通过设计、调试词法分析程序，实现从源程序中分出各种单词的方法；熟悉词法分析程序所用的工具自动机，进一步理解自动机理论。掌握文法转换成自动机的技术及有穷自动机实现的方法。确定词法分析器的输出形式及标识符与关键字的区分方法。加深对课堂教学的理解；提高词法分析方法的实践能力。通过本实验，应达到以下目标：

-Through the design, debug lexical analysis procedures, to achieve separation from the source in a variety of ways to word　familiar with the lexical analysis tools used in automatic machines, a better understanding of automata theory. Master grammar automata into the technology and the realization of DFA method. Lexical analyzer to determine the output form and the distinction between identifiers and keywords methods. Deepen understanding of classroom teaching　lexical analysis methods to improve the ability of the practice. Through this experiment should be to achieve the following objectives: