On Fri, Jul 22, 2016 at 1:05 PM, Dave Abrahams via swift-evolution < swift-evolution@swift.org> wrote:
> > on Thu Jul 21 2016, Duan <swift-evolution@swift.org> wrote: > > > Great proposal. I want to second that areSame may mislead user to > > think this is about identity. > > > > I like areEquivalent() but there may be better names. > > It really *is* about identity as I posted in a previous message. Correct me if I'm wrong: Identity is an equality relation, and `==` is about just that. By contrast, `areSame()` is to define an *equivalence* relation through which, by default, `==` is to be dispatched. Since this design specifically contemplates scenarios in which certain Equatables will override `==` *not* to dispatch through `areSame()`, the latter function evaluates only *equivalence* with respect to an arbitrary equivalence relation, not identity. Put another way, the future `Equatable` is a contract that conforming types will supply a definition of equality *and* an equivalence relation, where the former by default is dispatched through the latter; but it is specifically envisioned that the two may be separated in domain-specific scenarios. But > that doesn't change the fact that areEquivalent might be a better name. > It's one of the things we considered; it just seemed long for no real > benefit. > > > Daniel Duan > > Sent from my iPhone > > > >> On Jul 21, 2016, at 6:32 PM, Robert Widmann via swift-evolution > >> <swift-evolution@swift.org> wrote: > >> > >> > >>> On Jul 21, 2016, at 6:19 PM, Xiaodi Wu <xiaodi...@gmail.com> wrote: > >>> > >>> This is nice. Is `areSame()` being proposed because static `==` is > >>> the status quo and you're trying to make the point that `==` in the > >>> future need not guarantee the same semantics? > >> > >> Yep! Equivalence and equality are strictly very different things. > >> > >>> > >>> Nit: I think the more common term in stdlib would be > >>> `areEquivalent()`. Do you think `same` in that context (independent > >>> of the word "ordering") might erroneously suggest identity? > >> > >> There is room for improvement here. Keep ‘em coming. > >> > >>> > >>> > >>>> On Thu, Jul 21, 2016 at 8:11 PM, Robert Widmann via > >>>> swift-evolution > >>>> <swift-evolution@swift.org> wrote: > >>>> Hello Swift Community, > >>>> > >>>> Harlan Haskins, Jaden Geller, and I have been working on a > >>>> proposal to clean up the semantics of ordering relations in the > >>>> standard library. We have a draft that you can get as a gist. > >>>> Any feedback you might have about this proposal helps - though > >>>> please keeps your comments on Swift-Evolution and not on the gist. > >>>> > >>>> Cheers, > >>>> > >>>> ~Robert Widmann > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> _______________________________________________ > >>>> swift-evolution mailing list > >>>> swift-evolution@swift.org > >>>> https://lists.swift.org/mailman/listinfo/swift-evolution > >>>> > >>> > >> > >> _______________________________________________ > >> swift-evolution mailing list > >> swift-evolution@swift.org > >> https://lists.swift.org/mailman/listinfo/swift-evolution > > _______________________________________________ > > swift-evolution mailing list > > swift-evolution@swift.org > > https://lists.swift.org/mailman/listinfo/swift-evolution > > > > -- > Dave > > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution >
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