<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>If this happened how would legacy code be handled and a migratory written. I'm really nervous about small changes to semantics causing bugs. Would be more comfortable if the 'through' argument was renamed to force people to reconsider and check their code. It shouldn't have a migratory and the error on calling the old through variant should produce a very informative warning describing the semantic change.</div><div><br></div><div>Whether the change is worthwhile at all I'm not entirely sure, I haven't floating point stride much. </div><div><br></div><div>Joseph</div><div><br>On Feb 27, 2016, at 11:27 PM, Erica Sadun via swift-evolution <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=utf-8">Following up to myself. Thoughts and feedback are welcome. -- Erica<div class=""><br class=""></div><div class=""><h1 id="changingthebehaviorofstridethroughgenerator" style="margin: 0px 0px 0.875em; font-size: 1.5em; line-height: 0.875em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Changing the Behavior of StrideThroughGenerator</h1><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Swift offers two stride functions, <code class="">stride(to:, by:)</code> and <code class="">stride(through:, by:)</code>. I propose to change the way the <code class="">through</code> variation works. </p><h2 id="currentart" style="color: rgb(17, 17, 17); margin: 0px 0px 0.9545454545454546em; font-size: 1.375em; line-height: 0.9545454545454546em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Current Art</h2><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">A <code class="">Strideable to</code> sequence returns the sequence of values (<code class="">self</code>, <code class="">self + stride</code>, <code class="">self + stride + stride</code>, … <em class="">last</em>) where <em class="">last</em> is the last value in<br class="">the progression that is less than <code class="">end</code>. </p><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">A <code class="">Strideable through</code> sequence currently returns the sequence of values (<code class="">self</code>, <code class="">self + stride</code>, <code class="">self + tride + stride</code>, … <em class="">last</em>) where <em class="">last</em> is the last value in the progression less than or equal to <code class="">end</code>. There is no guarantee that <code class="">end</code> is an element of the sequence. </p><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Under the current implementation, each floating point addition accrues errors. The progression never reaches 2.0. </p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class=" lasso hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;">print(<span class="hljs-built_in" style="color: rgb(0, 134, 179);">Array</span>(<span class="hljs-number" style="color: rgb(0, 153, 153);">1.0</span><span class="hljs-built_in" style="color: rgb(0, 134, 179);">.</span>stride(through: <span class="hljs-number" style="color: rgb(0, 153, 153);">2.0</span>, <span class="hljs-keyword" style="font-weight: bold;">by</span>: <span class="hljs-number" style="color: rgb(0, 153, 153);">0.1</span>)))
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">/// Prints [1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9]</span></code></pre><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">To force the progression to include 2.0, you must add an (ugly) epsilon, as in the following example:</p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class=" lasso hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;">print(<span class="hljs-built_in" style="color: rgb(0, 134, 179);">Array</span>(<span class="hljs-number" style="color: rgb(0, 153, 153);">1.0</span><span class="hljs-built_in" style="color: rgb(0, 134, 179);">.</span>stride(through: <span class="hljs-number" style="color: rgb(0, 153, 153);">2.01</span>, <span class="hljs-keyword" style="font-weight: bold;">by</span>: <span class="hljs-number" style="color: rgb(0, 153, 153);">0.1</span>)))
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">/// Prints [1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0]</span></code></pre><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">This is problematic for the following reasons: </p><ul style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; font-size: 16px;" class=""><li style="font-size: 18px;" class="">The name of the calling function “through” suggests the progression will pass <em class="">through</em> the end point before stopping</li><li style="font-size: 18px;" class="">Floating point calls present an extremely common use-case</li><li style="font-size: 18px;" class="">It’s unreasonable to expect developers to consider every case of “will floating point math prevent my progression from actually reaching the end point, which has already been differentiated by using <code class="">through</code> rather than <code class="">to</code>”</li></ul><h2 id="proposedmodifications" style="color: rgb(17, 17, 17); margin: 0px 0px 0.9545454545454546em; font-size: 1.375em; line-height: 0.9545454545454546em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Proposed Modifications</h2><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">I recommend the following changes: </p><h4 id="changethedocumentationtextfrom" style="color: rgb(17, 17, 17); margin: 0px 0px 1.1666666666666667em; font-size: 1.125em; line-height: 1.1666666666666667em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Change the documentation text from</h4><blockquote style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; font-size: 16px;" class=""><p style="word-wrap: break-word; font-size: 18px; line-height: 1.6em; margin: 1.3125em 0px; font-style: italic;" class="">A <code class="">Strideable through</code> sequence currently returns the sequence of values (<code class="">self</code>, <code class="">self + stride</code>, <code class="">self + stride + stride</code>, … <em class="">last</em>) where <em class="">last</em> is the last value in the progression <strong class="">less than or equal to</strong> <code class="">end</code>. There is no guarantee that <code class="">end</code> is an element of the sequence. </p></blockquote><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">to </p><blockquote style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; font-size: 16px;" class=""><p style="word-wrap: break-word; font-size: 18px; line-height: 1.6em; margin: 1.3125em 0px; font-style: italic;" class="">A <code class="">Strideable through</code> sequence currently returns the sequence of values (<code class="">self</code>, <code class="">self + stride</code>, <code class="">self + stride + stride</code>, … <em class="">last</em>) where <em class="">last</em> is the last value in the progression <strong class="">greater than or equal to</strong> <code class="">end</code>. There is no guarantee that <code class="">end</code> is an element of the sequence. </p></blockquote><h4 id="modifytheimplementation" style="color: rgb(17, 17, 17); margin: 0px 0px 1.1666666666666667em; font-size: 1.125em; line-height: 1.1666666666666667em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Modify the implementation</h4><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Current:</p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class="swift ruby hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;"> /<span class="hljs-regexp" style="color: rgb(0, 153, 38);">//</span> <span class="hljs-constant" style="color: rgb(0, 153, 153);">Advance</span> to the <span class="hljs-keyword" style="font-weight: bold;">next</span> element <span class="hljs-keyword" style="font-weight: bold;">and</span> <span class="hljs-keyword" style="font-weight: bold;">return</span> it, <span class="hljs-keyword" style="font-weight: bold;">or</span> `<span class="hljs-keyword" style="font-weight: bold;">nil</span>` <span class="hljs-keyword" style="font-weight: bold;">if</span> no <span class="hljs-keyword" style="font-weight: bold;">next</span>
/<span class="hljs-regexp" style="color: rgb(0, 153, 38);">//</span> element exists.
public mutating func <span class="hljs-keyword" style="font-weight: bold;">next</span>() -> <span class="hljs-constant" style="color: rgb(0, 153, 153);">Element</span>? {
<span class="hljs-keyword" style="font-weight: bold;">if</span> done {
<span class="hljs-keyword" style="font-weight: bold;">return</span> <span class="hljs-keyword" style="font-weight: bold;">nil</span>
}
<span class="hljs-keyword" style="font-weight: bold;">if</span> stride > <span class="hljs-number" style="color: rgb(0, 153, 153);">0</span> ? current >= <span class="hljs-keyword" style="font-weight: bold;">end</span> <span class="hljs-symbol" style="color: rgb(153, 0, 115);">:</span> current <= <span class="hljs-keyword" style="font-weight: bold;">end</span> {
<span class="hljs-keyword" style="font-weight: bold;">if</span> current == <span class="hljs-keyword" style="font-weight: bold;">end</span> {
done = <span class="hljs-keyword" style="font-weight: bold;">true</span>
<span class="hljs-keyword" style="font-weight: bold;">return</span> current
}
<span class="hljs-keyword" style="font-weight: bold;">return</span> <span class="hljs-keyword" style="font-weight: bold;">nil</span>
}
let result = current
current += stride
<span class="hljs-keyword" style="font-weight: bold;">return</span> result
}</code></pre><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Proposed:</p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class="swift ruby hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;"> /<span class="hljs-regexp" style="color: rgb(0, 153, 38);">//</span> <span class="hljs-constant" style="color: rgb(0, 153, 153);">Advance</span> to the <span class="hljs-keyword" style="font-weight: bold;">next</span> element <span class="hljs-keyword" style="font-weight: bold;">and</span> <span class="hljs-keyword" style="font-weight: bold;">return</span> it, <span class="hljs-keyword" style="font-weight: bold;">or</span> `<span class="hljs-keyword" style="font-weight: bold;">nil</span>` <span class="hljs-keyword" style="font-weight: bold;">if</span> no <span class="hljs-keyword" style="font-weight: bold;">next</span>
/<span class="hljs-regexp" style="color: rgb(0, 153, 38);">//</span> element exists.
public mutating func <span class="hljs-keyword" style="font-weight: bold;">next</span>() -> <span class="hljs-constant" style="color: rgb(0, 153, 153);">Element</span>? {
<span class="hljs-keyword" style="font-weight: bold;">if</span> done {
<span class="hljs-keyword" style="font-weight: bold;">return</span> <span class="hljs-keyword" style="font-weight: bold;">nil</span>
}
<span class="hljs-keyword" style="font-weight: bold;">if</span> stride > <span class="hljs-number" style="color: rgb(0, 153, 153);">0</span> ? current >= <span class="hljs-keyword" style="font-weight: bold;">end</span> <span class="hljs-symbol" style="color: rgb(153, 0, 115);">:</span> current <= <span class="hljs-keyword" style="font-weight: bold;">end</span> {
<span class="hljs-regexp" style="color: rgb(0, 153, 38);">//</span> <span class="hljs-constant" style="color: rgb(0, 153, 153);">NOTE</span><span class="hljs-symbol" style="color: rgb(153, 0, 115);">:</span> `current >= <span class="hljs-keyword" style="font-weight: bold;">end</span>` <span class="hljs-keyword" style="font-weight: bold;">and</span> <span class="hljs-keyword" style="font-weight: bold;">not</span> `current == <span class="hljs-keyword" style="font-weight: bold;">end</span>`
<span class="hljs-keyword" style="font-weight: bold;">if</span> current >= <span class="hljs-keyword" style="font-weight: bold;">end</span> {
done = <span class="hljs-keyword" style="font-weight: bold;">true</span>
<span class="hljs-keyword" style="font-weight: bold;">return</span> current
}
<span class="hljs-keyword" style="font-weight: bold;">return</span> <span class="hljs-keyword" style="font-weight: bold;">nil</span>
}
let result = current
current += stride
<span class="hljs-keyword" style="font-weight: bold;">return</span> result
}
}
</code></pre><h2 id="introducedchanges" style="color: rgb(17, 17, 17); margin: 0px 0px 0.9545454545454546em; font-size: 1.375em; line-height: 0.9545454545454546em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Introduced Changes</h2><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Under these changes, the following progression ends at 2.0 not 1.9:</p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class=" lasso hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;">print(<span class="hljs-built_in" style="color: rgb(0, 134, 179);">Array</span>(<span class="hljs-number" style="color: rgb(0, 153, 153);">1.0</span><span class="hljs-built_in" style="color: rgb(0, 134, 179);">.</span>stride(through: <span class="hljs-number" style="color: rgb(0, 153, 153);">2.0</span>, <span class="hljs-keyword" style="font-weight: bold;">by</span>: <span class="hljs-number" style="color: rgb(0, 153, 153);">0.1</span>)))
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">// prints [1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0]</span></code></pre><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Integer progressions are unchanged:</p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class=" lasso hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;">print(<span class="hljs-built_in" style="color: rgb(0, 134, 179);">Array</span>(<span class="hljs-number" style="color: rgb(0, 153, 153);">1.</span>stride(through2: <span class="hljs-number" style="color: rgb(0, 153, 153);">10</span>, <span class="hljs-keyword" style="font-weight: bold;">by</span>: <span class="hljs-number" style="color: rgb(0, 153, 153);">1</span>)))
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">/// prints [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]</span></code></pre><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Floating point strides will extend up-to or past the <code class="">through</code> value:</p><pre style="color: rgb(17, 17, 17); font-size: 16px;" class=""><code class=" lasso hljs" style="display: block; padding: 0.5em; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248); background-position: initial initial; background-repeat: initial initial;"><span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">// Old</span>
print(<span class="hljs-built_in" style="color: rgb(0, 134, 179);">Array</span>(<span class="hljs-number" style="color: rgb(0, 153, 153);">1.0</span><span class="hljs-built_in" style="color: rgb(0, 134, 179);">.</span>stride(through: <span class="hljs-number" style="color: rgb(0, 153, 153);">1.9</span>, <span class="hljs-keyword" style="font-weight: bold;">by</span>: <span class="hljs-number" style="color: rgb(0, 153, 153);">0.25</span>)))
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">// prints [1.0, 1.25, 1.5, 1.75]</span>
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">// New</span>
print(<span class="hljs-built_in" style="color: rgb(0, 134, 179);">Array</span>(<span class="hljs-number" style="color: rgb(0, 153, 153);">1.0</span><span class="hljs-built_in" style="color: rgb(0, 134, 179);">.</span>stride(through: <span class="hljs-number" style="color: rgb(0, 153, 153);">1.9</span>, <span class="hljs-keyword" style="font-weight: bold;">by</span>: <span class="hljs-number" style="color: rgb(0, 153, 153);">0.25</span>)))
<span class="hljs-comment" style="color: rgb(153, 153, 136); font-style: italic;">// prints [1.0, 1.25, 1.5, 1.75, 2.0]</span></code></pre><h2 id="alternatesconsidered" style="color: rgb(17, 17, 17); margin: 0px 0px 0.9545454545454546em; font-size: 1.375em; line-height: 0.9545454545454546em; font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif;" class="">Alternates Considered</h2><p style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; word-wrap: break-word; font-size: 1.1429em; line-height: 1.3125em; margin: 1.3125em 0px;" class="">Other changes could include: </p><ul style="color: rgb(17, 17, 17); font-family: 'Helvetica Neue', Helvetica, Arial, Verdana, sans-serif; font-size: 16px;" class=""><li style="font-size: 18px;" class="">Introducing a <code class="">digitalStride</code> function with a set precision that works in integer math, multiplying each value by 10<sup style="font-size: 1.4ex; height: 0px; line-height: 1; position: relative;" class="">n</sup>, converting to integers, and then working back to floating point after each change</li><li style="font-size: 18px;" class="">Counting expected iterations by forming <code class="">(max - min) / by</code>, e.g. <code class="">(2.0 - 1.0) / 0.1</code>, which is 10, and performing each step as a pro-rated progression along those steps, which would remove most of the accumulated floating point errors along the way.</li><li style="font-size: 18px;" class="">Introducing a <code class="">DecimalNumber</code> type, with its own <code class="">stride</code> methods, e.g. <code class="">DecimalNumber(1.0).stride(through:DecimalNumber(2.0), by: DecimalNumber(0.1))</code>.</li></ul><div class=""><br class=""></div><div class=""><br class=""></div><div><blockquote type="cite" class=""><div class="">On Feb 26, 2016, at 5:12 PM, Erica Sadun 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=""><meta http-equiv="Content-Type" content="text/html charset=us-ascii" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><font class="">I have a problem with the way floating point ranges work with striding:</font></div><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;" class=""><font class=""><font face="Courier" class="">1.0.stride(through: 2.0, by: 0.1)</font></font><span style="font-family: Palatino-Roman;" class=""> returns the sequence [1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9]. </span></blockquote><blockquote class="" style="font-family: Palatino-Roman; margin: 0px 0px 0px 40px; border: none; padding: 0px;"><div class=""><i class="">Documentation: "It returns the sequence where last is less than or equal to `end`." </i></div></blockquote><font face="Palatino-Roman" class=""><div class="">(And yes, the same issue exists with tradition C-style for loops).</div></font><div class="" style="font-family: Palatino-Roman;"><div class=""><br class=""></div><div class="">Would it be really horrible if the implementation and definition was changed to: </div></div><blockquote class="" style="font-family: Palatino-Roman; margin: 0px 0px 0px 40px; border: none; padding: 0px;"><div class=""><div class=""><i class="">"It returns the sequence where last is greater than or equal to `end`?"</i></div></div></blockquote><div class="" style="font-family: Palatino-Roman;"><div class="">This would offer no change for integers, and include 2.0 for floating point sequences. </div><div class=""><br class=""></div><div class="">Alternatively, could there be <font face="Courier" class="">decimalStride</font>? Using Double but a rounding system with a fixed number of decimal places (e.g. 1, 2, 3), to ensure at least the end point is hit? It might look like:</div><div class=""><blockquote style="font-family: Palatino; margin: 0px 0px 0px 40px; border: none; padding: 0px;" class=""><font class=""><font face="Courier" class="">1.0.stride(through: 2.0, by: 0.1, places: 1)</font></font></blockquote><blockquote class="" style="margin: 0px 0px 0px 40px; border: none; padding: 0px;"></blockquote></div><div class=""><br class=""></div><div class="">I know there have been several discussions on-list about decimal number systems (<a href="http://article.gmane.org/gmane.comp.lang.swift.evolution/7130/match=decimal" class="">Re: Is there a need for a Decimal type?</a>) as well, but this could fix an ongoing annoyance without a major change.</div><div class=""><br class=""></div><div class="">Thanks for your thoughts,</div><div class=""><br class=""></div><div class="">-- Erica</div><div class=""><br class=""></div></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>swift-evolution mailing list</span><br><span><a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a></span><br><span><a href="https://lists.swift.org/mailman/listinfo/swift-evolution">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br></div></blockquote></body></html>