词法分析

对输入的字符串进行词法分析，形成词法分析产生的符号表。

内容：给定描述词法的文法为：

文法一：〈整型数值型数据〉→[+|-]〈数字〉〈数字〉*

〈数字〉→0|1|2|3|4|5|6|7|8|9

文法二：〈算符〉→+|-|*|/

利用以上二个文法对从键盘输入的字符串进行词法分析，对符合这两个文法的字符串建立单词符号表；对不符合这两个文法的字符串给出错误信息。编程序实现该功能，并上机调试。

-Lexical analysis, lexical analysis of the input string to form the symbol table generated by the lexical analysis. : Given to describe the lexical grammar: grammar: < integer numeric data>　→ [+ |-] < number>　< number> * < number>　→ 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 grammar two: < operator>　→+ |- |* |/use more than two grammar on lexical analysis from a string of keyboard input on these two grammatical string word in the symbol table　 give an error message string that do not meet these two grammar. Programmed to achieve the functionality and debugging on the machine.