parse tree

The single quotation mark in front of the null list is used to tell Scheme that you are using() as data and not as a part of your parse tree.

空列表前面的单引号用来告诉Scheme您正在使用（）作为数据，而不是用它作为解析树的一部分。

Working with a parse tree representation also makes debugging easy and speeds development time.

使用解析树表示还会使调试变得更容易，并缩短开发时间。

The DFA construction algorithm converts this parse tree into a set of states, as the previous column explains.

如前一篇专栏文章中所解释的，DFA构造算法将该解析树转换成一组状态。

A representation of parse tree for context free language

上下文无关语言分析树的一种表示形式

It expects the front end ( reread previous column for more on the front end and back end) to return a parse tree that contains all the XPaths to recognize.

该算法期望前端（请重新阅读上一篇专栏文章以了解更多有关前端和后端的信息）返回一个包含所有要识别的XPath的解析树。

The axpath() method returns what is known as an augmented parse tree& a parser tree with one extra node for the END_MARK.

axpath（）方法返回称之为扩张的解析树―该解析树额外地带有一个表示END MARK的节点。