简单的词法分析器

1. 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。

2．依次输出各个单词的内部编码及单词符号的自身值。

3．遇到错误时显示“无法识别的单词”，然后跳过错误部分继续显示

-Simple lexical analyzer 1. A process of reading words from the input source program, identify the meaning of each word independent, that is basically reserved words, identifiers, constants, operators, delimiters five categories. 2. Followed by the output of each internal code word and the word symbol itself value. 3. Encountered an error " can not recognize the word" , then skip the error part of the continued display