编制一个读单词过程，从输入的源程序中，识别出各个具有独立意义的单词，即基本保留字、标识符、常数、运算符、分隔符五大类。并依次输出各个单词的内部编码及单词符号自身值-Reading the course of the preparation of a word, from the input source program to identify the meaning of each word is an independent, that is the basic reserved words, identifiers, constant, operator, separator five categories. And followed by all the output of the internal code word and the word itself the value of symbols