Enum Term 

pub enum Term {
    Var(usize),
    App {
        op: String,
        args: Vec<Term>,
    },
}

A term in a term algebra: either a variable or a function application.

Variants

Var(usize)

A variable with an index.

App

An application of an operation symbol to subterms.

Fields

op: String

args: Vec<Term>

Implementations

impl Term

pub fn var(index: usize) -> Self

Construct a variable term.

pub fn apply(op: &str, args: Vec<Term>) -> Self

Construct a function application term.

pub fn constant(op: &str) -> Self

Construct a constant term (arity-0 operation).

pub fn depth(&self) -> usize

Return the depth (maximum nesting) of this term.

pub fn variables(&self) -> Vec<usize>

Return the set of variable indices appearing in this term.

pub fn subst(&self, var_idx: usize, replacement: &Term) -> Term

Substitute variable var_idx with replacement throughout this term.

pub fn eval(&self, alg: &Algebra, assignment: &[usize]) -> Option<usize>

Evaluate this term in a given algebra, given an assignment of variables to carrier elements.

Trait Implementations

impl Clone for Term

fn clone(&self) -> Term

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Term

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

Formats the value using the given formatter.

impl PartialEq for Term

fn eq(&self, other: &Term) -> 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 Term