<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On May 10, 2016, at 8:46 PM, Eduardo Mourey Lopez Ne <<a href="mailto:edmourey@icloud.com" class="">edmourey@icloud.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Chris<div class=""><br class=""></div><div class="">I do agree that it is incosistent that case works in an if but you can’t assign it to a bool.</div></div></div></blockquote><div><br class=""></div>Not to me. I can understand why you would think about it that way, but the let in “if let” is not assignable to a bool either. Nor is #available.</div><div><br class=""></div><div>-Chris<br class=""><div><br class=""></div><div><br class=""></div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">enum</span><span style="font-variant-ligatures: no-common-ligatures" class=""> Bar {</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> foo(name: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> notFoo</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> unknownFoo</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">}</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">var</span><span style="font-variant-ligatures: no-common-ligatures" class=""> xx = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">Bar</span><span style="font-variant-ligatures: no-common-ligatures" class="">.</span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">foo</span><span style="font-variant-ligatures: no-common-ligatures" class="">(name: </span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"Hello"</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">if</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> Bar.</span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">foo</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> name) = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">xx</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">where</span><span style="font-variant-ligatures: no-common-ligatures" class=""> name == </span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"Hello”</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { //This work ok</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">print</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"Hola"</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">}</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">var</span><span style="font-variant-ligatures: no-common-ligatures" class=""> bool = </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> Bar.foo(</span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> name) = xx </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">where</span><span style="font-variant-ligatures: no-common-ligatures" class=""> name == </span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">“Hello” </span>//But this doesn’t ???</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class="">//The other problem that I see is that the var “xx” seems to get lost int case by having it in the middle</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class="">//I think it will be better to have an alternative keyword for a single case, like ‘match’ that allows the variable</div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class="">//to be at the begging </div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class="">//This looks much better </div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">var</span><span style="font-variant-ligatures: no-common-ligatures" class=""> bool = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">xx</span><span style="font-variant-ligatures: no-common-ligatures" class=""> match </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">Bar</span><span style="font-variant-ligatures: no-common-ligatures" class="">.foo(</span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> name) </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">where</span><span style="font-variant-ligatures: no-common-ligatures" class=""> name == </span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">“Hello”</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class=""><br class=""></span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class=""><br class=""></span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">Thanks</span></div><div class=""><blockquote type="cite" class=""><div class="">On May 10, 2016, at 10:31 PM, Chris Lattner via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On May 10, 2016, at 4:33 AM, Sam Dods via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">I propose that <font face="Menlo" class=""><b class="">(case .Foo = bar)</b></font> should be treated as an expression with a Boolean value, so the result can be set to a variable or returned from a method.</div></div></div></blockquote><div class=""><br class=""></div><div class="">I agree that this is an important use case that Swift doesn’t serve well right now, but I don’t think this is the right way to go. </div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">Considering the following enumeration:</div><div class=""><br class=""></div><div class=""><font face="Menlo" class=""><b class="">enum Bar {</b></font></div><div class=""><font face="Menlo" class=""><b class=""> case foo(name: String)</b></font></div><div class=""><font face="Menlo" class=""><b class=""> case notFoo</b></font></div><div class=""><font face="Menlo" class=""><b class=""> case unknownFoo</b></font></div><div class=""><font face="Menlo" class=""><b class="">}</b></font></div></div></div></blockquote><div class=""><br class=""></div><div class="">One of the things we’ve discussed in the past is that we could have enums automatically “synthesize” instance members for projecting cases as optional values or bools. For example, the above enum could be compiled into the equivalent of:</div><div class=""><br class=""></div><div class="">extension Bar {</div><div class=""> func getAsFoo() -> String? { … }</div><div class=""> var isNotFoo : Bool { … }</div><div class=""> var isUnknownFoo : Bool { … }</div><div class="">}</div><div class=""><br class=""></div><div class="">Then you could just use:</div><div class=""><br class=""></div><div class=""> if someBar.isUnknownFoo { … }</div><div class=""> if someBar.isFoo != nil { … }</div><div class=""> if let name = someBar. getAsFoo() {... }</div><div class=""> someBar. getAsFoo()?.doThing() </div><div class=""><br class=""></div><div class="">etc. There is a question of naming, and getting the details right, of course.</div><div class=""><br class=""></div><div class="">-Chris</div></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></body></html>