<div dir="ltr">What about it?<div><br></div><div>"x ?? false" is simple. If x isn't nil, return x; if x is nil, return false.</div><div>"x?.isEmpty ?? false" again is already readable; if x isn't nil, return x.isEmpty; if x is nil, return false.</div><div><br></div><div><div>"Bool(x?.isEmpty)" seems be suggesting that the Bool type has a failable initialiser "init?(_: Bool?)". If x is nil, x.isEmpty would be nil, so the resulting Bool would be nil, not false - this code returns a Bool?, which you already had.</div></div><div><br></div><div>"??(false, x?.isEmpty)" ... uses an operator as an identifier, for a start. At best I'd try to interpret this like reduce - take a collection or variadic list of optionals, return the value of the first non-nil else return the "default". Except I'd still put the default at the end, because I can't think why it would be at the start.</div><div><br></div><div>So, if the given problem is taking the nil-coalescing and putting it up front, perhaps there should be a global generic function:</div><div><br></div><div>func firstNonOptional<T>(possibles:T?..., failsafe:T) -> T</div><div>{</div><div> return possibles.reduce(nil, combine:{ $0 ?? $1 }) ?? failsafe</div><div>}</div><div><br></div><div> <br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jan 29, 2016 at 1:48 PM, Amir Michail 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>On Jan 29, 2016, at 8:42 AM, Craig Cruden <<a href="mailto:ccruden@novafore.com" target="_blank">ccruden@novafore.com</a>> wrote:</div><br><div><div style="word-wrap:break-word">still much worse.<div><br></div></div></div></blockquote><div><br></div><div>What about: Bool(x?.isEmpty) // nil and false => false</div><div><div class="h5"><br><blockquote type="cite"><div><div style="word-wrap:break-word"><div><br><div><blockquote type="cite"><div>On 2016-01-29, at 20:41:06, Amir Michail via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</div><br><div><div style="word-wrap:break-word"><br><div><blockquote type="cite"><div>On Jan 29, 2016, at 5:03 AM, Thorsten Seitz <<a href="mailto:tseitz42@icloud.com" target="_blank">tseitz42@icloud.com</a>> wrote:</div><br><div><div><div>I agree with Erica. The ?? operator is very readable IMO.<br></div><div><br></div><div>Furthermore x?(false).isEmpty looks like it would evaluate false.isEmpty when x is nil which is certainly not what is intended.<br></div></div></div></blockquote><div><br></div><div>What about this then: ??(false, x?.isEmpty)</div><br><blockquote type="cite"><div><div><div>In addition it would not be clear which default should be used in case of multiple optional chainings happening, i.e. what should be the result of person?(false).address?.(true).isEmpty<br></div><div><br></div><div>-Thorsten</div><div><br></div><div><br>Am 26. Januar 2016 um 03:29 schrieb Erica Sadun via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>>:<br><br><div><blockquote type="cite"><div><div><span>Not loving this. I'm quite happy with ??-coalescing and don't see<br>a compelling reason it needs to be "cleaner". I find your suggested<br>enhancement less readable. Looks like an optional chaining across <br>a function.<br><br>-- E<br><br><blockquote type="cite">On Jan 25, 2016, at 7:03 PM, Amir Michail via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Examples:</blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">* instead of x ?? false, you would have x?(false)</blockquote><blockquote type="cite">* instead of x?.isEmpty ?? false, you would have x?(false).isEmpty</blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I think this change would result in cleaner looking code.</blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_______________________________________________</blockquote><blockquote type="cite">swift-evolution mailing list</blockquote><blockquote type="cite"><a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a><br></blockquote><blockquote type="cite"><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br></blockquote><br>_______________________________________________<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/mailman/listinfo/swift-evolution</a><br></span></div></div></blockquote></div></div></div></div></blockquote></div><br></div>_______________________________________________<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/mailman/listinfo/swift-evolution</a><br></div></blockquote></div><br></div></div></div></blockquote></div></div></div><br></div><br>_______________________________________________<br>
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