<!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">Those cases will produce <code style="background-color:#F7F7F7; border-radius:3px; margin:0; padding:0 0.4em" bgcolor="#F7F7F7">nil</code>. "Should" is a matter of expectation, but I think that it’s reasonable behavior since it feels truer to the intent the <code style="background-color:#F7F7F7; border-radius:3px; margin:0; padding:0 0.4em" bgcolor="#F7F7F7">exactly:</code> methods.</p>
<p dir="auto">On 16 Jun 2017, at 16:23, Jordan Rose via swift-evolution wrote:</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="8912443C-609A-4B32-8150-101B6343E7D6"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jun 14, 2017, at 13:59, Philippe Hausler 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 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;" class=""><br class="Apple-interchange-newline"><br class=""><blockquote type="cite" class=""><div class="">On Jun 14, 2017, at 1:47 PM, Dave Abrahams 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=""><br 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;"><span 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; float: none; display: inline !important;">on Wed Jun 14 2017, Philippe Hausler <</span><a href="mailto:swift-evolution@swift.org" 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;">swift-evolution@swift.org</a><span 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; float: none; display: inline !important;">> wrote:</span><br 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;"><br 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;"><blockquote type="cite" 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;">After implementing the proposal<br class=""><a href="https://github.com/apple/swift-evolution/blob/master/proposals/0170-nsnumber_bridge.md" class="">https://github.com/apple/swift-evolution/blob/master/proposals/0170-nsnumber_bridge.md</a><br class=""><<a href="https://github.com/apple/swift-evolution/blob/master/proposals/0170-nsnumber_bridge.md" class="">https://github.com/apple/swift-evolution/blob/master/proposals/0170-nsnumber_bridge.md</a>><br class="">we have gotten some initial feedback.<br class=""><br class="">It seems that there is definitely a fair amount of confusion and heartache for dealing with Float<br class="">and Double values being bridged.<br class=""><br class="">Specifically the cases like:<br class=""><br class="">NSNumber(value 0.1) as? Float<br class=""><br class="">which with the current implementation will return nil since the Double value 0.1 cannot be<br class="">represented exactly as a Float.<br class=""><br class="">It seems like the overwhelming majority of users know full well that<br class="">Float will result in a loss of precision (hence why they chose that<br class="">type over Double). This means that the floating point bridges for<br class="">Double, Float, and CGFloat should not be the pedantic “exactly” cases<br class="">but instead infer the conversion intent of a lax/approximated version.<br class=""></blockquote><br 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;"><span 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; float: none; display: inline !important;">+1</span><br 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;"><br 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;"><blockquote type="cite" 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;">So in short: for the betterment of the API ergonomics, the floating<br class="">point types as destinations will be pulled back to their initial Swift<br class="">3 behavior.<br class=""><br class="">Additionally to aide appropriate migration to the appropriate<br class="">truncating/exactly initializers the un-labeled, deprecated in Swift 4,<br class="">plain init methods to the numeric types with an NSNumber will now be<br class="">annotated with the suggested replacements.<br class=""></blockquote><br 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;"><span 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; float: none; display: inline !important;">Sorry, I don't quite understand what that last paragraph implies. Could</span><br 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;"><span 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; float: none; display: inline !important;">you describe what will be deprecated and what will be suggested instead?</span><br 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;"></div></blockquote><div class=""><br class=""></div><div class=""><a href="https://github.com/phausler/swift/commit/62218c85b6c494c4054ec9774dd6ce095a5d0fa4" class="">https://github.com/phausler/swift/commit/62218c85b6c494c4054ec9774dd6ce095a5d0fa4</a></div><div class=""><br class=""></div><div class="">So this is just an annotation of renaming to the init(truncating:)</div></div></div></blockquote><br class=""></div><div>How about cases where the value is a double that's greater than Float.greatestFiniteMagnitude? Should/Will that produce 'nil' or Float.infinity?</div><div><br class=""></div><div>Jordan</div><br class=""></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><blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><p dir="auto">_______________________________________________<br>
swift-evolution mailing list<br>
swift-evolution@swift.org<br>
<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" style="color:#777">https://lists.swift.org/mailman/listinfo/swift-evolution</a></p>
</blockquote></div>
<div style="white-space:normal">
</div>
</div>
</body>
</html>