<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 Dec 19, 2015, at 1:41 PM, Dennis Lysenko <<a href="mailto:dennis.s.lysenko@gmail.com" class="">dennis.s.lysenko@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><p dir="ltr" class="">Shadowing is good in this case because it lets you capture constant values for the exact scope in which you need them.</p></div></blockquote><div>That is completely independent of shadowing. You do that even if you choose different names inside the block from outside.</div><blockquote type="cite" class=""><div class=""><p dir="ltr" class="">This helps avoid overhead of repeated getters and method calls. Using shorter names is automatically less descriptive; otherwise, people would advocate using abbreviations in property names, which is a stylistic and readability faux pas. </p></div></blockquote><div>"More descriptive" ≠ "more readable". When writing, we don't go into reams of detail about everything; we go into detail about the salient things. We have pronouns for a reason, e.g. "when a person arriving at the refrigerator opens the door, <u class="">she</u> sees what's inside; then <u class="">she</u> decides whether <u class="">she</u> wants it." "She" is a short name used in a localized context as a stand-in for a more-descriptive phrase, "a person arriving at the refrigerator". Repeating the more descriptive phrase would harm readability.</div><div><br class=""></div><blockquote type="cite" class=""><div class="">
<br class=""><div class="gmail_quote"><div dir="ltr" class="">On Sat, Dec 19, 2015, 4:34 PM Dennis Lysenko <<a href="mailto:dennis.s.lysenko@gmail.com" class="">dennis.s.lysenko@gmail.com</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><p dir="ltr" class="">Disagree. Short names are less descriptive and less readable. And saying "shadowing is bad" without any argument is just silly for a mailing list. </p>
<br class=""><div class="gmail_quote"><div dir="ltr" class="">On Sat, Dec 19, 2015, 3:57 PM Dave Abrahams via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:<br class=""></div><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=""><div class=""><blockquote type="cite" class=""><div class="">On Dec 19, 2015, at 12:37 PM, ilya 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="font-family:AvenirNext-Regular;font-size:14px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:pre-wrap" class="">I prefer <br class=""><br class="">if let vc = someInterestingViewConroller {<br class=""> vc.doSomething()<br class="">}<br class=""><br class="">- Explicit is better than implicit<br class="">- shadowing is bad <br class="">- now there's no ambiguity about how to change the original property. <br class=""><br class="">Therefore I'm -1 on any proposal that hides explicit name binding and/or increases shadowing, including let foo and unwrap foo. <br class=""></div></div></blockquote><div class=""><br class=""></div></div></div><div style="word-wrap:break-word" class=""><div class="">+1 to that. IMO re-using the same name for the unwrapped version of an optional variable does not help readability, and I don't want to encourage it. In a localized context like this, a short name is often better anyway as it declutters the code inside the block.</div></div><div style="word-wrap:break-word" class=""><div class=""><br class=""><blockquote type="cite" class=""><div class=""><br style="font-family:AvenirNext-Regular;font-size:14px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><div class="gmail_quote" style="font-family:AvenirNext-Regular;font-size:14px;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><div dir="ltr" class="">On Sat, Dec 19, 2015 at 21:31 Kevin Wooten via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="auto" class=""><div class="">As much fun as it to example with foo, I would argue the opposite when you use some real world variable names:</div><div class=""><br class=""></div><div class="">if let someInterestingViewConroller =<span class=""> </span><span style="background-color:rgba(255,255,255,0)" class="">someInterestingViewConroller {</span></div><div class=""><span style="background-color:rgba(255,255,255,0)" class="">}</span></div><div class=""><br class=""></div><div class="">vs</div><div class=""><br class=""></div><div class="">If let <span style="background-color:rgba(255,255,255,0)" class="">someInterestingViewConroller {</span></div><div class="">}</div><div class=""><br class=""></div><div class="">We know what let does and it should be enough to impart the necessary information for this statement.</div><div class=""><br class=""></div><div class="">When it comes to newcomers I think you'd be hard pressed to find somebody who'd be able to understand either form without teaching; so not losing much there.<br class=""><br class=""></div></div><div dir="auto" class=""><div class=""><br class="">On Dec 19, 2015, at 10:01 AM, Chris Lattner via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class=""></div><blockquote type="cite" class=""><div class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Dec 11, 2015, at 8:19 AM, Jeff Kelley 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="">I’ve had similar ideas to this. Instead of ditching the<span class=""> </span><font face="Menlo" class="">if let</font><span class=""> </span>syntax altogether, another approach would be to use the existing name if no new name is given, so that this code:<div class=""><br class=""></div><div class=""><font face="Menlo" class=""><span style="white-space:pre-wrap" class=""> </span>if let foo = foo { /* use foo */ }</font></div><div class=""><br class=""></div><div class="">could become this code:</div><div class=""><br class=""></div><div class=""><font face="Menlo" class=""><span style="white-space:pre-wrap" class=""> </span>if let foo { /* use foo */ }</font></div><div class=""><br class=""></div><div class="">In both cases,<span class=""> </span><font face="Menlo" class="">foo</font><span class=""> </span>is non-optional inside the braces. If you gave it another name with the<span class=""> </span><font face="Menlo" class="">if let</font><span class=""> </span>syntax, that would work as it does today.<br class=""></div></div></div></blockquote><br class=""></div><div class="">Hi Jeff,</div><div class=""><br class=""></div><div class="">This is commonly requested - the problem is that while it does help reduce boilerplate, it runs counter to the goal of improving clarity.</div><div class=""><br class=""></div><div class="">-Chris</div><br class=""><img src="https://u2002410.ct.sendgrid.net/wf/open?upn=1Ry8ov4zuU66O51YNcjYWXuMGf2gObG8uPwoJz-2B4Z1VqMdeyeesw-2Bc9SDkZTEmLmnofSO3tNgiMGF47sxE879Ut5x-2F6sLSrTgmZhXJOq-2B59bEaSmJ0a44hp5limyi-2FpsrcKvySjRuPP0gLr6FoeZNJoisevK-2BimrVdnhvmWcLj69rx67MHqizgTcdJrprVSbV2f-2FkGqilX9aSsmL60yEZg-3D-3D" alt="" width="1" height="1" border="0" style="min-height:1px!important;width:1px!important;border-width:0px!important;margin:0px!important;padding:0px!important" 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