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

//
// Assignment three (Due: Monday, June 8, 2009)
//
// Total points: 180 points
//

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

staload "assignment3.sats"
staload _(*anonymous*) = "assignment3_solu.dats"

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

dynload "assignment3_solu.dats"

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val _(*assgn3ex3_test*) = () where {
  val xs = Emp (): ralist double
  #define N 10
// one way to print out a ralist
  fun printlst
    (xs: ralist double): void = begin
    try loop (xs) with ~Empty () => ()
  end where {
    fun loop (xs: ralist double): void = let
      val (x, xs) = rauncons (xs); val- S f = x in
      print f; print_newline (); loop (xs)
    end // end of [loop]  
  } (* end of [val] *)
  val xs = loop (N-1, Emp ()) where {
    fun loop (i: int, res: ralist double): ralist double =
      if i >= 0 then let
        val x = S (double_of_int i) in loop (i-1, racons (x, res))
      end else res
    // end of [loop]  
  } // end of [val]
  val () = print "xs=\n" 
  val () = printlst (xs)
// another way to print out a ralist
  fun printlst' (xs: ralist double): void = let
    fun loop (xs: ralist double, i: int): void =
      if i < N then let
        val- S f = ralookup (xs, i) 
        val () = printf ("%i: %f\n", @(i, f)) in loop (xs, i+1)
      end (* end of [if] *)
    // end of [loop]
  in
    loop (xs, 0)
  end // end of [val]
//
  val ys = loop (xs, 0) where {
    fun loop (xs: ralist double, i: int): ralist double =
      if i < N then let
        val x = S (double_of_int (N-1-i)); val xs = raupdate (xs, i, x)
      in
        loop (xs, i + 1)
      end else xs (* end of [if] *)
    // end of [loop]
  } (* end of [val] *)
  val () = print "ys=\n" 
  val () = printlst' (ys)
} (* end of [assgn3ex3_test] *)

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

implement main () = ()

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

(* end of [assignment3_test.dats] *)