Enum RelationCardinality 

pub enum RelationCardinality {
    SingleValued,
    MultiValued,
}

Whether a subject may hold one relation to many objects at the same time.

The axis that decides whether a new edge contradicts an existing one or merely adds to it. A subject works at one employer at a time (Self::SingleValued — a new works_at supersedes the old), but deploys to many environments over time and knows many people at once (Self::MultiValued — every deployed/knows edge coexists).

This is simultaneous cardinality, not “does the relation ever repeat”: “we deployed last weekend” and “we deployed Monday” are two true events, so deployed is multi-valued and neither supersedes the other.

Variants

SingleValued

One live object at a time; a newer edge supersedes the older.

MultiValued

Many live objects at once; every edge coexists, none supersedes.

Trait Implementations

impl Clone for RelationCardinality

fn clone(&self) -> RelationCardinality

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for RelationCardinality

impl Debug for RelationCardinality

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

Formats the value using the given formatter.

impl Eq for RelationCardinality

impl PartialEq for RelationCardinality

fn eq(&self, other: &RelationCardinality) -> 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 StructuralPartialEq for RelationCardinality