HaskellWorks.Polysemy.Error

Documentation

onLeft :: Monad m => (e -> m a) -> Either e a -> m a

onNothing :: Monad m => m b -> Maybe b -> m b

onLeftM :: Monad m => (e -> m a) -> m (Either e a) -> m a

onNothingM :: Monad m => m b -> m (Maybe b) -> m b

trap :: forall e r a. (e -> Sem r a) -> Sem (Error e ': r) a -> Sem r a