Module 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 the first time after they have been added.

AnyOf

The AnyOf query parameter fetches entities with any of the component types included in T.

Changed

A filter on a component that only retains results the first time after they have been added or mutably dereferenced.

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.

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.

QuerySortedIter

An Iterator over sorted query results of a Query.

QueryState

Provides scoped access to a World state according to a given QueryData and QueryFilter.

ReadFetch

The WorldQuery::Fetch type for & T.

With

Filter that selects entities with a component T.

Without

Filter that selects entities without a component T.

WriteFetch

The WorldQuery::Fetch type for &mut T.

Enums

AccessConflicts

Records how two accesses conflict with each other

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