Earlier quoted context omitted.
After doing functional programming for a while now (6 years of Elixir) it seems obvious to me that it is possible and no more complex than using imperative logic. In fact I would go so far as to say that managing complexity (i.e. state) is much easier to do in a functional style than imperative. Functional is all about transformation of data structures, and a game is nothing more than a function that takes {state, mo…
Could an expert strong man the argument that functional programming languages like Haskell could in theory be more performant than C because of the nice properties of pure functional languages?
But not all games are AAA FPS that require ingenious optimized codepaths to perform well, not in this day and age, so this is why you see commercial games running on "slower" abstractions such as C# (AOT compilation doesn't make it less of an abstraction layer), so you can very well design a commercial game in Haskell or Scheme or Lisp or Clojure if you wish. Nothing stops you, apart from the lack of serious game dev frameworks built in those languages.
It all depends on the compiler, really, and it is asymptotically hard to compile functional languages so they perform as fast as C for example. There is no market for "high performance Haskell or Clojure", so there is no compiler that good either.