<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body><div>I think I get where you are going. But I'm not going to drop it quite that easily. Forgive my insolence but I still think there is room for a sane default here.<br></div>
<div> </div>
<div>To answer your question: it is an enum that deliberately does not start at 0. If Swift made that the default import symantics then I think all the cases you covered (selfishly even my case) would be adequately addressable.<br></div>
<div> </div>
<div>Lets say there are, at least, 3 types of enums:<br></div>
<ol><li>A non-overlapping, non-option set enum<br></li><li>A non-overlapping option set</li><li>An overlapping option set<br></li></ol><div> </div>
<div>In this case, I'd say the enum was of type 2; a non-overlapping option set. If it was something the developer needed to conform to the `OptionSetType` then the developer who imported the type could provide a simple extension to the enum that provides conformance with the `OptionSetType`. Voila. Now it is an option set.<br></div>
<div> </div>
<div>More concretely:<br></div>
<div> </div>
<div> enum Foo: Int {<br></div>
<div> case A = 1<br></div>
<div> case B = 2<br></div>
<div> }<br></div>
<div> </div>
<div> // Not automatic but available in this hypothetical world<br></div>
<div> extension Foo: OptionSetType {<br></div>
<div> init(rawValue: Int) {<br></div>
<div> self = Foo.init(rawValue: rawValue) ?? Foo.A<br></div>
<div> }<br></div>
<div> }<br></div>
<div> </div>
<div>If it was really some sort of constant then now it can be accessed via it's `rawValue` property (isn't that the way it would be accessed as it currently stands?).<br></div>
<div> </div>
<div>If it was just an enum, well then that's covered too.<br></div>
<div> </div>
<div>I tried compiling a few contrived enums based on this one to illustrate how I'd expect them to be mapped. <a href="https://gist.github.com/anonymous/232d62d77999f5eb27cd">I've put them into this gist</a>.<br></div>
<div> </div>
<div>I think if you took it in terms of pattern matching where the the first case is the strictest pattern (and thus the hardest to conform to) by the time you reach the 3rd case your back to the current behavior. Swift would then be able to account for more generic enum imports than it currently can.<br></div>
<div> </div>
<div>On Mon, Jan 11, 2016, at 02:51 PM, Jordan Rose wrote:<br></div>
<blockquote type="cite"><div>Oh, you can certainly define a macro named NS_ENUM yourself, but that doesn't really seem like the right thing to do on Linux.<br></div>
<div> </div>
<div>As for why we can't "guess" that this is a true enum, consider the following:<br></div>
<div> </div>
<blockquote style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:40px;border-top-style:none;border-right-style:none;border-bottom-style:none;border-left-style:none;border-top-width:initial;border-right-width:initial;border-bottom-width:initial;border-left-width:initial;border-top-color:initial;border-right-color:initial;border-bottom-color:initial;border-left-color:initial;border-image-source:initial;border-image-slice:initial;border-image-width:initial;border-image-outset:initial;border-image-repeat:initial;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;"><div>enum Foo {<br></div>
<div> A = 1,<br></div>
<div> B = 2,<br></div>
<div>};<br></div>
</blockquote><div> </div>
<div>Is this a very small option set, or an enum that deliberately doesn't start at 0? Or just a way to define constants for some other type, rather than using "static const"? If the compiler guesses here, (a) it might guess wrong, making the type hard to use <i>now,</i> and (b) if the headers are updated in a newer version of the library, it might <i>change</i> its guess, which would break source compatibility. (This can happen anyway, e.g. the first time an annotation is added, but at least that's supposed to be changing in the right direction, and is unlikely to change again.)<br></div>
<div> </div>
<div>Hope that clarifies the motivation here, even if it's less than satisfactory.<br></div>
<div> </div>
<div>Jordan<br></div>
<div> </div>
<div> </div>
<div><blockquote type="cite"><div>On Jan 11, 2016, at 11:22, Ryan Lovelett <<a href="mailto:swift-dev@ryan.lovelett.me">swift-dev@ryan.lovelett.me</a>> wrote:<br></div>
<div> </div>
<div><div><div>Jordan,<br></div>
<div> </div>
<div>Perhaps I'm not following that parenthetical comment. Are you saying that even if I could add <span class="highlight" style="background-color: rgb(255, 255, 255)"><span style=""><span class="font" style="font-family:Menlo, monospace"><span class="size" style="font-size:12px">NS_ENUM </span></span></span></span>to the header it still wouldn't compile into a true Swift enum (on a non-Apple platform)?<br></div>
<div> </div>
<div>Swift's pattern matching capability is probably a top 3 reason why I am trying to port my C application to use Swift rather than just straight C. Not being able to get this nicety out-of-the-box is just part of doing business on a bleeding edge programming language.<br></div>
<div> </div>
<div>However this <i>seems</i> like something that should be able to be achieved. Looking at the fe_type enum definition, because it had no bit pattern associated with it, I would have assumed it was a true non-overlapping enum. Its probable I'm not seeing the whole landscape here so would you be able to illuminate why isn't this the default?<br></div>
<div> </div>
<div>On Mon, Jan 11, 2016, at 01:11 PM, Jordan Rose wrote:<br></div>
<blockquote type="cite"><div>Right. This is because Swift can't tell if your enum is actually an option set, a true, non-overlapping enum, or just a set of related constants, so it picks the lowest common denominator. We currently don't have a great way to override that in headers you don't control.<br></div>
<div> </div>
<div>(Heck, on non-Apple platforms we don't have a great way to do it in headers you do control; Swift is currently keying off the macro names.)<br></div>
<div> </div>
<div>Jordan<br></div>
<div> </div>
<div><blockquote type="cite"><div>On Jan 10, 2016, at 13:25 , Austin Zheng via swift-dev <<a href="mailto:swift-dev@swift.org">swift-dev@swift.org</a>> wrote:<br></div>
<div> </div>
<div><div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px">I spoke too soon, the cases are also defined as values of that type. So, a working version of your code:</span></span><br></div>
<div style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;orphans:auto;text-align:start;text-indent:0px;text-transform:none;white-space:normal;widows:auto;word-spacing:0px;-webkit-text-stroke-width:0px;"> </div>
<div style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;orphans:auto;text-align:start;text-indent:0px;text-transform:none;white-space:normal;widows:auto;word-spacing:0px;-webkit-text-stroke-width:0px;"><div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(112, 61, 170);"><span class="colour" style="color:rgb(187, 44, 162)">extension</span><span style=""><span></span></span><span class="colour" style="color:rgb(79, 129, 135)">fe_type</span><span style=""><span></span>:<span></span></span>CustomStringConvertible<span style=""><span></span>{</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;"><span></span><span class="colour" style="color:rgb(187, 44, 162)">public</span><span></span><span class="colour" style="color:rgb(187, 44, 162)">var</span><span></span>description:<span></span><span class="colour" style="color:rgb(112, 61, 170)">String</span><span></span>{<br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(187, 44, 162);"><span style=""><span></span></span>switch<span style=""><span></span></span>self<span style=""><span></span>{</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(187, 44, 162);"><span style=""><span></span></span>case<span style=""><span></span></span><span class="colour" style="color:rgb(79, 129, 135)">FE_QPSK</span><span style="">:<span></span></span>return<span style=""><span></span></span><span class="colour" style="color:rgb(209, 47, 27)">"QPSK"</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(187, 44, 162);"><span style=""><span></span></span>case<span style=""><span></span></span><span class="colour" style="color:rgb(79, 129, 135)">FE_QAM</span><span style="">:<span></span></span>return<span style=""><span></span></span><span class="colour" style="color:rgb(209, 47, 27)">"QAM"</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(187, 44, 162);"><span style=""><span></span></span>case<span style=""><span></span></span><span class="colour" style="color:rgb(79, 129, 135)">FE_OFDM</span><span style="">:<span></span></span>return<span style=""><span></span></span><span class="colour" style="color:rgb(209, 47, 27)">"OFDM"</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(187, 44, 162);"><span style=""><span></span></span>case<span style=""><span></span></span><span class="colour" style="color:rgb(79, 129, 135)">FE_ATSC</span><span style="">:<span></span></span>return<span style=""><span></span></span><span class="colour" style="color:rgb(209, 47, 27)">"ATSC"</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(209, 47, 27);"><span style=""><span></span></span><span class="colour" style="color:rgb(187, 44, 162)">default</span><span style="">:<span></span></span><span class="colour" style="color:rgb(61, 29, 129)">fatalError</span><span style="">(</span>"can't be exhaustive"<span style="">)</span><br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;"> }<br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;"> }<br></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;font-size:14px;line-height:normal;font-family:Menlo;">}<br></div>
<div> </div>
<div>Best,<br></div>
<div>Austin<br></div>
<div><div> </div>
<div><blockquote type="cite"><div>On Jan 10, 2016, at 1:22 PM, Austin Zheng <<a href="mailto:austinzheng@gmail.com">austinzheng@gmail.com</a>> wrote:<br></div>
<div> </div>
<div><div style="word-wrap:break-word;-webkit-line-break:after-white-space;"><div>Hi Ryan,<br></div>
<div> </div>
<div>Apologies, I should have been more clear. In Xcode you can alt(?)-click on a type (e.g the 'MyType' in "let a : MyType = 123") in the IDE to pop up a little window that shows you the definition, including the type and some other information. If you're on a Linux box or not using an IDE you probably don't have that option.<br></div>
<div> </div>
<div>The only methods I see exposed on the Swift imported type are initializers taking a integer raw value, and a 'rawValue' property for getting back out the raw value. Hope that helps.<br></div>
<div> </div>
<div>Austin<br></div>
<div> </div>
<div><blockquote type="cite"><div>On Jan 10, 2016, at 1:18 PM, Ryan Lovelett <<a href="mailto:swift-dev@ryan.lovelett.me">swift-dev@ryan.lovelett.me</a>> wrote:<br></div>
<div> </div>
<div><div><div>Austin,<br></div>
<div> </div>
<div>I guess I should say that the `typedef` is coming from a<span></span><a href="http://lxr.free-electrons.com/source/include/linux/dvb/frontend.h?v=3.2">Linux kernel header</a>. So I don't think I'm going to be able to add any macros to the definition.<br></div>
<div> </div>
<div>What do you mean about alt-click? Alt click where?<br></div>
<div> </div>
<div>On Sun, Jan 10, 2016, at 04:12 PM, Austin Zheng wrote:<br></div>
<blockquote type="cite"><div>fe_type is being imported as a struct (alt-click 'fe_type' in Swift). I think if you want it to be imported as an enum you need to use the NS_ENUM macro in the definition, which might not be possible in your case.<br></div>
<div> </div>
<div><div>Austin<br></div>
<div><div> </div>
<div><blockquote type="cite"><div>On Jan 10, 2016, at 1:06 PM, Ryan Lovelett via swift-dev <<a href="mailto:swift-dev@swift.org">swift-dev@swift.org</a>> wrote:<br></div>
<div> </div>
<div><div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px">typedef enum fe_type {</span></span><br></div>
<div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px"> FE_QPSK,</span></span><br></div>
<div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px"> FE_QAM,</span></span><br></div>
<div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px"> FE_OFDM,</span></span><br></div>
<div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px"> FE_ATSC</span></span><br></div>
<div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px">} fe_type_t;</span></span><br></div>
</div>
</blockquote></div>
</div>
</div>
</blockquote><div> </div>
</div>
</div>
</blockquote></div>
<div> </div>
</div>
</div>
</blockquote></div>
<div> </div>
</div>
</div>
<div><img src="https://www.fastmailusercontent.com/proxy/476b66b528f8dcfeaaf5c65def73bb0d6bcc943cc820fb9c858abeda082f79c1/8647470737a3f2f2777777e266163747d61696c65737562736f6e64756e647e236f6d6f20727f68797f256362353236373568303162393661363231373938366136603464333833366531646933303265346735336739323836326530343731313033333939303333336f283634373437303733373163366236623537323330333033323334333133303335623336343735623337353635663436373632373936343635623566353634373662373736363662366630373536356636633537303735663463316535343167343331373834393535663835383630353237333332363234303535373462323336343837303534333437356433333834363637353264336434623233363434373164303731373266313530333736326636643635333531343165303333353664346439363435353337343435393634373037313533353234343736643835383731363736366438333233323634643733346635333566316739353364336632663164343433333166336433363037363434373264363732643136353734643534383635333334323335373833313738353733373635353167316530333434333436373836313533643134373634623233323436343137353538363037323635333635346636333934346639373733393630373266303531363666323737363635373331343437313736333462323336343434313333373462323332343136333434343266346232333234353434373334326631363033316534363736373434373633343436643537346232333234333735663462323336343534316538333164313436353137373638333534363331343666393537333233353731663333343639363833346632363235313334353237373636343466363632373836313332363233373332353464393437343334393531373335383534663635373333363635303533363936373639363664356639343462333334343f2f60756e6/open" alt="" width="1" height="1" border="0" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;orphans:auto;text-align:start;text-indent:0px;text-transform:none;white-space:normal;widows:auto;word-spacing:0px;-webkit-text-stroke-width:0px;height:1px !important;width:1px !important;border-top-width:0px !important;border-right-width:0px !important;border-bottom-width:0px !important;border-left-width:0px !important;margin-top:0px !important;margin-right:0px !important;margin-bottom:0px !important;margin-left:0px !important;padding-top:0px !important;padding-right:0px !important;padding-bottom:0px !important;padding-left:0px !important;" ><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px"><span></span></span></span><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px">_______________________________________________</span></span><br></div>
<div><span class="font" style="font-family:Helvetica"><span class="size" style="font-size:12px">swift-dev mailing list</span></span><br></div>
<div><a href="mailto:swift-dev@swift.org" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;orphans:auto;text-align:start;text-indent:0px;text-transform:none;white-space:normal;widows:auto;word-spacing:0px;-webkit-text-stroke-width:0px;">swift-dev@swift.org</a><br></div>
<div><a href="https://lists.swift.org/mailman/listinfo/swift-dev" style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;orphans:auto;text-align:start;text-indent:0px;text-transform:none;white-space:normal;widows:auto;word-spacing:0px;-webkit-text-stroke-width:0px;">https://lists.swift.org/mailman/listinfo/swift-dev</a><br></div>
</div>
</blockquote></div>
</blockquote><div> </div>
</div>
</div>
</blockquote></div>
</blockquote><div> </div>
</body>
</html>