Control.Effects

Documentation

data Handler e m a r

Constructors

Handler

Fields

ret :: a -> m e

fin :: e -> m r

with :: Monad m => Handler e m a r -> (Proxy (ContT e m) -> ContT e m a) -> m r

operation :: forall m m' n a r. (m ~ ContT r m', AutoLift m n) => Proxy m -> ((a -> m' r) -> m' r) -> n a

run :: Cont a a -> a

runIO :: ContT () IO () -> IO ()

io :: AutoLift (ContT () IO) n => IO a -> n a

ioHandler :: Handler a IO a a

type Cont r = ContT r Identity

Continuation monad. Cont r a is a CPS computation that produces an intermediate result of type a within a CPS computation whose final result type is r.

The return function simply creates a continuation which passes the value on.

The >>= operator adds the bound function into the continuation chain.

data ContT r m a

The continuation monad transformer. Can be used to add continuation handling to other monads.

Instances

AutoLift' m1 m2 n1 n2 => AutoLift' m1 m2 (ContT r1 n1) (ContT r2 n2)

(AutoLift' m1 m2 Identity n, Monad m2) => AutoLift' m1 (ContT r m2) Identity (ContT s n)

(AutoLift' m1 m2 IO n, Monad m2) => AutoLift' m1 (ContT r m2) IO (ContT s n)

MonadTrans (ContT r)

Monad (ContT r m)

Functor (ContT r m)

Applicative (ContT r m)

MonadIO m => MonadIO (ContT r m)

data Proxy m

class AutoLift m1 m2

Instances

AutoLift' m1 m2 m1 m2 => AutoLift m1 m2