isOfpType :: Word8 -> Bool
isOfpType w = 
  case fromWord8 w of
    Just _  -> True
    Nothing -> False
isOfpType :: Word8 -> Bool
isOfpType w = 
  case fromWord8 w of
    Just _  -> True
    Nothing -> False
isOfpType w = 
  case fromWord8 w of
    Just _  -> True
    Nothing -> False