Control.Comonad.Trans.Discont

Discont is the Density comonad of a constant functor, just as Cont is a Codensity monad of a constant functor.

Note that Discont and Context are isomorphic, but DiscontT and ContextT are not.

Documentation

type Discont s = DiscontT s Identity

discont :: (s -> a) -> s -> Discont s a

runDiscont :: Discont s a -> (s -> a, s)

data DiscontT s w a

Constructors

DiscontT (w s -> a) (w s)

Instances

ComonadTrans (DiscontT s)

Functor w => Functor (DiscontT s w)

Comonad w => Comonad (DiscontT s w)

runDiscontT :: DiscontT s w a -> (w s -> a, w s)

callCV :: DiscontT s w (DiscontT s w (DiscontT s w a -> a) -> b) -> b