Source code in the ocaml programming language

let a1 = [| 'a'; 'b'; 'c' |]
and a2 = [| 'A'; 'B'; 'C' |]
and a3 = [| '1'; '2'; '3' |] ;;

Array.iteri (fun i c1 ->
  print_char c1;
  print_char a2.(i);
  print_char a3.(i);
  print_newline()
) a1 ;;

let n_arrays_iter ~f = function
  | [] -> ()
  | x::xs as al ->
      let len = Array.length x in
      let b = List.for_all (fun a -> Array.length a = len) xs in
      if not b then invalid_arg "n_arrays_iter: arrays of different 
length";
      for i = 0 to pred len do
        let ai = List.map (fun a -> a.(i)) al in
        f ai
      done

val n_arrays_iter : f:('a list -> unit) -> 'a 
array list -> unit

let () =
  n_arrays_iter [a1; a2; a3] ~f:(fun l ->
    List.iter print_char l;
    print_newline());
;;