Sepples is bad for your brain

Note that instead of adding virtual methods to the ExprAST class hierarchy, it could also make sense to use a visitor pattern or some other way to model this. Again, this tutorial won’t dwell on good software engineering practices: for our purposes, adding a virtual method is simplest.
visitor pattern
good practices
bloated shit that exists only to mitigate the utter uselessness and weakness of COP
good practices