fetchDifficulty :: IO (Maybe Double)
fetchDifficulty = do
   str <- difficultyText
   case readDouble str of
     Nothing -> return Nothing
     Just (d, _) -> return $ Just d
fetchDifficulty :: IO (Maybe Double)
fetchDifficulty = do
   str <- difficultyText
   case readDouble str of
     Nothing -> return Nothing
     Just (d, _) -> return $ Just d
fetchDifficulty = do
   str <- difficultyText
   case readDouble str of
     Nothing -> return Nothing
     Just (d, _) -> return $ Just d