code: private boolean hasFieldOrFunction() {
          int dot = 0, comma = 0;
          for (int currentIndex = i; currentIndex < cs.length; currentIndex++) {
              char c = cs[currentIndex];
              if (c == '.')
                  dot = currentIndex;
              if (c == ',')
                  comma = currentIndex;
          }
          return dot < comma || (dot != 0 && comma == 0);//点号在逗号前边或后边有点号没有逗号
      }
docs: 对象在参数中，是否后续获取属性或调用方法