Struct ReverseIndex 

pub struct ReverseIndex { /* private fields */ }

Reverse-reference index over a model snapshot.

Derived state: it reflects the model as it was when built. Mutating the model afterwards does not update it, and the borrow checker enforces that for the common &Model case.

Implementations

impl ReverseIndex

pub fn build(model: &Model) -> Self

Scan every entity once and record each reference by target.

pub fn referrers(&self, target: EntityId) -> &[Referrer]

Every reference pointing at target, in ascending (from, slot) order.

pub fn referrers_in_slot( &self, target: EntityId, slot: usize, ) -> impl Iterator<Item = EntityId> + '_

Entities referencing target from the given attribute slot.

This is the query objectified relationships need: “which relationship entities name me in their RelatingStructure slot”.

pub fn is_referenced(&self, target: EntityId) -> bool

Whether anything references target.

pub fn len(&self) -> usize

Number of distinct targets that have at least one referrer.

pub fn is_empty(&self) -> bool

Whether no entity references any other.

Trait Implementations

impl Clone for ReverseIndex

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ReverseIndex

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

Formats the value using the given formatter.

impl Default for ReverseIndex

fn default() -> Self

Returns the “default value” for a type.