An implementation of the lisp-like described in Build Your Own Lisp by Daniel Holden to practice C++ (though probably not very well since the tutorial focuses on C).
Uses ANTLR: http://www.antlr.org
https://github.com/antlr/antlr4/blob/master/doc/cpp-target.md
https://github.com/antlr/antlr4/tree/master/runtime/Cpp/demo