通过设计、编制、调试一个具体的词法分析程序，加深对词法分析原理的理解，并掌握在对程序设计语言源程序进行扫描过程中将其分解为各类单词的词法分析方法。-Through the design, preparation, debugging to a specific program, deepen the lexical analysis of lexical analysis principle understanding and mastering of programming language in source program will scan the decomposition of the word for lexical analysis method.