资 源 简 介
这是编程语言这门课的大作业（CS 383 Course Project ）
In this project, you are going to implement an interpreter for a simple programming language called
SimPL. The language is an extension of calculus which is the basis of functional programming but
includes some features imperative programming as well. Your interpreter should work like a shell, which
takes in an expression and produce correct evaluation results.
