parser

代码说明：

  简单的语法缝隙器，可以比较详尽的分析输入语句的语法成分。把想要分析的语句放到parser.in文件中，编译即可看到结果。(Simple syntax gap, you can enter a more detailed analysis of the syntax of the statement components. The statement you want to analyze into parser.in file, the compiler can see the results.)