<div dir="ltr">Thanks Charles ,<div><br></div><div>I know it&#39;s possible to do the same thing with filter. The syntax I drew attention to would be an alternate way. </div><div><br></div><div>My only rationale is that, if it works in one place, it ought to work everywhere. The redundancy bothers me too, but since the concept exists, we may as well allow it everywhere. Otherwise, it&#39;s still redundant in a &quot;for&quot; loop (maybe performance is better, but that could be optimized?), but also inconsistent because it seems intuitively like it ought to create a subset whereas in reality it is illegal.</div><div><br></div><div>Does it bother anyone else, or am I nitpicking?</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Dec 19, 2015 at 7:52 PM, Charles Srstka <span dir="ltr">&lt;<a href="mailto:cocoadev@charlessoft.com" target="_blank">cocoadev@charlessoft.com</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><div><div class="h5"><blockquote type="cite">On Dec 19, 2015, at 9:43 PM, Charles Constant via swift-evolution &lt;<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>&gt; wrote:<br></blockquote><div><blockquote type="cite"><br><div><div style="font-family:Helvetica;font-size:12px;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">I noticed several weeks ago that the following is illegal:<br></div><div style="font-family:Helvetica;font-size:12px;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"><br></div><span style="font-family:Helvetica;font-size:12px;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;float:none;display:inline!important">    let new_arr = el in arr where<span> </span></span><a href="http://el.is/" style="font-family:Helvetica;font-size:12px;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" target="_blank">el.is</a><span style="font-family:Helvetica;font-size:12px;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;float:none;display:inline!important">_foo // illegal</span><br style="font-family:Helvetica;font-size:12px;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 style="font-family:Helvetica;font-size:12px;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"><br></div><div style="font-family:Helvetica;font-size:12px;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">I assumed it would work because it&#39;s consistent with the filtering that exists in a &quot;for&quot; loop, i.e.:</div><div style="font-family:Helvetica;font-size:12px;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"><br></div><div style="font-family:Helvetica;font-size:12px;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">    for el in arr where<span> </span><a href="http://el.is/" target="_blank">el.is</a>_foo // legal<br></div><div style="font-family:Helvetica;font-size:12px;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"><br></div><div style="font-family:Helvetica;font-size:12px;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">Is this &quot;new proposal&quot; material? I thought I would check in case it&#39;s already on the roadmap, or inherently wrong.</div></div></blockquote></div><br></div></div><div>I believe what you want is already possible via the “filter” method.</div><span class="HOEnZb"><font color="#888888"><div><br></div><div>Charles</div><div><br></div></font></span></div></blockquote></div><br></div>