通过设计、编制、调试一个具体的词法分析程序，加深对词法分析原理的理解，并掌握在对程序设计语言源程序进行扫描过程中将其分解为各类单词的词法分析方法

输入：字符串。

输出：二元式（种别编码，单词自身）构成的序列。

举例：

输入：a=$ #

输出：（6，a）

（12，=）

FOUND ERROR

（13， ）

-The design, development, debugging a specific lexical analyzer, and deepen their understanding of the principles of lexical analysis, and mastery of the scanning process will be broken down into various types of word lexical analysis methods of input: string in the right programming language source code. Output: binary type (Do not encoded word itself) constitute a sequence. Example: Input: a = $ # output: (a) the (12, =) FOUND ERROR (13　)