<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div><blockquote type="cite" class=""><div class="">On Dec 21, 2017, at 10:02 AM, Dave DeLong 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="" style="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;">I would love to see some sort of formal API versioning that we could do instead in libraries, along with easy runtime support for checking the linked version of libraries, making it easy to strategize implementations based on version, etc.</div></div></blockquote><br class=""></div><div>This feature would have to be applied not only to switching on enums, but to *every* operation on a resilient value. In practice, I think it generalizes to one of:</div><div><br class=""></div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1. Pass a linked-against version number to every resilient call.</div><div><br class=""></div><div><span class="Apple-tab-span" style="white-space:pre"> </span>2. Have a way to fetch a substitute witness table for a given module version.</div><div><br class=""></div><div>Either one of these seems like a tall order.</div><br class=""><div class="">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div class=""><div style="font-size: 12px; " class="">-- </div><div style="font-size: 12px; " class="">Brent Royal-Gordon</div><div style="font-size: 12px; " class="">Architechies</div></div></span>
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