a3/code/Generics/GenMonad.dcl

   1 definition module GenMonad
   2
   3 import StdGeneric, StdMaybe, StdList
   4
   5 class Monad m where
   6         ret :: a:a -> m:(m a:a), [m <= a]
   7         (>>=) infixl 5 :: u:(m .a) v:(.a -> u:(m .b))  -> u:(m .b), [u <= v]
   8
   9 :: StMonad s a = { st_monad :: .(s -> *(a, s)) }
  10 derive bimap StMonad
  11 instance Monad Maybe, [], (StMonad .s)
  12
  13 generic gMapLM a b :: a:a -> m:(m b:b) | Monad m, [m <= b]
  14 derive gMapLM c, PAIR, EITHER, CONS, FIELD, OBJECT
  15 derive gMapLM [], Maybe, (,), (,,), (,,,), (,,,,), (,,,,,), (,,,,,,), (,,,,,,,)
  16
  17 generic gMapRM a b :: a:a -> m:(m b:b) | Monad m, [m <= b]
  18 derive gMapRM c, PAIR, EITHER, CONS, FIELD, OBJECT
  19 derive gMapRM [], Maybe, (,), (,,), (,,,), (,,,,), (,,,,,), (,,,,,,), (,,,,,,,)
  20