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、整数、小数、字符串、运算符、分隔符七大类。并依次输出各个单词的内部编码及单词符号自身值。（遇到错误时可显示“Error”，然后跳过错误部分继续显示） -The process of the preparation of a word read from the input source program, to identify each word has an independent significance, namely, the basic reserved words, identifier, integer, decimal, string, operator, separator seven categories. And in turn the output of each word in its own internal code and the word symbolic value. (Encountered an error displays " Error" , then skip the error part of the continued display)