> You still can, and do, model state in stateless systems; Yea, in functional programming it's easier to focus on the essential state inherent to the problem,

> You still can, and do, model state in stateless systems; Yea, in functional programming it's easier to focus on the essential state inherent to the problem, and avoid introducing accidental state. > Relatedly, "Immutability is not enough", from a couple days ago: https://news.ycombinator.com/item?id=27642263 https://news.ycombinator.com/item?id=27642263 Okay, interesting article, but I don't agree with this bit: > It turns out that our purely functional rendering code is sensitive to ordering in non-obvious ways. The first time I encountered this kind of bug, it felt strangely familiar – it’s something that often occurs in imperative programs. This is exactly the kind of problem that functional programming was supposed to help us avoid! I don't think functional programming is supposed to help you with if you misunderstand the essential logic of the problem. I'd argue that declarative languages (like Prolog and SQL) can help avoid this type of ordering bug though by making variable assignment explicit.