Comment by tombert
2 days ago
No disagreement on that but that's an implementation detail and from the coder's perspective there's no mutable references.
2 days ago
No disagreement on that but that's an implementation detail and from the coder's perspective there's no mutable references.
From the coder's perspective it is. There's just different syntax for assigning to them.
No, from the coder's perspective it looks like I'm passing an argument into a function. I suppose you could say that arguments in general are "mutable references", and I guess that's not necessarily "untrue", but that's not generally how I visualize it.
If I pass a persistent structure into a tail call, it looks like I'm passing a copy into there, in the same way that I might if I did something like `Math.abs(myValue * 3)`; the compiler converts it to a mutable reference but I see it as the same as passing a value.
From the coder's perspective, there are no mutable references only if the coder does not really rely on or care about the possibility that their code uses TCO. If they actively want TCO then they definitely care about the performance benefits they get from underlying mutability/memory reuse/frame elision.
Yeah but that's why I prefer Clojure's loop/recur thing. You're not allowed to have non-tail recursion there, so it's not implicit, so you really can pretend that there's no mutable references.