LamCalc: An implementation for Lambda Calculus

Features

Quick View

use lamcalc::{lambda, Error, parser::parse_exp};
fn main () -> Result<(), Error> {
 // define using macro
 let tt = lambda!(x. y. x); // use macro to define lambda
 let ff = lambda!(x. (y. y)); // add parentheses for clarity
 let and = lambda!(x.y.x y x); // space between dots are not necessary
 // multiple printing format
 println!("and = {}", and); // print lambda
 println!("and = {:#}", and); // lambda with De Bruijn index
 println!("and = {}", and.purify()); // De Bruijn encoding
 // use braces to refer to previously defined lambda
 let mut and_f_t = lambda!({and} {ff} {tt}); 
 and_f_t.simplify(true)?; // get simplified result
 assert_eq!(and_f_t, ff);
 // parse lambda expression string
 let y_combinator = lambda!(f.(x. f (x x)) (x. f (x x)));
 let y_str = r#"\f.(\x. f (x x)) (\x. f (x x))"#;
 let (y2, _) = parse_exp(y_str)?;
 
 assert_eq!(y2, y_combinator);
 Ok(())
}

Development

{
 "rust-analyzer.cargo.features": [
 "wasm"
 ]
}