Struct Arena 

pub struct Arena<T> {
    id: u32,
    items: Vec<T>,
}

Flat backing store for T, indexed by Id<T>.

Fields

id: u32

items: Vec<T>

Implementations

impl<T> Arena<T>

pub fn new() -> Self

pub fn with_capacity(cap: usize) -> Self

pub fn id(&self) -> u32

This arena’s unique id, e.g. for logging which arena an Id came from.

pub fn alloc(&mut self, item: T) -> Id<T>

Insert a node, returning its id.

pub fn get(&self, id: Id<T>) -> &T

pub fn get_mut(&mut self, id: Id<T>) -> &mut T

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

fn check_owner(&self, id: Id<T>, op: &str)

Panics with a clear message if id didn’t come from this arena. This is the check that turns cross-arena bugs into an obvious, immediate panic instead of silent corruption or a confusing out-of-bounds error somewhere else.

pub fn raw_parts_mut(&mut self) -> (u32, &mut Vec<T>)

Low-level access to this arena’s id and backing Vec, used only by Ast::merge_statements to implement arena merging. Bypasses the normal Id-checked API - not for general use.

Trait Implementations

impl<T: Debug> Debug for Arena<T>

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

Formats the value using the given formatter.

impl<T> Default for Arena<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Index<Id<T>> for Arena<T>

type Output = T

The returned type after indexing.

fn index(&self, id: Id<T>) -> &T

Performs the indexing (container[index]) operation.

impl<T> IndexMut<Id<T>> for Arena<T>

fn index_mut(&mut self, id: Id<T>) -> &mut T

Performs the mutable indexing (container[index]) operation.