Add examples

benches/general.luau

@@ -199,6 +199,7 @@ do
 			end
 
 			local q = world:query(A, B, C, D)
+			q:archetypes()
 			START()
 			for id in q do
 			end

benches/query.luau

@@ -11,15 +11,22 @@ end
 local jecs = require("@jecs")
 local mirror = require("@mirror")
 
-type i53 = number
-
 do
 	TITLE(testkit.color.white_underline("Jecs query"))
-	local ecs = jecs.world()
+	local ecs = jecs.world() :: jecs.World
 	do
 		TITLE("one component in common")
 
-		local function view_bench(world: jecs.World, A: i53, B: i53, C: i53, D: i53, E: i53, F: i53, G: i53, H: i53)
+		local function view_bench(world: jecs.World,
+			A: jecs.Id,
+			B: jecs.Id,
+			C: jecs.Id,
+			D: jecs.Id,
+			E: jecs.Id,
+			F: jecs.Id,
+			G: jecs.Id,
+			H: jecs.Id
+		)
 			BENCH("1 component", function()
 				for _ in world:query(A) do
 				end
@@ -131,11 +138,21 @@ end
 
 do
 	TITLE(testkit.color.white_underline("Mirror query"))
-	local ecs = mirror.World.new()
+	local ecs = mirror.World.new() :: jecs.World
 	do
 		TITLE("one component in common")
 
-		local function view_bench(world: jecs.World, A: i53, B: i53, C: i53, D: i53, E: i53, F: i53, G: i53, H: i53)
+		local function view_bench(
+			world: mirror.World,
+			A: jecs.Id,
+			B: jecs.Id,
+			C: jecs.Id,
+			D: jecs.Id,
+			E: jecs.Id,
+			F: jecs.Id,
+			G: jecs.Id,
+			H: jecs.Id
+		)
 			BENCH("1 component", function()
 				for _ in world:query(A) do
 				end

examples/luau/entities/basics.luau

@@ -1,15 +1,19 @@
 local jecs = require("@jecs")
-local world = jecs.World.new()
+local world = jecs.world()
 
-local Position = world:component()
+local Position = world:component() :: jecs.Id<vector>
 local Walking = world:component()
-local Name = world:component()
+local Name = world:component() :: jecs.Id<string>
+
+local function name(e: jecs.Entity): string
+	return assert(world:get(e, Name))
+end
 
 -- Create an entity with name Bob
 local bob = world:entity()
 
 -- The set operation finds or creates a component, and sets it.
-world:set(bob, Position, Vector3.new(10, 20, 30))
+world:set(bob, Position, vector.create(10, 20, 30))
 -- Name the entity Bob
 world:set(bob, Name, "Bob")
 -- The add operation adds a component without setting a value. This is
@@ -18,15 +22,16 @@ world:add(bob, Walking)
 
 -- Get the value for the Position component
 local pos = world:get(bob, Position)
-print(`\{{pos.X}, {pos.Y}, {pos.Z}\}`)
+assert(pos)
+print(`\{{pos.x}, {pos.y}, {pos.z}\}`)
 
 -- Overwrite the value of the Position component
-world:set(bob, Position, Vector3.new(40, 50, 60))
+world:set(bob, Position, vector.create(40, 50, 60))
 
 local alice = world:entity()
 -- Create another named entity
 world:set(alice, Name, "Alice")
-world:set(alice, Position, Vector3.new(10, 20, 30))
+world:set(alice, Position, vector.create(10, 20, 30))
 world:add(alice, Walking)
 
 -- Remove tag
@@ -34,7 +39,7 @@ world:remove(alice, Walking)
 
 -- Iterate all entities with Position
 for entity, p in world:query(Position) do
-	print(`{entity}: \{{p.X}, {p.Y}, {p.Z}\}`)
+	print(`{name(entity)}: \{{p.x}, {p.y}, {p.z}\}`)
 end
 
 -- Output:

examples/luau/queries/archetypes/targets.luau

@@ -0,0 +1,60 @@
+-- Using world:target is the recommended way to grab the target in a wildcard
+-- query. However the random access can add up in very hot paths. Accessing its
+-- column can drastically improve performance, especially when there are
+-- multiple adjacent pairs.
+
+local jecs = require("@jecs")
+local pair = jecs.pair
+local __ = jecs.Wildcard
+
+local world = jecs.world()
+
+local Likes = world:entity()
+local function name(e, name: string): string
+	if name then
+		world:set(e, jecs.Name, name)
+		return name
+	end
+	return assert(world:get(e, jecs.Name))
+end
+
+local e1 = world:entity()
+name(e1, "e1")
+local e2 = world:entity()
+name(e2, "e2")
+local e3 = world:entity()
+name(e3, "e3")
+
+world:add(e1, pair(Likes, e2))
+world:add(e1, pair(Likes, e3))
+
+local likes = jecs.component_record(world, pair(Likes, __))
+assert(likes)
+
+local likes_cr = likes.records
+local likes_counts = likes.counts
+
+local archetypes = world:query(pair(Likes, __)):archetypes()
+
+for _, archetype in archetypes do
+	local types = archetype.types
+
+	-- Get the starting index which is what the (R, *) alias is at
+	local wc = likes_cr[archetype.id]
+	local count = likes_counts[archetype.id]
+
+	local entities = archetype.entities
+	for i = #entities, 1, -1 do
+		-- It is generally a good idea to iterate backwards on arrays if you
+		-- need to delete the iterated entity to prevent iterator invalidation
+		local entity = entities[i]
+		for cr = wc, wc + count - 1 do
+			local person = jecs.pair_second(world, types[cr])
+			print(`entity ${entity} likes ${person}`)
+		end
+	end
+end
+
+-- Output:
+--  entity $273 likes $275
+--  entity $273 likes $274

examples/luau/queries/archetypes/visibility_cascades.luau

@@ -0,0 +1,44 @@
+-- To get the most out of performance, you can lift the inner loop of queries to
+-- the system in which you can do archetype-specific optimizations like finding
+-- the parent once per archetype rather than per entity.
+
+local jecs = require("@jecs")
+local pair = jecs.pair
+local ChildOf = jecs.ChildOf
+local __ = jecs.Wildcard
+
+local world = jecs.world()
+
+local Position = world:component() :: jecs.Id<vector>
+local Visible = world:entity()
+
+local parent = world:entity()
+world:set(parent, Position, vector.zero)
+world:add(parent, Visible)
+
+local child = world:entity()
+world:set(child, Position, vector.one)
+world:add(child, pair(ChildOf, parent))
+
+local parents = jecs.component_record(world, pair(ChildOf, __))
+assert(parents)
+
+local parent_cr = parents.records
+
+local archetypes = world:query(Position, pair(ChildOf, __)):archetypes()
+
+for _, archetype in archetypes do
+	local types = archetype.types
+	local p = jecs.pair_second(world, types[parent_cr[archetype.id]])
+	if world:has(p, Visible) then
+		local columns = archetype.columns_map
+		local positions = columns[Position]
+	  	for row, entity in archetype.entities do
+			local pos = positions[row]
+			print(`Child ${entity} of ${p} is visible at {pos}`)
+		end
+	end
+end
+
+-- Output:
+--  Child $274 of $273 is visibile at 1,1,1

examples/luau/queries/basics.luau

@@ -1,5 +1,5 @@
 local jecs = require("@jecs")
-local world = jecs.World.new()
+local world = jecs.world()
 
 local Position = world:component()
 local Velocity = world:component()

examples/luau/queries/changetracking.luau

@@ -1,19 +1,16 @@
 local jecs = require("@jecs")
 local pair = jecs.pair
 
-local world = jecs.World.new()
+local world = jecs.world()
-local Name = world:component()
+local Name = world:component() :: jecs.Id<string>
 
-local function named(ctr, name)
+
-	local e = ctr(world)
+local function name(e: jecs.Entity): string
-	world:set(e, Name, name)
+	return assert(world:get(e, Name))
-	return e
-end
-local function name(e)
-	return world:get(e, Name)
 end
 
-local Position = named(world.component, "Position") :: jecs.Entity<vector>
+local Position = world:component() :: jecs.Id<vector>
+world:set(Position, Name, "Position")
 local Previous = jecs.Rest
 
 local added = world
@@ -29,10 +26,14 @@ local removed = world
 	:cached()
 
 
-local e1 = named(world.entity, "e1")
+local e1 = world:entity()
+world:set(e1, Name, "e1")
 world:set(e1, Position, vector.create(10, 20, 30))
-local e2 = named(world.entity, "e2")
+
+local e2 = world:entity()
+world:set(e2, Name, "e2")
 world:set(e2, Position, vector.create(10, 20, 30))
+
 for entity, p in added do
 	print(`Added {name(entity)}: \{{p.x}, {p.y}, {p.z}}`)
 	world:set(entity, pair(Previous, Position), p)
@@ -40,10 +41,10 @@ end
 
 world:set(e1, Position, vector.create(999, 999, 1998))
 
-for _, archetype in changed:archetypes() do
+for entity, new, old in changed do
 	if new ~= old then
-		print(`{name(e)}'s Position changed from \{{old.x}, {old.y}, {old.z}\} to \{{new.x}, {new.y}, {new.z}\}`)
+		print(`{name(entity)}'s Position changed from \{{old.x}, {old.y}, {old.z}\} to \{{new.x}, {new.y}, {new.z}\}`)
-		world:set(e, pair(Previous, Position), new)
+		world:set(entity, pair(Previous, Position), new)
 	end
 end
 

examples/luau/queries/spatial_grids.luau

@@ -3,32 +3,47 @@ local pair = jecs.pair
 local ChildOf = jecs.ChildOf
 local __ = jecs.Wildcard
 local Name = jecs.Name
-local world = jecs.World.new()
+local world = jecs.world()
 
-type Id<T = nil> = number & { __T: T }
+local Voxel = world:component() :: jecs.Id
-local Voxel = world:component() :: Id
+local Position = world:component() :: jecs.Id<vector>
-local Position = world:component() :: Id<Vector3>
+local Perception = world:component() :: jecs.Id<{
-local Perception = world:component() :: Id<{
 	range: number,
 	fov: number,
-	dir: Vector3,
+	dir: vector,
 }>
-local PrimaryPart = world:component() :: Id<Part>
+type part = {
+	Position: vector
+}
+local PrimaryPart = world:component() :: jecs.Id<part>
 
-local local_player = game:GetService("Players").LocalPlayer
+local local_player = {
+	Character = {
+		PrimaryPart = {
+			Position = vector.create(50, 0, 30)
+		}
+	}
+}
+local workspace = {
+	CurrentCamera = {
+		CFrame = {
+			LookVector = vector.create(0, 0, -1)
+		}
+	}
+}
 
-local function distance(a: Vector3, b: Vector3)
+local function distance(a: vector, b: vector)
-	return (b - a).Magnitude
+	return vector.magnitude((b - a))
 end
 
-local function is_in_fov(a: Vector3, b: Vector3, forward_dir: Vector3, fov_angle: number)
+local function is_in_fov(a: vector, b: vector, forward_dir: vector, fov_angle: number)
 	local to_target = b - a
 
-	local forward_xz = Vector3.new(forward_dir.X, 0, forward_dir.Z).Unit
+	local forward_xz = vector.normalize(vector.create(forward_dir.x, 0, forward_dir.z))
-	local to_target_xz = Vector3.new(to_target.X, 0, to_target.Z).Unit
+	local to_target_xz = vector.normalize(vector.create(to_target.x, 0, to_target.z))
 
-	local angle_to_target = math.deg(math.atan2(to_target_xz.Z, to_target_xz.X))
+	local angle_to_target = math.deg(math.atan2(to_target_xz.z, to_target_xz.x))
-	local forward_angle = math.deg(math.atan2(forward_xz.Z, forward_xz.X))
+	local forward_angle = math.deg(math.atan2(forward_xz.z, forward_xz.z))
 
 	local angle_difference = math.abs(forward_angle - angle_to_target)
 
@@ -42,7 +57,7 @@ end
 local map = {}
 local grid = 50
 
-local function add_to_voxel(source: number, position: Vector3, prev_voxel_id: number?)
+local function add_to_voxel(source: jecs.Entity, position: vector, prev_voxel_id: jecs.Entity?)
 	local hash = position // grid
 	local voxel_id = map[hash]
 	if not voxel_id then
@@ -79,7 +94,7 @@ local function update_camera_direction(dt: number)
 end
 
 local function perceive_enemies(dt: number)
-	local it = world:query(Perception, Position, PrimaryPart)
+	local it = world:query(Perception, Position, PrimaryPart):iter()
 	-- There is only going to be one entity matching the query
 	local e, self_perception, self_position, self_primary_part = it()
 
@@ -93,28 +108,28 @@ local function perceive_enemies(dt: number)
 
 		if is_in_fov(self_position, target_position, self_perception.dir, self_perception.fov) then
 			local p = target_position
-			print(`Entity {world:get(e, Name)} can see target {world:get(enemy, Name)} at ({p.X}, {p.Y}, {p.Z})`)
+			print(`Entity {world:get(e, Name)} can see target {world:get(enemy, Name)} at ({p.x}, {p.y}, {p.z})`)
 		end
 	end
 end
 
 local player = world:entity()
 world:set(player, Perception, {
-	range = 100,
+	range = 200,
 	fov = 90,
-	dir = Vector3.new(1, 0, 0),
+	dir = vector.create(1, 0, 0),
 })
 world:set(player, Name, "LocalPlayer")
-local primary_part = (local_player.Character :: Model).PrimaryPart :: Part
+local primary_part = local_player.Character.PrimaryPart
 world:set(player, PrimaryPart, primary_part)
-world:set(player, Position, Vector3.zero)
+world:set(player, Position, vector.zero)
 
 local enemy = world:entity()
 world:set(enemy, Name, "Enemy $1")
-world:set(enemy, Position, Vector3.new(50, 0, 20))
+world:set(enemy, Position, vector.create(50, 0, 20))
 
 add_to_voxel(player, primary_part.Position)
-add_to_voxel(enemy, world)
+add_to_voxel(enemy, assert(world:get(enemy, Position)))
 
 local dt = 1 / 60
 reconcile_client_owned_assembly_to_voxel(dt)

jecs.d.ts

@@ -184,6 +184,11 @@ export class World {
 	 */
 	cleanup(): void;
 
+	/**
+	 * Removes all instances of specified component
+	 */
+	// purge<T>(component: Id<T>): void
+
 	/**
 	 * Clears all components and relationships from the given entity, but
 	 * does not delete the entity from the world.

jecs.luau

@@ -54,6 +54,8 @@ export type Query<T...> = typeof(setmetatable(
 		archetypes: (self: Query<T...>) -> { Archetype },
 		cached: (self: Query<T...>) -> Query<T...>,
 		ids: { Id<any> },
+		filter_with: { Id<any> }?,
+		filter_without: { Id<any> }?
 		-- world: World
 	},
 	{} :: {
@@ -92,13 +94,14 @@ type archetype = {
 }
 
 type componentrecord = {
+	component: i53,
 	records: { [number]: number },
 	counts: { [i53]: number },
 	flags: number,
 	size: number,
 
-	on_add: ((entity: i53, id: i53, value: any?) -> ())?,
+	on_add: ((entity: i53, id: i53, value: any, oldarchetype: archetype) -> ())?,
-	on_change: ((entity: i53, id: i53, value: any) -> ())?,
+	on_change: ((entity: i53, id: i53, value: any, oldarchetype: archetype) -> ())?,
 	on_remove: ((entity: i53, id: i53) -> ())?,
 
 	wildcard_pairs: { [number]: componentrecord },
@@ -137,7 +140,7 @@ type world = {
 	add: (self: world, id: i53, component: i53) -> (),
 	set: (self: world, id: i53, component: i53, data: any) -> (),
 	cleanup: (self: world) -> (),
-	clear: (self: world, id: i53) -> (),
+	clear: (self: world, entity: i53) -> (),
 	remove: (self: world, id: i53, component: i53) -> (),
 	get: (world, ...i53) -> (),
 	has: (world, ...i53) -> boolean,
@@ -166,9 +169,9 @@ export type World = {
 
 	observable: Map<Id, Map<Id, { Observer }>>,
 
-	added: <T>(World, Entity<T>, <e>(e: Entity<e>, id: Id<T>, value: T) -> ()) -> () -> (),
+	added: <T>(World, Entity<T>, <e>(e: Entity<e>, id: Id<T>, value: T, oldarchetype: Archetype) -> ()) -> () -> (),
 	removed: <T>(World, Entity<T>, (e: Entity, id: Id<T>) -> ()) -> () -> (),
-	changed:  <T>(World, Entity<T>, <e>(e: Entity<e>, id: Id<T>, value: T) -> ()) -> () -> (),
+	changed:  <T>(World, Entity<T>, <e>(e: Entity<e>, id: Id<T>, value: T, oldarchetype: Archetype) -> ()) -> () -> (),
 
 	--- Enforce a check on entities to be created within desired range
 	range: (self: World, range_begin: number, range_end: number?) -> (),
@@ -190,8 +193,9 @@ export type World = {
 	set: <T, a>(self: World, id: Entity<T>, component: Id<a>, data: a) -> (),
 
 	cleanup: (self: World) -> (),
-	-- Clears an entity from the world
+
-	clear: <a>(self: World, id: Id<a>) -> (),
+	-- Removes all components from the entity
+	clear: (self: World, entity: Entity) -> (),
 	--- Removes a component from the given entity
 	remove: <T, a>(self: World, id: Entity<T>, component: Id<a>) -> (),
 	--- Retrieves the value of up to 4 components. These values may be nil.
@@ -261,8 +265,8 @@ export type ComponentRecord = {
 	flags: number,
 	size: number,
 
-	on_add: (<T>(entity: Entity, id: Entity<T>, value: T?) -> ())?,
+	on_add: (<T>(entity: Entity, id: Entity<T>, value: T, oldarchetype: Archetype) -> ())?,
-	on_change: (<T>(entity: Entity, id: Entity<T>, value: T) -> ())?,
+	on_change: (<T>(entity: Entity, id: Entity<T>, value: T, oldArchetype: Archetype) -> ())?,
 	on_remove: ((entity: Entity, id: Entity) -> ())?,
 }
 export type ComponentIndex = Map<Id, ComponentRecord>
@@ -484,7 +488,7 @@ end
 
 local ECS_INTERNAL_ERROR_INCOMPATIBLE_ENTITY = "Entity is outside range"
 
-local function entity_index_new_id(entity_index: entityindex): i53
+local function ENTITY_INDEX_NEW_ID(entity_index: entityindex): i53
 	local dense_array = entity_index.dense_array
 	local alive_count = entity_index.alive_count
 	local sparse_array = entity_index.sparse_array
@@ -669,7 +673,7 @@ local function fetch(id: i53, columns_map: { [i53]: Column }, row: number): any
 	return column[row]
 end
 
-local function world_get(world: world, entity: i53,
+local function WORLD_GET(world: world, entity: i53,
 	a: i53, b: i53?, c: i53?, d: i53?, e: i53?): ...any
 	local record = entity_index_try_get(world.entity_index, entity)
 	if not record then
@@ -699,7 +703,7 @@ local function world_get(world: world, entity: i53,
 	end
 end
 
-local function world_has_one_inline(world: world, entity: i53, id: i53): boolean
+local function WORLD_HAS(world: world, entity: i53, id: i53): boolean
 	local record = entity_index_try_get(world.entity_index, entity)
 	if not record then
 		return false
@@ -713,7 +717,7 @@ local function world_has_one_inline(world: world, entity: i53, id: i53): boolean
 	return archetype.columns_map[id] ~= nil
 end
 
-local function world_target(world: world, entity: i53, relation: i53, index: number?): i53?
+local function WORLD_TARGET(world: world, entity: i53, relation: i53, index: number?): i53?
 	local entity_index = world.entity_index
 	local record = entity_index_try_get(entity_index, entity)
 	if not record then
@@ -771,15 +775,12 @@ local function id_record_get(world: World, id: Entity): ComponentRecord?
 	return nil
 end
 
-local function id_record_ensure(world: world, id: i53): componentrecord
+local function id_record_create(
-	local component_index = world.component_index
+	world: world,
+	component_index: Map<i53, componentrecord>,
+	id: i53
+): componentrecord
 	local entity_index = world.entity_index
-	local idr: componentrecord? = component_index[id]
-
-	if idr then
-		return idr
-	end
-
 	local flags = ECS_ID_MASK
 	local relation = id
 	local target = 0
@@ -796,31 +797,31 @@ local function id_record_ensure(world: world, id: i53): componentrecord
 		ecs_assert(target and entity_index_is_alive(
 			entity_index, target), ECS_INTERNAL_ERROR)
 
-		local cleanup_policy_target = world_target(world, relation, EcsOnDeleteTarget, 0)
+		local cleanup_policy_target = WORLD_TARGET(world, relation, EcsOnDeleteTarget, 0)
 
 		if cleanup_policy_target == EcsDelete then
 			has_delete = true
 		end
 
-		if world_has_one_inline(world, relation, EcsExclusive) then
+		if WORLD_HAS(world, relation, EcsExclusive) then
 			is_exclusive = true
 		end
 	end
 
-	local cleanup_policy = world_target(world, relation, EcsOnDelete, 0)
+	local cleanup_policy = WORLD_TARGET(world, relation, EcsOnDelete, 0)
 
 	if cleanup_policy == EcsDelete then
 		has_delete = true
 	end
 
-	local on_add, on_change, on_remove = world_get(world,
+	local on_add, on_change, on_remove = WORLD_GET(world,
 		relation, EcsOnAdd, EcsOnChange, EcsOnRemove)
 
-	local is_tag = not world_has_one_inline(world,
+	local is_tag = not WORLD_HAS(world,
 		relation, EcsComponent)
 
 	if is_tag and is_pair then
-		is_tag = not world_has_one_inline(world, target, EcsComponent)
+		is_tag = not WORLD_HAS(world, target, EcsComponent)
 	end
 
 	flags = bit32.bor(
@@ -830,7 +831,7 @@ local function id_record_ensure(world: world, id: i53): componentrecord
 		if is_exclusive then ECS_ID_IS_EXCLUSIVE else 0
 	)
 
-	idr = {
+	local idr = {
 		size = 0,
 		records = {},
 		counts = {},
@@ -846,6 +847,17 @@ local function id_record_ensure(world: world, id: i53): componentrecord
 	return idr
 end
 
+local function id_record_ensure(world: world, id: i53): componentrecord
+	local component_index = world.component_index
+	local idr: componentrecord? = component_index[id]
+
+	if idr then
+		return idr
+	end
+
+	return id_record_create(world, component_index, id)
+end
+
 local function archetype_append_to_records(
 	idr: componentrecord,
 	archetype_id: number,
@@ -915,14 +927,6 @@ local function archetype_create(world: world, id_types: { i53 }, ty, prev: i53?)
 
 			idr_t.size += 1
 			archetype_append_to_records(idr_t, archetype_id, columns_map, t, i, column)
-
-			-- Hypothetically this should only capture leaf component records
-			local idr_t_wc_pairs = idr_t.wildcard_pairs
-			if not idr_t_wc_pairs then
-				idr_t_wc_pairs = {} :: {[i53]: componentrecord }
-				idr_t.wildcard_pairs = idr_t_wc_pairs
-			end
-			idr_t_wc_pairs[component_id] = idr
 		end
 	end
 
@@ -2049,6 +2053,7 @@ local function ecs_bulk_insert(world: world, entity: i53, ids: { i53 }, values:
 		local dst_types = ids
 		local to = archetype_ensure(world, dst_types)
 		new_entity(entity, r, to)
+		local ROOT_ARCHETYPE = world.ROOT_ARCHETYPE
 		for i, id in ids do
 			local value = values[i]
 			local cdr = component_index[id]
@@ -2057,11 +2062,11 @@ local function ecs_bulk_insert(world: world, entity: i53, ids: { i53 }, values:
 			if value then
 				r.archetype.columns_map[id][r.row] = value
 				if on_add then
-					on_add(entity, id, value :: any)
+					on_add(entity, id, value, ROOT_ARCHETYPE)
 				end
 			else
 				if on_add then
-					on_add(entity, id)
+					on_add(entity, id, nil, ROOT_ARCHETYPE)
 				end
 			end
 		end
@@ -2103,10 +2108,10 @@ local function ecs_bulk_insert(world: world, entity: i53, ids: { i53 }, values:
 			local on_change = idr.on_change
 			local hook = if set then on_change else on_add
 			if hook then
-				hook(entity, id, value :: any)
+				hook(entity, id, value :: any, from)
 			end
 		elseif on_add then
-			on_add(entity, id)
+			on_add(entity, id, nil, from)
 		end
 	end
 end
@@ -2208,11 +2213,34 @@ local function world_new()
 	} :: world
 
 
+	local function entity_index_new_id(entity_index: entityindex): i53
+		local alive_count = entity_index.alive_count
+		local max_id = entity_index.max_id
+
+		if alive_count < max_id then
+			alive_count += 1
+			entity_index.alive_count = alive_count
+			local id = eindex_dense_array[alive_count]
+			return id
+		end
+
+		local id = max_id + 1
+		local range_end = entity_index.range_end
+		ecs_assert(range_end == nil or id < range_end, ECS_INTERNAL_ERROR_INCOMPATIBLE_ENTITY)
+
+		entity_index.max_id = id
+		alive_count += 1
+		entity_index.alive_count = alive_count
+		eindex_dense_array[alive_count] = id
+		eindex_sparse_array[id] = { dense = alive_count } :: record
+
+		return id
+	end
 
 	local ROOT_ARCHETYPE = archetype_create(world, {}, "")
 	world.ROOT_ARCHETYPE = ROOT_ARCHETYPE
 
-	local function inner_entity_index_try_get_any(entity: i53): record?
+	local function entity_index_try_get_any(entity: i53): record?
 		local r = eindex_sparse_array[ECS_ENTITY_T_LO(entity)]
 		return r
 	end
@@ -2274,7 +2302,6 @@ local function world_new()
 	end
 
 	local function inner_entity_move(
-		entity_index: entityindex,
 		entity: i53,
 		record: record,
 		to: archetype
@@ -2287,8 +2314,8 @@ local function world_new()
 		record.row = dst_row
 	end
 
-	-- local function inner_entity_index_try_get(entity: number): Record?
+	-- local function entity_index_try_get(entity: number): Record?
-	-- 	local r = inner_entity_index_try_get_any(entity)
+	-- 	local r = entity_index_try_get_any(entity)
 	-- 	if r then
 	-- 		local r_dense = r.dense
 	-- 		if r_dense > entity_index.alive_count then
@@ -2301,7 +2328,7 @@ local function world_new()
 	-- 	return r
 	-- end
 
-	local function inner_entity_index_try_get_unsafe(entity: i53): record?
+	local function entity_index_try_get_unsafe(entity: i53): record?
 		local r = eindex_sparse_array[ECS_ENTITY_T_LO(entity)]
 		if r then
 			local r_dense = r.dense
@@ -2331,8 +2358,8 @@ local function world_new()
 		return to
 	end
 
-	local function inner_world_set(world: world, entity: i53, id: i53, data): ()
+	local function world_set(world: world, entity: i53, id: i53, data): ()
-		local record = inner_entity_index_try_get_unsafe(entity)
+		local record = entity_index_try_get_unsafe(entity)
 		if not record then
 			return
 		end
@@ -2348,7 +2375,7 @@ local function world_new()
 			-- and just set the data directly.
 			local on_change = idr.on_change
 			if on_change then
-				on_change(entity, id, data)
+				on_change(entity, id, data, src)
 			end
 		else
 			local to: archetype
@@ -2418,7 +2445,7 @@ local function world_new()
 
 			if from then
 				-- If there was a previous archetype, then the entity needs to move the archetype
-				inner_entity_move(entity_index, entity, record, to)
+				inner_entity_move(entity, record, to)
 			else
 				new_entity(entity, record, to)
 			end
@@ -2428,18 +2455,17 @@ local function world_new()
 
 			local on_add = idr.on_add
 			if on_add then
-				on_add(entity, id, data)
+				on_add(entity, id, data, src)
 			end
 		end
 	end
 
-	local function inner_world_add(
+	local function world_add(
 		world: world,
 		entity: i53,
 		id: i53
 	): ()
-		local entity_index = world.entity_index
+		local record = entity_index_try_get_unsafe(entity :: number)
-		local record = inner_entity_index_try_get_unsafe(entity :: number)
 		if not record then
 			return
 		end
@@ -2517,7 +2543,7 @@ local function world_new()
 		end
 
 		if from then
-			inner_entity_move(entity_index, entity, record, to)
+			inner_entity_move(entity, record, to)
 		else
 			if #to.types > 0 then
 				new_entity(entity, record, to)
@@ -2527,13 +2553,13 @@ local function world_new()
 		local on_add = idr.on_add
 
 		if on_add then
-			on_add(entity, id)
+			on_add(entity, id, nil, src)
 		end
 	end
 
-	local function inner_world_get(world: world, entity: i53,
+	local function world_get(world: world, entity: i53,
 		a: i53, b: i53?, c: i53?, d: i53?, e: i53?): ...any
-		local record = inner_entity_index_try_get_unsafe(entity)
+		local record = entity_index_try_get_unsafe(entity)
 		if not record then
 			return nil
 		end
@@ -2561,7 +2587,7 @@ local function world_new()
 		end
 	end
 
-	type Listener<T> = (e: i53, id: i53, value: T?) -> ()
+	type Listener<T> = (e: i53, id: i53, value: T, oldarchetype: archetype) -> ()
 
 	world.added = function<T>(_: world, component: i53, fn: Listener<T>)
 		local listeners = signals.added[component]
@@ -2569,12 +2595,12 @@ local function world_new()
 			listeners = {}
 			signals.added[component] = listeners
 
-			local function on_add(entity, id, value)
+			local function on_add(entity, id, value, oldarchetype)
 				for _, listener in listeners :: { Listener<T> } do
-					listener(entity, id, value)
+					listener(entity, id, value, oldarchetype)
 				end
 			end
-			local existing_hook = inner_world_get(world, component, EcsOnAdd) :: Listener<T>
+			local existing_hook = world_get(world, component, EcsOnAdd) :: Listener<T>
 			if existing_hook then
 				table.insert(listeners, existing_hook)
 			end
@@ -2592,7 +2618,7 @@ local function world_new()
 					idr.on_add = on_add
 				end
 			end
-			inner_world_set(world, component, EcsOnAdd, on_add)
+			world_set(world, component, EcsOnAdd, on_add)
 		end
 		table.insert(listeners, fn)
 		return function()
@@ -2612,12 +2638,12 @@ local function world_new()
 		if not listeners then
 			listeners = {}
 			signals.changed[component] = listeners
-			local function on_change(entity, id, value: any)
+			local function on_change(entity, id, value, oldarchetype)
 				for _, listener in listeners :: { Listener<T> }  do
-					listener(entity, id, value)
+					listener(entity, id, value, oldarchetype)
 				end
 			end
-			local existing_hook = inner_world_get(world, component, EcsOnChange) :: Listener<T>
+			local existing_hook = world_get(world, component, EcsOnChange) :: Listener<T>
 			if existing_hook then
 				table.insert(listeners, existing_hook)
 			end
@@ -2637,7 +2663,7 @@ local function world_new()
 				end
 			end
 
-			inner_world_set(world, component, EcsOnChange, on_change)
+			world_set(world, component, EcsOnChange, on_change)
 		end
 		table.insert(listeners, fn)
 		return function()
@@ -2654,12 +2680,12 @@ local function world_new()
 			listeners = {}
 			signals.removed[component] = listeners
 			local function on_remove(entity, id)
-				for _, listener in listeners :: { Listener<T> } do
+				for _, listener in listeners :: { (...any) -> () } do
 					listener(entity, id)
 				end
 			end
 
-			local existing_hook = inner_world_get(world, component, EcsOnRemove) :: Listener<T>
+			local existing_hook = world_get(world, component, EcsOnRemove) :: Listener<T>
 			if existing_hook then
 				table.insert(listeners, existing_hook)
 			end
@@ -2679,7 +2705,7 @@ local function world_new()
 				end
 			end
 
-			inner_world_set(world, component, EcsOnRemove, on_remove)
+			world_set(world, component, EcsOnRemove, on_remove)
 		end
 
 		table.insert(listeners, fn)
@@ -2692,10 +2718,10 @@ local function world_new()
 		end
 	end
 
-	local function inner_world_has(world: World, entity: i53,
+	local function world_has(world: World, entity: i53,
 		a: i53, b: i53?, c: i53?, d: i53?, e: i53?): boolean
 
-		local record = inner_entity_index_try_get_unsafe(entity)
+		local record = entity_index_try_get_unsafe(entity)
 		if not record then
 			return false
 		end
@@ -2714,8 +2740,8 @@ local function world_new()
 			(e == nil or error("args exceeded"))
 	end
 
-	local function inner_world_target(world: world, entity: i53, relation: i53, index: number?): i53?
+	local function world_target(world: world, entity: i53, relation: i53, index: number?): i53?
-		local record = inner_entity_index_try_get_unsafe(entity)
+		local record = entity_index_try_get_unsafe(entity)
 		if not record then
 			return nil
 		end
@@ -2754,11 +2780,11 @@ local function world_new()
 		    ECS_PAIR_SECOND(nth))
 	end
 
-	local function inner_world_parent(world: world, entity: i53): i53?
+	local function world_parent(world: world, entity: i53): i53?
-		return inner_world_target(world, entity, EcsChildOf, 0)
+		return world_target(world, entity, EcsChildOf, 0)
 	end
 
-	local function inner_world_entity(world: world, entity: i53?): i53
+	local function world_entity(world: world, entity: i53?): i53
 		if entity then
 			local index = ECS_ID(entity)
 			local alive_count = entity_index.alive_count
@@ -2770,7 +2796,7 @@ local function world_new()
 					r.dense = index
 					dense = index
 					local e_swap = eindex_dense_array[dense]
-					local r_swap = inner_entity_index_try_get_any(e_swap) :: record
+					local r_swap = entity_index_try_get_any(e_swap) :: record
 
 					r_swap.dense = dense
 					alive_count += 1
@@ -2786,7 +2812,7 @@ local function world_new()
 				if any ~= entity then
 					if alive_count <= dense then
 						local e_swap = eindex_dense_array[dense]
-						local r_swap = inner_entity_index_try_get_any(e_swap) :: record
+						local r_swap = entity_index_try_get_any(e_swap) :: record
 
 						r_swap.dense = dense
 						alive_count += 1
@@ -2828,8 +2854,8 @@ local function world_new()
 		return entity_index_new_id(entity_index)
 	end
 
-	local function inner_world_remove(world: world, entity: i53, id: i53)
+	local function world_remove(world: world, entity: i53, id: i53)
-		local record = inner_entity_index_try_get_unsafe(entity)
+		local record = entity_index_try_get_unsafe(entity)
 		if not record then
 			return
 		end
@@ -2849,99 +2875,12 @@ local function world_new()
 
 			local to = archetype_traverse_remove(world, id, record.archetype)
 
-			inner_entity_move(entity_index, entity, record, to)
+			inner_entity_move(entity, record, to)
 		end
 	end
 
-	local function inner_world_clear(world: world, entity: i53)
+	local function world_delete(world: world, entity: i53)
-		local tgt = ECS_PAIR(EcsWildcard, entity)
+		local record = entity_index_try_get_unsafe(entity)
-		local idr_t = component_index[tgt]
-		local idr = component_index[entity]
-		local rel = ECS_PAIR(entity, EcsWildcard)
-		local idr_r = component_index[rel]
-
-		if idr then
-			local count = 0
-			local queue = {}
-			for archetype_id in idr.records do
-				local idr_archetype = archetypes[archetype_id]
-				local entities = idr_archetype.entities
-				local n = #entities
-				table.move(entities, 1, n, count + 1, queue)
-				count += n
-			end
-			for _, e in queue do
-				inner_world_remove(world, e, entity)
-			end
-		end
-
-		if idr_t then
-			local archetype_ids = idr_t.records
-			for archetype_id in archetype_ids do
-				local idr_t_archetype = archetypes[archetype_id]
-				local idr_t_types = idr_t_archetype.types
-				local entities = idr_t_archetype.entities
-
-				local node = idr_t_archetype
-
-				for _, id in idr_t_types do
-					if not ECS_IS_PAIR(id) then
-						continue
-					end
-					local object = entity_index_get_alive(
-					    entity_index, ECS_PAIR_SECOND(id))
-					if object ~= entity then
-						continue
-					end
-					node = archetype_traverse_remove(world, id, node)
-					local on_remove = component_index[id].on_remove
-					if on_remove then
-						for _, entity in entities do
-							on_remove(entity, id)
-						end
-					end
-				end
-
-				for i = #entities, 1, -1 do
-					local e = entities[i]
-					local r = inner_entity_index_try_get_unsafe(e) :: record
-					inner_entity_move(entity_index, e, r, node)
-				end
-			end
-		end
-
-		if idr_r then
-			local archetype_ids = idr_r.records
-			local records = idr_r.records
-			local counts = idr_r.counts
-			for archetype_id in archetype_ids do
-				local idr_r_archetype = archetypes[archetype_id]
-				local node = idr_r_archetype
-				local entities = idr_r_archetype.entities
-				local tr = records[archetype_id]
-				local tr_count = counts[archetype_id]
-				local types = idr_r_archetype.types
-				for i = tr, tr + tr_count - 1 do
-					local id = types[i]
-					node = archetype_traverse_remove(world, id, idr_r_archetype)
-					local on_remove = component_index[id].on_remove
-					if on_remove then
-						for _, entity in entities do
-							on_remove(entity, id)
-						end
-					end
-				end
-				for i = #entities, 1, -1 do
-					local e = entities[i]
-					local r = inner_entity_index_try_get_unsafe(e) :: record
-					inner_entity_move(entity_index, e, r, node)
-				end
-			end
-		end
-	end
-
-	local function inner_world_delete(world: world, entity: i53)
-		local record = inner_entity_index_try_get_unsafe(entity)
 		if not record then
 			return
 		end
@@ -2977,7 +2916,7 @@ local function world_new()
 					local entities = idr_archetype.entities
 					local n = #entities
 					for i = n, 1, -1 do
-						inner_world_delete(world, entities[i])
+						world_delete(world, entities[i])
 					end
 
 					archetype_destroy(world, idr_archetype)
@@ -3000,7 +2939,7 @@ local function world_new()
 								-- this is hypothetically not that expensive of an operation anyways
 								to = archetype_traverse_remove(world, entity, from)
 							end
-							inner_entity_move(entity_index, e, r, to)
+							inner_entity_move(e, r, to)
 						end
 
 						archetype_destroy(world, idr_archetype)
@@ -3022,53 +2961,49 @@ local function world_new()
 			end
 		end
 		if idr_t then
-			for id, cr in idr_t.wildcard_pairs do
+			local archetype_ids = idr_t.records
-				local flags = cr.flags
+			for archetype_id in archetype_ids do
-				local flags_delete_mask = bit32.btest(flags, ECS_ID_DELETE)
+				local idr_t_archetype = archetypes[archetype_id]
-				local on_remove = cr.on_remove
+				local idr_t_types = idr_t_archetype.types
-				if flags_delete_mask then
+				local entities = idr_t_archetype.entities
-					for archetype_id in cr.records do
+
-						local idr_t_archetype = archetypes[archetype_id]
+				for _, id in idr_t_types do
-						local entities = idr_t_archetype.entities
+					if not ECS_IS_PAIR(id) then
+						continue
+					end
+					local object = entity_index_get_alive(
+					    entity_index, ECS_PAIR_SECOND(id))
+					if object ~= entity then
+						continue
+					end
+					local id_record = component_index[id]
+					local flags = id_record.flags
+					local flags_delete_mask = bit32.btest(flags, ECS_ID_DELETE)
+					if flags_delete_mask then
 						for i = #entities, 1, -1 do
 							local child = entities[i]
-							inner_world_delete(world, child)
+							world_delete(world, child)
 						end
-					end
+						break
-				else
+					else
-					for archetype_id in cr.records do
+						local on_remove = id_record.on_remove
-						local idr_t_archetype = archetypes[archetype_id]
-						local entities = idr_t_archetype.entities
-						-- archetype_traverse_remove is not idempotent meaning
-						-- this access is actually unsafe because it can
-						-- incorrectly cache an edge despite a node of the
-						-- component id on the archetype does not exist. This
-						-- requires careful testing to ensure correct values are
-						-- being passed to the arguments.
-						local to = archetype_traverse_remove(world, id, idr_t_archetype)
 
 						for i = #entities, 1, -1 do
-							local e = entities[i]
+							local child = entities[i]
-							local r = eindex_sparse_array[ECS_ID(e :: number)]
 							if on_remove then
-								on_remove(e, id)
+								on_remove(child, id)
-
-								local from = r.archetype
-								if from ~= idr_t_archetype then
-									-- unfortunately the on_remove hook allows a window where `e` can have changed archetype
-									-- this is hypothetically not that expensive of an operation anyways
-									to = archetype_traverse_remove(world, id, from)
-								end
 							end
 
-							inner_entity_move(entity_index, e, r, to)
+							local r = entity_index_try_get_unsafe(child) :: record
+							local to = archetype_traverse_remove(world, id, r.archetype)
+							inner_entity_move(child, r, to)
 						end
 					end
 				end
+			end
 
-				for archetype_id in cr.records do
+			for archetype_id in archetype_ids do
-					archetype_destroy(world, archetypes[archetype_id])
+				archetype_destroy(world, archetypes[archetype_id])
-				end
 			end
 		end
 
@@ -3082,7 +3017,7 @@ local function world_new()
 					local entities = idr_r_archetype.entities
 					local n = #entities
 					for i = n, 1, -1 do
-						inner_world_delete(world, entities[i])
+						world_delete(world, entities[i])
 					end
 					archetype_destroy(world, idr_r_archetype)
 				end
@@ -3109,8 +3044,8 @@ local function world_new()
 
 					for i = #entities, 1, -1 do
 						local e = entities[i]
-						local r = inner_entity_index_try_get_unsafe(e) :: record
+						local r = entity_index_try_get_unsafe(e) :: record
-						inner_entity_move(entity_index, e, r, node)
+						inner_entity_move(e, r, node)
 					end
 				end
 
@@ -3120,12 +3055,13 @@ local function world_new()
 			end
 		end
 
+
 		local dense = record.dense
 		local i_swap = entity_index.alive_count
 		entity_index.alive_count = i_swap - 1
 
 		local e_swap = eindex_dense_array[i_swap]
-		local r_swap = inner_entity_index_try_get_any(e_swap) :: record
+		local r_swap = entity_index_try_get_any(e_swap) :: record
 		r_swap.dense = dense
 		record.archetype = nil :: any
 		record.row = nil :: any
@@ -3135,15 +3071,34 @@ local function world_new()
 		eindex_dense_array[i_swap] = ECS_GENERATION_INC(entity)
 	end
 
-	local function inner_world_exists(world: world, entity: i53): boolean
+	local function world_clear(world: world, entity: i53)
-		return inner_entity_index_try_get_any(entity) ~= nil
+		local record = entity_index_try_get_unsafe(entity)
+		if not record then
+			return
+		end
+
+		local archetype = record.archetype
+		for _, id in archetype.types do
+			local idr = component_index[id]
+			local on_remove = idr.on_remove
+			if on_remove then
+				on_remove(entity, id)
+			end
+		end
+		archetype_delete(world, record.archetype, record.row)
+		record.archetype = nil :: any
+		record.row = nil :: any
 	end
 
-	local function inner_world_contains(world: world, entity: i53): boolean
+	local function world_exists(world: world, entity: i53): boolean
+		return entity_index_try_get_any(entity) ~= nil
+	end
+
+	local function world_contains(world: world, entity: i53): boolean
 		return entity_index_is_alive(entity_index, entity)
 	end
 
-	local function inner_world_cleanup(world: world)
+	local function world_cleanup(world: world)
 		for _, archetype in archetypes do
 			if #archetype.entities == 0 then
 				archetype_destroy(world, archetype)
@@ -3173,26 +3128,27 @@ local function world_new()
 			error("Too many components, consider using world:entity() instead to create components.")
 		end
 		world.max_component_id = max_component_id
-		inner_world_add(world, max_component_id, EcsComponent)
+		world_add(world, max_component_id, EcsComponent)
 
 		return max_component_id
 	end
 
-	world.entity = inner_world_entity
+	world.entity = world_entity
 	world.query = world_query :: any
-	world.remove = inner_world_remove
+	world.remove = world_remove
-	world.clear = inner_world_clear
+	world.clear = world_clear
-	world.delete = inner_world_delete
+	-- world.purge = world_purge
+	world.delete = world_delete
 	world.component = world_component
-	world.add = inner_world_add
+	world.add = world_add
-	world.set = inner_world_set
+	world.set = world_set
-	world.get = inner_world_get :: any
+	world.get = world_get :: any
-	world.has = inner_world_has :: any
+	world.has = world_has :: any
-	world.target = inner_world_target
+	world.target = world_target
-	world.parent = inner_world_parent
+	world.parent = world_parent
-	world.contains = inner_world_contains
+	world.contains = world_contains
-	world.exists = inner_world_exists
+	world.exists = world_exists
-	world.cleanup = inner_world_cleanup
+	world.cleanup = world_cleanup
 	world.each = world_each
 	world.children = world_children
 	world.range = world_range
@@ -3202,36 +3158,36 @@ local function world_new()
 	end
 
 	for i = 1, max_component_id do
-		inner_world_add(world, i, EcsComponent)
+		world_add(world, i, EcsComponent)
 	end
 
-	inner_world_add(world, EcsName, EcsComponent)
+	world_add(world, EcsName, EcsComponent)
-	inner_world_add(world, EcsOnChange, EcsComponent)
+	world_add(world, EcsOnChange, EcsComponent)
-	inner_world_add(world, EcsOnAdd, EcsComponent)
+	world_add(world, EcsOnAdd, EcsComponent)
-	inner_world_add(world, EcsOnRemove, EcsComponent)
+	world_add(world, EcsOnRemove, EcsComponent)
-	inner_world_add(world, EcsWildcard, EcsComponent)
+	world_add(world, EcsWildcard, EcsComponent)
-	inner_world_add(world, EcsRest, EcsComponent)
+	world_add(world, EcsRest, EcsComponent)
 
-	inner_world_set(world, EcsOnAdd, EcsName, "jecs.OnAdd")
+	world_set(world, EcsOnAdd, EcsName, "jecs.OnAdd")
-	inner_world_set(world, EcsOnRemove, EcsName, "jecs.OnRemove")
+	world_set(world, EcsOnRemove, EcsName, "jecs.OnRemove")
-	inner_world_set(world, EcsOnChange, EcsName, "jecs.OnChange")
+	world_set(world, EcsOnChange, EcsName, "jecs.OnChange")
-	inner_world_set(world, EcsWildcard, EcsName, "jecs.Wildcard")
+	world_set(world, EcsWildcard, EcsName, "jecs.Wildcard")
-	inner_world_set(world, EcsChildOf, EcsName, "jecs.ChildOf")
+	world_set(world, EcsChildOf, EcsName, "jecs.ChildOf")
-	inner_world_set(world, EcsComponent, EcsName, "jecs.Component")
+	world_set(world, EcsComponent, EcsName, "jecs.Component")
 
-	inner_world_set(world, EcsOnDelete, EcsName, "jecs.OnDelete")
+	world_set(world, EcsOnDelete, EcsName, "jecs.OnDelete")
-	inner_world_set(world, EcsOnDeleteTarget, EcsName, "jecs.OnDeleteTarget")
+	world_set(world, EcsOnDeleteTarget, EcsName, "jecs.OnDeleteTarget")
 
-	inner_world_set(world, EcsDelete, EcsName, "jecs.Delete")
+	world_set(world, EcsDelete, EcsName, "jecs.Delete")
-	inner_world_set(world, EcsRemove, EcsName, "jecs.Remove")
+	world_set(world, EcsRemove, EcsName, "jecs.Remove")
-	inner_world_set(world, EcsName, EcsName, "jecs.Name")
+	world_set(world, EcsName, EcsName, "jecs.Name")
-	inner_world_set(world, EcsRest, EcsRest, "jecs.Rest")
+	world_set(world, EcsRest, EcsRest, "jecs.Rest")
 
-	inner_world_add(world, EcsChildOf, ECS_PAIR(EcsOnDeleteTarget, EcsDelete))
+	world_add(world, EcsChildOf, ECS_PAIR(EcsOnDeleteTarget, EcsDelete))
-	inner_world_add(world, EcsChildOf, EcsExclusive)
+	world_add(world, EcsChildOf, EcsExclusive)
 
-	inner_world_add(world, EcsOnDelete, EcsExclusive)
+	world_add(world, EcsOnDelete, EcsExclusive)
-	inner_world_add(world, EcsOnDeleteTarget, EcsExclusive)
+	world_add(world, EcsOnDeleteTarget, EcsExclusive)
 
 	for i = EcsRest + 1, ecs_max_tag_id do
 		entity_index_new_id(entity_index)
@@ -3240,9 +3196,9 @@ local function world_new()
 	for i, bundle in ecs_metadata do
 		for ty, value in bundle do
 			if value == NULL then
-				inner_world_add(world, i, ty)
+				world_add(world, i, ty)
 			else
-				inner_world_set(world, i, ty, value)
+				world_set(world, i, ty, value)
 			end
 		end
 	end
@@ -3273,7 +3229,7 @@ local function ecs_is_tag(world: world, entity: i53): boolean
 	if idr then
 		return bit32.btest(idr.flags, ECS_ID_IS_TAG)
 	end
-	return not world_has_one_inline(world, entity, EcsComponent)
+	return not WORLD_HAS(world, entity, EcsComponent)
 end
 
 local function ecs_entity_record(world: world, entity: i53)
@@ -3338,7 +3294,7 @@ return {
 	entity_index_try_get_fast = entity_index_try_get_fast :: (EntityIndex, Entity) -> Record?,
 	entity_index_try_get_any = entity_index_try_get_any :: (EntityIndex, Entity) -> Record,
 	entity_index_is_alive = entity_index_is_alive :: (EntityIndex, Entity) -> boolean,
-	entity_index_new_id = entity_index_new_id :: (EntityIndex) -> Entity,
+	entity_index_new_id = ENTITY_INDEX_NEW_ID :: (EntityIndex) -> Entity,
 
 	Query = Query,
 

test/tests.luau

@@ -24,39 +24,6 @@ type Id<T=unknown> = jecs.Id<T>
 local entity_visualiser = require("@tools/entity_visualiser")
 local dwi = entity_visualiser.stringify
 
-
-TEST("ardi", function()
-	local world = jecs.world()
-	local r = world:entity()
-	world:add(r, jecs.pair(jecs.OnDelete, jecs.Delete))
-
-	local e = world:entity()
-	local e1 = world:entity()
-	world:add(e, jecs.pair(r, e1))
-
-	world:delete(r)
-	CHECK(not world:contains(e))
-end)
-
-TEST("dai", function()
-	local world = jecs.world()
-	local C = world:component()
-
-	world:set(C, jecs.Name, "C")
-	CHECK(world:get(C, jecs.Name) == "C")
-	world:entity(2000)
-	CHECK(world:get(C, jecs.Name) == "C")
-end)
-
-TEST("another axen banger", function()
-	-- taken from jecs.luau
-	local world = jecs.world()
-	world:range(2000, 3000)
-
-	local e0v1_id = jecs.ECS_COMBINE(1000, 1) -- id can be both within or outside the world's range
-	local e0v1 = world:entity(e0v1_id)
-	assert(world:contains(e0v1)) -- fails
-end)
 TEST("Ensure archetype edges get cleaned", function()
 	local A = jecs.component()
 	local B = jecs.component()
@@ -91,6 +58,7 @@ TEST("Ensure archetype edges get cleaned", function()
 		CHECK(false)
 	end
 end)
+
 TEST("repeated entity cached query", function()
 	local pair = jecs.pair
 	local world = jecs.world()
@@ -591,100 +559,146 @@ TEST("world:children()", function()
 	jecs.ECS_META_RESET()
 end)
 
-TEST("world:clear()", function()
+-- TEST("world:purge()", function()
-	do CASE "should remove its components"
+-- 	do CASE "should remove all instances of specified component"
+-- 		local world = jecs.world()
+-- 		local A = world:component()
+-- 		local B = world:component()
+
+-- 		local e = world:entity()
+-- 		local e1 = world:entity()
+-- 		local _e2 = world:entity()
+
+-- 		world:set(e, A, true)
+-- 		world:set(e, B, true)
+
+-- 		world:set(e1, A, true)
+-- 		world:set(e1, B, true)
+
+-- 		CHECK(world:get(e, A))
+-- 		CHECK(world:get(e, B))
+
+-- 		world:purge(A)
+-- 		CHECK(world:get(e, A) == nil)
+-- 		CHECK(world:get(e, B))
+-- 		CHECK(world:get(e1, A) == nil)
+-- 		CHECK(world:get(e1, B))
+-- 	end
+
+-- 	do CASE "remove purged component from entities"
+-- 		local world = jecs.world()
+-- 		local A = world:component()
+-- 		local B = world:component()
+-- 		local C = world:component()
+
+-- 		do
+-- 			local id1 = world:entity()
+-- 			local id2 = world:entity()
+-- 			local id3 = world:entity()
+
+-- 			world:set(id1, A, true)
+
+-- 			world:set(id2, A, true)
+-- 			world:set(id2, B, true)
+
+-- 			world:set(id3, A, true)
+-- 			world:set(id3, B, true)
+-- 			world:set(id3, C, true)
+
+-- 			world:purge(A)
+
+-- 			CHECK(not world:has(id1, A))
+-- 			CHECK(not world:has(id2, A))
+-- 			CHECK(not world:has(id3, A))
+
+-- 			CHECK(world:has(id2, B))
+-- 			CHECK(world:has(id3, B, C))
+
+-- 			world:purge(C)
+
+-- 			CHECK(world:has(id2, B))
+-- 			CHECK(world:has(id3, B))
+
+-- 			CHECK(world:contains(A))
+-- 			CHECK(world:contains(C))
+-- 			CHECK(world:has(A, jecs.Component))
+-- 			CHECK(world:has(B, jecs.Component))
+-- 		end
+
+-- 		do
+-- 			local id1 = world:entity()
+-- 			local id2 = world:entity()
+-- 			local id3 = world:entity()
+
+-- 			local tgt = world:entity()
+
+-- 			world:add(id1, pair(A, tgt))
+-- 			world:add(id1, pair(B, tgt))
+-- 			world:add(id1, pair(C, tgt))
+
+-- 			world:add(id2, pair(A, tgt))
+-- 			world:add(id2, pair(B, tgt))
+-- 			world:add(id2, pair(C, tgt))
+
+-- 			world:add(id3, pair(A, tgt))
+-- 			world:add(id3, pair(B, tgt))
+-- 			world:add(id3, pair(C, tgt))
+
+-- 			world:purge(B)
+-- 			CHECK(world:has(id1, pair(A, tgt), pair(C, tgt)))
+-- 			CHECK(not world:has(id1, pair(B, tgt)))
+-- 			CHECK(world:has(id2, pair(A, tgt), pair(C, tgt)))
+-- 			CHECK(not world:has(id1, pair(B, tgt)))
+-- 			CHECK(world:has(id3, pair(A, tgt), pair(C, tgt)))
+
+-- 		end
+
+-- 	end
+-- end)
+
+TEST("world:clear", function()
+	do CASE "remove all components on entity"
 		local world = jecs.world()
 		local A = world:component()
 		local B = world:component()
 
 		local e = world:entity()
-		local e1 = world:entity()
-		local _e2 = world:entity()
 
 		world:set(e, A, true)
 		world:set(e, B, true)
 
-		world:set(e1, A, true)
+		world:clear(e)
-		world:set(e1, B, true)
 
-		CHECK(world:get(e, A))
+		CHECK(world:contains(e))
-		CHECK(world:get(e, B))
+		CHECK(not world:has(e, A))
-
+		CHECK(not world:has(e, B))
-		world:clear(A)
+		print(jecs.record(world, e).archetype == nil::any)
-		CHECK(world:get(e, A) == nil)
-		CHECK(world:get(e, B))
-		CHECK(world:get(e1, A) == nil)
-		CHECK(world:get(e1, B))
 	end
 
-	do CASE "remove cleared ID from entities"
+	do CASE "should invoke hooks"
 		local world = jecs.world()
 		local A = world:component()
+		local called = 0
+		world:set(A, jecs.OnRemove, function()
+			called += 1
+		end)
+
 		local B = world:component()
-		local C = world:component()
+		world:set(B, jecs.OnRemove, function()
+			called += 1
+		end)
 
-		do
+		local e = world:entity()
-			local id1 = world:entity()
-			local id2 = world:entity()
-			local id3 = world:entity()
 
-			world:set(id1, A, true)
+		world:set(e, A, true)
+		world:set(e, B, true)
 
-			world:set(id2, A, true)
+		world:clear(e)
-			world:set(id2, B, true)
-
-			world:set(id3, A, true)
-			world:set(id3, B, true)
-			world:set(id3, C, true)
-
-			world:clear(A)
-
-			CHECK(not world:has(id1, A))
-			CHECK(not world:has(id2, A))
-			CHECK(not world:has(id3, A))
-
-			CHECK(world:has(id2, B))
-			CHECK(world:has(id3, B, C))
-
-			world:clear(C)
-
-			CHECK(world:has(id2, B))
-			CHECK(world:has(id3, B))
-
-			CHECK(world:contains(A))
-			CHECK(world:contains(C))
-			CHECK(world:has(A, jecs.Component))
-			CHECK(world:has(B, jecs.Component))
-		end
-
-		do
-			local id1 = world:entity()
-			local id2 = world:entity()
-			local id3 = world:entity()
-
-			local tgt = world:entity()
-
-			world:add(id1, pair(A, tgt))
-			world:add(id1, pair(B, tgt))
-			world:add(id1, pair(C, tgt))
-
-			world:add(id2, pair(A, tgt))
-			world:add(id2, pair(B, tgt))
-			world:add(id2, pair(C, tgt))
-
-			world:add(id3, pair(A, tgt))
-			world:add(id3, pair(B, tgt))
-			world:add(id3, pair(C, tgt))
-
-			world:clear(B)
-			CHECK(world:has(id1, pair(A, tgt), pair(C, tgt)))
-			CHECK(not world:has(id1, pair(B, tgt)))
-			CHECK(world:has(id2, pair(A, tgt), pair(C, tgt)))
-			CHECK(not world:has(id1, pair(B, tgt)))
-			CHECK(world:has(id3, pair(A, tgt), pair(C, tgt)))
-
-		end
 
+		CHECK(world:contains(e))
+		CHECK(not world:has(e, A))
+		CHECK(not world:has(e, B))
+		CHECK(called == 2)
 	end
 end)
 
@@ -756,6 +770,60 @@ TEST("world:contains()", function()
 end)
 
 TEST("world:delete()", function()
+	do CASE "OnDelete cleanup policy cascades deletion to entites with idr_r pairs"
+		local world = jecs.world()
+		local r = world:entity()
+		world:add(r, jecs.pair(jecs.OnDelete, jecs.Delete))
+
+		local e = world:entity()
+		local e1 = world:entity()
+		world:add(e, jecs.pair(r, e1))
+
+		world:delete(r)
+		CHECK(not world:contains(e))
+	end
+
+	do CASE "OnDeleteTarget works correctly regardless of adjacent archetype iteration order"
+		local world = jecs.world()
+		local t = world:entity()
+		local c = world:component()
+		world:add(c, t)
+
+		local component = world:component()
+		local lifetime = world:component()
+
+		local tag = world:entity()
+		local rel1 = world:entity()
+		local rel2 = world:entity()
+		local rel3 = world:entity()
+
+		local destroyed = false
+
+		world:removed(lifetime, function(e)
+		    destroyed = true
+		end)
+
+		local parent = world:entity()
+		world:set(parent, component, "foo")
+		world:add(parent, jecs.pair(rel1, component))
+
+		local other1 = world:entity()
+		world:add(other1, tag)
+		world:add(other1, jecs.pair(jecs.ChildOf, parent))
+		world:add(other1, jecs.pair(rel1, component))
+
+		local child = world:entity()
+		world:set(child, lifetime, "")
+		world:add(child, jecs.pair(jecs.ChildOf, parent))
+		world:add(child, jecs.pair(rel3, parent))
+		world:add(child, jecs.pair(rel2, other1))
+
+		world:delete(parent)
+
+		CHECK(destroyed)
+		CHECK(not world:contains(child))
+	end
+
 	do CASE "Should delete children in different archetypes if they have the same parent"
 		local world = jecs.world()
 
@@ -810,7 +878,6 @@ TEST("world:delete()", function()
 		local world = jecs.world()
 		local A = world:component()
 		local B = world:component()
-		local C = world:component()
 		world:set(A, jecs.OnRemove, function(entity, id)
 			world:set(entity, B, true)
 		end)
@@ -1380,7 +1447,7 @@ TEST("world:range()", function()
 		CHECK(world.entity_index.alive_count == 400)
 		CHECK(e)
 	end
-	do CASE "axen"
+	do CASE "entity ID reuse works correctly across different world ranges"
 		local base = jecs.world()
 		base:range(1_000, 2_000)
 
@@ -1492,6 +1559,24 @@ TEST("world:range()", function()
 end)
 
 TEST("world:entity()", function()
+	do CASE "entity mirroring preserves IDs across world ranges"
+		local world = jecs.world()
+		world:range(2000, 3000)
+
+		local e0v1_id = jecs.ECS_COMBINE(1000, 1) -- id can be both within or outside the world's range
+		local e0v1 = world:entity(e0v1_id)
+		CHECK(world:contains(e0v1)) -- fails
+	end
+
+	do CASE "component names persist after entity creation"
+		local world = jecs.world()
+		local C = world:component()
+
+		world:set(C, jecs.Name, "C")
+		CHECK(world:get(C, jecs.Name) == "C")
+		world:entity(2000)
+		CHECK(world:get(C, jecs.Name) == "C")
+	end
 	do CASE "desired id"
 		local world = jecs.world()
 		local id = world:entity()