Safe Haskell	Safe-Inferred
Language	Haskell2010

Control.Carrier.Fail.Either

Contents

Fail carrier
Fail effect

Description

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

Synopsis

runFail :: FailC m a -> m (Either String a)
newtype FailC m a = FailC (ThrowC String m a)
module Control.Effect.Fail

Fail carrier

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

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 a Source #

Since: 1.0.0.0

Constructors

FailC (ThrowC String m a)

Instances

Instances details

MonadTrans FailC Source #
Instance details Defined in Control.Carrier.Fail.Either Methods lift :: Monad m => m a -> FailC m a #
Algebra sig m => MonadFail (FailC m) Source #
Instance details Defined in Control.Carrier.Fail.Either Methods fail :: String -> FailC m a #
MonadFix m => MonadFix (FailC m) Source #
Instance details Defined in Control.Carrier.Fail.Either Methods mfix :: (a -> FailC m a) -> FailC m a #
MonadIO m => MonadIO (FailC m) Source #
Instance details Defined in Control.Carrier.Fail.Either Methods liftIO :: IO a -> FailC m a #
(Alternative m, Monad m) => Alternative (FailC m) Source #
Instance details 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) Source #
Instance details 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) Source #
Instance details 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) Source #
Instance details 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) Source #
Instance details Defined in Control.Carrier.Fail.Either Methods mzero :: FailC m a # mplus :: FailC m a -> FailC m a -> FailC m a #
Algebra sig m => Algebra (Fail :+: sig) (FailC m) Source #
Instance details 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) Source #

Fail effect

module Control.Effect.Fail