[hxb] restore function tvoid optimization

src/compiler/hxb/hxbReader.ml

@@ -34,6 +34,15 @@ class hxb_reader
 	val mutable type_type_parameters = Array.make 0 (mk_type_param "" t_dynamic None)
 	val mutable field_type_parameters = Array.make 0 (mk_type_param "" t_dynamic None)
 
+	val mutable tvoid = None
+	method get_tvoid =
+		match tvoid with
+		| Some tvoid -> tvoid
+		| None ->
+				let t = type_of_module_type (resolve_type [] "StdTypes" "Void") in
+				tvoid <- Some t;
+				t
+
 	(* Primitives *)
 
 	method read_u8 =
@@ -615,18 +624,17 @@ class hxb_reader
 			let a = self#read_abstract_ref in
 			let tl = self#read_types in
 			TAbstract(a,tl)
-		(* TODO see writer *)
-		(* | 30 -> TFun([],t_void) *)
-		(* | 31 -> *)
-		(* 	let f () = *)
-		(* 		let name = self#read_string in *)
-		(* 		(1* Printf.eprintf "  Read type instance for %s\n" name; *1) *)
-		(* 		let opt = self#read_bool in *)
-		(* 		let t = self#read_type_instance in *)
-		(* 		(name,opt,t) *)
-		(* 	in *)
-		(* 	let args = self#read_list f in *)
-		(* 	TFun(args,t_void) *)
+		| 30 -> TFun([],self#get_tvoid)
+		| 31 ->
+			let f () =
+				let name = self#read_string in
+				(* Printf.eprintf "  Read type instance for %s\n" name; *)
+				let opt = self#read_bool in
+				let t = self#read_type_instance in
+				(name,opt,t)
+			in
+			let args = self#read_list f in
+			TFun(args,self#get_tvoid)
 		| 32 ->
 			let f () =
 				let name = self#read_string in

src/compiler/hxb/hxbWriter.ml

@@ -371,12 +371,11 @@ class ['a] hxb_writer
 			chunk#write_byte 17;
 			self#write_abstract_ref a;
 			self#write_types tl
-		(* TODO what to do with void special case? *)
-		(* | TFun([],t) when ExtType.is_void (follow t) -> *)
-		(* 	chunk#write_byte 30; *)
-		(* | TFun(args,t) when ExtType.is_void (follow t) -> *)
-		(* 	chunk#write_byte 31; *)
-		(* 	chunk#write_list args write_function_arg; *)
+		| TFun([],t) when ExtType.is_void (follow t) ->
+			chunk#write_byte 30;
+		| TFun(args,t) when ExtType.is_void (follow t) ->
+			chunk#write_byte 31;
+			chunk#write_list args write_function_arg;
 		| TFun(args,t) ->
 			chunk#write_byte 32;
 			chunk#write_list args write_function_arg;