该任务需要你为数学表达式构建一个单纯的语法分析程序lexer，它将一段输入的字符串转变为token(值)，token(值)里每个字符都属于数学表达式的组成部分。我们想将token(值)定义为如下几种(1)计算符号,+,-.(2)字母和下划线 (3)数字，这三者先不需要仔细区分。-In this assignment, you will build a simple lexer for arithmetic expressions. A lexer breaks an put str g to

java编写的C语言编译器，从C语言完成了到四元式的编译过程。其中包括词法分析，语法分析，语义分析，中间代码生成。-java written in C language compiler from the completion of the C language to quaternion-compilation process. Including lexical analysis, parsing, semantic analysis, intermediate code generatio

用java语言编写的语法分析程序，编译原理作业。个人编写，多多指教。-Java language parser, compiler theory job. Personal written exhibitions.