ -1491,8 +1554,15 @@ let generate com =
 		print ctx "end";
 		newline ctx
 	end;
-	List.iter (gen_block_element ~after:true ctx) (List.rev ctx.inits);
+
+	spr ctx "--[[ begin __static__impl --]]"; newline ctx;
+	List.iter (gen__static__impl ctx) (List.rev ctx.inits);
+	spr ctx "--[[ end __static__impl --]]"; newline ctx;
+
+	spr ctx "--[[ begin static fields --]]"; newline ctx;
 	List.iter (generate_static ctx) (List.rev ctx.statics);
+	spr ctx "--[[ end static fields --]]"; newline ctx;
+
 	(match com.main with
 	| None -> ()
 	| Some e -> gen_expr ctx e; newline ctx);