Function eval 

pub fn eval(
    expr: &Expr,
    env: &Env,
    heap: Heap,
    fuel: Fuel,
) -> Result<(Value, Heap, Fuel), Error>

Evaluate expr against env with the given heap and step budget.

Errors

See Error for the full list of failure modes.

Examples

use lambda_throw_cat::env::Env;
use lambda_throw_cat::eval::{eval, Fuel};
use lambda_throw_cat::heap::Heap;
use lambda_throw_cat::syntax::Expr;

let id = Expr::lam("x", Expr::var("x"));
let (value, _heap, _fuel) = eval(&id, &Env::empty(), Heap::empty(), Fuel::new(100))?;
assert_eq!(format!("{value}"), "\\x. x");