use glc::{grammar, Expression, Grammar};

fn build_grammar() -> Grammar {
    grammar!{
        S => A B;
        B => A B N;
        B => E;
        E => "";
        A => "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k",
             "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
             "w", "x", "y", "z";
        N => "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
    }
}

#[test]
fn test() {
    let grammar = build_grammar();
    let mut strings = Vec::new();

    for _ in 0..100 {
        strings.push(grammar.gen());
    }

    for s in strings {
        assert!(!s.is_empty());
        assert!(s.chars().next().unwrap().is_ascii_alphabetic());
    }
}

#[test]
fn test_derivation() {
    let grammar = build_grammar();
    let mut derivation = grammar.start_derivation();

    while !derivation.is_done() {
        derivation.derive_step(&grammar);
        println!("{derivation}");
    }

    let expr: Expression = derivation.into();
    dbg!(expr);
}