#use "AP1util.ml";;

let get_letter(): char =

  let continue : bool ref = ref true and letter : char ref = ref 'a' in
  (
    while !continue
    do
      print_newline();
      print_string("Entrez une lettre");
      print_newline();

      letter := read_char();

      if (!letter >= 'a' && !letter <= 'z') || (!letter >= 'A' && !letter <= 'Z')then
        continue := false
      else
        continue := true;


    done;
    (!letter);
  )


;;


get_letter()


let get_char(a,b: char * char): char =
  let continue : bool ref = ref true and letter : char ref = ref 'a' in
  (
    while !continue
    do
      print_newline();
      print_string("Entre le caractere");
      print_newline();

      letter := read_char();

      if (!letter >= a && !letter <= b) then
        continue := false
      else
        continue := true

    done;
    (!letter);
  )
;;



let get_code(): char * char * char =
  let letter1: char = get_letter() in
  let letter2 : char = get_char('0', '9') in
  if letter1 >= 'a' && letter1 <= 'z' then
    let letter3: char = get_char('A', 'Z') in
    (letter1, letter2, letter3)
  else
    let letter3: char = get_char('a', 'z') in
    (letter1, letter2, letter3)

;;

get_code()