Context::get_or_create_service

src/context.rs

@@ -46,9 +46,23 @@ impl Context{
 		self.superclass_iter("LuaSourceContainer").map(crate::runner::instance::Instance::new).collect()
 	}
 
+	fn get_service(&self,service:&str)->Option<Ref>{
+		self.dom.root().children().iter().find(|&&r|
+			self.dom.get_by_ref(r).is_some_and(|instance|instance.class==service)
+		).copied()
+	}
+	fn get_or_create_service(&mut self,service:&str,mut create:impl FnMut(&mut Context)->Ref)->Ref{
+		match self.get_service(service){
+			Some(referent)=>referent,
+			None=>create(self),
+		}
+	}
 	pub fn find_services(&self)->Option<Services>{
-		//nil instances isn't real, it doesn't exist in real roblox places
-		None
+		Some(Services{
+			workspace:self.get_service("Workspace")?,
+			nil:self.get_service("Nil")?,
+			game:self.dom.root_ref(),
+		})
 	}
 	pub fn convert_into_place(&mut self)->Services{
 		//snapshot root instances
@@ -56,13 +70,15 @@ impl Context{
 
 		//insert services
 		let game=self.dom.root_ref();
-		let terrain_bldr=InstanceBuilder::new("Terrain");
-		let workspace=self.dom.insert(game,
-			InstanceBuilder::new("Workspace")
-				//Set Workspace.Terrain property equal to Terrain
-				.with_property("Terrain",terrain_bldr.referent())
-				.with_child(terrain_bldr)
-		);
+		let workspace=self.get_or_create_service("Workspace",|context|{
+			let terrain_bldr=InstanceBuilder::new("Terrain");
+			context.dom.insert(game,
+				InstanceBuilder::new("Workspace")
+					//Set Workspace.Terrain property equal to Terrain
+					.with_property("Terrain",terrain_bldr.referent())
+					.with_child(terrain_bldr)
+			)
+		});
 		{
 			//Lowercase and upper case workspace property!
 			let game=self.dom.root_mut();
@@ -73,10 +89,12 @@ impl Context{
 		// Special nonexistent class that holds instances parented to nil,
 		// which can still be referenced by scripts.
 		// Using a sentinel value as a ref because global variables are hard.
-		let nil=self.dom.insert(
-			game,InstanceBuilder::new("Nil")
-			.with_referent(
-				<Ref as std::str::FromStr>::from_str("ffffffffffffffffffffffffffffffff").unwrap()
+		let nil=self.get_or_create_service("Nil",|context|
+			context.dom.insert(
+				game,InstanceBuilder::new("Nil")
+				.with_referent(
+					<Ref as std::str::FromStr>::from_str("ffffffffffffffffffffffffffffffff").unwrap()
+				)
 			)
 		);