<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Do I need to create a md file in the swift evolution repository to post my proposal?<div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Mar 19, 2016, at 00:12, Jordan Rose <<a href="mailto:jordan_rose@apple.com" class="">jordan_rose@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">[+swift-evolution] Sure! It's just a fancy word for doing something like this:</div><div class=""><br class=""></div><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;" class=""><div class="">protocol SelfAppendable {</div><div class=""> init()</div><div class=""> func +=(other: Self)</div><div class="">}</div><div class=""><br class=""></div><div class="">func *<Sequence: SelfAppendable >(sequence: Sequence, count: Int) -> Sequence {</div><div class=""> var result = Sequence()</div><div class=""> for _ in 0..<count {</div><div class=""> result += sequence</div><div class=""> }</div><div class=""> return result</div><div class="">}</div><div class=""><br class=""></div><div class=""><div class="">extension Array: SelfAppendable {}</div><div class="">extension String: SelfAppendable {}</div></div></blockquote><div class=""><br class=""></div>Both Array and String already have no-argument initializers and a += function, but they come from the standard library and don't (necessarily) satisfy any protocols, so they wouldn't be declared "implement". I can think of a few different ways to deal with this, but mostly I just want to make sure you (and everyone else) are considering this use case in your proposal. :-)<div class=""><div class=""><br class=""></div><div class="">Best,</div><div class="">Jordan<br class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Mar 18, 2016, at 17:04 , Victor Gao <<a href="mailto:victorgao44@gmail.com" class="">victorgao44@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Jordan,<div class=""><br class=""></div><div class="">Could you explain more of what retroactive modeling is and how it affects the proposal? I am unfamiliar with retroactive modeling. Thanks!</div><div class=""><br class=""></div><div class="">Victor Gao.</div></div></div></blockquote></div><br class=""></div></div></div></div></blockquote></div><br class=""></div></body></html>