[][src]Crate hecs

A handy ECS

hecs provides a high-performance, minimalist entity-component-system (ECS) world. It is a library, not a framework. In place of an explicit "System" abstraction, a World's entities are easily queried from regular code. Organize your application however you like!

In order of importance, hecs pursues:

  • fast traversals
  • a simple interface
  • a small dependency closure
  • exclusion of externally-implementable functionality
let mut world = World::new();
// Nearly any type can be used as a component with zero boilerplate
let a = world.spawn((123, true, "abc"));
let b = world.spawn((42, false));
// Systems can be simple for loops
for (id, (number, &flag)) in world.query::<(&mut i32, &bool)>().iter() {
  if flag { *number *= 2; }
}
// Random access is simple and safe
assert_eq!(*world.get::<i32>(a).unwrap(), 246);
assert_eq!(*world.get::<i32>(b).unwrap(), 42);

Structs

Archetype

A collection of entities having the same component types

ArchetypesGeneration

Determines freshness of information derived from World::archetypes

BatchedIter

Batched version of QueryIter

BuiltEntity

The output of an EntityBuilder, suitable for passing to World::spawn or World::insert

Entity

Lightweight unique ID of an entity

EntityBuilder

Helper for incrementally constructing a bundle of components with dynamic component types

EntityRef

Handle to an entity with any component types

Iter

Iterator over all of a world's entities

MissingComponent

Error indicating that an entity did not have a required component

NoSuchEntity

Error indicating that no entity with a particular ID exists

QueryBorrow

A borrow of a World sufficient to execute the query Q

QueryIter

Iterator over the set of entities with the components in Q

QueryOne

A borrow of a World sufficient to execute the query Q on a single entity

Ref

Shared borrow of an entity's component

RefMut

Unique borrow of an entity's component

SpawnBatchIter

Entity IDs created by World::spawn_batch

With

Query transformer skipping entities that do not have a T component

Without

Query transformer skipping entities that have a T component

World

An unordered collection of entities, each having any number of distinctly typed components

Enums

Access

Type of access a Query may have to an Archetype

ComponentError

Errors that arise when accessing components

Traits

Bundle

A statically typed collection of components

Component

Types that can be components, implemented automatically for all Send + Sync + 'static types

DynamicBundle

A dynamically typed collection of components

Query

A collection of component types to fetch from a World

Derive Macros

Bundle

Implement Bundle for a monomorphic struct