Struct DatumStore 

pub struct DatumStore { /* private fields */ }

The store of transforms that Location chains refer into.

One per document. Interning is not an optimisation here; it is what gives placements a stable notion of sameness, since two chains naming the same datum are known to agree without any floating-point comparison.

Handles are relative to their store, and know it

A DatumId means nothing without the store that issued it, and it says which one that was. A handle from another store resolves to None rather than to whatever transform happens to sit at that index, so mixing documents is an error that shows up where it happens rather than a wrong answer several operations later.

Implementations

impl DatumStore

pub const fn new() -> Self

An empty store.

pub fn insert(&mut self, transform: Datum) -> DatumId

Intern a transform, returning a handle to it.

Identical transforms are not deduplicated: recognising two matrices as equal is a tolerance question, and the whole point of the chain representation is to avoid asking it. Callers that want sharing hold on to the handle.

pub fn get(&self, id: DatumId) -> Option<Datum>

The transform behind id.

pub fn len(&self) -> usize

Number of interned transforms.

pub fn is_empty(&self) -> bool

Whether nothing has been interned.

pub fn iter(&self) -> impl Iterator<Item = (DatumId, Datum)>

Every datum, with its handle, in arena order.

Trait Implementations

impl Clone for DatumStore

fn clone(&self) -> DatumStore

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DatumStore

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

Formats the value using the given formatter.

impl Default for DatumStore

fn default() -> DatumStore

Returns the “default value” for a type.