编制一个词法分析程序，从输入的源程序中，分析出各个具有独立意义的单词，即基本保留字、标识符、常量、运算符、界符五大类。并依次输出每类单词，错误时记下出错的行列，出错原因，然后跳过错误部分继续分析-compiled a lexical analysis procedures from the importation of the source, the analysis of the various independent significance of the word, that is to