appx/lst/generic_eq.icl

   1 module generic_eq
   2 import StdEnv, StdGeneric
   3
   4 generic gEq a :: a a -> Bool
   5
   6 gEq{|Int|}           x            y           = x == y
   7 gEq{|Bool|}          x            y           = x == y
   8 gEq{|Real|}          x            y           = x == y
   9 gEq{|Char|}          x            y           = x == y
  10 gEq{|UNIT|}          x            y           = True
  11 gEq{|OBJECT|} f     (OBJECT x)   (OBJECT y)   = f x y
  12 gEq{|CONS|}   f     (CONS x)     (CONS y)     = f x y
  13 gEq{|RECORD|} f     (RECORD x)   (RECORD y)   = f x y
  14 gEq{|FIELD|}  f     (FIELD x)    (FIELD y)    = f x y
  15 gEq{|PAIR|}   fl fr (PAIR lx rx) (PAIR ly ry) = fl lx ly && fr rx ry
  16 gEq{|EITHER|} fl _  (LEFT x)     (LEFT y)     = fl x y
  17 gEq{|EITHER|} _  fr (RIGHT x)    (RIGHT y)    = fr x y
  18 gEq{|EITHER|} _  _  _            _            = False
  19
  20 :: T = C1 Int ([Char], ?Bool) | C2
  21 derive gEq [], T, (,), ?
  22
  23 Start = (gEq{|*|} C2 (C1 42 ([], ?Just True)), gEq{|*->*|} (<) [1,2,3] [2,3,4])
  24 // (False, True)