> On Feb 12, 2017, at 5:19 PM, David Hart via swift-evolution > <swift-evolution@swift.org> wrote: > > I was reading this nice listing of Swift keywords > (https://medium.com/the-traveled-ios-developers-guide/swift-keywords-v-3-0-1-f59783bf26c#.2s2yis3zh > > <https://medium.com/the-traveled-ios-developers-guide/swift-keywords-v-3-0-1-f59783bf26c#.2s2yis3zh>) > and three of them struck me as potentially not long for this world and I was > thinking if we needed/could deprecate them before any kind of ABI stability > set in. > > I'm listing them here but it might be worth starting separate discussions for > each of them. > > Final > > Can someone tell me what is the use of 'final' now that we have 'public' > default to disallowing subclassing in importing modules? I know that 'final' > has the added constraint of disallowing subclassing in the same module, but > how useful is that? Does it hold its weight? Would we add it now if it did > not exist?
To me, it's useful a lot. The module doesn't necessarily be a 1KLOC framework - I've been recently refactoring a 90KLOC module and the final keyword was fairly useful since some subclasses used hacks by overriding some vars or methods. This allowed me to look at it from a different perspecitve, make some members final and create better API endpoints for customization. Not to mention that it allows the compiler to access stored properties directly when they're final - if I recall correctly someone from the core team mentioning that. > > Lazy > > This one is clearer: if Joe Groff's property behaviors proposal from last > year is brought forward again, lazy can be demoted from a language keyword to > a Standard Library property behavior. If Joe or anybody from the core team > sees this: do we have any luck of having this awesome feature we > discussed/designed/implemented in the Swift 4 timeframe? > > Fileprivate > > I started the discussion early during the Swift 4 timeframe that I regret the > change in Swift 3 which introduced a scoped private keyword. For me, it's not > worth the increase in complexity in access modifiers. I was very happy with > the file-scope of Swift pre-3. When discussing that, Chris Latner mentioned > we'd have to wait for Phase 2 to re-discuss it and also show proof that > people mostly used 'fileprivate' and not the new 'private' modifier as proof > if we want the proposal to have any weight. Does anybody have a good idea for > compiling stats from GitHub on this subject? First of all, I've always found > the GitHub Search quite bad and don't know how much it can be trusted. > Secondly, because 'private' in Swift 2 and 3 have different meanings, a > simple textual search might get us wrong results if we don't find a way to > filter on Swift 3 code. I like the scoped access, I actually find it useful when declaring several classes within one file, so that I know I'm not accessing that class' private members. That said, I agree that the change to fileprivate was IMHO a mistake - aside from the fact that I dislike the fileprivate keyword, I was more leaning towards the idea that fileprivate would be default for private and when someone really wants to make some member scope-private, private(scope) could be used. > > Thanks for hearing me out! > > David. > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution
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