Return nil if nth is over count

addons/ob.luau

@@ -69,6 +69,9 @@ local function observers_new<T...>(
 	end
 
 	for _, term in terms do
+		if jecs.IS_PAIR(term) then
+			term = jecs.ECS_PAIR_FIRST(term)
+		end
 		world:added(term, emplaced)
 		world:changed(term, emplaced)
  	end
@@ -151,7 +154,7 @@ local function monitors_new<T...>(
 			i += 1
 			entities[i] = entity
 			if callback ~= nil then
-				callback(entity, id, value)
+				callback(entity, jecs.OnAdd)
 			end
 		end
 	end
@@ -164,6 +167,9 @@ local function monitors_new<T...>(
 	end
 
 	for _, term in terms do
+		if jecs.IS_PAIR(term) then
+			term = jecs.ECS_PAIR_FIRST(term)
+		end
 		world:added(term, emplaced)
 		world:removed(term, removed)
  	end

demo/src/ReplicatedStorage/main.client.luau

@@ -1,12 +1,11 @@
 local ReplicatedStorage = game:GetService("ReplicatedStorage")
 local jecs = require(ReplicatedStorage.ecs)
 local schedule = require(ReplicatedStorage.schedule)
-local observers_add = require(ReplicatedStorage.observers_add)
 
 local SYSTEM = schedule.SYSTEM
 local RUN = schedule.RUN
 require(ReplicatedStorage.components)
-local world = observers_add(jecs.world())
+local world = jecs.world()
 
 local systems = ReplicatedStorage.systems
 SYSTEM(world, systems.receive_replication)

demo/src/ReplicatedStorage/types.luau

@@ -1,7 +1,6 @@
 local jecs = require(game:GetService("ReplicatedStorage").ecs)
-local observers_add = require("../ReplicatedStorage/observers_add")
 
-export type World = typeof(observers_add(jecs.world()))
+export type World = typeof(jecs.world())
 export type Entity = jecs.Entity
 export type Id<T> = jecs.Id<T>
 export type Snapshot = {

jecs.luau

@@ -24,10 +24,10 @@ export type Archetype = {
 
 export type QueryInner = {
 	compatible_archetypes: { Archetype },
-	ids: { i53 },
-	filter_with: { i53 },
-	filter_without: { i53 },
-	next: () -> (number, ...any),
+	ids: { Id },
+	filter_with: { Id },
+	filter_without: { Id },
+	next: () -> (Entity, ...any),
 	world: World,
 }
 
@@ -54,6 +54,8 @@ export type Query<T...> = typeof(setmetatable(
 		archetypes: (self: Query<T...>) -> { Archetype },
 		cached: (self: Query<T...>) -> Query<T...>,
 		ids: { Id<any> },
+		patch: (self: Query<T...>, fn: (T...) -> (T...)) -> (),
+		view: (self: Query<T...>) -> View<T...>,
 		-- world: World
 	},
 	{} :: {
@@ -68,6 +70,12 @@ export type Observer = {
 	query: QueryInner,
 }
 
+
+export type observer = {
+	callback: (archetype: archetype) -> (),
+	query: query,
+}
+
 type archetype = {
 	id: number,
 	types: { i53 },
@@ -504,7 +512,7 @@ local function ecs_pair_second(world: world, e: i53)
 	return ecs_get_alive(world, obj)
 end
 
-local function query_match(query: QueryInner, archetype: archetype)
+local function query_match(query: query, archetype: archetype)
 	local columns_map = archetype.columns_map
 	local with = query.filter_with
 
@@ -526,7 +534,7 @@ local function query_match(query: QueryInner, archetype: archetype)
 	return true
 end
 
-local function find_observers(world: world, event: i53, component: i53): { Observer }?
+local function find_observers(world: world, event: i53, component: i53): { observer }?
 	local cache = world.observable[event]
 	if not cache then
 		return nil
@@ -725,7 +733,7 @@ local function world_target(world: world, entity: i53, relation: i53, index: num
 	local nth = index or 0
 
 	if nth >= count then
-		nth = nth + count + 1
+		return nil
 	end
 
 	nth = archetype.types[nth + idr.records[archetype_id]]
@@ -871,6 +879,7 @@ local function archetype_create(world: world, id_types: { i53 }, ty, prev: i53?)
 
 	for i, component_id in archetype.types do
 		local idr = id_record_ensure(world, component_id)
+		idr.size += 1
 		local is_tag = bit32.btest(idr.flags, ECS_ID_IS_TAG)
 		local column = if is_tag then NULL_ARRAY else {}
 		columns[i] = column
@@ -882,11 +891,13 @@ local function archetype_create(world: world, id_types: { i53 }, ty, prev: i53?)
 			local object = ECS_PAIR_SECOND(component_id)
 			local r = ECS_PAIR(relation, EcsWildcard)
 			local idr_r = id_record_ensure(world, r)
+			idr_r.size += 1
 
 			archetype_append_to_records(idr_r, archetype_id, columns_map, r, i, column)
 
 			local t = ECS_PAIR(EcsWildcard, object)
 			local idr_t = id_record_ensure(world, t)
+			idr_t.size += 1
 
 			archetype_append_to_records(idr_t, archetype_id, columns_map, t, i, column)
 		end
@@ -2615,7 +2626,7 @@ local function world_new()
 				table.insert(listeners, existing_hook)
 			end
 
-			local idr = world.component_index[component]
+			local idr = component_index[ECS_PAIR(component, EcsWildcard)] or component_index[component]
 			if idr then
 				idr.on_add = on_add
 			else
@@ -2650,7 +2661,7 @@ local function world_new()
 				table.insert(listeners, existing_hook)
 			end
 
-			local idr = world.component_index[component]
+			local idr = component_index[ECS_PAIR(component, EcsWildcard)] or component_index[component]
 			if idr then
 				idr.on_change = on_change
 			else
@@ -2681,7 +2692,7 @@ local function world_new()
 				table.insert(listeners, existing_hook)
 			end
 
-			local idr = world.component_index[component]
+			local idr = component_index[ECS_PAIR(component, EcsWildcard)] or component_index[component]
 			if idr then
 				idr.on_remove = on_remove
 			else
@@ -2748,7 +2759,7 @@ local function world_new()
 		local nth = index or 0
 
 		if nth >= count then
-			nth = nth + count + 1
+			return nil
 		end
 
 		nth = archetype.types[nth + idr.records[archetype_id]]

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@rbxts/jecs",
-	"version": "0.9.0-rc.6",
+	"version": "0.9.0-rc.8",
 	"description": "Stupidly fast Entity Component System",
 	"main": "jecs.luau",
 	"repository": {

test/addons/observers.luau

@@ -2,11 +2,28 @@ local jecs = require("@jecs")
 local testkit = require("@testkit")
 local test = testkit.test()
 local CASE, TEST, FINISH, CHECK = test.CASE, test.TEST, test.FINISH, test.CHECK
+local FOCUS = test.FOCUS
 local ob = require("@addons/ob")
 
 TEST("addons/observers", function()
-	local world = jecs.world()
 
+	local world = jecs.world()
+	do CASE "monitors should accept pairs"
+		local A = world:component()
+		local B = world:component()
+
+		local c = 1
+		ob.monitor(world:query(jecs.pair(A, B)), function (_, event)
+			c += 1
+		end)
+
+		local child = world:entity()
+		world:add(child, jecs.pair(A, B))
+		CHECK(c == 2)
+
+		world:remove(child, jecs.pair(A, B))
+		CHECK(c == 3)
+	end
 	do CASE "Ensure ordering between signals and observers"
 		local A = world:component()
 		local B = world:component()

test/tests.luau

@@ -1064,40 +1064,77 @@ end)
 
 TEST("world:added", function()
 	local world = jecs.world()
-
 	do CASE "Should work even if set after the component has been used"
 		local A = world:component()
-
 		world:set(world:entity(), A, 2)
 		local ran = false
 		world:added(A, function()
 			ran = true
 		end)
-
 		local entity = world:entity()
 		world:set(entity, A, 3)
+		CHECK(ran)
+	end
+
+
+	do CASE "Should work even if set after the pair has been used"
+		local A = world:component()
+		local B = world:component()
+
+		world:set(world:entity(), A, 2)
+		world:set(world:entity(), pair(A, B), 2)
+
+		world:added(A, function()
+			ran = true
+		end)
+
+		local entity = world:entity()
+		world:set(entity, pair(A, B), 3)
+		CHECK(ran)
+	end
+
+	do CASE "Should allow setting signal after Relation has been used as a component"
+		local A = world:component()
+		local B = world:component()
+
+		world:add(world:entity(), A)
+
+		world:added(A, function()
+			ran = true
+		end)
+
+		world:add(world:entity(), pair(A, B))
+		CHECK(ran)
+	end
+
+	do CASE "Should invoke signal for the Relation being set as a key despite a pair with Relation having been cached"
+		local A = world:component()
+		local B = world:component()
+
+		world:add(world:entity(), pair(A, B))
+
+		world:added(A, function()
+			ran = true
+		end)
+
+		world:add(world:entity(), A)
 
 		CHECK(ran)
 	end
 
 	do CASE "Should not override hook"
 		local A = world:component()
-
 		local count = 1
 		local function counter()
 			count += 1
 		end
-
 		world:set(A, jecs.OnAdd, counter)
 		world:added(A, counter)
 		world:set(world:entity(), A, false)
 		CHECK(count == (1 + 2))
 		world:set(world:entity(), A, false)
-
 		CHECK(count == (1 + (2 * 2)))
 	end
-
-
 end)
 
 TEST("world:range()", function()

wally.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ukendio/jecs"
-version = "0.9.0-rc.6"
+version = "0.9.0-rc.8"
 registry = "https://github.com/UpliftGames/wally-index"
 realm = "shared"
 license = "MIT"