This post is the closing post of a series on mastering data structures in Ruby where I introduce the concept of persistent data structures, a term coined by Driscoll in an article from 1986 that these days it’s at the core of most purely functional data structures. On this article, I’ll review the core aspects of persistent data structures and show you how to implement persistent, immutable linked lists using the Ruby programming language. I hope you like it! Mastering data structures in Ruby — Persistent lists