Control.Effects.Early

Documentation

module Control.Effects

data Early a

Instances

Monad m => MonadEffect (Early a) (ExceptT a m)

Methods

effect :: proxy (Early a) -> EffectMsg (Early a) -> ExceptT a m (EffectRes (Early a))

type EffectRes (Early a)

type EffectRes (Early a) = Void

type EffectMsg (Early a)

type EffectMsg (Early a) = a

earlyReturn :: forall a b m. MonadEffect (Early a) m => a -> m b

Allows you to return early from a function. Make sure you handleEarly to get the actual result out.

handleEarly :: Monad m => ExceptT a m a -> m a

Get the result from a computation. Either the early returned one, or the regular result.

onlyDo :: MonadEffect (Early a) m => m a -> m b

Only do the given action and exit early with it's result.

ifNothingEarlyReturn :: MonadEffect (Early a) m => a -> Maybe b -> m b

Early return the given value if the Maybe is Nothing. Otherwise, contnue with the value inside of it.

ifNothingDo :: MonadEffect (Early a) m => m a -> Maybe b -> m b

Only do the given action and early return with it's result if the given value is Nothing. Otherwise continue with the value inside of the Maybe.