Cont Implementierung

callcc.hs

callCC :: ((a -> Cont r b) -> Cont r a) -> Cont r a
callCC f = Cont $ \k -> runCont (f (\a -> Cont $ \_ -> k a)) k

monad_cont.hs

instance Monad (Cont r) where
  return n = Cont (\k -> k n)
  m >>= f  = Cont (\k -> runCont m (\a -> runCont (f a) k))

type_cont.hs

newtype Cont r a = Cont { runCont :: (a -> r) -> r }