Post #986217

"A more nuanced approach would differentiate between a function that just happens to be written in a different language, and one that actually performs an effect." This is very suggestive to me. It reminds that you can have a procedure that uses mutable state, or even one in a really hairy imperative language, but have it provide a pure interface (as with Haskell's ST). A quicksort function, for example. https://math.andrej.com/2019/10/28/runners-in-action/