update roadmap

This reverts commit fb6d13ca74.

.luacov

@@ -0,0 +1,5 @@
+modules = {
+    ['evolved'] = 'evolved.lua'
+}
+reporter = 'html'
+reportfile = 'luacov.report.html'

.vscode/settings.json

@@ -4,5 +4,12 @@
         "files.insertFinalNewline": true,
         "files.trimFinalNewlines": true,
         "files.trimTrailingWhitespace": true
+    },
+    "markdown.extension.toc.levels": "2..6",
+    "markdown.extension.toc.omittedFromToc": {
+        "README.md": [
+            "# Changelog",
+            "# API Reference"
+        ]
     }
 }

GUIDES.md

@@ -0,0 +1,22 @@
+# Guidelines
+
+## Checklists
+
+### New Version Releasing
+
+1. Ensure all tests pass on CI.
+2. Update the version number in `evolved.lua`.
+3. Update the **Changelog** section in `README.md`.
+4. Create a new rockspec file in `rockspecs`.
+5. Commit the changes with a message like `vX.Y.Z`.
+6. Push and merge the changes to the `main` branch.
+7. Create the release on GitHub.
+8. Upload the new package to LuaRocks.
+
+### Adding a New Top-Level Function
+1. Insert the new function into the `evolved` table in `evolved.lua`.
+2. Create tests for the function in `develop/testing/function_name_tests.lua`.
+3. Add the new test to `develop/all.lua`.
+4. Document the function in the **Cheat Sheet** and **API Reference** sections of `README.md`.
+5. Provide a description in the **Overview** section of `README.md`.
+6. Describe the update in the **Changelog** section of `README.md`.

README.md

@@ -1,4 +1,4 @@
-# evolved.lua (work in progress)
+# evolved.lua
 
 > Evolved ECS (Entity-Component-System) for Lua
 
@@ -19,6 +19,47 @@
 
 [evolved]: https://github.com/BlackMATov/evolved.lua
 
+- [Introduction](#introduction)
+  - [Performance](#performance)
+  - [Simplicity](#simplicity)
+  - [Flexibility](#flexibility)
+- [Installation](#installation)
+- [Quick Start](#quick-start)
+- [Overview](#overview)
+  - [Identifiers](#identifiers)
+  - [Entities, Fragments, and Components](#entities-fragments-and-components)
+    - [Traits](#traits)
+    - [Singletons](#singletons)
+  - [Chunks](#chunks)
+  - [Structural Changes](#structural-changes)
+    - [Spawning Entities](#spawning-entities)
+    - [Entity Builders](#entity-builders)
+  - [Access Operations](#access-operations)
+  - [Iterating Over Fragments](#iterating-over-fragments)
+  - [Modifying Operations](#modifying-operations)
+  - [Debug Mode](#debug-mode)
+  - [Queries](#queries)
+    - [Deferred Operations](#deferred-operations)
+    - [Batch Operations](#batch-operations)
+  - [Systems](#systems)
+  - [Predefined Traits](#predefined-traits)
+    - [Fragment Tags](#fragment-tags)
+    - [Fragment Hooks](#fragment-hooks)
+    - [Unique Fragments](#unique-fragments)
+    - [Explicit Fragments](#explicit-fragments)
+    - [Shared Components](#shared-components)
+    - [Fragment Requirements](#fragment-requirements)
+    - [Destruction Policies](#destruction-policies)
+- [Cheat Sheet](#cheat-sheet)
+  - [Aliases](#aliases)
+  - [Predefs](#predefs)
+  - [Core Functions](#core-functions)
+  - [Relation Functions](#relation-functions)
+  - [Classes](#classes)
+    - [Chunk](#chunk)
+    - [Builder](#builder)
+- [License](#license)
+
 ## Introduction
 
 `evolved.lua` is a fast and flexible ECS (Entity-Component-System) library for Lua. It is designed to be simple and easy to use, while providing all the features needed to create complex systems with blazing performance. Before we start exploring the library, let's take a look at the main advantages of using `evolved.lua`:
@@ -41,211 +82,21 @@ And yes, the library has some unusual concepts at its core, but once you get the
 
 On the other hand, `evolved.lua` tries to be minimalistic and does not provide features that can be implemented outside the library. I'm trying to find a balance between minimalism and the number of possibilities, which forces me to make flexible decisions in the library's design. I hope you will find this balance acceptable.
 
-## Requirements
-
-- [lua](https://www.lua.org/) **>= 5.1**
-- [luajit](https://luajit.org/) **>= 2.0**
-
 ## Installation
 
-You can install `evolved.lua` using [luarocks](https://luarocks.org/) with the following command:
+`evolved.lua` is a single-file pure Lua library and does not require any external dependencies. It is designed to work with [Lua 5.1](https://www.lua.org/) and later, [LuaJIT](https://luajit.org/), and [Luau](https://luau.org/) (Roblox).
+
+All you need to start using the library is the [evolved.lua](./evolved.lua) source file. You can download it from the [releases](https://github.com/BlackMATov/evolved.lua/releases) page or clone the [repository](https://github.com/BlackMATov/evolved.lua) and copy the file to your project.
+
+If you are using [LuaRocks](https://luarocks.org/), you can install the library using the following command:
 
 ```bash
 luarocks install evolved.lua
 ```
 
-Or just clone the [repository](https://github.com/BlackMATov/evolved.lua) and copy the [evolved.lua](evolved.lua) file to your project.
-
 ## Quick Start
 
-To start using `evolved.lua`, read the [Overview](#overview) section first. It will give you a basic understanding of how the library works and how to use it. After that, check the full-featured [Example](develop/example.lua), which demonstrates complex usage of the library. Finally, refer to the [Cheat Sheet](#cheat-sheet) for a quick reference of all the functions and classes provided by the library.
-
-Enjoy! :suspect:
-
-## Cheat Sheet
-
-### Aliases
-
-```
-id :: implementation-specific
-
-entity :: id
-fragment :: id
-query :: id
-system :: id
-
-component :: any
-storage :: component[]
-
-default :: component
-duplicate :: {component -> component}
-
-execute :: {chunk, entity[], integer}
-prologue :: {}
-epilogue :: {}
-
-set_hook :: {entity, fragment, component, component?}
-assign_hook :: {entity, fragment, component, component}
-insert_hook :: {entity, fragment, component}
-remove_hook :: {entity, fragment, component}
-
-each_state :: implementation-specific
-execute_state :: implementation-specific
-
-each_iterator :: {each_state? -> fragment?, component?}
-execute_iterator :: {execute_state? -> chunk?, entity[]?, integer?}
-```
-
-### Predefs
-
-```
-TAG :: fragment
-NAME :: fragment
-
-UNIQUE :: fragment
-EXPLICIT :: fragment
-
-DEFAULT :: fragment
-DUPLICATE :: fragment
-
-PREFAB :: fragment
-DISABLED :: fragment
-
-INCLUDES :: fragment
-EXCLUDES :: fragment
-
-ON_SET :: fragment
-ON_ASSIGN :: fragment
-ON_INSERT :: fragment
-ON_REMOVE :: fragment
-
-GROUP :: fragment
-
-QUERY :: fragment
-EXECUTE :: fragment
-
-PROLOGUE :: fragment
-EPILOGUE :: fragment
-
-DESTRUCTION_POLICY :: fragment
-DESTRUCTION_POLICY_DESTROY_ENTITY :: id
-DESTRUCTION_POLICY_REMOVE_FRAGMENT :: id
-```
-
-### Functions
-
-```
-id :: integer? -> id...
-
-pack :: integer, integer -> id
-unpack :: id -> integer, integer
-
-defer :: boolean
-commit :: boolean
-
-spawn :: <fragment, component>? -> entity
-clone :: entity -> <fragment, component>? -> entity
-
-alive :: entity -> boolean
-alive_all :: entity... -> boolean
-alive_any :: entity... -> boolean
-
-empty :: entity -> boolean
-empty_all :: entity... -> boolean
-empty_any :: entity... -> boolean
-
-has :: entity, fragment -> boolean
-has_all :: entity, fragment... -> boolean
-has_any :: entity, fragment... -> boolean
-
-get :: entity, fragment...  -> component...
-
-set :: entity, fragment, component -> ()
-remove :: entity, fragment... -> ()
-clear :: entity... -> ()
-destroy :: entity... -> ()
-
-batch_set :: query, fragment, component -> ()
-batch_remove :: query, fragment... -> ()
-batch_clear :: query... -> ()
-batch_destroy :: query... -> ()
-
-each :: entity -> {each_state? -> fragment?, component?}, each_state?
-execute :: query -> {execute_state? -> chunk?, entity[]?, integer?}, execute_state?
-
-process :: system... -> ()
-
-debug_mode :: boolean -> ()
-collect_garbage :: ()
-```
-
-### Classes
-
-#### Chunk
-
-```
-chunk :: fragment, fragment... -> chunk, entity[], integer
-
-chunk_mt:alive :: boolean
-chunk_mt:empty :: boolean
-
-chunk_mt:has :: fragment -> boolean
-chunk_mt:has_all :: fragment... -> boolean
-chunk_mt:has_any :: fragment... -> boolean
-
-chunk_mt:entities :: entity[], integer
-chunk_mt:fragments :: fragment[], integer
-chunk_mt:components :: fragment... -> storage...
-```
-
-#### Builder
-
-```
-builder :: builder
-
-builder_mt:spawn :: entity
-builder_mt:clone :: entity -> entity
-
-builder_mt:has :: fragment -> boolean
-builder_mt:has_all :: fragment... -> boolean
-builder_mt:has_any :: fragment... -> boolean
-
-builder_mt:get :: fragment... -> component...
-
-builder_mt:set :: fragment, component -> builder
-builder_mt:remove :: fragment... -> builder
-builder_mt:clear :: builder
-
-builder_mt:tag :: builder
-builder_mt:name :: string -> builder
-
-builder_mt:unique :: builder
-builder_mt:explicit :: builder
-
-builder_mt:default :: component -> builder
-builder_mt:duplicate :: {component -> component} -> builder
-
-builder_mt:prefab :: builder
-builder_mt:disabled :: builder
-
-builder_mt:include :: fragment... -> builder
-builder_mt:exclude :: fragment... -> builder
-
-builder_mt:on_set :: {entity, fragment, component, component?} -> builder
-builder_mt:on_assign :: {entity, fragment, component, component} -> builder
-builder_mt:on_insert :: {entity, fragment, component} -> builder
-builder_mt:on_remove :: {entity, fragment} -> builder
-
-builder_mt:group :: system -> builder
-
-builder_mt:query :: query -> builder
-builder_mt:execute :: {chunk, entity[], integer} -> builder
-
-builder_mt:prologue :: {} -> builder
-builder_mt:epilogue :: {} -> builder
-
-builder_mt:destruction_policy :: id -> builder
-```
+To get started with `evolved.lua`, read the [Overview](#overview) section to understand the basic concepts and how to use the library. After that, check the [Samples](develop/samples), which demonstrate complex usage of the library. Finally, refer to the [Cheat Sheet](#cheat-sheet) for a quick reference of all the functions and classes provided by the library.
 
 ## Overview
 
@@ -300,11 +151,14 @@ Sometimes (for debugging purposes, for example), it is necessary to extract the
 ---@param index integer
 ---@param version integer
 ---@return evolved.id id
+---@nodiscard
 function evolved.pack(index, version) end
 
 ---@param id evolved.id
----@return integer index
----@return integer version
+---@return integer primary
+---@return integer secondary
+---@return integer options
+---@nodiscard
 function evolved.unpack(id) end
 ```
 
@@ -556,7 +410,7 @@ evolved.set(enemy1, stamina, 42)
 
 #### Entity Builders
 
-Another way to avoid structural changes when spawning entities is to use the [`evolved.builder`](#evolvedbuilder) fluid interface. The [`evolved.builder`](#evolvedbuilder) function returns a builder object that allows you to spawn entities with a specific set of fragments and components without the necessity of setting them one by one with structural changes for each change.
+Another way to avoid structural changes when spawning entities is to use the [`evolved.builder`](#evolvedbuilder) fluent interface. The [`evolved.builder`](#evolvedbuilder) function returns a builder object that allows you to spawn entities with a specific set of fragments and components without the necessity of setting them one by one with structural changes for each change.
 
 ```lua
 local evolved = require 'evolved'
@@ -598,6 +452,35 @@ The [`evolved.alive`](#evolvedalive) function checks whether an entity is alive.
 
 All of these functions can be safely called on non-alive entities and non-alive fragments. Also, they do not cause any structural changes, because they do not modify anything.
 
+### Iterating Over Fragments
+
+Sometimes, you may need to iterate over all fragments attached to an entity. You can use the [`evolved.each`](#evolvedeach) function for this purpose.
+
+```lua
+local evolved = require 'evolved'
+
+local health = evolved.builder()
+    :name('health')
+    :spawn()
+
+local stamina = evolved.builder()
+    :name('stamina')
+    :spawn()
+
+local player = evolved.builder()
+    :set(health, 100)
+    :set(stamina, 50)
+    :spawn()
+
+for fragment, component in evolved.each(player) do
+    print(string.format('Fragment (%s) has value %d',
+        evolved.name(fragment), component))
+end
+```
+
+> [!NOTE]
+> [Structural changes](#structural-changes) are not allowed during iteration. If you want to spawn new entities or insert/remove fragments while iterating, defer these operations until the iteration is complete. See the [Deferred Operations](#deferred-operations) section for more details.
+
 ### Modifying Operations
 
 The library provides a classic set of functions for modifying entities. These functions are used to insert, override, and remove fragments from entities.
@@ -823,6 +706,28 @@ The [`evolved.process`](#evolvedprocess) function is used to process systems. It
 function evolved.process(...) end
 ```
 
+If you don't specify a query for the system, the system itself will be treated as a query. This means the system can contain `evolved.INCLUDES` and `evolved.EXCLUDES` fragments, and it will be processed according to them. This is useful for creating systems with unique queries that don't need to be reused in other systems.
+
+```lua
+local evolved = require 'evolved'
+
+local health = evolved.id()
+
+local system = evolved.builder()
+    :include(health)
+    :execute(function(chunk, entity_list, entity_count)
+        local health_components = chunk:components(health)
+
+        for i = 1, entity_count do
+            health_components[i] = math.max(
+                health_components[i] - 1,
+                0)
+        end
+    end):spawn()
+
+evolved.process(system)
+```
+
 To group systems together, you can use the [`evolved.GROUP`](#evolvedgroup) fragment. Systems with a specified group will be processed when you call the [`evolved.process`](#evolvedprocess) function with this group. For example, you can group all physics systems together and process them in one [`evolved.process`](#evolvedprocess) call.
 
 ```lua
@@ -895,7 +800,7 @@ The prologue and epilogue fragments do not require an explicit query. They will
 > [!NOTE]
 > And one more thing about systems. Execution callbacks are called in the [deferred scope](#deferred-operations), which means that all modifying operations inside the callback will be queued and applied after the system has processed all chunks. But prologue and epilogue callbacks are not called in the deferred scope, so all modifying operations inside them will be applied immediately. This is done to avoid confusion and to make it clear that prologue and epilogue callbacks are not part of the chunk processing.
 
-### Advanced Topics
+### Predefined Traits
 
 #### Fragment Tags
 
@@ -1039,6 +944,35 @@ local enemy2 = evolved.builder()
 assert(evolved.get(enemy1, position) ~= evolved.get(enemy2, position))
 ```
 
+#### Fragment Requirements
+
+Sometimes you want to add additional fragments to an entity when it receives a specific fragment. For example, you might want to add `position` and `velocity` fragments when an entity is given a `physical` fragment. This can be done using the [`evolved.REQUIRES`](#evolvedrequires) fragment trait. This trait expects a list of fragments that will be added to the entity when the fragment is inserted.
+
+```lua
+local evolved = require 'evolved'
+
+local position = evolved.builder()
+    :default(vector2(0, 0))
+    :duplicate(vector2_duplicate)
+    :spawn()
+
+local velocity = evolved.builder()
+    :default(vector2(0, 0))
+    :duplicate(vector2_duplicate)
+    :spawn()
+
+local physical = evolved.builder()
+    :tag()
+    :require(position, velocity)
+    :spawn()
+
+local enemy = evolved.builder()
+    :set(physical)
+    :spawn()
+
+assert(evolved.has_all(enemy, position, velocity))
+```
+
 #### 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.
@@ -1086,10 +1020,248 @@ evolved.destroy(world)
 assert(not evolved.alive(entity))
 ```
 
+## Cheat Sheet
+
+### Aliases
+
+```
+id :: implementation-specific
+pair :: id
+
+entity :: id
+fragment :: id
+query :: id
+system :: id
+
+component :: any
+storage :: component[]
+
+default :: component
+duplicate :: {component -> component}
+
+execute :: {chunk, entity[], integer}
+prologue :: {}
+epilogue :: {}
+
+set_hook :: {entity, fragment, component, component?}
+assign_hook :: {entity, fragment, component, component}
+insert_hook :: {entity, fragment, component}
+remove_hook :: {entity, fragment, component}
+
+each_state :: implementation-specific
+execute_state :: implementation-specific
+primaries_state :: implementation-specific
+secondaries_state :: implementation-specific
+
+each_iterator :: {each_state? -> fragment?, component?}
+execute_iterator :: {execute_state? -> chunk?, entity[]?, integer?}
+primaries_iterator :: {primaries_state? -> fragment?, component?}
+secondaries_iterator :: {secondaries_state? -> fragment?, component?}
+```
+
+### Predefs
+
+```
+ANY :: fragment
+
+TAG :: fragment
+NAME :: fragment
+
+UNIQUE :: fragment
+EXPLICIT :: fragment
+INTERNAL :: fragment
+
+DEFAULT :: fragment
+DUPLICATE :: fragment
+
+PREFAB :: fragment
+DISABLED :: fragment
+
+INCLUDES :: fragment
+EXCLUDES :: fragment
+REQUIRES :: fragment
+
+ON_SET :: fragment
+ON_ASSIGN :: fragment
+ON_INSERT :: fragment
+ON_REMOVE :: fragment
+
+GROUP :: fragment
+
+QUERY :: fragment
+EXECUTE :: fragment
+
+PROLOGUE :: fragment
+EPILOGUE :: fragment
+
+DESTRUCTION_POLICY :: fragment
+DESTRUCTION_POLICY_DESTROY_ENTITY :: id
+DESTRUCTION_POLICY_REMOVE_FRAGMENT :: id
+```
+
+### Core Functions
+
+```
+id :: integer? -> id...
+name :: id... -> string...
+
+pack :: integer, integer -> id
+unpack :: id -> integer, integer, integer
+
+defer :: boolean
+commit :: boolean
+
+spawn :: <fragment, component>? -> entity
+clone :: entity -> <fragment, component>? -> entity
+
+alive :: entity -> boolean
+alive_all :: entity... -> boolean
+alive_any :: entity... -> boolean
+
+empty :: entity -> boolean
+empty_all :: entity... -> boolean
+empty_any :: entity... -> boolean
+
+has :: entity, fragment -> boolean
+has_all :: entity, fragment... -> boolean
+has_any :: entity, fragment... -> boolean
+
+get :: entity, fragment...  -> component...
+
+set :: entity, fragment, component -> ()
+remove :: entity, fragment... -> ()
+clear :: entity... -> ()
+destroy :: entity... -> ()
+
+batch_set :: query, fragment, component -> ()
+batch_remove :: query, fragment... -> ()
+batch_clear :: query... -> ()
+batch_destroy :: query... -> ()
+
+each :: entity -> {each_state? -> fragment?, component?}, each_state?
+execute :: query -> {execute_state? -> chunk?, entity[]?, integer?}, execute_state?
+
+process :: system... -> ()
+
+debug_mode :: boolean -> ()
+collect_garbage :: ()
+```
+
+### Relation Functions
+
+```
+pair :: id, id -> pair
+unpair :: pair -> id, id
+
+is_pair :: id -> boolean
+is_wildcard :: id -> boolean
+
+primary :: entity, fragment, integer? -> fragment?, component?
+secondary :: entity, fragment, integer? -> fragment?, component?
+
+primaries :: entity, fragment -> {primaries_state? -> fragment?, component?}, primaries_state?
+secondaries :: entity, fragment -> {secondaries_state? -> fragment?, component?}, secondaries_state?
+
+primary_count :: entity, fragment -> integer
+secondary_count :: entity, fragment -> integer
+```
+
+### Classes
+
+#### Chunk
+
+```
+chunk :: fragment, fragment... -> chunk, entity[], integer
+
+chunk_mt:alive :: boolean
+chunk_mt:empty :: boolean
+
+chunk_mt:has :: fragment -> boolean
+chunk_mt:has_all :: fragment... -> boolean
+chunk_mt:has_any :: fragment... -> boolean
+
+chunk_mt:entities :: entity[], integer
+chunk_mt:fragments :: fragment[], integer
+chunk_mt:components :: fragment... -> storage...
+```
+
+#### Builder
+
+```
+builder :: builder
+
+builder_mt:spawn :: entity
+builder_mt:clone :: entity -> entity
+
+builder_mt:has :: fragment -> boolean
+builder_mt:has_all :: fragment... -> boolean
+builder_mt:has_any :: fragment... -> boolean
+
+builder_mt:get :: fragment... -> component...
+
+builder_mt:set :: fragment, component -> builder
+builder_mt:remove :: fragment... -> builder
+builder_mt:clear :: builder
+
+builder_mt:tag :: builder
+builder_mt:name :: string -> builder
+
+builder_mt:unique :: builder
+builder_mt:explicit :: builder
+builder_mt:internal :: builder
+
+builder_mt:default :: component -> builder
+builder_mt:duplicate :: {component -> component} -> builder
+
+builder_mt:prefab :: builder
+builder_mt:disabled :: builder
+
+builder_mt:include :: fragment... -> builder
+builder_mt:exclude :: fragment... -> builder
+builder_mt:require :: fragment... -> builder
+
+builder_mt:on_set :: {entity, fragment, component, component?} -> builder
+builder_mt:on_assign :: {entity, fragment, component, component} -> builder
+builder_mt:on_insert :: {entity, fragment, component} -> builder
+builder_mt:on_remove :: {entity, fragment} -> builder
+
+builder_mt:group :: system -> builder
+
+builder_mt:query :: query -> builder
+builder_mt:execute :: {chunk, entity[], integer} -> builder
+
+builder_mt:prologue :: {} -> builder
+builder_mt:epilogue :: {} -> builder
+
+builder_mt:destruction_policy :: id -> builder
+```
+
+## License
+
+`evolved.lua` is licensed under the [MIT License][license]. For more details, see the [LICENSE.md](./LICENSE.md) file in the repository.
+
+# Changelog
+
+## vX.X.X
+
+- Added the new [`evolved.name`](#evolvedname-1) function
+- Added the new [`evolved.INTERNAL`](#evolvedinternal) fragment trait
+
+## v1.1.0
+
+- [`Systems`](#systems) can be queries themselves now
+- Added the new [`evolved.REQUIRES`](#evolvedrequires) fragment trait
+
+## v1.0.0
+
+- Initial release
+
 # API Reference
 
 ## Predefs
 
+### `evolved.ANY`
+
 ### `evolved.TAG`
 
 ### `evolved.NAME`
@@ -1098,6 +1270,8 @@ assert(not evolved.alive(entity))
 
 ### `evolved.EXPLICIT`
 
+### `evolved.INTERNAL`
+
 ### `evolved.DEFAULT`
 
 ### `evolved.DUPLICATE`
@@ -1110,6 +1284,8 @@ assert(not evolved.alive(entity))
 
 ### `evolved.EXCLUDES`
 
+### `evolved.REQUIRES`
+
 ### `evolved.ON_SET`
 
 ### `evolved.ON_ASSIGN`
@@ -1134,7 +1310,7 @@ assert(not evolved.alive(entity))
 
 ### `evolved.DESTRUCTION_POLICY_REMOVE_FRAGMENT`
 
-## Functions
+## Core Functions
 
 ### `evolved.id`
 
@@ -1145,6 +1321,15 @@ assert(not evolved.alive(entity))
 function evolved.id(count) end
 ```
 
+### `evolved.name`
+
+```lua
+---@param ... evolved.id ids
+---@return string... names
+---@nodiscard
+function evolved.name(...) end
+```
+
 ### `evolved.pack`
 
 ```lua
@@ -1159,8 +1344,9 @@ function evolved.pack(index, version) end
 
 ```lua
 ---@param id evolved.id
----@return integer index
----@return integer version
+---@return integer primary
+---@return integer secondary
+---@return integer options
 ---@nodiscard
 function evolved.unpack(id) end
 ```
@@ -1392,6 +1578,112 @@ function evolved.debug_mode(yesno) end
 function evolved.collect_garbage() end
 ```
 
+## Relation Functions
+
+### `evolved.pair`
+
+```lua
+---@param primary evolved.id
+---@param secondary evolved.id
+---@return evolved.pair pair
+---@nodiscard
+function evolved.pair(primary, secondary) end
+```
+
+### `evolved.unpair`
+
+```lua
+---@param pair evolved.pair
+---@return evolved.id primary
+---@return evolved.id secondary
+---@nodiscard
+function evolved.unpair(pair) end
+```
+
+### `evolved.is_pair`
+
+```lua
+---@param id evolved.id
+---@return boolean
+---@nodiscard
+function evolved.is_pair(id) end
+```
+
+### `evolved.is_wildcard`
+
+```lua
+---@param id evolved.id
+---@return boolean
+---@nodiscard
+function evolved.is_wildcard(id) end
+```
+
+### `evolved.primary`
+
+```lua
+---@param entity evolved.entity
+---@param secondary evolved.fragment
+---@param index? integer
+---@return evolved.fragment? primary
+---@return evolved.component? component
+---@nodiscard
+function evolved.primary(entity, secondary, index) end
+```
+
+### `evolved.secondary`
+
+```lua
+---@param entity evolved.entity
+---@param primary evolved.fragment
+---@param index? integer
+---@return evolved.fragment? secondary
+---@return evolved.component? component
+---@nodiscard
+function evolved.secondary(entity, primary, index) end
+```
+
+### `evolved.primaries`
+
+```lua
+---@param entity evolved.entity
+---@param secondary evolved.fragment
+---@return evolved.primaries_iterator iterator
+---@return evolved.primaries_state? iterator_state
+---@nodiscard
+function evolved.primaries(entity, secondary) end
+```
+
+### `evolved.secondaries`
+
+```lua
+---@param entity evolved.entity
+---@param primary evolved.fragment
+---@return evolved.secondaries_iterator iterator
+---@return evolved.secondaries_state? iterator_state
+---@nodiscard
+function evolved.secondaries(entity, primary) end
+```
+
+### `evolved.primary_count`
+
+```lua
+---@param entity evolved.entity
+---@param secondary evolved.fragment
+---@return integer
+---@nodiscard
+function evolved.primary_count(entity, secondary) end
+```
+
+### `evolved.secondary_count`
+
+```lua
+---@param entity evolved.entity
+---@param primary evolved.fragment
+---@return integer
+---@nodiscard
+function evolved.secondary_count(entity, primary) end
+```
+
 ## Classes
 
 ### Chunk
@@ -1592,6 +1884,13 @@ function evolved.builder_mt:unique() end
 function evolved.builder_mt:explicit() end
 ```
 
+#### `evolved.builder_mt:internal`
+
+```lua
+---@return evolved.builder builder
+function evolved.builder_mt:internal() end
+```
+
 #### `evolved.builder_mt:default`
 
 ```lua
@@ -1638,6 +1937,14 @@ function evolved.builder_mt:include(...) end
 function evolved.builder_mt:exclude(...) end
 ```
 
+### `evolved.builder_mt:require`
+
+```lua
+---@param ... evolved.fragment fragments
+---@return evolved.builder builder
+function evolved.builder_mt:require(...) end
+```
+
 #### `evolved.builder_mt:on_set`
 
 ```lua
@@ -1717,5 +2024,3 @@ function evolved.builder_mt:epilogue(epilogue) end
 ---@return evolved.builder builder
 function evolved.builder_mt:destruction_policy(destruction_policy) end
 ```
-
-## [License (MIT)](./LICENSE.md)

ROADMAP.md

@@ -2,11 +2,18 @@
 
 ## Backlog
 
-## After first release
-
-- cached queries
+- Improve the performance of required fragments by caching first-level required chunks.
+- Improve the performance of builders that are used multiple times by caching hint chunks.
+- Queries can cache major chunks to avoid finding them every time.
+- Add multi-spawn to the builder to spawn multiple entities at once.
+- Add a function to shrink storages to free unused memory.
 - observers and events
 - add INDEX fragment trait
-- add REQUIRES fragment trait
 - use compact prefix-tree for chunks
 - optional ffi component storages
+
+## Thoughts
+
+- We can return deferred status from modifying operations and spawn/clone methods.
+- Should we make one builder:build method instead of :spawn and :clone?
+- Should we cache the result of without_unique_fragments to clone faster?

develop/all.lua

@@ -1,6 +1,14 @@
-require 'develop.example'
-require 'develop.unbench'
+require 'develop.samples.relations'
+require 'develop.samples.systems'
+
+require 'develop.testing.name_tests'
+require 'develop.testing.pairs_tests'
+require 'develop.testing.requires_fragment_tests'
+require 'develop.testing.system_as_query_tests'
+
 require 'develop.untests'
+
+require 'develop.unbench'
 require 'develop.usbench'
 
 local basics = require 'develop.basics'
@@ -12,4 +20,10 @@ basics.describe_fuzz 'develop.fuzzing.batch_destroy_fuzz'
 print '----------------------------------------'
 basics.describe_fuzz 'develop.fuzzing.explicit_fuzz'
 print '----------------------------------------'
+basics.describe_fuzz 'develop.fuzzing.pack_unpack_fuzz'
+print '----------------------------------------'
+basics.describe_fuzz 'develop.fuzzing.requires_fuzz'
+print '----------------------------------------'
 basics.describe_fuzz 'develop.fuzzing.unique_fuzz'
+print '----------------------------------------'
+basics.describe_fuzz 'develop.fuzzing.wildcard_fuzz'

develop/basics.lua

@@ -1,5 +1,13 @@
 local basics = {}
 
+local MIN_FUZZ_SECS = 0.5
+local MIN_BENCH_SECS = 0.1
+local MIN_WARMUP_SECS = 0.1
+
+local MIN_FUZZ_ITERS = 100
+local MIN_BENCH_ITERS = 100
+local MIN_WARMUP_ITERS = 100
+
 local __table_pack = (function()
     ---@diagnostic disable-next-line: deprecated
     return table.pack or function(...)
@@ -23,8 +31,13 @@ end
 
 ---@param modname string
 function basics.describe_fuzz(modname)
+    basics.unload('evolved')
+
     print(string.format('| %s ... |', modname))
 
+    collectgarbage('collect')
+    collectgarbage('stop')
+
     do
         local iters = 0
 
@@ -36,7 +49,7 @@ function basics.describe_fuzz(modname)
                 iters = iters + 1
                 basics.unload(modname)
                 require(modname)
-            until os.clock() - start_s > 0.5
+            until iters >= MIN_FUZZ_ITERS and os.clock() - start_s >= MIN_FUZZ_SECS
         end)
 
         local finish_s = os.clock()
@@ -52,6 +65,9 @@ function basics.describe_fuzz(modname)
             print('|-- FUZZ FAIL: ' .. result)
         end
     end
+
+    collectgarbage('restart')
+    collectgarbage('collect')
 end
 
 ---@param name string
@@ -59,17 +75,22 @@ end
 ---@param init? fun(): ...
 ---@param fini? fun(...): ...
 function basics.describe_bench(name, loop, init, fini)
+    basics.unload('evolved')
+
     print(string.format('| %s ... |', name))
 
     local state = init and __table_pack(init()) or {}
 
     do
+        local iters = 0
+
         local warmup_s = os.clock()
 
         local success, result = pcall(function()
             repeat
+                iters = iters + 1
                 loop(__table_unpack(state))
-            until os.clock() - warmup_s > 0.1
+            until iters >= MIN_WARMUP_ITERS and os.clock() - warmup_s > MIN_WARMUP_SECS
         end)
 
         if not success then
@@ -91,7 +112,7 @@ function basics.describe_bench(name, loop, init, fini)
             repeat
                 iters = iters + 1
                 loop(__table_unpack(state))
-            until os.clock() - start_s > 0.1
+            until iters >= MIN_BENCH_ITERS and os.clock() - start_s > MIN_BENCH_SECS
         end)
 
         local finish_s = os.clock()

develop/fuzzing/batch_destroy_fuzz.lua

@@ -117,5 +117,12 @@ end
 ---
 ---
 
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end
+
 evo.destroy(__table_unpack(all_entity_list))
-evo.collect_garbage()
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end

develop/fuzzing/destroy_fuzz.lua

@@ -123,5 +123,12 @@ end
 ---
 ---
 
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end
+
 evo.destroy(__table_unpack(all_entity_list))
-evo.collect_garbage()
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end

develop/fuzzing/explicit_fuzz.lua

@@ -77,5 +77,12 @@ end
 ---
 ---
 
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end
+
 evo.destroy(__table_unpack(all_entity_list))
-evo.collect_garbage()
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end

develop/fuzzing/pack_unpack_fuzz.lua

@@ -0,0 +1,21 @@
+local evo = require 'evolved'
+
+evo.debug_mode(true)
+
+---
+---
+---
+---
+---
+
+for _ = 1, 1000 do
+    local initial_primary = math.random(1, 2 ^ 20 - 1)
+    local initial_secondary = math.random(1, 2 ^ 20 - 1)
+
+    local packed_id = evo.pack(initial_primary, initial_secondary)
+    local unpacked_primary, unpacked_secondary, unpacked_options = evo.unpack(packed_id)
+
+    assert(initial_primary == unpacked_primary)
+    assert(initial_secondary == unpacked_secondary)
+    assert(0 == unpacked_options)
+end

develop/fuzzing/requires_fuzz.lua

@@ -0,0 +1,131 @@
+local evo = require 'evolved'
+
+evo.debug_mode(true)
+
+---
+---
+---
+---
+---
+
+local __table_unpack = (function()
+    ---@diagnostic disable-next-line: deprecated
+    return table.unpack or unpack
+end)()
+
+---
+---
+---
+---
+---
+
+local all_fragment_list = {} ---@type evolved.fragment[]
+
+for i = 1, math.random(1, 10) do
+    local fragment = evo.builder()
+        :default(42)
+        :spawn()
+    all_fragment_list[i] = fragment
+end
+
+for _, fragment in ipairs(all_fragment_list) do
+    if math.random(1, 2) == 1 then
+        for _ = 0, math.random(0, #all_fragment_list) do
+            local require_list = evo.get(fragment, evo.REQUIRES) or {}
+            require_list[#require_list + 1] = all_fragment_list[math.random(1, #all_fragment_list)]
+            evo.set(fragment, evo.REQUIRES, require_list)
+        end
+    end
+end
+
+local all_entity_list = {} ---@type evolved.entity[]
+
+for i = 1, math.random(1, 10) do
+    local entity = evo.id()
+    all_entity_list[i] = entity
+
+    for _ = 0, math.random(0, #all_fragment_list) do
+        local fragment = all_fragment_list[math.random(1, #all_fragment_list)]
+
+        if math.random(1, 2) == 1 then
+            evo.set(entity, fragment, 42)
+        else
+            local query = evo.builder()
+                :include(all_fragment_list[math.random(1, #all_fragment_list)])
+                :spawn()
+            evo.batch_set(query, fragment, 42)
+            evo.destroy(query)
+        end
+    end
+end
+
+for _ = 1, math.random(1, #all_entity_list) do
+    local components = {}
+    for _ = 1, math.random(1, #all_fragment_list) do
+        local fragment = all_fragment_list[math.random(1, #all_fragment_list)]
+        components[fragment] = 42
+    end
+    all_entity_list[#all_entity_list + 1] = evo.spawn(components)
+end
+
+for _ = 1, math.random(1, #all_entity_list) do
+    local prefab = all_entity_list[math.random(1, #all_entity_list)]
+    all_entity_list[#all_entity_list + 1] = evo.clone(prefab)
+end
+
+---
+---
+---
+---
+---
+
+local function collect_required_fragments_for(fragment, req_fragment_set, req_fragment_list)
+    local fragment_requires = evo.get(fragment, evo.REQUIRES) or {}
+    for _, required_fragment in ipairs(fragment_requires) do
+        if not req_fragment_set[required_fragment] then
+            req_fragment_set[required_fragment] = true
+            req_fragment_list[#req_fragment_list + 1] = required_fragment
+            collect_required_fragments_for(required_fragment, req_fragment_set, req_fragment_list)
+        end
+    end
+end
+
+for _, entity in ipairs(all_entity_list) do
+    for fragment in evo.each(entity) do
+        local req_fragment_list = {}
+        collect_required_fragments_for(fragment, {}, req_fragment_list)
+        for _, required_fragment in ipairs(req_fragment_list) do
+            assert(evo.has(entity, required_fragment))
+            local required_component = evo.get(entity, required_fragment)
+            assert(required_component == 42)
+        end
+    end
+end
+
+---
+---
+---
+---
+---
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end
+
+if math.random(1, 2) == 1 then
+    evo.destroy(__table_unpack(all_entity_list))
+    if math.random(1, 2) == 1 then
+        evo.collect_garbage()
+    end
+    evo.destroy(__table_unpack(all_fragment_list))
+else
+    evo.destroy(__table_unpack(all_fragment_list))
+    if math.random(1, 2) == 1 then
+        evo.collect_garbage()
+    end
+    evo.destroy(__table_unpack(all_entity_list))
+end
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end

develop/fuzzing/unique_fuzz.lua

@@ -63,5 +63,12 @@ end
 ---
 ---
 
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end
+
 evo.destroy(__table_unpack(all_entity_list))
-evo.collect_garbage()
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end

develop/fuzzing/wildcard_fuzz.lua

@@ -0,0 +1,275 @@
+local evo = require 'evolved'
+
+evo.debug_mode(true)
+
+---
+---
+---
+---
+---
+
+local __table_unpack = (function()
+    ---@diagnostic disable-next-line: deprecated
+    return table.unpack or unpack
+end)()
+
+---
+---
+---
+---
+---
+
+local all_entity_list = {} ---@type evolved.entity[]
+local all_fragment_list = {} ---@type evolved.fragment[]
+
+for i = 1, math.random(1, 5) do
+    local fragment_builder = evo.builder()
+
+    if math.random(1, 3) == 1 then
+        fragment_builder:explicit()
+    end
+
+    if math.random(1, 3) == 1 then
+        if math.random(1, 2) == 1 then
+            fragment_builder:destruction_policy(evo.DESTRUCTION_POLICY_DESTROY_ENTITY)
+        else
+            fragment_builder:destruction_policy(evo.DESTRUCTION_POLICY_REMOVE_FRAGMENT)
+        end
+    end
+
+    all_fragment_list[i] = fragment_builder:spawn()
+end
+
+for i = 1, math.random(50, 100) do
+    local entity_builder = evo.builder()
+
+    for _ = 0, math.random(0, #all_fragment_list) do
+        if math.random(1, 2) == 1 then
+            local fragment = all_fragment_list[math.random(1, #all_fragment_list)]
+            entity_builder:set(fragment)
+        else
+            local primary = all_fragment_list[math.random(1, #all_fragment_list)]
+            local secondary = all_fragment_list[math.random(1, #all_fragment_list)]
+            entity_builder:set(evo.pair(primary, secondary))
+        end
+    end
+
+    all_entity_list[i] = entity_builder:spawn()
+end
+
+---
+---
+---
+---
+---
+
+for _ = 1, math.random(1, 100) do
+    local query_builder = evo.builder()
+
+    local query_include_set = {} ---@type table<evolved.fragment, integer>
+    local query_include_list = {} ---@type evolved.entity[]
+    local query_include_count = 0 ---@type integer
+
+    local query_exclude_set = {} ---@type table<evolved.fragment, integer>
+    local query_exclude_list = {} ---@type evolved.entity[]
+    local query_exclude_count = 0 ---@type integer
+
+    for _ = 1, math.random(0, 2) do
+        if math.random(1, 2) == 1 then
+            local fragment = all_fragment_list[math.random(1, #all_fragment_list)]
+
+            query_builder:include(fragment)
+
+            if not query_include_set[fragment] then
+                query_include_count = query_include_count + 1
+                query_include_set[fragment] = query_include_count
+                query_include_list[query_include_count] = fragment
+            end
+        else
+            local primary = all_fragment_list[math.random(1, #all_fragment_list)]
+            local secondary = all_fragment_list[math.random(1, #all_fragment_list)]
+
+            if math.random(1, 3) == 1 then
+                primary = evo.ANY
+            end
+
+            if math.random(1, 3) == 1 then
+                secondary = evo.ANY
+            end
+
+            local pair = evo.pair(primary, secondary)
+
+            query_builder:include(pair)
+
+            if not query_include_set[pair] then
+                query_include_count = query_include_count + 1
+                query_include_set[pair] = query_include_count
+                query_include_list[query_include_count] = pair
+            end
+        end
+    end
+
+    for _ = 1, math.random(0, 2) do
+        if math.random(1, 2) == 1 then
+            local fragment = all_fragment_list[math.random(1, #all_fragment_list)]
+
+            query_builder:exclude(fragment)
+
+            if not query_exclude_set[fragment] then
+                query_exclude_count = query_exclude_count + 1
+                query_exclude_set[fragment] = query_exclude_count
+                query_exclude_list[query_exclude_count] = fragment
+            end
+        else
+            local primary = all_fragment_list[math.random(1, #all_fragment_list)]
+            local secondary = all_fragment_list[math.random(1, #all_fragment_list)]
+
+            if math.random(1, 3) == 1 then
+                primary = evo.ANY
+            end
+
+            if math.random(1, 3) == 1 then
+                secondary = evo.ANY
+            end
+
+            local pair = evo.pair(primary, secondary)
+
+            query_builder:exclude(pair)
+
+            if not query_exclude_set[pair] then
+                query_exclude_count = query_exclude_count + 1
+                query_exclude_set[pair] = query_exclude_count
+                query_exclude_list[query_exclude_count] = pair
+            end
+        end
+    end
+
+    local query_entity_set = {} ---@type table<evolved.entity, integer>
+    local query_entity_count = 0 ---@type integer
+
+    do
+        local query = query_builder:spawn()
+
+        for chunk, entity_list, entity_count in evo.execute(query) do
+            if not chunk:has(evo.INTERNAL) then
+                for i = 1, entity_count do
+                    local entity = entity_list[i]
+                    assert(not query_entity_set[entity])
+                    query_entity_count = query_entity_count + 1
+                    query_entity_set[entity] = query_entity_count
+                end
+            end
+        end
+
+        if query_entity_set[query] then
+            query_entity_set[query] = nil
+            query_entity_count = query_entity_count - 1
+        end
+
+        evo.destroy(query)
+    end
+
+    do
+        local expected_entity_count = 0
+
+        for _, entity in ipairs(all_entity_list) do
+            local is_entity_expected =
+                not evo.empty(entity) and
+                evo.has_all(entity, __table_unpack(query_include_list)) and
+                not evo.has_any(entity, __table_unpack(query_exclude_list))
+
+            for fragment in evo.each(entity) do
+                local is_fragment_explicit = false
+
+                if not is_fragment_explicit and evo.is_pair(fragment) then
+                    is_fragment_explicit = evo.has(evo.unpair(fragment), evo.EXPLICIT)
+                end
+
+                if not is_fragment_explicit and not evo.is_pair(fragment) then
+                    is_fragment_explicit = evo.has(fragment, evo.EXPLICIT)
+                end
+
+                if is_fragment_explicit then
+                    local is_fragment_included = false
+
+                    if not is_fragment_included then
+                        is_fragment_included = query_include_set[fragment] ~= nil
+                    end
+
+                    if not is_fragment_included and evo.is_pair(fragment) then
+                        local fragment_primary = evo.unpair(fragment)
+                        is_fragment_included = query_include_set[evo.pair(fragment_primary, evo.ANY)] ~= nil
+                    end
+
+                    if not is_fragment_included and not evo.is_pair(fragment) then
+                        is_fragment_included = query_include_set[evo.pair(fragment, evo.ANY)] ~= nil
+                    end
+
+                    if not is_fragment_included then
+                        is_entity_expected = false
+                        break
+                    end
+                end
+            end
+
+            if is_entity_expected then
+                assert(query_entity_set[entity])
+                expected_entity_count = expected_entity_count + 1
+            else
+                assert(not query_entity_set[entity])
+            end
+        end
+
+        for _, entity in ipairs(all_fragment_list) do
+            local is_entity_expected =
+                not evo.empty(entity) and
+                evo.has_all(entity, __table_unpack(query_include_list)) and
+                not evo.has_any(entity, __table_unpack(query_exclude_list))
+
+            for fragment in evo.each(entity) do
+                if evo.has(fragment, evo.EXPLICIT) then
+                    is_entity_expected = is_entity_expected and
+                        (query_include_set[fragment] ~= nil) or
+                        (evo.is_pair(fragment) and query_include_set[evo.pair(fragment, evo.ANY)] ~= nil)
+                end
+            end
+
+            if is_entity_expected then
+                assert(query_entity_set[entity])
+                expected_entity_count = expected_entity_count + 1
+            else
+                assert(not query_entity_set[entity])
+            end
+        end
+
+        assert(query_entity_count == expected_entity_count)
+    end
+end
+
+---
+---
+---
+---
+---
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end
+
+if math.random(1, 2) == 1 then
+    evo.destroy(__table_unpack(all_entity_list))
+    if math.random(1, 2) == 1 then
+        evo.collect_garbage()
+    end
+    evo.destroy(__table_unpack(all_fragment_list))
+else
+    evo.destroy(__table_unpack(all_fragment_list))
+    if math.random(1, 2) == 1 then
+        evo.collect_garbage()
+    end
+    evo.destroy(__table_unpack(all_entity_list))
+end
+
+if math.random(1, 2) == 1 then
+    evo.collect_garbage()
+end

develop/samples/relations.lua

@@ -0,0 +1,79 @@
+---@diagnostic disable: unused-local
+
+local evo = require 'evolved'
+
+evo.debug_mode(true)
+
+local fragments = {
+    planet = evo.builder()
+        :name('planet')
+        :tag()
+        :spawn(),
+    spaceship = evo.builder()
+        :name('spaceship')
+        :tag()
+        :spawn(),
+}
+
+local relations = {
+    docked_to = evo.builder()
+        :name('docked_to')
+        :tag()
+        :spawn(),
+}
+
+local planets = {
+    mars = evo.builder()
+        :name('Mars')
+        :set(fragments.planet)
+        :spawn(),
+    venus = evo.builder()
+        :name('Venus')
+        :set(fragments.planet)
+        :spawn(),
+}
+
+local spaceships = {
+    falcon = evo.builder()
+        :name('Millennium Falcon')
+        :set(fragments.spaceship)
+        :set(evo.pair(relations.docked_to, planets.mars))
+        :spawn(),
+    enterprise = evo.builder()
+        :name('USS Enterprise')
+        :set(fragments.spaceship)
+        :set(evo.pair(relations.docked_to, planets.venus))
+        :spawn(),
+}
+
+local queries = {
+    all_docked_spaceships = evo.builder()
+        :include(fragments.spaceship)
+        :include(evo.pair(relations.docked_to, evo.ANY))
+        :spawn(),
+    docked_spaceships_to_mars = evo.builder()
+        :include(fragments.spaceship)
+        :include(evo.pair(relations.docked_to, planets.mars))
+        :spawn(),
+
+}
+
+print '-= | All Docked Spaceships | =-'
+
+for chunk, entity_list, entity_count in evo.execute(queries.all_docked_spaceships) do
+    for i = 1, entity_count do
+        local entity = entity_list[i]
+        local planet = evo.secondary(entity, relations.docked_to)
+        print(string.format('%s is docked to %s', evo.name(entity), evo.name(planet)))
+    end
+end
+
+print '-= | Docked Spaceships to Mars | =-'
+
+for chunk, entity_list, entity_count in evo.execute(queries.docked_spaceships_to_mars) do
+    for i = 1, entity_count do
+        local entity = entity_list[i]
+        local planet = evo.secondary(entity, relations.docked_to)
+        print(string.format('%s is docked to %s', evo.name(entity), evo.name(planet)))
+    end
+end

develop/testing/name_tests.lua

@@ -0,0 +1,43 @@
+local evo = require 'evolved'
+
+do
+    local id = evo.id()
+
+    local index, version, options = evo.unpack(id)
+    assert(evo.name(id) == string.format('$%d#%d:%d:%d', id, index, version, options))
+
+    evo.set(id, evo.NAME, 'hello')
+    assert(evo.name(id) == 'hello')
+
+    evo.set(id, evo.NAME, 'world')
+    assert(evo.name(id) == 'world')
+
+    evo.destroy(id)
+    assert(evo.name(id) == string.format('$%d#%d:%d:%d', id, index, version, options))
+end
+
+do
+    local id1, id2, id3, id4, id5 = evo.id(5)
+
+    evo.set(id1, evo.NAME, 'id1')
+    evo.set(id2, evo.NAME, 'id2')
+    evo.set(id3, evo.NAME, 'id3')
+    evo.set(id4, evo.NAME, 'id4')
+    evo.set(id5, evo.NAME, 'id5')
+
+    do
+        local id1_n, id3_n, id5_n = evo.name(id1, id3, id5)
+        assert(id1_n == 'id1')
+        assert(id3_n == 'id3')
+        assert(id5_n == 'id5')
+    end
+
+    do
+        local id1_n, id2_n, id3_n, id4_n, id5_n = evo.name(id1, id2, id3, id4, id5)
+        assert(id1_n == 'id1')
+        assert(id2_n == 'id2')
+        assert(id3_n == 'id3')
+        assert(id4_n == 'id4')
+        assert(id5_n == 'id5')
+    end
+end

develop/testing/requires_fragment_tests.lua

@@ -0,0 +1,245 @@
+local evo = require 'evolved'
+
+do
+    local f1, f2 = evo.id(2)
+    evo.set(f1, evo.REQUIRES)
+    evo.set(f2, evo.REQUIRES, evo.get(f1, evo.REQUIRES))
+    local f1_rs = evo.get(f1, evo.REQUIRES)
+    local f2_rs = evo.get(f2, evo.REQUIRES)
+    assert(f1_rs and f2_rs and #f1_rs == 0 and #f2_rs == 0 and f1_rs ~= f2_rs)
+end
+
+do
+    local f1, f2 = evo.id(2)
+    local f3 = evo.builder():require(f1):require(f2):spawn()
+    local f3_rs = evo.get(f3, evo.REQUIRES)
+    assert(f3_rs and #f3_rs == 2 and f3_rs[1] == f1 and f3_rs[2] == f2)
+end
+
+do
+    local f1, f2 = evo.id(2)
+    local f3 = evo.builder():require(f1, f2):spawn()
+    local f3_rs = evo.get(f3, evo.REQUIRES)
+    assert(f3_rs and #f3_rs == 2 and f3_rs[1] == f1 and f3_rs[2] == f2)
+end
+
+do
+    local f1, f2, f3 = evo.id(3)
+    evo.set(f1, evo.REQUIRES, { f2 })
+    evo.set(f3, evo.REQUIRES, { f1, f2 })
+
+    do
+        local e = evo.id()
+        evo.set(e, f1)
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == true)
+    end
+
+    do
+        local e = evo.builder():set(f1):spawn()
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == true)
+    end
+
+    do
+        local e = evo.spawn { [f1] = true }
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == true)
+
+        evo.remove(e, f2)
+        assert(not evo.has(e, f2))
+
+        local e2 = evo.clone(e)
+        assert(evo.has(e2, f2))
+        assert(evo.get(e2, f2) == true)
+
+        local e3 = evo.clone(e, { [f3] = true })
+        assert(evo.has(e3, f2))
+        assert(evo.get(e3, f2) == true)
+    end
+
+    do
+        local f0 = evo.id()
+        local q0 = evo.builder():include(f0):spawn()
+
+        local e1 = evo.builder():set(f0):spawn()
+        local e2 = evo.builder():set(f0):spawn()
+        local e3 = evo.builder():set(f0):set(f2, false):spawn()
+
+        evo.batch_set(q0, f1)
+
+        assert(evo.has(e1, f2) and evo.get(e1, f2) == true)
+        assert(evo.has(e2, f2) and evo.get(e2, f2) == true)
+        assert(evo.has(e3, f2) and evo.get(e3, f2) == false)
+    end
+end
+
+do
+    local f1, f2, f3 = evo.id(3)
+    evo.set(f1, evo.REQUIRES, { f2 })
+    evo.set(f2, evo.DEFAULT, 42)
+    evo.set(f3, evo.REQUIRES, { f1, f2 })
+
+    do
+        local e = evo.id()
+        evo.set(e, f1)
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == 42)
+    end
+
+    do
+        local e = evo.builder():set(f1):spawn()
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == 42)
+    end
+
+    do
+        local e = evo.spawn { [f1] = true, }
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == 42)
+
+        evo.remove(e, f2)
+        assert(not evo.has(e, f2))
+
+        local e2 = evo.clone(e)
+        assert(evo.has(e2, f2))
+        assert(evo.get(e2, f2) == 42)
+
+        local e3 = evo.clone(e, { [f3] = true })
+        assert(evo.has(e3, f2))
+        assert(evo.get(e3, f2) == 42)
+    end
+
+    do
+        local f0 = evo.id()
+        local q0 = evo.builder():include(f0):spawn()
+
+        local e1 = evo.builder():set(f0):spawn()
+        local e2 = evo.builder():set(f0):spawn()
+        local e3 = evo.builder():set(f0):set(f2, 21):spawn()
+
+        evo.batch_set(q0, f1)
+
+        assert(evo.has(e1, f2) and evo.get(e1, f2) == 42)
+        assert(evo.has(e2, f2) and evo.get(e2, f2) == 42)
+        assert(evo.has(e3, f2) and evo.get(e3, f2) == 21)
+    end
+end
+
+do
+    local f1, f2, f3 = evo.id(3)
+    evo.set(f1, evo.REQUIRES, { f2 })
+    evo.set(f2, evo.REQUIRES, { f3 })
+    evo.set(f3, evo.DEFAULT, 42)
+    evo.set(f3, evo.REQUIRES, { f1, f2 })
+
+    do
+        local e = evo.id()
+        evo.set(e, f1)
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == true)
+        assert(evo.has(e, f3))
+        assert(evo.get(e, f3) == 42)
+    end
+
+    do
+        local e = evo.builder():set(f1):spawn()
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == true)
+        assert(evo.has(e, f3))
+        assert(evo.get(e, f3) == 42)
+    end
+
+    do
+        local e = evo.spawn { [f1] = true }
+        assert(evo.has(e, f2))
+        assert(evo.get(e, f2) == true)
+        assert(evo.has(e, f3))
+        assert(evo.get(e, f3) == 42)
+
+        evo.remove(e, f2, f3)
+        assert(not evo.has(e, f2))
+        assert(not evo.has(e, f3))
+
+        local e2 = evo.clone(e, { [f1] = 21 })
+        assert(evo.has(e2, f1) and evo.get(e2, f1) == 21)
+        assert(evo.has(e2, f2) and evo.get(e2, f2) == true)
+        assert(evo.has(e2, f3) and evo.get(e2, f3) == 42)
+
+        local e3 = evo.clone(e, { [f3] = 21 })
+        assert(evo.has(e3, f1) and evo.get(e3, f1) == true)
+        assert(evo.has(e3, f2) and evo.get(e3, f2) == true)
+        assert(evo.has(e3, f3) and evo.get(e3, f3) == 21)
+    end
+end
+
+do
+    local f1, f2, f3 = evo.id(3)
+    evo.set(f1, evo.REQUIRES, { f2 })
+    evo.set(f2, evo.REQUIRES, { f3 })
+    evo.set(f3, evo.REQUIRES, { f1, f2, f3 })
+
+    do
+        local e = evo.id()
+        evo.set(e, f1, 42)
+        assert(evo.has(e, f1) and evo.get(e, f1) == 42)
+        assert(evo.has(e, f2) and evo.get(e, f2) == true)
+        assert(evo.has(e, f3) and evo.get(e, f3) == true)
+    end
+
+    do
+        local e = evo.builder():set(f1, 42):spawn()
+        assert(evo.has(e, f1) and evo.get(e, f1) == 42)
+        assert(evo.has(e, f2) and evo.get(e, f2) == true)
+        assert(evo.has(e, f3) and evo.get(e, f3) == true)
+    end
+
+    do
+        local e = evo.spawn { [f1] = 42 }
+        assert(evo.has(e, f1) and evo.get(e, f1) == 42)
+        assert(evo.has(e, f2) and evo.get(e, f2) == true)
+        assert(evo.has(e, f3) and evo.get(e, f3) == true)
+
+        evo.remove(e, f2, f3)
+        assert(not evo.has(e, f2))
+        assert(not evo.has(e, f3))
+
+        local e2 = evo.clone(e, { [f1] = 21 })
+        assert(evo.has(e2, f1) and evo.get(e2, f1) == 21)
+        assert(evo.has(e2, f2) and evo.get(e2, f2) == true)
+        assert(evo.has(e2, f3) and evo.get(e2, f3) == true)
+
+        local e3 = evo.clone(e, { [f3] = 21 })
+        assert(evo.has(e3, f1) and evo.get(e3, f1) == 42)
+        assert(evo.has(e3, f2) and evo.get(e3, f2) == true)
+        assert(evo.has(e3, f3) and evo.get(e3, f3) == 21)
+    end
+end
+
+do
+    local f1, f2, f3, f4 = evo.id(4)
+
+    do
+        evo.set(f1, evo.REQUIRES, { f2 })
+        do
+            local e = evo.id()
+            evo.set(e, f1)
+            assert(evo.has(e, f2) and evo.get(e, f2) == true)
+        end
+        evo.set(f1, evo.REQUIRES, { f2, f3 })
+        do
+            local e = evo.id()
+            evo.set(e, f1)
+            assert(evo.has(e, f2) and evo.get(e, f2) == true)
+            assert(evo.has(e, f3) and evo.get(e, f3) == true)
+        end
+        evo.set(f3, evo.REQUIRES, { f4 })
+        do
+            local e = evo.id()
+            evo.set(e, f1)
+            assert(evo.has(e, f2) and evo.get(e, f2) == true)
+            assert(evo.has(e, f3) and evo.get(e, f3) == true)
+            assert(evo.has(e, f4) and evo.get(e, f4) == true)
+        end
+    end
+end

develop/testing/system_as_query_tests.lua

@@ -0,0 +1,128 @@
+local evo = require 'evolved'
+
+do
+    local f1, f2, f3 = evo.id(3)
+
+    local q1e3 = evo.builder():include(f1):exclude(f3):spawn()
+    local q2e3 = evo.builder():include(f2):exclude(f3):spawn()
+
+    local e1 = evo.builder():set(f1, 1):spawn()
+    local e12 = evo.builder():set(f1, 11):set(f2, 12):spawn()
+    local e2 = evo.builder():set(f2, 2):spawn()
+    local e23 = evo.builder():set(f2, 23):set(f3, 3):spawn()
+
+    local c1 = evo.chunk(f1)
+    local c12 = evo.chunk(f1, f2)
+    local c2 = evo.chunk(f2)
+
+    do
+        local _, entity_list, entity_count = evo.chunk(f2, f3)
+        assert(entity_count == 1 and entity_list[1] == e23)
+    end
+
+    do
+        local entity_sum = 0
+
+        local s = evo.builder()
+            :query(q1e3)
+            :execute(function(chunk, entity_list, entity_count)
+                for i = 1, entity_count do
+                    entity_sum = entity_sum + entity_list[i]
+                end
+
+                if chunk == c1 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e1)
+                elseif chunk == c12 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e12)
+                else
+                    assert(false, "Unexpected chunk: " .. tostring(chunk))
+                end
+            end):spawn()
+
+        evo.process(s)
+
+        assert(entity_sum == e1 + e12)
+    end
+
+    do
+        local entity_sum = 0
+
+        local s = evo.builder()
+            :query(q2e3)
+            :execute(function(chunk, entity_list, entity_count)
+                for i = 1, entity_count do
+                    entity_sum = entity_sum + entity_list[i]
+                end
+
+                if chunk == c12 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e12)
+                elseif chunk == c2 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e2)
+                else
+                    assert(false, "Unexpected chunk: " .. tostring(chunk))
+                end
+            end):spawn()
+
+        evo.process(s)
+
+        assert(entity_sum == e12 + e2)
+    end
+
+    do
+        local entity_sum = 0
+
+        local s = evo.builder()
+            :include(f1)
+            :exclude(f3)
+            :execute(function(chunk, entity_list, entity_count)
+                for i = 1, entity_count do
+                    entity_sum = entity_sum + entity_list[i]
+                end
+
+                if chunk == c1 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e1)
+                elseif chunk == c12 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e12)
+                else
+                    assert(false, "Unexpected chunk: " .. tostring(chunk))
+                end
+            end):spawn()
+
+        evo.process(s)
+
+        assert(entity_sum == e1 + e12)
+    end
+
+    do
+        local entity_sum = 0
+
+        local s = evo.builder()
+            :include(f2)
+            :exclude(f3)
+            :execute(function(chunk, entity_list, entity_count)
+                for i = 1, entity_count do
+                    entity_sum = entity_sum + entity_list[i]
+                end
+
+                if chunk == c12 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e12)
+                elseif chunk == c2 then
+                    assert(entity_count == 1)
+                    assert(entity_list[1] == e2)
+                else
+                    assert(false, "Unexpected chunk: " .. tostring(chunk))
+                end
+            end):spawn()
+
+        evo.process(s)
+
+        assert(entity_sum == e12 + e2)
+    end
+end

develop/unbench.lua

@@ -7,6 +7,11 @@ local N = 1000
 local B = evo.builder()
 local F1, F2, F3, F4, F5 = evo.id(5)
 local Q1 = evo.builder():include(F1):spawn()
+local R1 = evo.builder():require(F1):spawn()
+local R2 = evo.builder():require(F1, F2):spawn()
+local R3 = evo.builder():require(F1, F2, F3):spawn()
+local R4 = evo.builder():require(F1, F2, F3, F4):spawn()
+local R5 = evo.builder():require(F1, F2, F3, F4, F5):spawn()
 
 print '----------------------------------------'
 
@@ -610,7 +615,6 @@ basics.describe_bench(string.format('create and destroy %d entities with 5 compo
 
 print '----------------------------------------'
 
-
 basics.describe_bench(string.format('create and destroy %d entities with 1 components / clone', N),
     ---@param entities evolved.id[]
     function(entities)
@@ -690,3 +694,167 @@ basics.describe_bench(string.format('create and destroy %d entities with 5 compo
     end, function()
         return {}
     end)
+
+print '----------------------------------------'
+
+basics.describe_bench(string.format('create and destroy %d entities with 1 requires / spawn', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local spawn = evo.spawn
+
+        local components = { [R1] = true }
+
+        for i = 1, N do
+            entities[i] = spawn(components)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 2 requires / spawn', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local spawn = evo.spawn
+
+        local components = { [R2] = true }
+
+        for i = 1, N do
+            entities[i] = spawn(components)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 3 requires / spawn', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local spawn = evo.spawn
+
+        local components = { [R3] = true }
+
+        for i = 1, N do
+            entities[i] = spawn(components)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 4 requires / spawn', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local spawn = evo.spawn
+
+        local components = { [R4] = true }
+
+        for i = 1, N do
+            entities[i] = spawn(components)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 5 requires / spawn', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local spawn = evo.spawn
+
+        local components = { [R5] = true }
+
+        for i = 1, N do
+            entities[i] = spawn(components)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+print '----------------------------------------'
+
+basics.describe_bench(string.format('create and destroy %d entities with 1 requires / clone', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local clone = evo.clone
+
+        local prefab = evo.spawn({ [R1] = true })
+
+        for i = 1, N do
+            entities[i] = clone(prefab)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 2 requires / clone', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local clone = evo.clone
+
+        local prefab = evo.spawn({ [R2] = true })
+
+        for i = 1, N do
+            entities[i] = clone(prefab)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 3 requires / clone', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local clone = evo.clone
+
+        local prefab = evo.spawn({ [R3] = true })
+
+        for i = 1, N do
+            entities[i] = clone(prefab)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 4 requires / clone', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local clone = evo.clone
+
+        local prefab = evo.spawn({ [R4] = true })
+
+        for i = 1, N do
+            entities[i] = clone(prefab)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)
+
+basics.describe_bench(string.format('create and destroy %d entities with 5 requires / clone', N),
+    ---@param entities evolved.id[]
+    function(entities)
+        local clone = evo.clone
+
+        local prefab = evo.spawn({ [R5] = true })
+
+        for i = 1, N do
+            entities[i] = clone(prefab)
+        end
+
+        evo.batch_destroy(Q1)
+    end, function()
+        return {}
+    end)

develop/untests.lua

@@ -6325,3 +6325,36 @@ do
         assert(not chunk and not entity_list and not entity_count)
     end
 end
+
+do
+    local function v2(x, y) return { x = x or 0, y = y or 0 } end
+    local function v2_clone(v) return { x = v.x, y = v.y } end
+
+    local v2_default = v2(1, 2)
+
+    do
+        local f = evo.builder():default(v2_default):spawn()
+
+        local b = evo.builder()
+
+        b:set(f)
+        evo.remove(f, evo.DEFAULT)
+
+        local e = b:spawn()
+        assert(evo.has(e, f) and evo.get(e, f).x == 1 and evo.get(e, f).y == 2)
+        assert(evo.get(e, f) == v2_default)
+    end
+
+    do
+        local f = evo.builder():default(v2_default):duplicate(v2_clone):spawn()
+
+        local b = evo.builder()
+
+        b:set(f)
+        evo.remove(f, evo.DEFAULT, evo.DUPLICATE)
+
+        local e = b:spawn()
+        assert(evo.has(e, f) and evo.get(e, f).x == 1 and evo.get(e, f).y == 2)
+        assert(evo.get(e, f) ~= v2_default)
+    end
+end

rockspecs/evolved.lua-1.1.0-0.rockspec

@@ -0,0 +1,34 @@
+rockspec_format = "3.0"
+package = "evolved.lua"
+version = "1.1.0-0"
+source = {
+   url = "git://github.com/BlackMATov/evolved.lua",
+   tag = "v1.1.0",
+}
+description = {
+   homepage = "https://github.com/BlackMATov/evolved.lua",
+   summary = "Evolved ECS (Entity-Component-System) for Lua",
+   detailed = [[
+      `evolved.lua` is a fast and flexible ECS (Entity-Component-System) library for Lua.
+      It is designed to be simple and easy to use, while providing all the features needed to create complex systems with blazing performance.
+   ]],
+   license = "MIT",
+   labels = {
+      "ecs",
+      "entity",
+      "entities",
+      "component",
+      "components",
+      "entity-component",
+      "entity-component-system",
+   },
+}
+dependencies = {
+   "lua >= 5.1",
+}
+build = {
+   type = "builtin",
+   modules = {
+      evolved = "evolved.lua",
+   }
+}