<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 26 Jul 2017, at 14:37, Jonathan Hull 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 class="">Is there a reason why the migration only applies to Swift 3? I have some older files which I haven’t gotten around to upgrading until now, and Xcode Beta says I need to migrate them with an older version of Xcode. Right now, I still have that older version, but once Xcode gets upgraded in the fall it will no longer be possible (or is it a temporary limitation)?<br class=""><br class="">Seeing as there is a Swift 3 compatibility mode, we should at least provide the ability to migrate from 2->3, seeing as it already exists, no?<br class=""></div></div></blockquote><div><br class=""></div><div>It’s <b class="">not</b> a temporary limitation. The migrator needs to be able to parse the input language before it can do the migration:</div><div><br class=""></div><div>1) Xcode 9 doesn’t come with a Swift 2 compiler built in.</div><div>2) Even if it did, writing a migrator that could migrate from 2 to 4 would dramatically increase the complexity of the migrator.</div><div>3) Even if Xcode tried to automatically migrate 2 -> 3, then 3 -> 4, it would only work in very few cases because you often need to do manual fixes after the migrator has run.</div><div><br class=""></div><div>David.</div><br class=""><blockquote type="cite" class=""><div class=""><div class="">Thanks,<br class="">Jon<br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""></div></div></blockquote></div><br class=""></body></html>