Make ChildOf exclusive

jecs.luau

@@ -1,4 +1,3 @@
-
 --!optimize 2
 --!native
 --!strict
@@ -935,10 +934,12 @@ local function find_archetype_with(world: World, id: Id, from: Archetype): Arche
 		local idr = world.component_index[ECS_PAIR(first, EcsWildcard)]
 		if idr and bit32.btest(idr.flags, EcsExclusive) then
 			local cr = idr.records[from.id]
+			if cr then
 				dst[cr] = id
 				return archetype_ensure(world, dst)
 			end
 		end
+	end
 
 	local at = find_insert(id_types :: { number } , id :: number)
 
@@ -2203,37 +2204,6 @@ local function world_new()
 		return r
 	end
 
-	local function inner_world_add<T, a>(
-		world: World,
-		entity: Entity<T>,
-		id: Id<a>
-	): ()
-		local entity_index = world.entity_index
-		local record = inner_entity_index_try_get_unsafe(entity :: number)
-		if not record then
-			return
-		end
-
-		local from = record.archetype
-		local to = archetype_traverse_add(world, id, from)
-		if from == to then
-			return
-		end
-		if from then
-			entity_move(entity_index, entity, record, to)
-		else
-			if #to.types > 0 then
-				new_entity(entity, record, to)
-			end
-		end
-
-		local idr = world.component_index[id]
-		local on_add = idr.hooks.on_add
-
-		if on_add then
-			on_add(entity, id)
-		end
-	end
 
 	local function inner_world_get(world: World, entity: Entity,
 		a: Id, b: Id?, c: Id?, d: Id?, e: Id?): ...any
@@ -2349,6 +2319,38 @@ local function world_new()
 		return to
 	end
 
+	local function inner_world_add<T, a>(
+		world: World,
+		entity: Entity<T>,
+		id: Id<a>
+	): ()
+		local entity_index = world.entity_index
+		local record = inner_entity_index_try_get_unsafe(entity :: number)
+		if not record then
+			return
+		end
+
+		local from = record.archetype
+		local to = archetype_traverse_add(world, id, from)
+		if from == to then
+			return
+		end
+		if from then
+			entity_move(entity_index, entity, record, to)
+		else
+			if #to.types > 0 then
+				new_entity(entity, record, to)
+			end
+		end
+
+		local idr = world.component_index[id]
+		local on_add = idr.hooks.on_add
+
+		if on_add then
+			on_add(entity, id)
+		end
+	end
+
 	local function inner_world_set<T, a>(world: World, entity: Entity<T>, id: Id<a>, data: a): ()
 		local record = inner_entity_index_try_get_unsafe(entity :: number)
 		if not record then
@@ -2571,7 +2573,6 @@ local function world_new()
 				end
 			end
 		end
-
 	end
 
 	local function inner_world_delete<T>(world: World, entity: Entity<T>)
@@ -2858,6 +2859,7 @@ local function world_new()
 	inner_world_set(world, EcsRest, EcsRest, "jecs.Rest")
 
 	inner_world_add(world, EcsChildOf, ECS_PAIR(EcsOnDeleteTarget, EcsDelete))
+	inner_world_add(world, EcsChildOf, EcsExclusive)
 
 	for i = EcsRest + 1, ecs_max_tag_id do
 		entity_index_new_id(entity_index)

test/tests.luau

@@ -1686,7 +1686,9 @@ end)
 TEST("#repro2", function()
 	local world = jecs.world()
 	local Lifetime = world:component() :: Id<number>
+	world:set(Lifetime, jecs.Name, "Lifetime")
 	local Particle = world:entity()
+	world:set(Particle, jecs.Name, "Particle")
 	local Beam = world:entity()
 
 	local entity = world:entity()
@@ -1694,19 +1696,24 @@ TEST("#repro2", function()
 	world:set(entity, pair(Lifetime, Beam), 2)
 	world:set(entity, pair(4 :: any, 5 :: any), 6) -- noise
 
+	CHECK(world:get(entity, pair(Lifetime, Particle)) == 1)
+	CHECK(world:get(entity, pair(Lifetime, Beam)) == 2)
+
+	CHECK(world:target(entity, Lifetime, 0) == Particle)
+	CHECK(world:target(entity, Lifetime, 1) == Beam)
+
 	-- entity_visualizer.components(world, entity)
 
+	-- print(CHECK(world:has(jecs.ChildOf, jecs.Exclusive)))
+
 	for e in world:each(pair(Lifetime, __)) do
 		local i = 0
 		local nth = world:target(e, Lifetime, i)
 		while nth do
 			-- entity_visualizer.components(world, e)
-
 			local data = world:get(e, pair(Lifetime, nth)) :: number
+		 	if data > 0 then
 				data -= 1
-		 	if data <= 0 then
-                world:remove(e, pair(Lifetime, nth))
-            else
                 world:set(e, pair(Lifetime, nth), data)
             end
 			i += 1
@@ -1714,7 +1721,7 @@ TEST("#repro2", function()
 		end
 	end
 
-	CHECK(not world:has(entity, pair(Lifetime, Particle)))
+	CHECK(world:get(entity, pair(Lifetime, Particle)) == 0)
 	CHECK(world:get(entity, pair(Lifetime, Beam)) == 1)
 end)