Enum Arity 

pub enum Arity {
    Exact(usize),
    Range {
        min: usize,
        max: usize,
    },
    AtLeast(usize),
}

How many operands an Op accepts.

Replaces a bare usize where 0 had to stand in for three unrelated things — a genuine leaf, an optional operand, and “variadic, don’t check”. Because verify skipped anything reporting 0, every variadic op opted out of arity checking entirely, and the optional-operand case needed a hand-written exception alongside the table.

Variants

Exact(usize)

Exactly n operands.

Range

Between min and max operands, inclusive — an optional trailing operand such as a seed.

Fields

min: usize

max: usize

AtLeast(usize)

n or more — genuinely variadic (Concat, While).

Implementations

impl Arity

pub fn accepts(self, n: usize) -> bool

Whether n operands satisfy this arity.

pub fn min_operands(self) -> usize

The fewest operands this arity permits.

pub fn max_operands(self) -> Option<usize>

The most operands permitted, or None when unbounded.

pub fn is_unconstrained(self) -> bool

Whether any operand count is permitted (AtLeast(0)), i.e. this arity constrains nothing.

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 Copy for Arity

impl Debug for Arity

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

Formats the value using the given formatter.

impl Display for Arity

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

Formats the value using the given formatter.

impl Eq for Arity

impl PartialEq for Arity

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Arity