regression/redundant.1.sml

   1
   2 datatype ilist = nill | cons of int * ilist
   3
   4 fun f Xs =
   5  case Xs of
   6    nill => nill
   7  | cons( z, zs ) =>
   8  let
   9    fun g( a, b, c, ds ) =
  10      case ds of
  11        nill => cons( c, nill )
  12      | cons( e, es ) =>
  13      case ( e < b ) of
  14        false => cons( c, ds )
  15      | true =>
  16          cons(
  17            e,
  18            case ( z < a ) of
  19              false =>
  20                g( b, c, c, es )
  21            | true => cons( c, nill )
  22            )
  23  in
  24    case zs of
  25      nill => Xs
  26    | cons( y, ys ) =>
  27        g(
  28          z,
  29          z,
  30          z,
  31          f( g( z, z, y, ys ) )
  32          )
  33  end
  34
  35 fun print_ilist( nill ) = print "\n"
  36   | print_ilist( cons( X, Xs ) ) = ( print (Int.toString X ^ " "); print_ilist Xs )
  37
  38 val Input = cons( 6, cons( 5, cons( 7, cons( 3, cons( 1, cons( 2, cons( 4, nill ) ) ) ) ) ) )
  39
  40 val _ = print_ilist( f Input )