(*
**
** Course: Concepts of Programming Languages (BU CAS CS 320)
** Semester: Summer I, 2009
**
** Instructor: Hongwei Xi (hwxi AT cs DOT bu DOT edu)
**
*)

(* ****** ****** *)

%{^

/*

int gcd (int m, int n) {
  int r ;
  while (n != 0) {
    r = m % n; m = n; n = r;
  }
  return m ;
}

*/

/*

int gcd (int m, int n) {
  return (n != 0 ? gcd (n, m % n) : m) ;
}

*/

%}

(* ****** ****** *)

extern fun gcd (m: int, n: int): int

implement gcd (m, n) =
  if n <> 0 then gcd (n, m mod n) else m
// end of [gcd]

(* ****** ****** *)

implement main (argc, argv) = let
  val () = assert (argc >= 3)
  val m = int_of_string (argv.[1])
  val n = int_of_string (argv.[2])
in
  printf ("gcd (%i, %i) = %i\n", @(m, n, gcd (m, n)))
end // end of [main]

(* ****** ****** *)

(* end of [lecture01_gcd.dats] *)