gistfile1.txt

let str_to_list (src : string) : char list =
  let rec _stol (src : string) (pos : int) (rest : char list) =
    let c = get src pos in
    if pos > 0 then
      _stol src (pos - 1) (c :: rest)
    else
      c :: rest
  in _stol src (length src - 1) []