contJoin.hs

newtype ContBool a = ContBool { (>-) :: (a -> Bool) -> Bool }

instance Functor ContBool where
    fmap f m = ContBool $ \k ->
        m >-
            \a ->
                k $ f a
            
instance Applicative ContBool where
    pure a = ContBool $ \k -> k a
    m <*> n = ContBool $ \k ->
        m >-
            \f ->
                n >-
                    \x -> k $ f x
                
class (Monad' f) where
    return' :: a -> f a
    join' :: f (f a) -> f a
    
instance Monad' ContBool where
    return' = pure
    join' m' = ContBool $ \k ->
        m' >- 
            \m -> m >- k