<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>I'm not sure this is even possible (at least on x86/ARM), but could we do something like how the Mill CPU handles errors?</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">If you're not familiar with it, my understanding is that it just ignores errors (and cascades them through operations) until you try to write the invalid value to memory, at which point the exception is raised.<br><br>Seems like, in principle anyway, if Swift supported pure functions, the compiler could just silently propagate the nil until you try to store it in a non-optional variable, at which point you'd get the standard "didn't unwrap optional" error.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">Like I said, I'm not sure this is even possible for compiled code, if the target platform doesn't have hardware support for it anyway.<br><br>Sent from my iPhone</div><div><br>On Jan 28, 2016, at 20:38, Craig Cruden via swift-evolution <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=utf-8"><div class=""><br class=""></div><blockquote type="cite" class=""><div dir="ltr" class=""><div class=""> manager.doSomething(data: data, count: n?)</div></div></blockquote><div class=""><br class=""></div>What if the return value of doSomething is not an optional? Expressions are easy — but there might be some conflicts with this one.<div class=""><br class=""><div class=""><div dir="ltr" class=""><div class=""><br class=""></div></div></div><div><blockquote type="cite" class=""><div class="">On 2016-01-28, at 14:34:58, Jacob Bandes-Storch 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 dir="ltr" class="">I've wanted this sort of thing a lot. It would also work for other functions, such as<div class=""><br class=""></div><div class=""> manager.doSomething(data: data, count: n?)</div><div class=""><br class=""></div><div class="">which is equivalent to</div><div class=""><br class=""></div><div class=""> n.map { manager.doSomething(data: data, count: $0) }</div><div class="gmail_extra"><br class=""></div><div class="gmail_extra">It might be hard to see exactly which operator/function applications such a thing applies to, if used in the context of a complex expression.</div><div class="gmail_extra"><br clear="all" class=""><div class=""><div class="gmail_signature"><div dir="ltr" class=""><div class="">Jacob<br class=""></div></div></div></div>
<br class=""><div class="gmail_quote">On Wed, Jan 27, 2016 at 9:50 PM, Paul Ossenbruggen via swift-evolution <span dir="ltr" class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>></span> wrote:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class="">Maybe something like this?<div class=""><br class=""></div><div class=""><span class=""><div class=""><div style="margin:0px;line-height:normal;font-family:Menlo" class=""><span style="color:#bb2ca2" class="">let</span> n : <span style="color:#703daa" class="">Int</span>? = <span style="color:#272ad8" class="">5</span></div><div class=""><span style="color:#272ad8" class=""><br class=""></span></div></div></span><div class=""><div style="margin:0px;line-height:normal;font-family:Menlo" class=""><span style="color:#bb2ca2" class="">let</span> r = <span style="color:#4f8187" class="">n</span>? + <span style="color:#272ad8" class="">5</span></div><div class=""><span style="color:#272ad8" class=""><br class=""></span></div><div class=""><span style="color:#272ad8" class=""><br class=""></span></div></div><div class=""><div class="h5"><div class=""><blockquote type="cite" class=""><div class="">On Jan 27, 2016, at 9:46 PM, Thorsten Seitz <<a href="mailto:tseitz42@icloud.com" target="_blank" class="">tseitz42@icloud.com</a>> wrote:</div><br class=""><div class=""><div dir="auto" class=""><div class=""></div><div class="">Too much hidden magic IMO. This would mean loosing the benefits of optionals, i.e. making explicit where optional cases occur and that handling the missing case has to be considered. </div><div class=""><br class=""></div><div class="">-Thorsten </div><div class=""><br class="">Am 28.01.2016 um 06:30 schrieb Craig Cruden via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>>:<br class=""><br class=""></div><blockquote type="cite" class=""><div class="">Yes<br class=""><div class=""><blockquote type="cite" class=""><div class="">On 2016-01-28, at 12:28:40, Paul Ossenbruggen <<a href="mailto:possen@gmail.com" target="_blank" class="">possen@gmail.com</a>> wrote:</div><br class=""><div class=""><div style="word-wrap:break-word" class="">Trying to see if I got this. So the type of r would be Int? at the end of this? And if n were nil then r would be nil? Otherwise it r is 10?<div class=""><br class=""></div><div class=""><div class=""><br class=""></div><div class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Jan 27, 2016, at 9:19 PM, Craig Cruden via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:</div><br class=""><div class=""><div style="word-wrap:break-word" class="">Swift currently encourages a lot of conditional code - especially when it comes to optionals. In most cases when you are computing etc. on an Optional you would expect that you would want an optional result and things to be able to use optionals. <div class=""><br class=""></div><div class="">In another language I generally just `map` one optional to another - which may not be the most readable code to some not use to optionals. </div><div class=""><br class=""></div><div class="">I was wondering if maybe an expression is not available that it would rewrite the syntax to map from one to another value. </div><div class=""><br class=""></div><div class="">So things like:</div><div class=""><br class=""></div><div class="">let n : Int? = 5</div><div class=""><br class=""></div><div class="">let r = n + 5</div><div class=""><br class=""></div><div class="">would actually compile as </div><div class=""><br class=""></div><div class="">let r = n.map <span style="font-family:Menlo;font-size:11px" class="">{$0 + </span><span style="font-family:Menlo;font-size:11px;color:rgb(39,42,216)" class="">5</span><span style="font-family:Menlo;font-size:11px" class="">}</span></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></div></div></div></blockquote></div><br class=""></div></blockquote><blockquote type="cite" class=""><div class=""><span class="">_______________________________________________</span><br class=""><span class="">swift-evolution mailing list</span><br class=""><span class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a></span><br class=""><span class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br class=""></div></blockquote></div></div></blockquote></div><br class=""></div></div></div></div><br class="">_______________________________________________<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" rel="noreferrer" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class="">
<br class=""></blockquote></div><br class=""></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">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>swift-evolution mailing list</span><br><span><a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a></span><br><span><a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br></div></blockquote></body></html>