<div dir="ltr"><div>These are a couple comments from Chris Lattner that come to mind</div><div><br></div><div>"FWIW, this has been discussed before on swift-evolution. Adding them isn’t out of the question, but it is a lot more complicated than it looks for the type checker."</div><div><br></div><div>"Here is my concern: Swift enums should be good enough that we don’t need an Either type. If defining your own custom enum is hard or bad, then we should fix that.</div><div><br></div><div>There are a number of concepts floating around that would make enums better in various ways. One specific one would be to synthesize optional accessors that line up with enum cases."</div><div>- in "Either in the Swift Standard Library"</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Aug 17, 2016 at 7:06 PM, Karl via swift-evolution <span dir="ltr"><<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><br><div><blockquote type="cite"><div><div class="h5"><div>On 11 Aug 2016, at 07:18, Chris Lattner via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</div><br></div></div><div><div><div class="h5"><div style="word-wrap:break-word"><br><div><blockquote type="cite"><div>On Aug 10, 2016, at 8:15 PM, Xiaodi Wu via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</div><br><div>I don't know if the core team feels differently now with respect to Swift 4, but union types are listed as a "commonly rejected change":<br><br><a href="https://github.com/apple/swift-evolution/blob/master/commonly_proposed.md" target="_blank">https://github.com/apple/<wbr>swift-evolution/blob/master/<wbr>commonly_proposed.md</a><br></div></blockquote></div><br><div>There is no change in opinion here. This topic is also out of scope for Swift 4 stage 1 in any case.</div><div><br></div><div>-Chris</div></div></div></div><span class="">______________________________<wbr>_________________<br>swift-evolution mailing list<br><a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a><br><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank">https://lists.swift.org/<wbr>mailman/listinfo/swift-<wbr>evolution</a><br></span></div></blockquote></div><br><div>While I appreciate if you don’t want to reply, given the way the tone of this discussion seems to have turned:</div><div><br></div><div>The section on this topic in the “commonly-proposed” section could use some elaborating. On the face of it, it seems like a handy feature, and I’m sure many would like to know (now and in the future) why the core-team feels this way. Only then can they properly judge when circumstances may have changed, and if/when to raise the issue again.</div><div><br></div><div>Thanks</div><div><br></div><div>Karl</div></div><br>______________________________<wbr>_________________<br>
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