extensible-effects-1.7.1.0: An Alternative to Monad Transformers

Safe HaskellTrustworthy
LanguageHaskell98

Control.Eff.Lift

Description

Lifting primitive Monad types to effectful computations. We only allow a single Lifted Monad because Monads aren't commutative (e.g. Maybe (IO a) is functionally distinct from IO (Maybe a)).

Synopsis

Documentation

data Lift m v Source

Lift a Monad m to an effect.

Constructors

forall a . Lift (m a) (a -> v) 

Instances

Functor (Lift m) 
Typeable ((* -> *) -> * -> *) Lift 
SetMember ((* -> *) -> * -> *) * Lift (Lift m) ((:>) * (Lift m) ()) 

lift :: (Typeable m, SetMember Lift (Lift m) r) => m a -> Eff r a Source

Lift a Monad to an Effect.

runLift :: (Monad m, Typeable m) => Eff (Lift m :> ()) w -> m w Source

The handler of Lift requests. It is meant to be terminal: we only allow a single Lifted Monad.