Macro parsley::eval

macro_rules! eval {
    ( $( $expression:expr ),* ) => { ... };
    ( $context:expr; $expression:expr ) => { ... };
    ( $context:expr; $( $expression:expr ),* ) => { ... };
}

Evaluate one or more S-Expressions, in the base context or your own custom one.

Examples

use parsley::prelude::*;
assert!(eval!(sexp![SExp::sym("list"), "potato", true, 5]).is_ok());
assert!(eval!(sexp!["potato", true, 5]).is_err());

use parsley::prelude::*;

let evaluated = eval!(
    sexp![
        SExp::sym("define"),
        sexp![SExp::sym("square"), SExp::sym("x")],
        sexp![SExp::sym("*"), SExp::sym("x"), SExp::sym("x")]
    ],
    sexp![SExp::sym("square"), 12]
);

assert!(evaluated.is_ok());
assert_eq!(evaluated.unwrap(), SExp::from(144));

use parsley::prelude::*;
let mut ctx = Context::base();

eval!(
    ctx;
    sexp![
        SExp::sym("define"),
        sexp![SExp::sym("potato"), SExp::sym("x"), SExp::sym("y")],
        SExp::sym("y")
    ]
);
let evaluated = eval!(ctx; sexp![SExp::sym("potato"), true, 5]);

assert!(evaluated.is_ok());
assert_eq!(evaluated.unwrap(), SExp::from(5));