Comment by cygned

I have quite some background in OOP and switched to functional programming a few years ago, now working a lot with Clojure, where you actually have the "code is data" paradigm. And from my experience, it's way easier to model data with three simple structures; vectors (= arrays), maps and sets. There are other things, too, but most of the time these three types are sufficient. It requires some discipline in the beginning but it can give you a lot of benefits.