It's not purely functional if it supports side effects all willy-nilly. Scheme sans mutation (which is not the same as Racket, since Racket's stdlib still suppo

It's not purely functional if it supports side effects all willy-nilly. Scheme sans mutation (which is not the same as Racket, since Racket's stdlib still supports mutation) is no more purely functional than modern C++ sans mutation. With that said, purely functional programming is arguably just a hassle; I tend to think that "functional-first," as I call it, programming, a la Clojure, is a good balance between practical and pure. In this way, side effects are adhoc, but all definitions are immutable by default.