<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 Jun 8, 2016, at 10:51 PM, Erica Sadun 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 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;" class=""><blockquote type="cite" class=""><div class=""><br class="Apple-interchange-newline">On Jun 8, 2016, at 9:36 PM, Brent Royal-Gordon <<a href="mailto:brent@architechies.com" class="">brent@architechies.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><blockquote type="cite" class="">Upon accepting SE-0099, the core team is removing `where` clauses from condition clauses, writing "the 'where' keyword can be retired from its purpose as a boolean condition introducer."<span class="Apple-converted-space"> </span><br class=""><br class="">Inspiried by Xiaodi Wu, I now propose removing `where` clauses from `for in` loops, where they are better expressed (and read) as guard conditions.<span class="Apple-converted-space"> </span><br class=""></blockquote><br class="">Do you propose to remove `for case` as well? That can equally be handled by a `guard case` in the loop body.<br class=""><br class="">Alternate proposal: Move `where` clauses to be adjacent to the pattern—rather than the sequence expression—in a `for` loop, just as they are in these other syntaxes.<br class=""><br class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>for n where n.isOdd in 1...1_000 { … }<br class=""><br class="">This makes them more consistent with the syntax in `switch` cases and `catch` statements, while also IMHO clarifying the role of the `where` clause as a filter on the elements seen by the loop.<br class=""></div></div></blockquote></div><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;">I saw your post on that *after* I finished sending this. Moving `where` next to the pattern, like you'd find in `catch` and switch `case`, the code would look like this:</div><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;"><br class=""></div><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;"><font face="Menlo" class="">for i where i % 2 == 0 in sequence {</font></div><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;"><font face="Menlo" class=""> // do stuff</font></div><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;"><font face="Menlo" class="">}</font></div></div></blockquote><br class=""><div>What about just this?</div><div><div class=""><div class="" style="margin: 0px; line-height: normal; font-family: Menlo;"><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(187, 44, 162);">for</span><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><span class="" style="font-variant-ligatures: no-common-ligatures;">i % </span><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(39, 42, 216);">2</span><span class="" style="font-variant-ligatures: no-common-ligatures;"> == </span><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(39, 42, 216);">0</span><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(187, 44, 162);">in</span><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(79, 129, 135);">sequence</span><span class="" style="font-variant-ligatures: no-common-ligatures;"> { <font color="#bb2ca2" class="">...</font></span> }</div></div><div class=""><div class="" style="margin: 0px; line-height: normal;"><div class="" style="margin: 0px; line-height: normal;"><br class=""></div><div class="" style="margin: 0px; line-height: normal;">The first new identifier gets to be the index variable and subsequent new identifiers are errors.</div><div class="" style="margin: 0px; line-height: normal;"><br class=""></div><div class="" style="margin: 0px; line-height: normal;">- Dave Sweeris</div></div></div></div></div><br class=""></body></html>