> The idea of distinguishing all mutating/non-mutating functions with only the > assignment operator did occur to me as I wrote that. > Using such a rule would allow automatic generation of mutating methods from > non-mutating ones, since the naming would no longer need changing. > However, this would also mean scrapping half the Naming Guidelines, so I'm > hesitant to put that possibility forward as a serious proposal. > > I think union (verb) vs union (noun) would work as a one off, though, since > it fits the guidelines as they currently stand. It would be a nice way to > demonstrate that the compiler can make the distinction in a public API. > > > From James F > On 24 Apr 2016, at 15:49, Tim Vermeulen<[email protected]>wrote: > > > > The whole naming issue seems to be caused by the .union(_:) function. The > > > Swift Guidelines say that mutating functions should use a verb, and > > > non-mutating forms should use a noun, but in this case, the word union > > > itself is a verb and a noun. > > > > > > Have we considered this, then: > > > > > > a.union(b) //mutating > > > > > > _ = a.union(b) //non-mutating > > > > > > There is no ambiguity in most situations, and the fact the Swift compiler > > > can't disambiguate this at the moment is a bug I'd like to see fixed in > > > the Swift 3 timeframe. I think this wouldn't be such a bad compromise, > > > and other functions could still use the standard -ed/-ing system > > > alongside this without the API looking inconsistent, unlike with the > > > form- prefix. > > > > > > Admittedly, there is merit to the idea that functional methods should > > > make non-mutating forms the primary form, but I feel like we should > > > figure out what our stance is on this methodology in general. A mention > > > in the Guidelines one way or the other would be nice, since the current > > > rules seem to support this. > > > > > > > From James F > > > > Can’t we do this for every mutating method? i.e. > > > > var numbers = [1,3,2] > > let sorted = numbers.sort() > > // sorted is [1,2,3], numbers is [1,3,2] > > numbers.sort() > > // numbers is [1,2,3] > > > > I suppose this would require that the mutating version doesn’t return > > anything, and I don’t know if that’s ever a problem. > > >
Well, this change would render a big part of the naming guidelines meaningless, but isn’t that a good thing? Guidelines are often in place to prevent ambiguity, and this solution would do that without the need for guidelines. Anyways, I wouldn’t be surprised if this idea has come up before and has been rejected, but to me it sounds like a good idea. _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
