Struct rs_ecs::QueryRef

pub struct QueryRef<'w, S> where
    S: QuerySpec,  { /* private fields */ }

Borrow of the World for a Query. Required to obtain an iterator.

Implementations

impl<S> QueryRef<'_, S> where
    S: QuerySpec, 

pub fn for_each<'q, F>(&'q mut self, f: F) where
    F: FnMut(<S::Fetch as Fetch<'q>>::Item), 

Visit all entities matching the query.

pub fn iter<'q>(&'q mut self) -> QueryIter<'q, S>

Create an iterator over the entities matching the query.

pub fn par_iter<'q>(&'q mut self) -> QueryParIter<'q, S> where
    <S::Fetch as Fetch<'q>>::Ty: Send + Sync,
    <S::Fetch as Fetch<'q>>::Item: Send, 

Create a parallel iterator over the entities matching the query.

pub fn map<'q>(&'q mut self) -> QueryMap<'q, S>

Create a map of the entities matching the query.

This is an alternative to get and get_mut for repeated calls, to amortize the set-up costs.

Examples

let mut world = World::new();

let entity = world.alloc();
world.insert(entity, (42_i32, 1.0_f32));

let mut query = Query::<(&i32, &f32)>::new();
let mut query = query.borrow(&world);
let mut query = query.map();

let (i, f) = query.get_mut(entity).unwrap();

assert_eq!(*i, 42);
assert_eq!(*f, 1.0);