使用循环分支方法实现PL/0语言的词法分析器，该词法分析器能够读入使用PL/0语言书写的源程序，输出单词符号及其属性到一中间文件中，具有一定的错误处理能力，给出词法错误提示及错误位置。-Ways of using recycled implementation branch PL/0 language lexical analyzer, the lexical analyzer to be able to read the use of PL/0 of the source language, the output word symbols and their property to between one document, the error must have the ability to deal with, lexical error and give the wrong location.