a12/mart/skeleton12.icl

   1 module skeleton12
   2
   3 import Data.Maybe
   4 import Control.Monad
   5 import StdInt, StdString, StdBool
   6
   7 class arith x where
   8         lit :: a -> x a | toString a
   9         (+.) infixl 6 :: (x a) (x a) -> x a | + a // integer addition, Boolean OR
  10         (*.) infixl 7 :: (x a) (x a) -> x a | * a // integer multiplication, Boolean AND
  11 class store x where
  12         read  :: (x Int)
  13         write :: (x Int) -> x Int
  14 class truth x where
  15         (XOR) infixr 3 :: (x Bool) (x Bool) -> x Bool
  16         -.    :: (x Bool) -> x Bool
  17 class (=.=) infix 4 x :: (x a) (x a) -> x Bool | == a
  18 class except x where
  19         throw :: (x a)
  20         try   :: (x a) (x a) -> x a
  21
  22 class aexpr x | arith, store, except, =.= x
  23 class bexpr x | arith, truth, except, =.= x
  24 class expr x  | aexpr, bexpr x
  25
  26 :: Step a = Step (State -> (Maybe a, State))
  27 :: State :== Int
  28
  29 /*seven :: e Int | aexpr e
  30 seven = lit 3 +. lit 4
  31
  32 throw1 :: e Int | expr e
  33 throw1 = lit 3 +. throw
  34
  35 six :: e Int | expr e
  36 six = write (lit 3) +. read
  37
  38 try1 :: e Int | expr e
  39 try1 = try throw1 (lit 42)
  40
  41 loge :: e Bool | expr e
  42 loge = lit True *. -. (lit True)
  43
  44 comp :: e Bool | expr e
  45 comp = lit 1 =.= lit 2 XOR -. (-. (lit True))*/
  46
  47 Start = 0