readWord16 :: ReadValue Word16
readWord16 = readIntegral f
  where f (U16LIT x) = Just x
        f _          = Nothing
readWord16 :: ReadValue Word16
readWord16 = readIntegral f
  where f (U16LIT x) = Just x
        f _          = Nothing
readWord16 = readIntegral f
  where f (U16LIT x) = Just x
        f _          = Nothing