findFilter :: (a -> FilePath -> Maybe b) -> Find a b
findFilter p = Find $ \(a, fp) -> return $ maybe [] (\b -> [(b, fp)]) $ p a fp
findFilter :: (a -> FilePath -> Maybe b) -> Find a b
findFilter p = Find $ \(a, fp) -> return $ maybe [] (\b -> [(b, fp)]) $ p a fp
findFilter p = Find $ \(a, fp) -> return $ maybe [] (\b -> [(b, fp)]) $ p a fp