On Jun 16, 2015, at 00:34 , Roland King <r...@rols.org> wrote: > > I think Protocol Extensions are the power feature to Swift this year
Yes, though I’ve been trying to convert a fair-sized app, and I ran into a conceptual difficulty when a protocol has a Self constraint. In essence, a Self constraint prevents a protocol from being used like a base class. This shows up quickly when (say) you try to construct a Set<MyProtocol> which is going to contain various types that are unified only by MyProtocol. The underlying Set class has to Hashable, which means its also Equatable, which has a Self requirement to ensure that two objects being compared by == are of the same type. You’d see this problem with the example in that video if you tried to make the SegueIdentifier protocol Hashable or Equatable. Other really good features: value-type programming, and the ‘guard’ statement, which is much better in use than you’d expect. The other major problem I ran into — unrelated, but I’m mentioning it in case someone wants to jump in and tell me the easy way — is that I’m trying to use frameworks in order to break the project into modules so that I can use the access controls (private and internal) to keep implementation details of related groups of files out of the grasp of unrelated code. This is in a cross-platform (OS X, iOS) project with shared code. Since the different platforms need different frameworks, and the frameworks/modules have to have different names to tell them apart, I can’t share source code files across platforms because of the “import” statements. Maybe I’m missing something obvious here. > And now I know what Kyle looks like too! What’s the video? _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
