Module bevy::ecs::query

Contains APIs for retrieving component data from the world.

Structs

• Access
  Tracks read and write access to specific elements in a collection.
• Added
  A filter on a component that only retains results added after the system last ran.
• AnyOf
  The AnyOf query parameter fetches entities with any of the component types included in T.
• BatchingStrategy
  Dictates how a parallel query chunks up large tables/archetypes during iteration.
• Changed
  A filter on a component that only retains results added or mutably dereferenced after the system last ran.
• FilteredAccess
  An Access that has been filtered to include and exclude certain combinations of elements.
• FilteredAccessSet
  A collection of FilteredAccess instances.
• Has
  Returns a bool that describes if an entity has the component T.
• NopWorldQuery
  WorldQuery used to nullify queries by turning Query<D> into Query<NopWorldQuery<D>>
• Or
  A filter that tests if any of the given filters apply.
• QueryBuilder
  Builder struct to create QueryState instances at runtime.
• QueryCombinationIter
  An iterator over K-sized combinations of query items without repetition.
• QueryIter
  An Iterator over query results of a Query.
• QueryManyIter
  An Iterator over the query items generated from an iterator of Entitys.
• QueryParIter
  A parallel iterator over query results of a Query.
• QueryState
  Provides scoped access to a World state according to a given QueryData and QueryFilter.
• With
  Filter that selects entities with a component T.
• Without
  Filter that selects entities without a component T.

Enums

• QueryComponentError
  An error that occurs when retrieving a specific Entity’s component from a Query.
• QueryEntityError
  An error that occurs when retrieving a specific Entity’s query result from Query or QueryState.
• QuerySingleError
  An error that occurs when evaluating a Query or QueryState as a single expected result via get_single or get_single_mut.

Traits

• ArchetypeFilter
  A marker trait to indicate that the filter works at an archetype level.
• QueryData
  Types that can be fetched from a World using a Query.
• QueryFilter
  Types that filter the results of a Query.
• ReadOnlyQueryData
  A QueryData that is read only.
• WorldQuery
  Types that can be used as parameters in a Query. Types that implement this should also implement either QueryData or QueryFilter

Type Aliases

• QueryItem
  The item type returned when a WorldQuery is iterated over
• ROQueryItem
  The read-only variant of the item type returned when a QueryData is iterated over immutably

Derive Macros

• QueryData
  Implement QueryData to use a struct as a data parameter in a query
• QueryFilter
  Implement QueryFilter to use a struct as a filter parameter in a query