update README

README.md

@@ -53,6 +53,7 @@
     - [Internal Fragments](#internal-fragments)
     - [Shared Components](#shared-components)
     - [Fragment Requirements](#fragment-requirements)
+    - [Id Names](#id-names)
     - [Destruction Policies](#destruction-policies)
     - [Custom Component Storages](#custom-component-storages)
   - [Garbage Collection](#garbage-collection)
@@ -64,6 +65,7 @@
     - [Chunk](#chunk)
     - [Builder](#builder)
 - [Changelog](#changelog)
+  - [vX.Y.Z](#vxyz)
   - [v1.9.0](#v190)
   - [v1.8.0](#v180)
   - [v1.7.0](#v170)
@@ -1161,6 +1163,41 @@ local enemy = evolved.builder()
 assert(evolved.has_all(enemy, position, velocity))
 ```
 
+#### Id Names
+
+The library provides a way to assign names to any id using the [`evolved.NAME`](#evolvedname) fragment. This is useful for debugging and development purposes, as it allows you to identify entities or fragments by their names instead of their identifiers. The name of an entity can be retrieved using the [`evolved.name`](#evolvedname-1) function.
+
+```lua
+local evolved = require 'evolved'
+
+local player = evolved.builder()
+    :name('Player')
+    :build()
+
+assert(evolved.name(player) == 'Player')
+```
+
+Names are not unique, so multiple entities can have the same name. Also, the name of an entity can be changed at any time by setting a new name using the [`evolved.NAME`](#evolvedname) fragment as a usual component.
+
+You can find entities by their names using the [`evolved.lookup`](#evolvedlookup) and [`evolved.multi_lookup`](#evolvedmulti_lookup) functions. The [`evolved.lookup`](#evolvedlookup) function returns the first entity with the specified name, while the [`evolved.multi_lookup`](#evolvedmulti_lookup) function returns a list of all entities with the specified name.
+
+```lua
+local evolved = require 'evolved'
+
+local player1 = evolved.builder()
+    :name('Player')
+    :build()
+
+local player2 = evolved.builder()
+    :name('Player')
+    :build()
+
+assert(evolved.lookup('Player') == player1)
+
+local player_list, player_count = evolved.multi_lookup('Player')
+assert(player_count == 2 and player_list[1] == player1 and player_list[2] == player2)
+```
+
 #### Destruction Policies
 
 Typically, fragments remain alive for the entire lifetime of the program. However, in some cases, you might want to destroy fragments when they are no longer needed. For example, you can use some runtime entities as fragments for other entities. In this case, you might want to destroy such fragments even while they are still attached to other entities. Since entities cannot have destroyed fragments, a destruction policy must be applied to resolve this. By default, the library will remove the destroyed fragment from all entities that have it.
@@ -1496,6 +1533,9 @@ execute :: query -> {execute_state? -> chunk?, entity[]?, integer?}, execute_sta
 
 locate :: entity -> chunk?, integer
 
+lookup :: string -> entity?
+multi_lookup :: string -> entity[], integer
+
 process :: system... -> ()
 process_with :: system, ... -> ()
 
@@ -1585,6 +1625,11 @@ builder_mt:destruction_policy :: id -> builder
 
 ## Changelog
 
+### vX.Y.Z
+
+- Added the new [`evolved.lookup`](#evolvedlookup) and [`evolved.multi_lookup`](#evolvedmulti_lookup) functions that allow finding ids by their names
+- Added a non-shrinking version of the [`evolved.collect_garbage`](#evolvedcollect_garbage) function that only collects garbage without shrinking storages
+
 ### v1.9.0
 
 - Performance improvements of the [`evolved.destroy`](#evolveddestroy) and [`evolved.batch_destroy`](#evolvedbatch_destroy) functions
@@ -2001,6 +2046,25 @@ function evolved.execute(query) end
 function evolved.locate(entity) end
 ```
 
+### `evolved.lookup`
+
+```lua
+---@param name string
+---@return evolved.entity? entity
+---@nodiscard
+function evolved.lookup(name) end
+```
+
+### `evolved.multi_lookup`
+
+```lua
+---@param name string
+---@return evolved.entity[] entity_list
+---@return integer entity_count
+---@nodiscard
+function evolved.multi_lookup(name) end
+```
+
 ### `evolved.process`
 
 ```lua

develop/all.lua

@@ -4,6 +4,7 @@ require 'develop.testing.clone_tests'
 require 'develop.testing.depth_tests'
 require 'develop.testing.destroy_tests'
 require 'develop.testing.locate_tests'
+require 'develop.testing.lookup_tests'
 require 'develop.testing.main_tests'
 require 'develop.testing.mappers_tests'
 require 'develop.testing.multi_spawn_tests'

develop/testing/lookup_tests.lua

@@ -0,0 +1,176 @@
+local evo = require 'evolved'
+
+evo.debug_mode(true)
+
+do
+    local e1, e2, e3 = evo.id(3)
+
+    do
+        assert(evo.lookup('lookup_hello') == nil)
+        assert(evo.lookup('lookup_world') == nil)
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_hello')
+            assert(entity_list and #entity_list == 0 and entity_count == 0)
+        end
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_world')
+            assert(entity_list and #entity_list == 0 and entity_count == 0)
+        end
+    end
+
+    evo.set(e1, evo.NAME, 'lookup_hello')
+
+    do
+        assert(evo.lookup('lookup_hello') == e1)
+        assert(evo.lookup('lookup_world') == nil)
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_hello')
+            assert(entity_list and #entity_list == 1 and entity_count == 1)
+            assert(entity_list[1] == e1)
+        end
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_world')
+            assert(entity_list and #entity_list == 0 and entity_count == 0)
+        end
+    end
+
+    evo.set(e2, evo.NAME, 'lookup_hello')
+    evo.set(e3, evo.NAME, 'lookup_hello')
+
+    do
+        assert(evo.lookup('lookup_hello') == e1)
+        assert(evo.lookup('lookup_world') == nil)
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_hello')
+            assert(entity_list and #entity_list == 3 and entity_count == 3)
+            assert(entity_list[1] == e1 and entity_list[2] == e2 and entity_list[3] == e3)
+        end
+    end
+
+    evo.set(e2, evo.NAME, 'lookup_world')
+
+    do
+        assert(evo.lookup('lookup_hello') == e1)
+        assert(evo.lookup('lookup_world') == e2)
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_hello')
+            assert(entity_list and #entity_list == 2 and entity_count == 2)
+            assert(entity_list[1] == e1 and entity_list[2] == e3)
+        end
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_world')
+            assert(entity_list and #entity_list == 1 and entity_count == 1)
+            assert(entity_list[1] == e2)
+        end
+    end
+
+    evo.set(e3, evo.NAME, 'lookup_world')
+
+    do
+        assert(evo.lookup('lookup_hello') == e1)
+        assert(evo.lookup('lookup_world') == e2)
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_hello')
+            assert(entity_list and #entity_list == 1 and entity_count == 1)
+            assert(entity_list[1] == e1)
+        end
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_world')
+            assert(entity_list and #entity_list == 2 and entity_count == 2)
+            assert(entity_list[1] == e2 or entity_list[1] == e3)
+        end
+    end
+
+    evo.remove(e1, evo.NAME)
+
+    do
+        assert(evo.lookup('lookup_hello') == nil)
+        assert(evo.lookup('lookup_world') == e2)
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_hello')
+            assert(entity_list and #entity_list == 0 and entity_count == 0)
+        end
+
+        do
+            local entity_list, entity_count = evo.multi_lookup('lookup_world')
+            assert(entity_list and #entity_list == 2 and entity_count == 2)
+            assert(entity_list[1] == e2 or entity_list[1] == e3)
+        end
+    end
+end
+
+do
+    local e1, e2, e3 = evo.id(3)
+
+    evo.set(e1, evo.NAME, 'lookup_e')
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 1 and entity_count == 1)
+        assert(entity_list[1] == e1)
+    end
+
+    evo.set(e2, evo.NAME, 'lookup_e')
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 2 and entity_count == 2)
+        assert(entity_list[1] == e1 and entity_list[2] == e2)
+    end
+
+    evo.set(e3, evo.NAME, 'lookup_e')
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 3 and entity_count == 3)
+        assert(entity_list[1] == e1 and entity_list[2] == e2 and entity_list[3] == e3)
+    end
+
+    evo.clear(e1, e2, e3)
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 0 and entity_count == 0)
+    end
+
+    evo.set(e3, evo.NAME, 'lookup_e')
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 1 and entity_count == 1)
+        assert(entity_list[1] == e3)
+    end
+
+    evo.set(e2, evo.NAME, 'lookup_e')
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 2 and entity_count == 2)
+        assert(entity_list[1] == e3 and entity_list[2] == e2)
+    end
+
+    evo.set(e1, evo.NAME, 'lookup_e')
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 3 and entity_count == 3)
+        assert(entity_list[1] == e3 and entity_list[2] == e2 and entity_list[3] == e1)
+    end
+
+    evo.destroy(e3, e2, e1)
+
+    do
+        local entity_list, entity_count = evo.multi_lookup('lookup_e')
+        assert(entity_list and #entity_list == 0 and entity_count == 0)
+    end
+end

evolved.d.tl

@@ -208,6 +208,9 @@
 
     locate: function(entity: Entity): Chunk | nil, integer
 
+    lookup: function(name: string): Entity | nil
+    multi_lookup: function(name: string): { Entity }, integer
+
     process: function(...: System)
     process_with: function(system: System, ...: any)
 

evolved.lua

@@ -144,6 +144,9 @@ local __major_queries = {} ---@type table<evolved.fragment, evolved.assoc_list<e
 local __entity_chunks = {} ---@type (evolved.chunk|false)[]
 local __entity_places = {} ---@type integer[]
 
+local __named_entity = {} ---@type table<string, evolved.entity>
+local __named_entities = {} ---@type table<string, evolved.assoc_list<evolved.entity>>
+
 local __sorted_includes = {} ---@type table<evolved.query, evolved.assoc_list<evolved.fragment>>
 local __sorted_excludes = {} ---@type table<evolved.query, evolved.assoc_list<evolved.fragment>>
 local __sorted_variants = {} ---@type table<evolved.query, evolved.assoc_list<evolved.fragment>>
@@ -896,6 +899,22 @@ function __assoc_list_fns.new(reserve)
     }
 end
 
+---@generic K
+---@param ... K
+---@return evolved.assoc_list<K>
+---@nodiscard
+function __assoc_list_fns.from(...)
+    local item_count = __lua_select('#', ...)
+
+    local al = __assoc_list_fns.new(item_count)
+
+    for item_index = 1, item_count do
+        __assoc_list_fns.insert(al, __lua_select(item_index, ...))
+    end
+
+    return al
+end
+
 ---@generic K
 ---@param src_item_list K[]
 ---@param src_item_first integer
@@ -1039,6 +1058,46 @@ function __assoc_list_fns.remove_ex(al_item_set, al_item_list, al_item_count, it
     return al_item_count
 end
 
+---@generic K
+---@param al evolved.assoc_list<K>
+---@param item K
+---@return integer new_al_count
+function __assoc_list_fns.unordered_remove(al, item)
+    local new_al_count = __assoc_list_fns.unordered_remove_ex(
+        al.__item_set, al.__item_list, al.__item_count,
+        item)
+
+    al.__item_count = new_al_count
+    return new_al_count
+end
+
+---@generic K
+---@param al_item_set table<K, integer>
+---@param al_item_list K[]
+---@param al_item_count integer
+---@param item K
+---@return integer new_al_count
+---@nodiscard
+function __assoc_list_fns.unordered_remove_ex(al_item_set, al_item_list, al_item_count, item)
+    local item_index = al_item_set[item]
+
+    if not item_index then
+        return al_item_count
+    end
+
+    if item_index ~= al_item_count then
+        local al_last_item = al_item_list[al_item_count]
+        al_item_set[al_last_item] = item_index
+        al_item_list[item_index] = al_last_item
+    end
+
+    al_item_set[item] = nil
+    al_item_list[al_item_count] = nil
+    al_item_count = al_item_count - 1
+
+    return al_item_count
+end
+
 ---
 ---
 ---
@@ -1090,6 +1149,11 @@ local __DESTRUCTION_POLICY_REMOVE_FRAGMENT = __acquire_id()
 ---
 
 local __safe_tbls = {
+    __EMPTY_ENTITY_LIST = __lua_setmetatable({}, {
+        __tostring = function() return 'empty entity list' end,
+        __newindex = function() __error_fmt 'attempt to modify empty entity list' end
+    }) --[=[@as evolved.id[]]=],
+
     __EMPTY_FRAGMENT_SET = __lua_setmetatable({}, {
         __tostring = function() return 'empty fragment set' end,
         __newindex = function() __error_fmt 'attempt to modify empty fragment set' end
@@ -1155,6 +1219,9 @@ local __evolved_execute
 
 local __evolved_locate
 
+local __evolved_lookup
+local __evolved_multi_lookup
+
 local __evolved_process
 local __evolved_process_with
 
@@ -4857,7 +4924,7 @@ end
 ---@return integer entity_count
 function __evolved_multi_spawn(entity_count, component_table, component_mapper)
     if entity_count <= 0 then
-        return {}, 0
+        return __safe_tbls.__EMPTY_ENTITY_LIST, 0
     end
 
     if __debug_mode then
@@ -4938,7 +5005,7 @@ end
 ---@return integer entity_count
 function __evolved_multi_clone(entity_count, prefab, component_table, component_mapper)
     if entity_count <= 0 then
-        return {}, 0
+        return __safe_tbls.__EMPTY_ENTITY_LIST, 0
     end
 
     if __debug_mode then
@@ -6086,6 +6153,39 @@ function __evolved_locate(entity)
     return entity_chunk, __entity_places[entity_primary]
 end
 
+---@param name string
+---@return evolved.entity? entity
+---@nodiscard
+function __evolved_lookup(name)
+    return __named_entity[name]
+end
+
+---@param name string
+---@return evolved.entity[] entity_list
+---@return integer entity_count
+---@nodiscard
+function __evolved_multi_lookup(name)
+    do
+        local named_entities = __named_entities[name]
+        local named_entity_list = named_entities and named_entities.__item_list
+        local named_entity_count = named_entities and named_entities.__item_count or 0
+
+        if named_entity_count > 0 then
+            return __list_fns.dup(named_entity_list, named_entity_count), named_entity_count
+        end
+    end
+
+    do
+        local named_entity = __named_entity[name]
+
+        if named_entity then
+            return { named_entity }, 1
+        end
+    end
+
+    return __safe_tbls.__EMPTY_ENTITY_LIST, 0
+end
+
 ---@param ... evolved.system systems
 function __evolved_process(...)
     local argument_count = __lua_select('#', ...)
@@ -6481,7 +6581,7 @@ end
 ---@return integer entity_count
 function __builder_mt:multi_spawn(entity_count, component_mapper)
     if entity_count <= 0 then
-        return {}, 0
+        return __safe_tbls.__EMPTY_ENTITY_LIST, 0
     end
 
     local chunk = self.__chunk
@@ -6565,7 +6665,7 @@ end
 ---@return integer entity_count
 function __builder_mt:multi_clone(entity_count, prefab, component_mapper)
     if entity_count <= 0 then
-        return {}, 0
+        return __safe_tbls.__EMPTY_ENTITY_LIST, 0
     end
 
     local component_table = self.__component_table
@@ -7153,6 +7253,75 @@ __evolved_set(__ON_REMOVE, __UNIQUE)
 ---
 ---
 
+---@param name string
+---@param entity evolved.entity
+local function __insert_named_entity(name, entity)
+    ---@type evolved.entity?
+    local named_entity = __named_entity[name]
+
+    if not named_entity then
+        __named_entity[name] = entity
+        return
+    end
+
+    ---@type evolved.assoc_list<evolved.entity>?
+    local named_entities = __named_entities[name]
+
+    if not named_entities then
+        __named_entities[name] = __assoc_list_fns.from(named_entity, entity)
+        return
+    end
+
+    __assoc_list_fns.insert(named_entities, entity)
+end
+
+---@param name string
+---@param entity evolved.entity
+local function __remove_named_entity(name, entity)
+    ---@type evolved.assoc_list<evolved.entity>?
+    local named_entities = __named_entities[name]
+
+    if named_entities then
+        if __assoc_list_fns.remove(named_entities, entity) == 0 then
+            __named_entities[name], named_entities = nil, nil
+        end
+    end
+
+    ---@type evolved.entity?
+    local named_entity = __named_entity[name]
+
+    if named_entity == entity then
+        __named_entity[name] = named_entities and named_entities.__item_list[1] or nil
+    end
+end
+
+---@param entity evolved.entity
+---@param new_name? string
+---@param old_name? string
+__evolved_set(__NAME, __ON_SET, function(entity, _, new_name, old_name)
+    if old_name then
+        __remove_named_entity(old_name, entity)
+    end
+
+    if new_name then
+        __insert_named_entity(new_name, entity)
+    end
+end)
+
+---@param entity evolved.entity
+---@param old_name? string
+__evolved_set(__NAME, __ON_REMOVE, function(entity, _, old_name)
+    if old_name then
+        __remove_named_entity(old_name, entity)
+    end
+end)
+
+---
+---
+---
+---
+---
+
 ---@param query evolved.query
 local function __insert_query(query)
     local query_includes = __sorted_includes[query]
@@ -7524,6 +7693,9 @@ evolved.execute = __evolved_execute
 
 evolved.locate = __evolved_locate
 
+evolved.lookup = __evolved_lookup
+evolved.multi_lookup = __evolved_multi_lookup
+
 evolved.process = __evolved_process
 evolved.process_with = __evolved_process_with