<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/xhtml; charset=utf-8">
</head>
<body>
<div style="font-family:sans-serif"><div style="white-space:normal">
<p dir="auto">I don’t think there’s much of a difference between adding an "optional" primitive (which has a default implementation in terms of a different primitive) and simply having that type adopt <code style="background-color:#F7F7F7; border-radius:3px; margin:0; padding:0 0.4em" bgcolor="#F7F7F7">Codable</code> itself and not be a primitive. You can still switch on the type dynamically (and we do), but you don’t need the optional overload for it.</p>
<p dir="auto">On 19 Mar 2017, at 19:33, Jonathan Hull wrote:</p>
<p dir="auto"></p></div>
<div style="white-space:normal"></div>
<blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><div id="93156EB2-88B5-46CB-8FB7-235C652B795E"><div 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 Mar 17, 2017, at 1:23 PM, Brent Royal-Gordon 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="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><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-stroke-width: 0px;"><div class=""><div class="" style="font-family: sans-serif;"><div class="" style="white-space: normal;"><blockquote class="" style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(119, 119, 119); color: rgb(119, 119, 119); margin: 0px 0px 5px; padding-left: 5px;"><p dir="auto" class="">(Also, is there any sense in adding `Date` to this set, since it needs special treatment in many of our formats?)</p></blockquote></div><div class="" style="white-space: normal;"><p dir="auto" class="">We’ve considered adding<span class="Apple-converted-space"> </span><code bgcolor="#F7F7F7" class="" style="background-color: rgb(247, 247, 247); border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; margin: 0px; padding: 0px 0.4em;">Date</code><span class="Apple-converted-space"> </span>to this list. However, this means that any format that is a part of this system needs to be able to make a decision about how to format dates. Many binary formats have no native representations of dates, so this is not necessarily a guarantee that all formats can make.</p><p dir="auto" class="">Looking for additional opinions on this one.</p><div class=""></div></div><div class="" style="white-space: normal;"><blockquote class="" style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(119, 119, 119); color: rgb(119, 119, 119); margin: 0px 0px 5px; padding-left: 5px;"><blockquote class="" style="border-left-width: 2px; border-left-style: solid; color: rgb(153, 153, 153); margin: 0px 0px 5px; padding-left: 5px; border-left-color: rgb(153, 153, 153);"></blockquote></blockquote></div></div></div></blockquote><div 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-stroke-width: 0px;" class="">I think that, if you're taking the view that you want to provide a set of pre-specified primitive methods as a list of things you want encoders to make a policy decision about, Date is a good candidate. But as I said earlier, I'd prefer to radically reduce the set of primitives, not add to it.</div><div 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-stroke-width: 0px;" class=""><br class=""></div><div 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-stroke-width: 0px;" class="">IIUC, two of your three proposed, Foundation-provided coders need to do something special with dates; perhaps one of the three needs to do something special with different integer sizes and types. Think of that as a message about your problem domain.</div></div></div></div></blockquote></div><br class=""><div class="">Have you considered having a very small set of true primitives, and a larger set of optional primitives. For the optional primitives, a default implementation would be provided that converts it to/from one of the true primitives (e.g. date <—> string), but it would still provide an override point for formats that want to support it more directly.</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Jon</div></div></div></blockquote>
<div style="white-space:normal">
<blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px">
</blockquote></div>
<div style="white-space:normal">
</div>
</div>
</body>
</html>