一个很一般的编译程序

有词法分析，语法分析，语议分析，和最终生成四元式，但是出错处理较简单，大部分用的C语言，但加了一个四元式类，本人感觉这个程序很垃圾，但可以做个参考！-a very general compilers have lexical analysis, grammar, language proposed analysis, and generate the final-four yuan, But mistakes in handling more simple, with most of the C language, but added a category-four yuan, I feel that this procedure is rubbish, but can make reference!