(* comparing performance of factorial implementations *)

(* the first factorial function *)
fun fact1(n) = if n = 0 then 1 else n * fact1(n-1);

(* the second factorial function *)
fun afact(n, accum) = if n = 1 then accum else afact(n-1, n*accum);
fun fact2(n) = afact(n, 1);

(* note that loopFactorial prints the results of each iteration *)
(* note also that F is a functional parameter *)
fun loopFactorial(i:int,n:int,F) = 
if i = n then print (Int.toString( F(i) )^"\n")
else 
  let 
    val dummy =
      let val ans1 = print(Int.toString( F(i) ))
      in print "\n"
      end
    val dummy2 = loopFactorial(i+1,n,F) 
  in dummy2 (* any expression could be used *)
  end;

val t1 = Timer.startCPUTimer();
loopFactorial(1,12,fact1);
Timer.checkCPUTimer t1;

val t2 = Timer.startCPUTimer();
loopFactorial(1,12,fact2);
Timer.checkCPUTimer t2;