Enum Arity 

pub enum Arity {
    One,
    Many,
}

Structural arity - whether an expression matches one or many positions.

Variants

One

Exactly one node position.

Many

Multiple sequential positions.

Implementations

impl Arity

pub fn combine(self, other: Arity) -> Arity

Combine arities: Many wins.

When combining expressions, if either has Many arity, the result has Many arity.

pub fn is_one(self) -> bool

Check if this is singular arity.

pub fn is_many(self) -> bool

Check if this is plural arity.

Trait Implementations

impl Clone for Arity

fn clone(&self) -> Arity

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Arity

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

Formats the value using the given formatter.

impl PartialEq for Arity

fn eq(&self, other: &Arity) -> 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 Copy for Arity

impl Eq for Arity

impl StructuralPartialEq for Arity