Struct ArenaIndex 

pub struct ArenaIndex(/* private fields */);

Index into the arena.

This is a lightweight wrapper around usize that directly indexes the arena’s internal array.

Safety Note

Indices should only be obtained from arena operations (alloc, iter). Manually constructing indices bypasses the type system’s protection and should only be used for serialization/deserialization.

Implementations

impl ArenaIndex

pub const NULL: ArenaIndex

A sentinel “null” index that is never valid.

This can be used as a placeholder when an optional index is needed but Option<ArenaIndex> is not desired.

pub const fn new(index: usize) -> ArenaIndex

Create a new arena index with the given slot index.

Warning

This is a low-level constructor intended for serialization/deserialization. For normal use, obtain indices from [Arena::alloc] or [Arena::iter]. Fabricating indices manually may lead to undefined behavior if the index doesn’t correspond to a valid allocation.

pub const fn raw(self) -> usize

Get the raw slot index value.

pub const fn is_null(self) -> bool

Check if this is the null index.

Trait Implementations

impl Clone for ArenaIndex

fn clone(&self) -> ArenaIndex

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ArenaIndex

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

Formats the value using the given formatter.

impl Default for ArenaIndex

fn default() -> ArenaIndex

Returns ArenaIndex::NULL.

impl<const N: usize> FromLisp<N> for ArenaIndex

ArenaIndex can be passed through directly (for when you want raw Lisp values)

fn from_lisp(_lisp: &Lisp<N>, idx: ArenaIndex) -> ArenaResult<Self>

Convert a Lisp value at the given index to this Rust type.

impl Hash for ArenaIndex

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ArenaIndex

fn eq(&self, other: &ArenaIndex) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const N: usize> ToLisp<N> for ArenaIndex

fn to_lisp(&self, _lisp: &Lisp<N>) -> ArenaResult<ArenaIndex>

Convert this Rust value to a Lisp value, allocating in the arena.

impl Copy for ArenaIndex

impl Eq for ArenaIndex

impl StructuralPartialEq for ArenaIndex