Struct la_arena::Arena

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pub struct Arena<T> { /* private fields */ }

Expand description

Yet another index-based arena.

Implementations§

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impl<T> Arena<T>

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pub const fn new() -> Arena<T>

Creates a new empty arena.

let arena: la_arena::Arena<i32> = la_arena::Arena::new();
assert!(arena.is_empty());

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pub fn with_capacity(capacity: usize) -> Arena<T>

Create a new empty arena with specific capacity.

let arena: la_arena::Arena<i32> = la_arena::Arena::with_capacity(42);
assert!(arena.is_empty());

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pub fn clear(&mut self)

Empties the arena, removing all contained values.

let mut arena = la_arena::Arena::new();

arena.alloc(1);
arena.alloc(2);
arena.alloc(3);
assert_eq!(arena.len(), 3);

arena.clear();
assert!(arena.is_empty());

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pub fn len(&self) -> usize

Returns the length of the arena.

let mut arena = la_arena::Arena::new();
assert_eq!(arena.len(), 0);

arena.alloc("foo");
assert_eq!(arena.len(), 1);

arena.alloc("bar");
assert_eq!(arena.len(), 2);

arena.alloc("baz");
assert_eq!(arena.len(), 3);

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pub fn is_empty(&self) -> bool

Returns whether the arena contains no elements.

let mut arena = la_arena::Arena::new();
assert!(arena.is_empty());

arena.alloc(0.5);
assert!(!arena.is_empty());

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pub fn alloc(&mut self, value: T) -> Idx<T>

Allocates a new value on the arena, returning the value’s index.

let mut arena = la_arena::Arena::new();
let idx = arena.alloc(50);

assert_eq!(arena[idx], 50);

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pub fn alloc_many<II: IntoIterator<Item = T>>( &mut self, iter: II ) -> IdxRange<T> ⓘ

Densely allocates multiple values, returning the values’ index range.

let mut arena = la_arena::Arena::new();
let range = arena.alloc_many(0..4);

assert_eq!(arena[range], [0, 1, 2, 3]);

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pub fn iter( &self ) -> impl Iterator<Item = (Idx<T>, &T)> + ExactSizeIterator + DoubleEndedIterator + Clone

Returns an iterator over the arena’s elements.

let mut arena = la_arena::Arena::new();
let idx1 = arena.alloc(20);
let idx2 = arena.alloc(40);
let idx3 = arena.alloc(60);

let mut iterator = arena.iter();
assert_eq!(iterator.next(), Some((idx1, &20)));
assert_eq!(iterator.next(), Some((idx2, &40)));
assert_eq!(iterator.next(), Some((idx3, &60)));

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pub fn iter_mut( &mut self ) -> impl Iterator<Item = (Idx<T>, &mut T)> + ExactSizeIterator + DoubleEndedIterator

Returns an iterator over the arena’s mutable elements.

let mut arena = la_arena::Arena::new();
let idx1 = arena.alloc(20);

assert_eq!(arena[idx1], 20);

let mut iterator = arena.iter_mut();
*iterator.next().unwrap().1 = 10;
drop(iterator);

assert_eq!(arena[idx1], 10);

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pub fn values( &self ) -> impl Iterator<Item = &T> + ExactSizeIterator + DoubleEndedIterator

Returns an iterator over the arena’s values.

let mut arena = la_arena::Arena::new();
let idx1 = arena.alloc(20);
let idx2 = arena.alloc(40);
let idx3 = arena.alloc(60);

let mut iterator = arena.values();
assert_eq!(iterator.next(), Some(&20));
assert_eq!(iterator.next(), Some(&40));
assert_eq!(iterator.next(), Some(&60));

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pub fn values_mut( &mut self ) -> impl Iterator<Item = &mut T> + ExactSizeIterator + DoubleEndedIterator

Returns an iterator over the arena’s mutable values.

let mut arena = la_arena::Arena::new();
let idx1 = arena.alloc(20);

assert_eq!(arena[idx1], 20);

let mut iterator = arena.values_mut();
*iterator.next().unwrap() = 10;
drop(iterator);

assert_eq!(arena[idx1], 10);