parseFileGlob :: FilePath -> Maybe FileGlob
parseFileGlob filepath = case splitExtensions filepath of
  (filepath', ext) -> case splitFileName filepath' of
    (dir, "*") | '*' `elem` dir
              || '*' `elem` ext
              || null ext            -> Nothing
               | null dir            -> Just (FileGlob "." ext)
               | otherwise           -> Just (FileGlob dir ext)
    _          | '*' `elem` filepath -> Nothing
               | otherwise           -> Just (NoGlob filepath)
parseFileGlob :: FilePath -> Maybe FileGlob
parseFileGlob filepath = case splitExtensions filepath of
  (filepath', ext) -> case splitFileName filepath' of
    (dir, "*") | '*' `elem` dir
              || '*' `elem` ext
              || null ext            -> Nothing
               | null dir            -> Just (FileGlob "." ext)
               | otherwise           -> Just (FileGlob dir ext)
    _          | '*' `elem` filepath -> Nothing
               | otherwise           -> Just (NoGlob filepath)
parseFileGlob filepath = case splitExtensions filepath of
  (filepath', ext) -> case splitFileName filepath' of
    (dir, "*") | '*' `elem` dir
              || '*' `elem` ext
              || null ext            -> Nothing
               | null dir            -> Just (FileGlob "." ext)
               | otherwise           -> Just (FileGlob dir ext)
    _          | '*' `elem` filepath -> Nothing
               | otherwise           -> Just (NoGlob filepath)