> On Jun 10, 2016, at 4:20 PM, L. Mihalkovic <[email protected]> > wrote: > > I noticed that the "impacted" section was not updated to the new syntax.
apologies, I was looking at the last reference to Any, and it is indeed correct as it is. as for the grammar, I guess it is just a matter of removing the reference to protocol<> and swapping in the new & operator in composition types: GRAMMAR OF A PROTOCOL COMPOSITION TYPE <>protocol-composition-type → protocol<protocol-identifier-list <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier-list>opt> <>protocol-identifier-list → protocol-identifier <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier> protocol-identifier <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier>,protocol-identifier-list <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier-list> <>protocol-identifier → type-identifier <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/type-identifier> GRAMMAR OF A PROTOCOL COMPOSITION TYPE <>protocol-composition-type → protocol-identifier-list <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier-list> <>protocol-identifier-list → protocol-identifier <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier> protocol-identifier <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier>&protocol-identifier-list <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/protocol-identifier-list> <>protocol-identifier → type-identifier <https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html#//apple_ref/swift/grammar/type-identifier> In this form there is the problem of the degenerate case where protocol-identifier-list is empty which is required for Any. The syntax I have been playing with for generalized existential would degenerate fine for covering this gap. https://gist.github.com/lmihalkovic/8aa66542f5cc4592e967bade260477ef > Additionally it might be useful to show the impact on the grammar. > Regards > (From mobile) > On Jun 2, 2016, at 7:42 AM, Austin Zheng via swift-evolution > <[email protected] <mailto:[email protected]>> wrote: > >> Excellent. >> >> I put together a PR with a revised proposal containing the core team's >> recommended approach. If anyone is curious they can see it here: >> https://github.com/austinzheng/swift-evolution/blob/ef6adbe0fe09bff6c44c6aa9d73ee407629235ce/proposals/0095-any-as-existential.md >> >> <https://github.com/austinzheng/swift-evolution/blob/ef6adbe0fe09bff6c44c6aa9d73ee407629235ce/proposals/0095-any-as-existential.md> >> >> Since this is the de-facto second round discussion thread, I'll start with >> my personal opinion (which is *not* reflected in the PR): the '&' separators >> in lieu of commas are a good idea, but I would still prefer the types to be >> wrapped in "Any<>", at least when being used as existentials. >> >> My reasons: >> >> - Jordan Rose brought up a good point in one of the discussion threads >> today: a resilience goal is to allow a library to add an associated type to >> a protocol that had none and not have it break user code. If this is true >> whatever syntax is used for existentials in Swift 3 should be a valid subset >> of the generalized existential syntax used to describe protocol compositions >> with no associated types. >> >> - I would rather have "Any<>" be used consistently across all existential >> types eventually than have it only be used for (e.g.) existential types with >> `where` constraints, or allowing two different representations of the same >> existential type (one with Any, and one without). >> >> - I think any generalized existential syntax without delimiting markers >> (like angle braces) is harder to read than syntax with such markers, so I >> would prefer a design with those markers. >> >> Best, >> Austin >> >>> On Jun 1, 2016, at 10:17 PM, Chris Lattner <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> >>>> On Jun 1, 2016, at 9:53 PM, Austin Zheng <[email protected] >>>> <mailto:[email protected]>> wrote: >>>> >>>> This was indeed a very thorough review by the core team. I'll prepare a v2 >>>> proposal with this feedback taken into account so we can continue moving >>>> things along. >>>> >>>> One quick question - is making whatever syntax is chosen for Swift 3 >>>> "forward-compatible" with a future generalized existential feature a >>>> concern? >>> >>> Yes it is a concern, but we assume that the “X & Y” syntax will always be >>> accepted going forward, as sugar for the more general feature that is yet >>> to be designed. >>> >>> -Chris >> >> _______________________________________________ >> 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>
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