(*  Auto-tester for compose function.  *)
use "tester.sml";   (* common utility functions *)

(*  Avoid "unbound variable or constructor" errors.  *)
exception Negative of int;
fun compose _ _ _ = raise Undefined;

(*  Load file.  *)
print "\n--> Loading file \"compose.sml\"\n";
use "../compose.sml" handle _ => ();

(*  Run test cases.  *)
( print "\n--> Beginning test cases for function 'compose'...\n";
  print "--> For these tests, 'compose f (n,x)' = 'compose n f x'.\n";
  runtests total grade
    (fn (n,r:real) => compose n (fn x => 1.0 / (x + 1.0)) r
        handle Negative x => real(x))
    "compose (fn x => 1.0 / (x + 1.0))"
    (fn (n,r) => ("(" ^ int2string n ^ "," ^ real2string r ^ ")"))
    real2string real_eq
    [ ((0,0.0), 0.0, "(* base case *)", 0.5),
      ((1,0.0), 1.0, "(* small n *)", 0.5),
      ((2,1.0), 2.0 / 3.0, "(* small n *)", 0.5),
      ((11,0.0), 89.0 / 144.0, "(* large n *)", 0.5),
      ((20,~2.0), 0.618034055728, "(* larger n *)", 0.5),
      ((~1,0.0), ~1.0, "(* negative n *)", 0.5) ];
  runtests total grade
    (fn (n,s) => compose n (fn x => x ^ (string_rev x)) s
        handle Negative x => int2string x)
    "compose (fn x => x ^ (string_rev x))"
    (fn (n,s) => ("(" ^ int2string n ^ ",\"" ^ s ^ "\")")) string2string
    (op =)
    [ ((0,"hi"), "hi", "(* base case *)", 0.5),
      ((1,"hi"), "hiih", "(* small n *)", 0.5),
      ((2,"a"), "aaaa", "(* small n *)", 0.5),
      ((4,"hi"), "hiihhiihhiihhiihhiihhiihhiihhiih",
        "(* large n *)", 0.5),
      ((31,""), "", "(* larger n *)", 0.5),
      ((~1,"hi"), "~1", "(* negative n *)", 0.5) ] );

(*  Print total grade.  *)
print ("\n--> Grade = "
        ^ real2string (!grade) ^ " / " ^ real2string (!total) ^ "\n\n");

(*  Quit the SML interpreter.  *)
exit 0;