Struct lambda_calc::ast::Ast

pub struct Ast { /* fields omitted */ }

The abstract syntax tree constructed from the lambda expression.

Methods

impl Ast

pub fn new(expr: Expr) -> Ast

pub fn expr_ref(&self) -> &Expr

Get an un-mutable reference to the underlying expression.

pub fn beta_reduce_print(self) -> Ast

Applies beta reductions until it's no longer possible, printing the result after each round of beta reduction.

Uses normal order reduction strategy (leftmost outermost redex first), otherwise certain reductions would loop infintely:

let mut parser = Parser::new();
let redex = parser
    .parse("(lambda x . a) ((lambda y . y y) (lambda y . y y))")
    .unwrap();
let non_redex = redex.beta_reduce_print();
assert_eq!(non_redex, Ast::new(Expr::Var{name: "a".to_string(), is_free: true}));

This function does not attempt to predict infinite loops.

pub fn beta_reduce_quiet(self) -> Ast

Identical to beta_reduce_print() but doesn't print anything.

pub fn substitute_symbols_from(&mut self, symbol_table: &HashMap<String, Ast>)

Trait Implementations

impl Clone for Ast

fn clone(&self) -> Ast

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Eq for Ast

impl PartialEq<Ast> for Ast

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Display for Ast

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

Formats the value using the given formatter.

impl Debug for Ast

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

Formats the value using the given formatter.