Safe Haskell | Safe-Inferred |
---|---|
Language | Haskell98 |
Convenience function for turning (Maybe a) values into (MonadError e a) actions plus a function for expressing Data.Map lookups as MonadError actions
- maybeThrow :: MonadError e m => e -> Maybe a -> m a
- lookupE :: (Ord k, Show k, MonadError String m) => k -> Map k a -> m a
Documentation
maybeThrow :: MonadError e m => e -> Maybe a -> m a Source
Turn an error value and a (Maybe a) into a (MonadError e a) action