Trait Fetch

pub trait Fetch<'w>: for<'q> FetchItem<'q> {
    type Prepared: for<'x> PreparedFetch<'x, Item = <Self as FetchItem<'x>>::Item> + 'w;

    const MUTABLE: bool;

    // Required methods
    fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>;
    fn filter_arch(&self, data: FetchAccessData<'_>) -> bool;
    fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>);
    fn describe(&self, f: &mut Formatter<'_>) -> Result;

    // Provided methods
    fn searcher(&self, _searcher: &mut ArchetypeSearcher) { ... }
    fn by_ref(&self) -> RefFetch<'_, Self>
       where Self: Sized { ... }
}

A fetch describes a retrieval of data from the world and archetypes during a query.

A fetch is prepared, wherein borrows are acquired and a PreparedFetch is returned, which is used to provide the query with values.

The PreparedFetch can in turn control the ranges of slots which are requested by the query, e.g; filtering changed components

Required Associated Constants

const MUTABLE: bool

true if the fetch mutates any component and thus needs a change event

Required Associated Types

type Prepared: for<'x> PreparedFetch<'x, Item = <Self as FetchItem<'x>>::Item> + 'w

The prepared version of the fetch

Required Methods

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

Prepares the fetch for an archetype by acquiring borrows.

Returns None if the archetype does not match.

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

Returns true if the archetype matches the fetch

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

Returns which components and how will be accessed for an archetype.

fn describe(&self, f: &mut Formatter<'_>) -> Result

Describes the fetch in a human-readable fashion

Provided Methods

fn searcher(&self, _searcher: &mut ArchetypeSearcher)

Returns the required component for the fetch.

This is used for the query to determine which archetypes to visit

fn by_ref(&self) -> RefFetch<'_, Self>

where Self: Sized,

Convert the fetch to a reference type which works with HRTB

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'a, 'w, F> Fetch<'w> for &'a F

where F: Fetch<'w>, 'a: 'w,

const MUTABLE: bool = F::MUTABLE

type Prepared = <F as Fetch<'w>>::Prepared

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w> Fetch<'w> for bool

const MUTABLE: bool = false

type Prepared = bool

fn prepare(&'w self, _: FetchPrepareData<'_>) -> Option<Self::Prepared>

fn filter_arch(&self, _: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, _: FetchAccessData<'_>, _: &mut Vec<Access>)

impl<'w> Fetch<'w> for ()

const MUTABLE: bool = false

type Prepared = ()

fn prepare(&self, _: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, _: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, _: FetchAccessData<'_>, _: &mut Vec<Access>)

impl<'w, A> Fetch<'w> for (A,)

where A: Fetch<'w>,

const MUTABLE: bool = A::MUTABLE

type Prepared = (<A as Fetch<'w>>::Prepared,)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B> Fetch<'w> for (A, B)

where A: Fetch<'w>, B: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C> Fetch<'w> for (A, B, C)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C, D> Fetch<'w> for (A, B, C, D)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared, <D as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C, D, E> Fetch<'w> for (A, B, C, D, E)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared, <D as Fetch<'w>>::Prepared, <E as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C, D, E, F> Fetch<'w> for (A, B, C, D, E, F)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>, F: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared, <D as Fetch<'w>>::Prepared, <E as Fetch<'w>>::Prepared, <F as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C, D, E, F, H> Fetch<'w> for (A, B, C, D, E, F, H)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>, F: Fetch<'w>, H: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared, <D as Fetch<'w>>::Prepared, <E as Fetch<'w>>::Prepared, <F as Fetch<'w>>::Prepared, <H as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C, D, E, F, H, I> Fetch<'w> for (A, B, C, D, E, F, H, I)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>, F: Fetch<'w>, H: Fetch<'w>, I: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared, <D as Fetch<'w>>::Prepared, <E as Fetch<'w>>::Prepared, <F as Fetch<'w>>::Prepared, <H as Fetch<'w>>::Prepared, <I as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

impl<'w, A, B, C, D, E, F, H, I, J> Fetch<'w> for (A, B, C, D, E, F, H, I, J)

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>, F: Fetch<'w>, H: Fetch<'w>, I: Fetch<'w>, J: Fetch<'w>,

const MUTABLE: bool

type Prepared = (<A as Fetch<'w>>::Prepared, <B as Fetch<'w>>::Prepared, <C as Fetch<'w>>::Prepared, <D as Fetch<'w>>::Prepared, <E as Fetch<'w>>::Prepared, <F as Fetch<'w>>::Prepared, <H as Fetch<'w>>::Prepared, <I as Fetch<'w>>::Prepared, <J as Fetch<'w>>::Prepared)

fn prepare(&'w self, data: FetchPrepareData<'w>) -> Option<Self::Prepared>

fn filter_arch(&self, data: FetchAccessData<'_>) -> bool

fn describe(&self, f: &mut Formatter<'_>) -> Result

fn access(&self, data: FetchAccessData<'_>, dst: &mut Vec<Access>)

fn searcher(&self, searcher: &mut ArchetypeSearcher)

Implementors

impl<'a> Fetch<'a> for Nothing

const MUTABLE: bool = false

type Prepared = Nothing

impl<'a> Fetch<'a> for With

const MUTABLE: bool = false

type Prepared = All

impl<'a> Fetch<'a> for WithoutRelation

const MUTABLE: bool = false

type Prepared = All

impl<'a, 'w, F> Fetch<'w> for RefFetch<'a, F>

where F: Fetch<'w>,

const MUTABLE: bool = F::MUTABLE

type Prepared = <F as Fetch<'w>>::Prepared

impl<'w> Fetch<'w> for Slice

const MUTABLE: bool = false

type Prepared = Slice

impl<'w> Fetch<'w> for Entity

const MUTABLE: bool = false

type Prepared = PreparedEntity

impl<'w> Fetch<'w> for All

const MUTABLE: bool = false

type Prepared = All

impl<'w> Fetch<'w> for BatchSize

const MUTABLE: bool = false

type Prepared = BatchSize

impl<'w> Fetch<'w> for WithRelation

const MUTABLE: bool = false

type Prepared = All

impl<'w> Fetch<'w> for Without

const MUTABLE: bool = false

type Prepared = All

impl<'w> Fetch<'w> for EntityIds

const MUTABLE: bool = false

type Prepared = ReadEntities<'w>

impl<'w> Fetch<'w> for EntityRefs

const MUTABLE: bool = false

type Prepared = PreparedEntityRef<'w>

impl<'w, A> Fetch<'w> for Or<(A,)>

where A: Fetch<'w>,

const MUTABLE: bool = A::MUTABLE

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>,)>

impl<'w, A, B> Fetch<'w> for Or<(A, B)>

where A: Fetch<'w>, B: Fetch<'w>,

const MUTABLE: bool

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>, Option<<B as Fetch<'w>>::Prepared>)>

impl<'w, A, B, C> Fetch<'w> for Or<(A, B, C)>

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>,

const MUTABLE: bool

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>, Option<<B as Fetch<'w>>::Prepared>, Option<<C as Fetch<'w>>::Prepared>)>

impl<'w, A, B, C, D> Fetch<'w> for Or<(A, B, C, D)>

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>,

const MUTABLE: bool

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>, Option<<B as Fetch<'w>>::Prepared>, Option<<C as Fetch<'w>>::Prepared>, Option<<D as Fetch<'w>>::Prepared>)>

impl<'w, A, B, C, D, E> Fetch<'w> for Or<(A, B, C, D, E)>

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>,

const MUTABLE: bool

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>, Option<<B as Fetch<'w>>::Prepared>, Option<<C as Fetch<'w>>::Prepared>, Option<<D as Fetch<'w>>::Prepared>, Option<<E as Fetch<'w>>::Prepared>)>

impl<'w, A, B, C, D, E, F> Fetch<'w> for Or<(A, B, C, D, E, F)>

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>, F: Fetch<'w>,

const MUTABLE: bool

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>, Option<<B as Fetch<'w>>::Prepared>, Option<<C as Fetch<'w>>::Prepared>, Option<<D as Fetch<'w>>::Prepared>, Option<<E as Fetch<'w>>::Prepared>, Option<<F as Fetch<'w>>::Prepared>)>

impl<'w, A, B, C, D, E, F, H> Fetch<'w> for Or<(A, B, C, D, E, F, H)>

where A: Fetch<'w>, B: Fetch<'w>, C: Fetch<'w>, D: Fetch<'w>, E: Fetch<'w>, F: Fetch<'w>, H: Fetch<'w>,

const MUTABLE: bool

type Prepared = Or<(Option<<A as Fetch<'w>>::Prepared>, Option<<B as Fetch<'w>>::Prepared>, Option<<C as Fetch<'w>>::Prepared>, Option<<D as Fetch<'w>>::Prepared>, Option<<E as Fetch<'w>>::Prepared>, Option<<F as Fetch<'w>>::Prepared>, Option<<H as Fetch<'w>>::Prepared>)>

impl<'w, F> Fetch<'w> for Cloned<F>

where F: Fetch<'w> + for<'q> FetchItem<'q>, for<'q> <F as FetchItem<'q>>::Item: Deref, for<'q> <<F as FetchItem<'q>>::Item as Deref>::Target: 'static + Clone,

const MUTABLE: bool = F::MUTABLE

type Prepared = Cloned<<F as Fetch<'w>>::Prepared>

impl<'w, F> Fetch<'w> for Opt<F>

where F: Fetch<'w>,

const MUTABLE: bool = F::MUTABLE

type Prepared = PreparedOpt<<F as Fetch<'w>>::Prepared>

impl<'w, F, M> Fetch<'w> for Cmp<F, M>

where F: Fetch<'w>, F::Prepared: for<'x> RandomFetch<'x>, M: for<'x> CmpMethod<<F::Prepared as PreparedFetch<'x>>::Item> + 'w,

const MUTABLE: bool = F::MUTABLE

type Prepared = PreparedCmp<'w, <F as Fetch<'w>>::Prepared, M>

impl<'w, F, V> Fetch<'w> for AsDeref<F>

where F: Fetch<'w> + for<'q> FetchItem<'q, Item = &'q V>, V: 'static + Deref,

const MUTABLE: bool = F::MUTABLE

type Prepared = AsDeref<<F as Fetch<'w>>::Prepared>

impl<'w, F, V> Fetch<'w> for OptOr<F, V>

where F: Fetch<'w> + for<'q> FetchItem<'q, Item = &'q V>, V: 'static,

const MUTABLE: bool = F::MUTABLE

type Prepared = OptOr<Option<<F as Fetch<'w>>::Prepared>, &'w V>

impl<'w, F: Fetch<'w>> Fetch<'w> for Satisfied<F>

const MUTABLE: bool = false

type Prepared = PreparedSatisfied<<F as Fetch<'w>>::Prepared>

impl<'w, L, R> Fetch<'w> for And<L, R>

where L: Fetch<'w>, R: Fetch<'w>,

const MUTABLE: bool = false

type Prepared = And<<L as Fetch<'w>>::Prepared, <R as Fetch<'w>>::Prepared>

impl<'w, Q, F> Fetch<'w> for Filtered<Q, F>

where Q: Fetch<'w>, F: Fetch<'w>,

const MUTABLE: bool = Q::MUTABLE

type Prepared = Filtered<<Q as Fetch<'w>>::Prepared, <F as Fetch<'w>>::Prepared>

impl<'w, Q, F, T> Fetch<'w> for Map<Q, F>

where Q: Fetch<'w>, F: for<'q> Fn(<Q as FetchItem<'q>>::Item) -> T + 'static, T: 'static,

const MUTABLE: bool = Q::MUTABLE

type Prepared = Map<<Q as Fetch<'w>>::Prepared, &'w F>

impl<'w, Q, S> Fetch<'w> for Source<Q, S>

where Q: Fetch<'w>, Q::Prepared: for<'x> RandomFetch<'x>, S: FetchSource,

const MUTABLE: bool = Q::MUTABLE

type Prepared = PreparedSource<'w, <Q as Fetch<'w>>::Prepared>

impl<'w, T> Fetch<'w> for Component<T>

where T: ComponentValue,

const MUTABLE: bool = false

type Prepared = ReadComponent<'w, T>

impl<'w, T> Fetch<'w> for ChangeFilter<T>

where T: ComponentValue,

const MUTABLE: bool = false

type Prepared = PreparedChangeFilter<'w, T>

impl<'w, T> Fetch<'w> for Not<T>

where T: Fetch<'w>,

const MUTABLE: bool = true

type Prepared = Not<Option<<T as Fetch<'w>>::Prepared>>

impl<'w, T> Fetch<'w> for Union<T>

where T: Fetch<'w>, T::Prepared: UnionFilter,

const MUTABLE: bool = T::MUTABLE

type Prepared = Union<<T as Fetch<'w>>::Prepared>

impl<'w, T> Fetch<'w> for Mutable<T>

where T: ComponentValue,

const MUTABLE: bool = true

type Prepared = WriteComponent<'w, T>

impl<'w, T> Fetch<'w> for NthRelation<T>

where T: ComponentValue,

const MUTABLE: bool = false

type Prepared = PreparedNthRelation<'w, T>

impl<'w, T> Fetch<'w> for Relations<T>

where T: ComponentValue,

const MUTABLE: bool = false

type Prepared = PreparedRelations<'w, T>

impl<'w, T> Fetch<'w> for RelationsMut<T>

where T: ComponentValue,

const MUTABLE: bool = false

type Prepared = PreparedRelationsMut<'w, T>

impl<'w, T: ComponentValue> Fetch<'w> for MaybeMut<T>

const MUTABLE: bool = false

type Prepared = PreparedMaybeMut<'w, T>