> On May 27, 2016, at 8:18 AM, Thorsten Seitz via swift-evolution > <[email protected]> wrote: > > Personally I think `&` is more lightweight (and it is established in other > languages like Ceylon and Typescript) and `where` is more expressive (and > established in Swift for introducing constraints), so I would stay with these.
I agree. If we can make `&` with `where` work syntactically it would be nice to go in this lighter weight direction. If we decide to do that the question then becomes what to do with `protocol`. Would it be feasible to replace it with `&` in Swift 3 if we decide on that direction? > > -Thorsten > > >> Am 27.05.2016 um 14:34 schrieb Vladimir.S <[email protected] >> <mailto:[email protected]>>: >> >> Btw, in case we have `where` keyword in syntax related to types/protocols >> (when defining constrains. and not some symbol like '>>'.. don't know, for >> example), why we can't have 'and' keyword also when discuss the syntax of >> type/protocol conjunction? >> I.e. >> >> let x: P and Q >> let x: P and Q where P.T == Q.T >> let x: P and Q and R >> >> or, for consistency, as I understand it, we should have >> let x: P & Q >> P.T == Q.T >> >> On 27.05.2016 11:55, Thorsten Seitz via swift-evolution wrote: >>> We could just write >>> >>> let x: P & Q >>> instead of >>> let x: Any<P, Q> >>> >>> let x: Collection where .Element: P >>> instead of >>> let x: Any<Collection where .Element: P> >>> >>> let x: P & Q where P.T == Q.T >>> instead of >>> let x: Any<P, Q where P.T == Q.T> >>> >>> let x: P & Q & R >>> instead of >>> let x: Any<P, Q, R> >>> >>> let x: Collection >>> instead of >>> let x: Any<Collection> >>> >>> >>> This would avoid the confusion of Any<T1, T2> being something completely >>> different than a generic type (i.e. order of T1, T2 does not matter whereas >>> for generic types it is essential). >>> >>> >>> -Thorsten >>> >>> >>> >>>> Am 26.05.2016 um 20:11 schrieb Adrian Zubarev via swift-evolution >>>> <[email protected] <mailto:[email protected]> >>>> <mailto:[email protected] <mailto:[email protected]>>>: >>>> >>>> Something like |type<…>| was considered at the very start of the whole >>>> discussion (in this thread >>>> <https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160502/016523.html >>>> >>>> <https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160502/016523.html>>), >>>> but it does not solve the meaning of an existential type and also might >>>> lead to even more confusion. >>>> >>>> From my perspective I wouldn’t use parentheses here because it looks more >>>> like an init without any label |Type.init(…)| or |Type(…)|. I could live >>>> with |Any[…]| but this doesn’t look shiny and Swifty to me. Thats only my >>>> personal view. ;) >>>> >>>> >>>> >>>> >>>> -- >>>> Adrian Zubarev >>>> Sent with Airmail >>>> >>>> Am 26. Mai 2016 bei 19:48:04, Vladimir.S via swift-evolution >>>> ([email protected] <mailto:[email protected]> >>>> <mailto:[email protected] <mailto:[email protected]>>) >>>> schrieb: >>>> >>>>> Don't think {} is better here, as they also have "established meaning in >>>>> Swift today". >>>>> >>>>> How about just Type(P1 & P2 | P3) - as IMO we can think of such >>>>> construction as "creation" of new type and `P1 & P2 | P3` could be treated >>>>> as parameters to initializer. >>>>> >>>>> func f(t: Type(P1 & P2 | P3)) {..} >>>>> >>>>> >>>>> On 26.05.2016 20:32, L. Mihalkovic via swift-evolution wrote: >>>>> > How about something like Type{P1 & P2 | P3} the point being that >>>>> > "<...>" has an established meaning in Swift today which is not what is >>>>> > expressed in the "<P1,P2,P3>" contained inside Any<P1, P2,P3>. >>>>> > >>>>> >> On May 26, 2016, at 7:11 PM, Dave Abrahams via swift-evolution >>>>> >> <[email protected] <mailto:[email protected]> >>>>> >> <mailto:[email protected] <mailto:[email protected]>>> >>>>> >> wrote: >>>>> >> >>>>> >> >>>>> >>> on Thu May 26 2016, Adrian Zubarev <[email protected] >>>>> >>> <mailto:[email protected]> <mailto:[email protected] >>>>> >>> <mailto:[email protected]>>> wrote: >>>>> >>> >>>>> >>> There is great feedback going on here. I'd like to consider a few >>>>> >>> things here: >>>>> >>> >>>>> >>> * What if we name the whole thing `Existential<>` to sort out all >>>>> >>> confusion? >>>>> >> >>>>> >> Some of us believe that “existential” is way too theoretical a word to >>>>> >> force into the official lexicon of Swift. I think “Any<...>” is much >>>>> >> more conceptually accessible. >>>>> >> >>>>> >>> >>>>> >>> This would allow `typealias Any = Existential<>`. * Should >>>>> >>> `protocol A: Any<class>` replace `protocol A: class`? Or at least >>>>> >>> deprecate it. * Do we need `typealias AnyClass = Any<class>` or do we >>>>> >>> want to use any class requirement existential directly? If second, we >>>>> >>> will need to allow direct existential usage on protocols (right now we >>>>> >>> only can use typealiases as a worksround). >>>>> >> >>>>> >> -- >>>>> >> Dave >>>>> >> >>>>> >> _______________________________________________ >>>>> >> swift-evolution mailing list >>>>> >> [email protected] <mailto:[email protected]> >>>>> >> <mailto:[email protected] <mailto:[email protected]>> >>>>> >> https://lists.swift.org/mailman/listinfo/swift-evolution >>>>> >> <https://lists.swift.org/mailman/listinfo/swift-evolution> >>>>> > _______________________________________________ >>>>> > swift-evolution mailing list >>>>> > [email protected] <mailto:[email protected]> >>>>> > <mailto:[email protected] <mailto:[email protected]>> >>>>> > https://lists.swift.org/mailman/listinfo/swift-evolution >>>>> > <https://lists.swift.org/mailman/listinfo/swift-evolution> >>>>> > >>>>> _______________________________________________ >>>>> swift-evolution mailing list >>>>> [email protected] <mailto:[email protected]> >>>>> <mailto:[email protected] <mailto:[email protected]>> >>>>> https://lists.swift.org/mailman/listinfo/swift-evolution >>>>> <https://lists.swift.org/mailman/listinfo/swift-evolution> >>>> >>>> _______________________________________________ >>>> swift-evolution mailing list >>>> [email protected] <mailto:[email protected]> >>>> <mailto:[email protected] <mailto:[email protected]>> >>>> https://lists.swift.org/mailman/listinfo/swift-evolution >>>> <https://lists.swift.org/mailman/listinfo/swift-evolution> >>> >>> >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> [email protected] <mailto:[email protected]> >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> <https://lists.swift.org/mailman/listinfo/swift-evolution> > _______________________________________________ > swift-evolution mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-evolution
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