It is based on infix to postfix evaluation.

《编译原理》表达式翻译器 构造一个中缀表达式到后缀表达式的翻译器，初步了解递归下降语法分析原理及语法制导翻译的过程。-Compiler theory expression translator construct an infix expression to postfix expression translator, a preliminary understanding of recursive descent parsing principle and Syntax translation

编译原理实验 表达式翻译器:一个中缀表达式到后缀表达式的翻译器 表达式文法及其翻译模式定义如下： expr  expr + term {print(‘+’)} | expr - term {print(‘-’)}| term term  term * factor {print(‘*’)} | term / factor {print(‘/’)} | factor factor  ( expr ) | id {print(id.