readHintLine :: [String] -> String -> [Hint]
readHintLine allowed line =
    case words line of
        [] -> []
        cmd:args | cmd `notElem` allowed -> []
                 | otherwise -> parseHint cmd args
readHintLine :: [String] -> String -> [Hint]
readHintLine allowed line =
    case words line of
        [] -> []
        cmd:args | cmd `notElem` allowed -> []
                 | otherwise -> parseHint cmd args
readHintLine allowed line =
    case words line of
        [] -> []
        cmd:args | cmd `notElem` allowed -> []
                 | otherwise -> parseHint cmd args