mlton/ssa/three-point-lattice.fun

   1 (* Copyright (C) 1999-2006 Henry Cejtin, Matthew Fluet, Suresh
   2  *    Jagannathan, and Stephen Weeks.
   3  * Copyright (C) 1997-2000 NEC Research Institute.
   4  *
   5  * MLton is released under a BSD-style license.
   6  * See the file MLton-LICENSE for details.
   7  *)
   8
   9 functor ThreePointLattice(S: THREE_POINT_LATTICE_STRUCTS): THREE_POINT_LATTICE =
  10 struct
  11
  12 open S
  13
  14 structure L = NPointLattice(val names = [bottom, mid, top])
  15 open L
  16
  17 val isBottom = fn x => isN (x, 0)
  18 val isMid = fn x => isN (x, 1)
  19 val isTop = fn x => isN (x, 2)
  20 val makeMid = fn x => makeN (x, 1)
  21 val makeTop = fn x => makeN (x, 2)
  22 val whenMid = fn (x, h) => whenN (x, 1, h)
  23 val whenTop = fn (x, h) => whenN (x, 2, h)
  24 end