Crate parsley

A Scheme parsing and evaluation framework.

Example

use parsley::{Context, SExp};
let mut ctx = Context::base();

let expr = "(null? '())";
let value = "#t";
assert_eq!(
    expr.parse::<SExp>().unwrap().eval(&mut ctx).unwrap(),
    value.parse::<SExp>().unwrap().eval(&mut ctx).unwrap()
);

let expr = "(* (+ 3 4 5) (- 5 2))";
let value = "36";
assert_eq!(
    expr.parse::<SExp>().unwrap().eval(&mut ctx).unwrap(),
    value.parse::<SExp>().unwrap().eval(&mut ctx).unwrap()
);

let expr = r#"
(define (sqr x) (* x x))
(define (sum-of-squares x y) (+ (sqr x) (sqr y)))
(sum-of-squares 3 4)
"#;
let value = "25";
assert_eq!(
    expr.parse::<SExp>().unwrap().eval(&mut ctx).unwrap(),
    value.parse::<SExp>().unwrap().eval(&mut ctx).unwrap()
);

Structs

Context

Evaluation context for LISP expressions.

Enums

LispError

Multipurpose error type.

SExp

An S-Expression. Can be parsed from a string via FromStr, or constructed programmatically.

Constants

NULL

The null list.

Traits

AsAtom

Type Definitions

LispResult

A shorthand Result type.