Control.Carrier.Fail.Either

A carrier for a Fail effect, returning the result as an Either String. Failed computations will return a Left containing the String value passed to fail.

Since: 1.0.0.0

Fail carrier

runFail :: FailC m a -> m (Either String a)

Run a Fail effect, returning failure messages in Left and successful computations’ results in Right.

runFail (pure a) = pure (Right a)

runFail (fail s) = pure (Left s)

Since: 1.0.0.0

newtype FailC (m :: Type -> Type) a

Since: 1.0.0.0

Constructors

FailC (ThrowC String m a)

Instances

MonadTrans FailC

Defined in Control.Carrier.Fail.Either

Methods

lift :: Monad m => m a -> FailC m a

MonadIO m => MonadIO (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

liftIO :: IO a -> FailC m a

(Alternative m, Monad m) => Alternative (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

empty :: FailC m a

(<|>) :: FailC m a -> FailC m a -> FailC m a

some :: FailC m a -> FailC m [a]

many :: FailC m a -> FailC m [a]

Monad m => Applicative (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

pure :: a -> FailC m a

(<*>) :: FailC m (a -> b) -> FailC m a -> FailC m b

liftA2 :: (a -> b -> c) -> FailC m a -> FailC m b -> FailC m c

(*>) :: FailC m a -> FailC m b -> FailC m b

(<*) :: FailC m a -> FailC m b -> FailC m a

Functor m => Functor (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

fmap :: (a -> b) -> FailC m a -> FailC m b

(<$) :: a -> FailC m b -> FailC m a

Monad m => Monad (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

(>>=) :: FailC m a -> (a -> FailC m b) -> FailC m b

(>>) :: FailC m a -> FailC m b -> FailC m b

return :: a -> FailC m a

(Alternative m, Monad m) => MonadPlus (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

mzero :: FailC m a

mplus :: FailC m a -> FailC m a -> FailC m a

Algebra sig m => MonadFail (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

fail :: String -> FailC m a

MonadFix m => MonadFix (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

mfix :: (a -> FailC m a) -> FailC m a

Algebra sig m => Algebra (Fail :+: sig) (FailC m)

Defined in Control.Carrier.Fail.Either

Methods

alg :: forall ctx (n :: Type -> Type) a. Functor ctx => Handler ctx n (FailC m) -> (Fail :+: sig) n a -> ctx () -> FailC m (ctx a)

Fail effect

module Control.Effect.Fail