<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=""><div><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><h5 style="box-sizing: border-box; margin-top: 1em; margin-bottom: 16px; line-height: 1.4; font-size: 1em; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; background-color: rgb(255, 255, 255);" class=""></h5><ul style="box-sizing: border-box; padding: 0px 0px 0px 2em; margin-top: 0px; margin-bottom: 16px; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; font-size: 16px; background-color: rgb(255, 255, 255);" class=""><li style="box-sizing: border-box;" class="">What is your evaluation of the proposal?</li></ul></div></div></blockquote><div>It’s “ok”. It is obviously scaled-back from earlier attempts, enough to be useful but not enough to be exciting.</div><div><br class=""></div><div>The main shortcoming here is the complete lack of composability. I understand why behavior composition got cut, but I’m not convinced it was the right decision.</div><div><br class=""></div><div>As far as I have followed it, it does seem that it’s only `synchronized`-style behaviors that are fundamentally-problematic under composition; that is, using the terminology in the proposal, linear behavior composition would work fine, and to my eyes most behaviors are “linear”.</div><div><br class=""></div><div>If it’s actually the case that almost all behaviors would compose reasonably (being “linear”), what’s the actual harm in going back to the more-composable earlier proposals and simply accepting that although one *can* write `synchronized`-style behaviors, they’re going to be fragile and doing so will thus be ill-advised?</div><div><br class=""></div><div>It feels like a lot of useful functionality has been given-up upon merely to avoid *potential* problems with a specific few, IMHO questionable, behaviors (like property-level `synchronized`).</div><div><br class=""></div><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><ul style="box-sizing: border-box; padding: 0px 0px 0px 2em; margin-top: 0px; margin-bottom: 16px; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; font-size: 16px; background-color: rgb(255, 255, 255);" class=""><li style="box-sizing: border-box;" class="">Is the problem being addressed significant enough to warrant a change to Swift?</li></ul></div></div></blockquote><div>A good version of a feature like this will lead to huge robustness-of-implementation improvements.</div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><ul style="box-sizing: border-box; padding: 0px 0px 0px 2em; margin-top: 0px; margin-bottom: 16px; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; font-size: 16px; background-color: rgb(255, 255, 255);" class=""><li style="box-sizing: border-box;" class="">Does this proposal fit well with the feel and direction of Swift?</li></ul></div></div></blockquote><div>The general idea very much so. The proposed behavior declaration syntax is odd, and only seems justifiable to me if a specific flavor of behavior composition winds up being the feature's future.</div><br class=""><blockquote type="cite" class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><ul style="box-sizing: border-box; padding: 0px 0px 0px 2em; margin-top: 0px; margin-bottom: 16px; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'; font-size: 16px; background-color: rgb(255, 255, 255);" class=""><li style="box-sizing: border-box;" class="">If you have used other languages or libraries with a similar feature, how do you feel that this proposal compares to those?</li><li style="box-sizing: border-box;" class="">How much effort did you put into your review? A glance, a quick reading, or an in-depth study?</li></ul></div></div></blockquote><div>A lot of thought towards earlier proposals, a skim of this one.</div></div><br class=""></body></html>