Lua : OOP tweaks

Previously, I was using an array to store the inherited method
metatables for a given instance.  It's actually a lot cleaner just to
use __index recursively on tables.  I've made the necessary changes.

I've also cleaned up some of the metatable generation code, and avoid
creating the method index table instance if there are no methods for the
current class.

genlua.ml

@@ -61,6 +61,9 @@ let dot_path = Ast.s_type_path
 
 let s_path ctx = dot_path
 
+let debug_expression expression  =
+	"/* " ^ Type.s_expr_kind expression  ^ " */";;
+
 let kwds =
 	let h = Hashtbl.create 0 in
 	List.iter (fun s -> Hashtbl.add h s ()) [
@@ -270,9 +273,9 @@ let rec gen_call ctx e el in_value =
 		(match ctx.current.cl_super with
 		| None -> error "Missing api.setCurrentClass" e.epos
 		| Some (c,_) ->
-			print ctx "self = %s.new(%s" (ctx.type_accessor (TClassDecl c)) (this ctx);
+			print ctx "setmetatable(self, %s.new(%s" (ctx.type_accessor (TClassDecl c)) (this ctx);
 			List.iter (fun p -> print ctx ","; gen_value ctx p) params;
-			spr ctx ")";
+			spr ctx "))";
 		);
 	| TField ({ eexpr = TConst TSuper },f) , params ->
 		(match ctx.current.cl_super with
@@ -954,6 +957,18 @@ and gen_return ctx e eo =
 	    );
 	    spr ctx " end")
 
+and has_class ctx c =
+    has_feature ctx "lua.Boot.getClass" && (c.cl_super <> None || c.cl_ordered_fields <> [] || c.cl_constructor <> None)
+
+and has_metatable ctx c =
+    c.cl_super <> None || (has_class ctx c) || List.exists (can_gen_class_field ctx) c.cl_ordered_fields
+
+and can_gen_class_field ctx = function
+	| { cf_expr = (None | Some { eexpr = TConst TNull }) } when not (has_feature ctx "Type.getInstanceFields") ->
+		false
+	| f ->
+		not (is_extern_field f)
+
 let generate_package_create ctx (p,_) =
 	let rec loop acc = function
 		| [] -> ()
@@ -1000,11 +1015,6 @@ let gen_class_static_field ctx c f =
 		| _ ->
 			ctx.statics <- (c,f.cf_name,e) :: ctx.statics
 
-let can_gen_class_field ctx = function
-	| { cf_expr = (None | Some { eexpr = TConst TNull }) } when not (has_feature ctx "Type.getInstanceFields") ->
-		false
-	| f ->
-		not (is_extern_field f)
 
 let gen_class_field ctx c f =
 	check_field_name c f;
@@ -1088,17 +1098,11 @@ let generate_class ctx c =
 				    | TBlock el ->
 					let bend = open_block ctx in
 					newline ctx;
-					spr ctx "self = {}";
-					newline ctx;
-					spr ctx "self.__methods = {}";
-					newline ctx;
-					spr ctx "setmetatable(self, {__index = lua.Boot.resolveMethod })";
-					newline ctx;
+					if (has_metatable ctx c) then
+					    print ctx "self = %s.mt" p;
 					List.iter (gen_block_element ctx) el;
 					newline ctx;
 					(* TODO: use nonconflict var instead of mt *)
-					print ctx "table.insert(self.__methods, %s.mt)" p;
-					newline ctx;
 					spr ctx "return self";
 					bend();
 					newline ctx;
@@ -1139,25 +1143,21 @@ let generate_class ctx c =
 
 	List.iter (gen_class_static_field ctx c) c.cl_ordered_statics;
 
-	let has_class = has_feature ctx "lua.Boot.getClass" && (c.cl_super <> None || c.cl_ordered_fields <> [] || c.cl_constructor <> None) in
-	let has_prototype = c.cl_super <> None || has_class || List.exists (can_gen_class_field ctx) c.cl_ordered_fields in
-	if has_prototype then begin
+	newline ctx;
+	if (has_metatable ctx c) then begin
 		(match c.cl_super with
-		| None ->
-			(* TODO: use nonconflict var instead of mt *)
-			print ctx "%s.mt = {" p;
-			newline ctx;
+		| None -> ()
 		| Some (csup,_) ->
 			let psup = ctx.type_accessor (TClassDecl csup) in
 			print ctx "%s.__super__ = %s" p psup;
 			newline ctx;
 			(* TODO: use nonconflict var instead of mt *)
-			print ctx "%s.mt = {" p;
-			newline ctx;
 		);
+		print ctx "%s.mt = {" p;
+		newline ctx;
 
 		List.iter (fun f -> if can_gen_class_field ctx f then gen_class_field ctx c f) c.cl_ordered_fields;
-		if has_class then begin
+		if (has_class ctx c) then begin
 			newprop ctx;
 			print ctx "__class__: %s" p;
 		end;