一个词法分析器程序，能识别出单词并区分是整数还是标识符。标识符中是否有while,do,if,then,else,begin,end,and,or,not等保留字。若单词是整数则输出整数的编码及数值，是标识符则判定是否为保留字，是保留字则将保留字及其对应的编码输出，否则输出表示符号及其编码。-A lexical analyzer procedures, able to identify and distinguish the words is an integer or identifier.If there are while, if, then identifier, do, else, begin, end, and, or, not reserved word. If the word is a code and numerical integral output integer identifier, is to determine whether it is a reserved word is a reserved word will be a reserved word and the corresponding code output, otherwise the output symbol and code.