Since member items need to be valid objects prior to their inclusion in larger structures, the simplest recursive descent approach would not work. 由于在成员项所包含的内容出现在较大型的结构之前,成员项必须是有效对象,所以最简单的递归继承方法不起作用。
This paper gives a brief sketch of how to build a recursive descent parser using classes and a hierarchy of classes. 本文给出了一个骨架:如何用类以及类分层来建造一个递归下降扫描程序。
The operator precedence parsing and recursive descent parsing are used in the syntax analysis and the intermediate code is quadruples. 语法分析中使用了算符优先分析法和递归下降分析法;
The lexical analysis uses the advanced search method while the syntax analysis adopts the top-down recursive descent parsing. Furthermore, we give some sample codes, arithmetical statement and the design of related classes. 其中词法分析是利用超前搜索的方法,语法分析则采用了自上而下的递归下降分析法,并给出了示例代码、算法描述和相关类的结构设计。