On Tue, Jun 8, 2021 at 1:25 AM Robert Engels <reng...@ix.netcom.com> wrote:
> I think that is why it is inconsistent and obtuse to me. The Log() method > doesn’t need a pointer receiver. It works fine without it. > I don't understand how you can continue to say that. I've linked the code several times. It does not work. Or, if it does work, it also works with interfaces. The behavior is the same in both cases. > It only needs a pointer receiver because when passed to a function > declared as taking an interface a copy is made (and a reference to the copy > held). This copy is implicit not explicit. > Yes. But (as the FAQ entry points out) copying values when passing is how Go works in general. > This is a difficult model when working on large multi person projects - > thus the “best practice” of using only pointer or value receivers I think. > Suggesting that the linter flags code not adhering to this seems to have > very little downside if any. > It has the downside of flagging correct code as incorrect. A quick search on the web (and the faq language) makes me think I am not > alone in this opinion. > > I guess I still don’t see the downside to linter changes. As I said I > reviewed a lot of the stdlib and I don’t see any obvious mixed receiver > structs. They can be disabled on a per struct basis if needed. > > Anyway it was just my opinion based on my experiences. > > On Jun 7, 2021, at 6:05 PM, Axel Wagner <axel.wagner...@googlemail.com> > wrote: > > > On Mon, Jun 7, 2021 at 11:42 PM Robert Engels <reng...@ix.netcom.com> > wrote: > >> I don’t think that represents the problem fairly. In the non interface >> case I know I can’t accept a copy so I would declare the method as taking a >> pointer to the struct. >> > > How methods are declared should, in general, not be a matter of whether or > not they are assigned to an interface, but to whether or not they need a > pointer. Again: Your code is incorrect without interfaces > <https://play.golang.org/p/WpIzYYLOKn->. The problem doesn't happen when > you put that value into an interface - it happens when you pass a copy of > it and expect it to refer to the original. Interfaces are just one way to > create such a copy, but they do not matter for the correctness of this code > and for whether or not that method needs a pointer receiver (it does). > > But again, to be clear: I'm not saying problems like this *never* happen > and I'm not even saying that interfaces may obscure it in some cases. Just > that a) the root cause here is that your method really needs to take a > pointer-receiver, interfaces or not and b) that it seems very much an > overstatement to me to call this "the most inconsistent and obtuse aspect > of the Go language". > > With interfaces this is lost - as the interface is implicitly a pointer >> > > Well, it seems a bad idea to say that interfaces are implicitly pointers > then. That seems to indicate that Rob's original phrasing is indeed an > important clarification - the language behaves as if the value contained in > them is copied when the interface value is copied. > > It seems the confusion here is, that you assume it's not. And that > interfaces act as a pointers, when they don't. > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAEkBMfG%3DT4fdNHvpT--aY1v9mTr9GrZp-iTkfM6Cy51-Gq-sGA%40mail.gmail.com.
