old/expr/exist/while.dcl

   1 definition module while
   2
   3 :: Then = Then
   4 :: Else = Else
   5 :: Do = Do
   6 :: WhileExpr
   7         = (=.) infix 1 String WhileInt
   8         | If WhileBool Then WhileExpr Else WhileExpr
   9         | (:.) infixr 0 WhileExpr WhileExpr
  10         | While WhileBool Do WhileExpr
  11         | Skip
  12         | E.e: WExpr e & eval e & print e
  13
  14 :: WhileBool
  15         = Bool Bool
  16         | (==.) infix 4 WhileInt WhileInt
  17         | (&.) infix 3 WhileBool WhileBool
  18         | Not WhileBool
  19         | E.e: WBool e & evalb e & print e
  20
  21 :: WhileInt
  22         = Int Int
  23         | Var String
  24         | (+.) infixl 6 WhileInt WhileInt
  25         | E.e: WInt e & evali e & print e
  26
  27 class gamma g
  28 where
  29         put :: g String Int -> g
  30         get :: g String -> Int
  31 instance gamma Gamma
  32
  33 :: Gamma
  34 emptyGamma :: Gamma
  35
  36 class eval  m :: m -> (g -> g)    | gamma g
  37 class evali m :: m -> (g -> Int)  | gamma g
  38 class evalb m :: m -> (g -> Bool) | gamma g
  39
  40 instance eval WhileExpr
  41 instance evali WhileInt
  42 instance evalb WhileBool
  43
  44 class print m :: m -> String
  45
  46 instance print WhileExpr
  47 instance print WhileInt
  48 instance print WhileBool