Hbro.Error

Documentation

type MonadFail m = MonadError () m

MonadError with trivial error.

die :: MonadFail m => m a

throwError for MonadFail.

runFailT :: Monad m => ExceptT () m a -> m (Maybe a)

runErrorT with trivial error.

liftMaybe :: MonadFail m => Maybe a -> m a

Lift a Maybe value into a MonadFail computation

liftEither :: MonadError e m => Either e a -> m a

Lift an Either value into a MonadError computation

failWith :: MonadError e m => Maybe a -> e -> m a

(<!>) :: MonadError e m => m (Maybe a) -> e -> m a

Monadic and infix version of failWith