How would a class partially implement a protocol? That’s a compile error.
> On Nov 2, 2017, at 2:30 PM, C. Keith Ray via swift-evolution > <swift-evolution@swift.org> wrote: > > If a class partially implemented a protocol, it also would not be > instantiatable, but a subclass can supply the missing method(s). Doesn’t the > compiler already handle that? How are abstract classes harder? > > C. Keith Ray > https://leanpub.com/wepntk <https://leanpub.com/wepntk> <- buy my book? > http://agilesolutionspace.blogspot.com/ > <http://agilesolutionspace.blogspot.com/> > twitter: @ckeithray > http://www.thirdfoundationsw.com/keith_ray_resume_2014_long.pdf > <http://www.thirdfoundationsw.com/keith_ray_resume_2014_long.pdf> > > On Nov 2, 2017, at 2:22 PM, Slava Pestov <spes...@apple.com > <mailto:spes...@apple.com>> wrote: > >> Abstract methods and classes seem like they will introduce a fair amount of >> complexity in the type checker, particularly around metatypes and >> constructors, because now we have this new concept of a class that cannot be >> directly instantiated. I’m not sure the cost is worth the benefit. >> >> Slava >> >>> On Nov 2, 2017, at 12:45 PM, C. Keith Ray via swift-evolution >>> <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: >>> >>> How many "subclass must override" assertions or comments in base class >>> methods do we need to see, to want to add "abstract" to the Swift language? >>> 5? 50? 500? >>> >>> It's a not uncommon idiom in Objective-C. >>> >>> I'm about to port a substantial amount of C++ code to swift, and compiler >>> help to enforce abstract classes would be very useful. >>> >>> >>> -- >>> C. Keith Ray >>> Senior Software Engineer / Trainer / Agile Coach >>> * http://www.thirdfoundationsw.com/keith_ray_resume_2014_long.pdf >>> <http://www.thirdfoundationsw.com/keith_ray_resume_2014_long.pdf> >>> >>> >>> >>> _______________________________________________ >>> 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 > https://lists.swift.org/mailman/listinfo/swift-evolution
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