可以打开任意位置和名称的原文件进行词法分析，可以进行非法字符和数字后边跟字母的错误判断，如果没有错误则提示“词法分析正确完成！”-can open arbitrary locations and names of the original documents lexical analysis can be carried out illegal characters and figures behind the letters with the wrong judgment, and if no error is suggested "lexical analysis is correct!"