Instance FindFirstChild + WaitForChild (no difference in implementation)

src/runner/instance.rs

@@ -158,6 +158,29 @@ impl Instance{
 				Ok(children)
 			})
 		);
+		let ffc=|lua,this:&T,(name,search_descendants):(mlua::String,mlua::Value)|{
+			let name_str=name.to_str()?;
+			let search_descendants=match search_descendants{
+				mlua::Value::Nil=>false,
+				mlua::Value::Boolean(b)=>b,
+				_=>Err(mlua::Error::runtime("Invalid argument #3 bool expected"))?,
+			};
+			dom(lua,|dom|{
+				let instance=this.get(dom)?;
+				let child=match search_descendants{
+					true=>dom.descendants_of(this.referent()).find(|inst|inst.name==name_str),
+					false=>instance.children().iter().filter_map(|&r|
+						dom.get_by_ref(r)
+					).find(|inst|inst.name==name_str),
+				};
+				match child{
+					Some(instance)=>Instance::new(instance.referent()).into_lua(lua),
+					None=>mlua::Value::Nil.into_lua(lua),
+				}
+			})
+		};
+		methods.add_method("FindFirstChild",ffc);
+		methods.add_method("WaitForChild",ffc);
 		methods.add_method("GetDescendants",|lua,this,_:()|
 			dom(lua,|dom|{
 				let children:Vec<_>=dom