<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="">Here's some hypothetical code example. Let suppose an extension on key paths allows us to invoke desc and asc to help create sort orderings. This is what it would look using the two different notations:<div class=""><br class=""><div class=""><font face="Monaco" color="#009400" class=""><span style="font-size: 12px;" class="">// Order by totalAmount descending, then by address.zip ascending<br class=""></span></font><div class=""><div class=""><font face="Monaco" class=""><span style="font-size: 12px;" class="">let orderings = [ (</span></font><span style="font-family: Monaco; font-size: 12px;" class="">\</span><font face="Monaco" class=""><span style="font-size: 12px;" class=""><font color="#af00f4" class="">Order.totalAmount</font>).desc, (</span></font><span style="font-family: Monaco; font-size: 12px;" class="">\</span><font face="Monaco" class=""><span style="font-size: 12px;" class=""><font color="#af00f4" class="">Order.address.zip</font>).asc ]</span></font></div><div class=""></div><div class=""><font face="Monaco" class=""><span style="font-size: 12px;" class="">let orderings = [ </span></font><span style="font-family: Monaco; font-size: 12px;" class="">\</span><span style="color: rgb(175, 0, 244); font-family: Monaco; font-size: 12px;" class="">Order.totalAmount</span><span style="font-family: Monaco; font-size: 12px;" class="">\</span><font face="Monaco" class=""><span style="font-size: 12px;" class="">.desc, </span></font><span style="font-family: Monaco; font-size: 12px;" class="">\</span><span style="color: rgb(175, 0, 244); font-family: Monaco; font-size: 12px;" class="">Order.address.zip</span><span style="font-family: Monaco; font-size: 12px;" class="">\</span><font face="Monaco" class=""><span style="font-size: 12px;" class="">.asc ]</span></font></div><div class=""><br class=""></div></div><div class="">The second one saves one character every time you want to invoke a method on the key path but I would have to go back and add the left parenthesis, which could be a bit annoying as I'm typing these things in, unless the editor were to come to the rescue add the left parenthesis automatically somehow. But anyways, I can go with either one.</div><div class=""><br class=""></div><div class="">Still +1 on the proposal. :-)</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><div><blockquote type="cite" class=""><div class="">On Apr 5, 2017, at 11:13 PM, Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" class="">xiaodi.wu@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">On Wed, Apr 5, 2017 at 9:21 PM, Ricardo Parada via swift-evolution<span class="Apple-converted-space"> </span><span dir="ltr" class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>></span><span class="Apple-converted-space"> </span>wrote:<br class=""><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; border-left-width: 1px; border-left-style: solid; border-left-color: rgb(204, 204, 204); padding-left: 1ex;"><div style="word-wrap: break-word;" class=""><span class="gmail-"><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Apr 5, 2017, at 9:41 PM, Brent Royal-Gordon via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:</div><br class="gmail-m_-7606062616642485556Apple-interchange-newline"><div class=""><span style="font-family: helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; float: none; display: inline;" class="">It's worth noting that, if you write `\Person.name.valueType`, this syntax is ambiguous—it could mean "make a key path for the `valueType` property on `name` property of `Person`", or it could mean "make a key path for the `name` property of `Person`, then access the key path's `valueType` property". We can solve this by always interpreting it as the former and requiring parentheses for the latter—that is, `(\Person.name).valueType`—but I thought it was worth calling out explicitly.</span><br class="gmail-m_-7606062616642485556Apple-interchange-newline"></div></blockquote></div><br class=""></span><div class="">Good point. </div><div class=""><br class=""></div><div class=""> I'm thinking about the hypothetical code examples from previous emails:</div><div class=""><br class=""></div><div class=""><blockquote type="cite" class=""><div class=""></div></blockquote></div><div class=""><span class="gmail-"><div class=""><font face="Monaco" style="font-size: 12px;" class=""> let isPuppyQualifier =<span class="Apple-converted-space"> </span><font color="#af00f4" class="">\Pet.type</font><span class="Apple-converted-space"> </span>== .dog &&<span class="Apple-converted-space"> </span><font color="#af00f4" class="">\Pet.age</font><span class="Apple-converted-space"> </span>< 12</font></div></span><div class=""><font face="Monaco" style="font-size: 12px;" class=""> let familyQualifier = </font><span style="font-family: monaco; font-size: 12px;" class="">(</span><font face="Monaco" style="font-size: 12px;" class=""><font color="#af00f4" class="">\Family.pets</font></font><span style="font-family: monaco; font-size: 12px;" class="">)</span><font face="Monaco" style="font-size: 12px;" class="">.contains(<wbr class="">where: isPuppyQualifier)</font></div><span class="gmail-"><div class=""><font face="Monaco" style="font-size: 12px;" class=""> let familiesWithPuppies = Family.fetch(editingContext, familyQualifier)</font></div></span></div><div class=""><div class=""><br class=""></div></div></div></blockquote><div class=""><br class=""></div><div class="">That's an interesting point. While `\` alone seems acceptable, I think it's unfortunate that we'll have `(\...)` and `\(...)` both in the language.</div><div class="">Can we maybe consider instead:</div><div class=""><br class=""></div><div class=""><div class=""><span class="gmail-Apple-tab-span" style="white-space: pre;"> </span>let firstFriendsNameKeyPath = \Person.friends[0].name\</div><div class=""><br class=""></div><div class="">It is also worth mentioning that, with the sigil, the `keyPath` label may not be so necessary:</div><div class=""><br class=""></div><div class=""><span class="gmail-Apple-tab-span" style="white-space: pre;"> </span>print(luke[\.friends[0].name])</div></div><div class=""><span style="white-space: pre;" class=""> // or, if the suggestion above is accepted</span><br class=""></div><div class=""><span style="white-space: pre;" class=""> print(luke[\.friends[0].name\])</span></div></div></div></div></div></blockquote></div><br class=""></div></div></div></body></html>