<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><br class=""></div><br class=""><div><blockquote type="cite" class=""><div class="">On Jul 5, 2016, at 7:42 PM, Xi Ge via swift-dev <<a href="mailto:swift-dev@swift.org" class="">swift-dev@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="font-family: Palatino-Roman; font-size: 14px; font-style: normal; font-variant-caps: 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;" class=""><blockquote type="cite" class=""><div class=""><br class="Apple-interchange-newline">On Jul 5, 2016, at 5:39 PM, Xi Ge via swift-dev <<a href="mailto:swift-dev@swift.org" class="">swift-dev@swift.org</a>> wrote:</div><div class=""><br class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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 class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: 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;"><blockquote type="cite" class=""><div class="">On Jul 5, 2016, at 5:19 PM, Ben Langmuir <<a href="mailto:blangmuir@apple.com" class="">blangmuir@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><blockquote type="cite" class="" style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: 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 class=""><br class="Apple-interchange-newline">On Jul 5, 2016, at 4:34 PM, Xi Ge via swift-dev <<a href="mailto:swift-dev@swift.org" class="">swift-dev@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><span id="docs-internal-guid-d07b8252-bd62-362d-862c-7fd88323b9e5" class=""><div class="" style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;"><span class="" style="font-size: 14.666666666666666px; font-family: Arial; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; vertical-align: baseline; white-space: pre-wrap;">Hi Swift-devs,</span></div><div class="" style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;"><span class="" style="font-size: 14.666666666666666px; font-family: Arial; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; vertical-align: baseline; white-space: pre-wrap;">I have tried to add a fixit to help developers using trailing closures more, motivated by my observation during WWDC that some developers </span></div><div class="" style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;"><span class="" style="font-size: 14.666666666666666px; font-family: Arial; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; vertical-align: baseline; white-space: pre-wrap;">do not even realize that we have such a feature. In my opinion, trailing closures are more concise, and once you get used to it, more readable; </span></div><div class="" style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;"><span class="" style="font-size: 14.666666666666666px; font-family: Arial; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; vertical-align: baseline; white-space: pre-wrap;">therefore users should adopt trailing closures whenever doing so introduces no ambiguity.</span></div></span></div></div></blockquote></div></blockquote></div></div></blockquote></div></div></blockquote></div><br class=""><div class=""><br class=""></div><div class="">I prefer trailing closures for -> Void signatures and in-line closures for anything (notably sequences and collections) that is likely to be iterated through or chained functionally. I also prefer inline closures for items that have multiple states for callback (completion handlers, error handlers, etc, where there is going to be a test of some kind -- we don't have a Result type but if we did, it would fall here -- and contains error/value pairs) and trailing closures for no-state-will-execute such as GCD.</div><div class=""><br class=""></div><div class="">-- E</div><div class=""><br class=""></div></body></html>