| Safe Haskell | None |
|---|
Algebra.Monad.Error
- class Monad m => MonadError e m | m -> e where
- try :: MonadError e m => m a -> m a -> m a
- (!+) :: MonadError Void m => m a -> m a -> m a
- tryMay :: MonadError e m => m a -> m (Maybe a)
- throwIO :: Exception e => e -> IO ()
- data EitherT e m a
- _eitherT :: Functor m => Iso (EitherT e m a) (EitherT f m b) (m (e :+: a)) (m (f :+: b))
The MonadError class
class Monad m => MonadError e m | m -> e whereSource
Instances
| MonadError SomeException IO | |
| MonadError Void [] | |
| MonadError Void Maybe | |
| MonadError e (Either e) | |
| Monad m => MonadError Void (ListT m) | |
| MonadError e m => MonadError e (StateT s m) | |
| (Monoid w, MonadError e m) => MonadError e (RWST r w s m) |
try :: MonadError e m => m a -> m a -> m aSource
(!+) :: MonadError Void m => m a -> m a -> m aSource
tryMay :: MonadError e m => m a -> m (Maybe a)Source
The Either transformer
Instances
| MonadTrans (EitherT e) | |
| Unit m => Unit (EitherT e m) | |
| MonadFix m => MonadFix (EitherT e m) | |
| Monad m => Monad (EitherT e m) | |
| Applicative m => Applicative (EitherT e m) | |
| Functor m => Functor (EitherT e m) | |
| Foldable m => Foldable (EitherT e m) | |
| Traversable m => Traversable (EitherT e m) |