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。-Debugging through the design of the preparation of a specific lexical analysis program , to deepen understanding of the principles of lexical analysis . And control in the progr