<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jan 8, 2018, at 9:04 AM, Daryle Walker <<a href="mailto:darylew@mac.com" class="">darylew@mac.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; 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; text-decoration: none;" class="">I saw that I missed this discussion when I skipped out for 1.5 months. I’m not sure what the problem with IndexDistance was; abstraction is generally a good thing. </div></div></blockquote><div><br class=""></div><div>Abstraction is a means, not an end. Abstractions that result in impedance with little benefit are bad. IndexDistance was a clear case of this.</div><div><br class=""></div><blockquote type="cite" class=""><div class=""><blockquote type="cite" 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-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;"><div class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="">What’s also interesting is you could (with conditional conformance now that’s landed) make it a RandomAccessCollection if the base were random access, but<span class="Apple-converted-space"> </span><i class="">not</i> if the base is bidirectional, because you need to be able to calculate the size of the last element in constant time.</div></div></div></blockquote><div style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; 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; text-decoration: none;" class=""><br class=""></div><div style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; 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; text-decoration: none;" class="">Is this active, at least in Xcode 9.2?</div></div></blockquote></div><br class=""><div class="">Xcode 9.2 shipped with a variant of Swift 4.0. IndexDistance should be removed in 4.1 and later. You can try it in Xcode today though by downloading the latest master or 4.1 snapshot toolchain from <a href="http://swift.org" class="">swift.org</a>.</div><div class=""><br class=""></div><div class=""><br class=""></div></body></html>