build c++ program with given starter file

The goal of this project is to designing and implementing multiple modules that are used together to solve a problem. You will also gain experience using the standard library as well as unit testing. You will write an interpreter for a simple programming language we will call slisp. It is an expression-based language using prefix Lisp notation.

code lisp in c++ with example from python version https://norvig.com/lispy.html where I will provide description of scope and starter code to follow