I filled a bug report. https://bugs.swift.org/browse/SR-4811 <https://bugs.swift.org/browse/SR-4811>
> On May 5, 2017, at 9:38 AM, Jose Cheyo Jimenez <ch...@masters3d.com> wrote: > > >> On May 5, 2017, at 8:34 AM, Vladimir.S <sva...@gmail.com >> <mailto:sva...@gmail.com>> wrote: >> >> On 05.05.2017 6:12, Jose Cheyo Jimenez via swift-evolution wrote: >>> I can't think of a single time when I would need a tuple shuffle but I >>> don't really work with tuples much. It would be great to hear other >>> people's usage of this feature. >>> I did not know that types could be overloaded with values. That was very >>> surprising to me. Honestly I think that is the issue here. Not sure what >>> can be done about it. >> >>> let Int = 5 // works >>> let Void = "what?" // works. >> >> Very interesting. Could some one clarify, why this is allowed? Isn't this is >> a bug we want to fix? At least by requiring a tilda like `Int` >> And of course, you can't "overload" user defined type: >> struct S {} >> let S = 10 // Error: invalid redeclaration of ’S' > > What version of swift are you using? Could it be a regression? > > Welcome to Apple Swift version 3.1 (swiftlang-802.0.51 clang-802.0.41). Type > :help for assistance. > 1> struct S {} > 2> let S = 10 > S: Int = 10 > 3> print(S) > error: repl.swift:3:7: error: ambiguous use of 'S' > print(S) > ^ > > > >> >>> On May 4, 2017, at 7:14 PM, Robert Widmann via swift-evolution >>> <swift-evolution@swift.org <mailto:swift-evolution@swift.org> >>> <mailto:swift-evolution@swift.org <mailto:swift-evolution@swift.org>>> >>> wrote: >>>> Hi all, >>>> >>>> So sorry that this proposal comes so late in the game, but I feel it’s too >>>> important not to bring it to the attention of the community now. Attached >>>> is a proposal to deprecate a language feature many of you will probably >>>> have never had the chance to use: Tuple Shuffles. I’ve attached a copy of >>>> the first draft of the proposal below, but the latest copy can be read on >>>> Github <https://github.com/apple/swift-evolution/pull/705/files >>>> <https://github.com/apple/swift-evolution/pull/705/files>>. >>>> >>>> Thanks! >>>> >>>> ~Robert Widmann >>>> >>>> >>>> Deprecate Tuple Shuffles >>>> >>>> * Proposal: SE-NNNN >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-filename.md >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-filename.md>> >>>> * Authors: Robert Widmann <https://github.com/codafi >>>> <https://github.com/codafi>> >>>> * Review Manager: TBD >>>> * Status: Awaiting review >>>> >>>> >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#introduction >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#introduction>>Introduction >>>> >>>> This proposal seeks the deprecation of a little-known feature of Swift >>>> called a "Tuple Shuffle". >>>> >>>> >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#motivation >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#motivation>>Motivation >>>> >>>> A tuple-shuffle is an undocumented feature of Swift in which one can >>>> re-order the indices of a tuple by writing a pattern that describes a >>>> permutation in a syntax reminiscent of adding type-annotations to a >>>> parameter list: >>>> >>>> let a= (x:1,y:2) >>>> var b: (y:Int,x:Int) >>>> b= a >>>> >>>> It can be used to simultaneously destructure and reorder a tuple: >>>> >>>> let tuple= (first:0,second: (x:1,y:2)) >>>> let (second: (x: b,y: c),first: a)= tuple >>>> >>>> It can also be used to map parameter labels out of order in a call >>>> expression: >>>> >>>> func foo(_ : (x :Int, y :Int)) {} >>>> foo((y:5,x:10))// Valid >>>> >>>> Note that a tuple shuffle is distinct from a re-assignment through a tuple >>>> pattern. For example, this series of statements will continue to function >>>> as before: >>>> >>>> var x= 5 >>>> var y= 10 >>>> var z= 15 >>>> (z, y, x)= (x, z, y) >>>> >>>> Their inclusion in the language complicates every part of the compiler >>>> stack, uses a syntax that can be confused for type annotations >>>> <https://twitter.com/CodaFi_/status/860246169854894081 >>>> <https://twitter.com/CodaFi_/status/860246169854894081>>, contradicts the >>>> goals of earlier SE's (see SE-0060 >>>> <https://github.com/apple/swift-evolution/blob/9cf2685293108ea3efcbebb7ee6a8618b83d4a90/proposals/0060-defaulted-parameter-order.md >>>> >>>> <https://github.com/apple/swift-evolution/blob/9cf2685293108ea3efcbebb7ee6a8618b83d4a90/proposals/0060-defaulted-parameter-order.md>>), >>>> and makes non-sensical patterns possible in surprising places. >>>> >>>> Take switch-statements, for example: >>>> >>>> switch ((0,0),0){ >>>> case (_ :let (y, z),_ :let s): ()// We are forbidden from giving >>>> these patterns names other than "_" >>>> default: () >>>> } >>>> >>>> This proposal seeks to deprecate them in Swift 3 compatibility mode and >>>> enforce that deprecation as a hard error in Swift 4 to facilitate their >>>> eventual removal from the language. >>>> >>>> >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#proposed-solution >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#proposed-solution>>Proposed >>>> solution >>>> >>>> Construction of Tuple Shuffle Expressions will become a warning in Swift 3 >>>> compatibility mode and will be a hard-error in Swift 4. >>>> >>>> >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#detailed-design >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#detailed-design>>Detailed >>>> design >>>> >>>> In addition to the necessary diagnostics, the grammar will be ammended to >>>> simplify the following productions: >>>> >>>> tuple-pattern → (tuple-pattern-element-list <opt>) >>>> tuple-pattern-element-list → tuple-pattern-element | tuple-pattern-element >>>> , tuple-pattern-element-list >>>> - tuple-pattern-element → pattern | identifier:pattern >>>> + tuple-pattern-element → pattern >>>> >>>> >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#impact-on-existing-code >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#impact-on-existing-code>>Impact >>>> on Existing Code >>>> >>>> Because very little code is intentionally using Tuple Shuffles, impact on >>>> existing code will be negligible but not non-zero. >>>> >>>> >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#alternatives-considered >>>> >>>> <https://github.com/CodaFi/swift-evolution/blob/8eaf320b3c2a117909fc0269c398e89c033a4b9f/proposals/NNNN-deprecate-tuple-shuffles.md#alternatives-considered>>Alternatives >>>> considered >>>> >>>> Continue to keep the architecture in place to facilitate this feature. >>>> _______________________________________________ >>>> swift-evolution mailing list >>>> swift-evolution@swift.org <mailto:swift-evolution@swift.org> >>>> <mailto: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 <mailto:swift-evolution@swift.org> >>> https://lists.swift.org/mailman/listinfo/swift-evolution >
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