Massive refactor to support ref structs.

This was required because Lua semantics are always by reference.
With the original struct-by-value implementation, it was impossible to do something like "myStruct.subStruct.i = 10", because, subStruct would be copy.

luad/conversions/classes.d

@@ -17,50 +17,32 @@ import core.memory;
 import std.traits;
 import std.typetuple;
 
-extern(C) private int classCleaner(lua_State* L)
-{
-	GC.removeRoot(lua_touserdata(L, 1));
-	return 0;
-}
-
-private extern(C) int indexClass(lua_State* L)
-{
-	auto field = lua_tostring(L, 2);
-
-	// check the getter table
-	lua_getfield(L, lua_upvalueindex(1), field);
-	if(!lua_isnil(L, -1))
-	{
-		lua_pushvalue(L, 1);
-		lua_call(L, 1, LUA_MULTRET);
-		return lua_gettop(L) - 2;
-	}
-	else
-		lua_pop(L, 1);
-
-	// return method
-	lua_getfield(L, lua_upvalueindex(2), field);
-	return 1;
-}
 
-private extern(C) int newIndexClass(lua_State* L)
+void pushGetter(T, string member)(lua_State* L)
 {
-	auto field = lua_tostring(L, 2);
-
-	// call setter
-	lua_getfield(L, lua_upvalueindex(1), field);
-	if(!lua_isnil(L, -1))
+	alias RT = typeof(mixin("T."~member));
+	final class C
 	{
-		lua_pushvalue(L, 1);
-		lua_pushvalue(L, 3);
-		lua_call(L, 2, LUA_MULTRET);
-	}
-	else
-	{
-		// TODO: error?
+		static if((!isMemberFunction!(T, member) || returnsRef!(AliasMember!(T, member))) && isUserStruct!RT)
+		{
+			ref RT get()
+			{
+				T _this = *cast(T*)&this;
+				return mixin("_this."~member);
+			}
+		}
+		else
+		{
+			RT get()
+			{
+				T _this = *cast(T*)&this;
+				return mixin("_this."~member);
+			}
+		}
 	}
 
-	return 0;
+	lua_pushlightuserdata(L, (&C.init.get).funcptr);
+	lua_pushcclosure(L, &methodWrapper!(typeof(&C.init.get), T, false), 1);
 }
 
 private void pushGetters(T)(lua_State* L)
@@ -71,9 +53,9 @@ private void pushGetters(T)(lua_State* L)
 	// populate getters
 	foreach(member; __traits(derivedMembers, T))
 	{
-		static if(!skipField!(T, member) &&
-				  !isStaticMember!(T, member) &&
-				  member != "Monitor")
+		static if(!skipMember!(T, member) &&
+		          !isStaticMember!(T, member) &&
+		          member != "Monitor")
 		{
 			static if(isMemberFunction!(T, member) && !isProperty!(T, member))
 			{
@@ -88,7 +70,36 @@ private void pushGetters(T)(lua_State* L)
 		}
 	}
 
-	lua_pushcclosure(L, &indexClass, 2);
+	lua_pushcclosure(L, &index, 2);
+}
+
+void pushSetter(T, string member)(lua_State* L)
+{
+	// TODO: This is broken if setter argument is different from the getter's return type...
+	alias ArgType = typeof(mixin("T."~member));
+
+	final class C
+	{
+		static if(isUserStruct!ArgType)
+		{
+			final void set(ref ArgType value)
+			{
+				T _this = *cast(T*)&this;
+				mixin("_this."~member) = value;
+			}
+		}
+		else
+		{
+			final void set(ArgType value)
+			{
+				T _this = *cast(T*)&this;
+				mixin("_this."~member) = value;
+			}
+		}
+	}
+
+	lua_pushlightuserdata(L, (&C.init.set).funcptr);
+	lua_pushcclosure(L, &methodWrapper!(typeof(&C.init.set), T, false), 1);
 }
 
 private void pushSetters(T)(lua_State* L)
@@ -98,10 +109,10 @@ private void pushSetters(T)(lua_State* L)
 	// populate setters
 	foreach(member; __traits(derivedMembers, T))
 	{
-		static if(!skipField!(T, member) &&
-				  !isStaticMember!(T, member) &&
-				  canWrite!(T, member) &&
-				  member != "Monitor")
+		static if(!skipMember!(T, member) &&
+		          !isStaticMember!(T, member) &&
+		          canWrite!(T, member) && // TODO: move into the setter for readonly fields
+		          member != "Monitor")
 		{
 			static if(!isMemberFunction!(T, member) || isProperty!(T, member))
 			{
@@ -111,7 +122,7 @@ private void pushSetters(T)(lua_State* L)
 		}
 	}
 
-	lua_pushcclosure(L, &newIndexClass, 1);
+	lua_pushcclosure(L, &newIndex, 1);
 }
 
 private void pushMeta(T)(lua_State* L)
@@ -120,11 +131,13 @@ private void pushMeta(T)(lua_State* L)
 		return;
 
 	pushValue(L, T.stringof);
-	lua_setfield(L, -2, "__dclass");
+	lua_setfield(L, -2, "__dtype");
+
+	// TODO: mangled names can get REALLY long in D, it might be nicer to store a hash instead?
 	pushValue(L, T.mangleof);
 	lua_setfield(L, -2, "__dmangle");
 
-	lua_pushcfunction(L, &classCleaner);
+	lua_pushcfunction(L, &userdataCleaner);
 	lua_setfield(L, -2, "__gc");
 
 	pushGetters!T(L);
@@ -157,28 +170,10 @@ void pushClassInstance(T)(lua_State* L, T obj) if (is(T == class))
 	lua_setmetatable(L, -2);
 }
 
-//TODO: handle foreign userdata properly (i.e. raise errors)
 T getClassInstance(T)(lua_State* L, int idx) if (is(T == class))
 {
-	if(lua_getmetatable(L, idx) == 0)
-	{
-		luaL_error(L, "attempt to get 'userdata: %p' as a D object", lua_topointer(L, idx));
-	}
-
-	lua_getfield(L, -1, "__dmangle"); //must be a D object
-
-	static if(!is(T == Object)) //must be the right object
-	{
-		size_t manglelen;
-		auto cmangle = lua_tolstring(L, -1, &manglelen);
-		if(cmangle[0 .. manglelen] != T.mangleof)
-		{
-			lua_getfield(L, -2, "__dclass");
-			auto cname = lua_tostring(L, -1);
-			luaL_error(L, `attempt to get instance %s as type "%s"`, cname, toStringz(T.stringof));
-		}
-	}
-	lua_pop(L, 2); //metatable and metatable.__dmangle
+	//TODO: handle foreign userdata properly (i.e. raise errors)
+	verifyType!T(L, idx);
 
 	Object obj = *cast(Object*)lua_touserdata(L, idx);
 	return cast(T)obj;