parseLogin :: Login -> Either LoginError Token
parseLogin l
  | null (token l) = Left (toLoginError l)
  | otherwise = Right (token l)
parseLogin :: Login -> Either LoginError Token
parseLogin l
  | null (token l) = Left (toLoginError l)
  | otherwise = Right (token l)
parseLogin l
  | null (token l) = Left (toLoginError l)
  | otherwise = Right (token l)