Function eval_term

2020/src/bin/18.rs:47–54

(s: &[u8])

}

fn eval_term(s: &[u8]) -> (usize, usize) {
  if s[0] == b'(' {
    let j = find_matching_par(s);
    (eval_p2(&s[1..j]), j)
  } else {
    ((s[0] - b'0') as usize, 0)
  }
}

fn eval_p2(s: &[u8]) -> usize {
  let (mut val, mut i) = (1,0);