> On Jan 24, 2017, at 8:12 AM, Chris Eidhof <ch...@eidhof.nl> wrote: > > But if we want to add "copyOf" we should do that to every method that takes a > struct? Also, what if you pass in an object? > > I see the concern, but I don't think adding `copyOf` will increase clarity. > That said, I'm open to suggestions.
I’m not really trying to advocate for “copyOf”. I think we should really have something more concise in a case like this. My main point is that just using `mutating` is inaccurate and therefore probably not the right solution. Your question about passing in an object (I assume you mean a reference type here) is a good one. In an ideal world that would probably not be allowed as it doesn’t really make sense to replace the reference during reduction. Unfortunately I don’t think we have a way to prevent that at the moment. > > On Tue, Jan 24, 2017 at 2:43 PM, Xiaodi Wu <xiaodi...@gmail.com > <mailto:xiaodi...@gmail.com>> wrote: > It's only verbose if the words aren't needed! The shortest way to describe > something with sufficient accuracy can never be verbose, let alone > undesirable, and I highly agree with this concern. We already have names of > this form, such as `FloatingPoint.init(signOf:magnitudeOf:)`. I mostly agree with this Xiaodi, but I also think that commonly known and frequently used methods like `reduce` deserve to be as concise as possible. That is less a concern with less common and less frequently used signatures. > > On Tue, Jan 24, 2017 at 07:33 Matthew Johnson via swift-evolution > <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: > > > Sent from my iPad > > On Jan 24, 2017, at 1:54 AM, Chris Eidhof via swift-evolution > <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: > >> I've thought about it for a few days, and really like `reduce(mutating:_)`. > > I'm not a fan of this. It reads in a way that makes it seem like the > parameter should be inout, but it isn't. A variation of reduce where the > initial value parameter *is* inout is perfectly sensible (whether or not we > want it in the standard library). With that in mind, I don't think we should > use this name. > > Unfortunately I don't have a better suggestion. I think it was Brent who > suggested "mutatingCopyOf" which is more accurate, but also undesirably > verbose. > >> I've updated the PR, and am now happy for this to go into review. >> >> https://github.com/apple/swift-evolution/pull/587 >> <https://github.com/apple/swift-evolution/pull/587> >> >> On Mon, Jan 23, 2017 at 8:27 AM, Russ Bishop <xen...@gmail.com >> <mailto:xen...@gmail.com>> wrote: >> >>> On Jan 22, 2017, at 10:56 PM, Chris Eidhof <ch...@eidhof.nl >>> <mailto:ch...@eidhof.nl>> wrote: >>> >>> Not as a direct reply to Russ, but just to reiterate: to me, there are two >>> clear benefits of using the `inout` version of reduce: >>> >>> 1. The performance (currently discussed at length) >>> 2. Readability (because we can use mutating methods on `inout` arguments). >>> >>> Even if the compiler were to optimize the unnecessary copy of `return arr + >>> [el]` away, there are still a lot of other mutable methods that you might >>> want to use within the reduce closure. So I think the proposal is still >>> very valid even if the compiler optimizations would magically appear >>> tomorrow. >>> >>> To push this proposal forward a little bit, I'd like to come up with a good >>> name. It seems like we shouldn't overload `reduce`, but choose a different >>> name, so that we don't stress the typechecker. Any other suggestions? >>> >>> On Mon, Jan 23, 2017 at 7:11 AM, Russ Bishop <xen...@gmail.com >>> <mailto:xen...@gmail.com>> wrote: >>> -- >>> Chris Eidhof >> >> >> Sorry for the derail! >> >> reduce(mutating:_:) { } is still my favorite; You can take mutating to mean >> we will copy the value now but mutate it later. >> >> >> Some alternatives: >> >> reduce(forMutating:_:) { } >> >> reduce(forInout:_:) { } >> >> reduce(initial:_:) { } >> >> reduce(copying:mutate:) { } >> >> // just kidding... >> reduce(copyForLaterMutating:_:) { } >> >> >> >> It should definitely be some form of reduce. >> >> Russ >> >> >> >> -- >> Chris Eidhof >> _______________________________________________ >> swift-evolution mailing list >> swift-evolution@swift.org <mailto:swift-evolution@swift.org> >> https://lists.swift.org/mailman/listinfo/swift-evolution >> <https://lists.swift.org/mailman/listinfo/swift-evolution> > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org <mailto:swift-evolution@swift.org> > https://lists.swift.org/mailman/listinfo/swift-evolution > <https://lists.swift.org/mailman/listinfo/swift-evolution> > > > > -- > Chris Eidhof
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