<div dir="ltr"><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Right, there were a few things missing!</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Thanks so much for pointing them out everyone.</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Dave - Great idea! I have updated the motivation section section as you suggested!</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Neil - Yes I also think the wording could be a bit better but since the word `clamped` is already being used </div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"> I thought I would keep it consistent. </div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Sean - Looks as if its a term of art to me as well. </div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Nate,</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Good catch! Yes I also thing clamping on an empty range should be a fatal error as well.</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">An empty range is impossible to create with `ClosedRange` so I left the implementation </div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">of that alone, but it is possible with `Range` so I updated the extension on `Strideable` like so:</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><pre style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;margin-top:0px;margin-bottom:0px;font-stretch:normal;line-height:1.45;word-wrap:normal;padding:16px;overflow:auto;background-color:rgb(246,248,250);border-radius:3px;word-break:normal;color:rgb(36,41,46)"><span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">extension</span> <span class="gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)"><span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Strideable</span></span> <span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">where</span> <span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Stride</span><span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">:</span> <span class="gmail-pl-e" style="box-sizing:border-box;color:rgb(121,93,163)"><span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Integer</span></span> {
<span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">func</span> <span class="gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)">clamped</span>(<span class="gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)">to</span> <span class="gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">range</span>: <span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Range</span><<span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Self</span>>) <span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">-></span> <span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Self</span> {
<span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">if</span> range.<span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">isEmpty</span> { <span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">fatalError</span>(<span class="gmail-pl-s" style="box-sizing:border-box;color:rgb(24,54,145)"><span class="gmail-pl-pds" style="box-sizing:border-box">"</span>Can't form Range with upperBound < lowerBound<span class="gmail-pl-pds" style="box-sizing:border-box">"</span></span>) }
<span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">return</span> <span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: range.<span class="gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">lowerBound</span><span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">...</span>(range.<span class="gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">upperBound</span> <span class="gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">-</span> <span class="gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">1</span>))
}
}</pre></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Jaden,</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Yeah I think a simple `if` check would work as well.</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Mar 16, 2017 at 10:19 AM, Jaden Geller <span dir="ltr"><<a href="mailto:jaden.geller@gmail.com" target="_blank">jaden.geller@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><br><div><span class=""><blockquote type="cite"><div>On Mar 15, 2017, at 12:40 PM, Nate Cook via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</div><br class="m_-2247452335458820292Apple-interchange-newline"><div><div style="word-wrap:break-word"><div>Hi Nick,</div><div><br></div><div>I think this might have come up in an earlier thread, but clamped(to:) with a half-open range argument brings up the question of how to clamp to an empty range. As proposed, the implementation of this method would result in an error when passed an empty range:</div><div><br></div><div><font face="Menlo"> foo.clamped(to: 0..<0)</font></div><div><font face="Menlo"> // fatal error: Can't form Range with upperBound < lowerBound</font></div></div></div></blockquote><div><br></div></span><div>Ahh, good catch! The implementation ought to add something like:</div><div><br></div><div><div style="margin:0px 0px 0px 101.1px;font-size:14px;line-height:normal;font-family:Menlo;color:rgb(223,0,2)"><span style="color:#c800a4">guard</span><span style="color:#000000"> </span><span style="color:#c800a4">!</span><span style="color:#000000">range</span><span style="color:#c800a4">.</span><span style="color:#000000">isEmpty </span><span style="color:#c800a4">else</span><span style="color:#000000"> { fatalError(</span>"Cannot clamp to an empty range"<span style="color:#000000">) }</span></div></div><div><br></div><div>I don’t think that this is problematic. Ideally we could express in the type-system that the range must not be empty, but it is definitely not worthwhile creating a `NonemptyRange` type.</div><div><div class="h5"><br><blockquote type="cite"><div><div style="word-wrap:break-word"><div><br></div><div>Is that the desired behavior? Providing documentation for both new methods would help make it clear what the expected functionality is.</div><div><br></div><div>Thanks!</div><div>Nate</div><div><br></div><br><div><blockquote type="cite"><div>On Mar 13, 2017, at 9:16 PM, Nicholas Maccharoli via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>> wrote:</div><br class="m_-2247452335458820292Apple-interchange-newline"><div><div dir="ltr"><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Swift-Evolution,</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">After considering the indispensable feedback from the community here is a slightly more polished draft.</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">If anyone is interested the draft can be downloaded here:</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><a href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md" style="font-size:12.8px" target="_blank">https://github.com/Nirma/swift<wbr>-evolution/blob/clamp_function<wbr>/proposals/NNNN-add-clamp-<wbr>function.md</a><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">Thank you so much, </div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)">- Nick</div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><br></div><div class="gmail_default" style="font-family:"comic sans ms",sans-serif;color:rgb(39,78,19)"><h1 style="box-sizing:border-box;margin:0px 0px 16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol"">Add clamp(to:) to the stdlib</h1><ul style="box-sizing:border-box;padding-left:2em;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><li style="box-sizing:border-box">Proposal: <a href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-filename.md" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">SE-NNNN</a></li><li style="box-sizing:border-box;margin-top:0.25em">Authors: <a href="https://github.com/Nirma" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">Nicholas Maccharoli</a></li><li style="box-sizing:border-box;margin-top:0.25em">Review Manager: TBD</li><li style="box-sizing:border-box;margin-top:0.25em">Status: <span style="box-sizing:border-box;font-weight:600">Awaiting review</span></li></ul><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><em style="box-sizing:border-box">During the review process, add the following fields as needed:</em></p><ul style="box-sizing:border-box;padding-left:2em;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><li style="box-sizing:border-box">Decision Notes: <a href="https://lists.swift.org/pipermail/swift-evolution/" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">Rationale</a>, <a href="https://lists.swift.org/pipermail/swift-evolution/" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">Additional Commentary</a></li><li style="box-sizing:border-box;margin-top:0.25em">Bugs: <a href="https://bugs.swift.org/browse/SR-NNNN" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">SR-NNNN</a>, <a href="https://bugs.swift.org/browse/SR-MMMM" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">SR-MMMM</a></li><li style="box-sizing:border-box;margin-top:0.25em">Previous Revision: <a href="https://github.com/apple/swift-evolution/blob/...commit-ID.../proposals/NNNN-filename.md" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">1</a></li><li style="box-sizing:border-box;margin-top:0.25em">Previous Proposal: <a href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/XXXX-filename.md" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">SE-XXXX</a></li></ul><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-introduction" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#introduction" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Introduction</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">This proposal aims to add functionality to the standard library for clamping a value to a <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">ClosedRange</code>. The proposed function would allow the user to specify a range to clamp a value to where if the value fell within the range, the value would be returned as is, if the value being clamped exceeded the upper or lower bound in value the value of the boundary the value exceeded would be returned.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">Swift-evolution thread: <a href="https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20170306/thread.html#33674" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none" target="_blank">Add a <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamp</code> function to Algorithm.swift</a></p><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-motivation" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#motivation" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Motivation</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">There have been quite a few times in my professional and personal programming life where I reached for a <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped</code>function and was disappointed it was not part of the standard library.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">Having functionality like <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped(to:)</code> added to <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">Comparable</code> as a protocol extension would benefit users of the Swift language who wish to guarantee that a value is kept within bounds.</p><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-proposed-solution" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#proposed-solution" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Proposed solution</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The solution proposed is simply that there be a <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped(to:)</code> function added to the Swift Standard Library. The function would behave much like its name describes.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">Given a <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped(to:)</code> function existed it could be called in the following way, yielding the results in the adjacent comments:</p><div class="m_-2247452335458820292gmail-highlight m_-2247452335458820292gmail-highlight-source-swift" style="box-sizing:border-box;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><pre style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;margin-top:0px;margin-bottom:0px;font-stretch:normal;line-height:1.45;word-wrap:normal;padding:16px;overflow:auto;background-color:rgb(246,248,250);border-radius:3px;word-break:normal"><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">let</span> foo <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">=</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">100</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> Closed range variant</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>
foo.<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">0</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">...</span><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">50</span>) <span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> 50</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>foo.<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">200</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">...</span><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">300</span>) <span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> 200</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>foo.<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">0</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">...</span><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">150</span>) <span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> 100</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> Half-Open range variant</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>
foo.<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">0</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">..<</span><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">50</span>) <span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> 49</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>foo.<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">200</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">..<</span><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">300</span>) <span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> 200</span>
<span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"></span>foo.<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">0</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">..<</span><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">150</span>) <span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box;color:rgb(150,152,150)"><span class="m_-2247452335458820292gmail-pl-c" style="box-sizing:border-box">//</span> 100</span></pre></div><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-detailed-design" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#detailed-design" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Detailed design</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The implementation of <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped(to:)</code> that is being proposed is composed of two protocol extensions; one protocol extension on <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">Comparable</code> and another on <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">Strideable</code>.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The implementation for <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped(to:)</code> as an extension to <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">Comparable</code> accepting a range of type <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">ClosedRange<Self></code>would look like the following:</p><div class="m_-2247452335458820292gmail-highlight m_-2247452335458820292gmail-highlight-source-swift" style="box-sizing:border-box;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><pre style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;margin-top:0px;margin-bottom:0px;font-stretch:normal;line-height:1.45;word-wrap:normal;padding:16px;overflow:auto;background-color:rgb(246,248,250);border-radius:3px;word-break:normal"><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">extension</span> <span class="m_-2247452335458820292gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)"><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Comparable</span></span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">func</span> <span class="m_-2247452335458820292gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)">to</span> <span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">range</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">ClosedRange</span><<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Self</span>>) <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">-></span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Self</span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">if</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">self</span> <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">></span> range.<span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">upperBound</span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">return</span> range.<span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">upperBound</span>
} <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">else</span> <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">if</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">self</span> <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)"><</span> range.<span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">lowerBound</span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">return</span> range.<span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">lowerBound</span>
} <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">else</span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">return</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">self</span>
}
}
}</pre></div><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The implementation of <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">clamped(to:)</code> as an extension on <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">Strideable</code> would be confined to cases where the stride is of type <code style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(27,31,35,0.0470588);border-radius:3px">Integer</code>. The implementation would be as follows:</p><div class="m_-2247452335458820292gmail-highlight m_-2247452335458820292gmail-highlight-source-swift" style="box-sizing:border-box;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><pre style="box-sizing:border-box;font-family:sfmono-regular,consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;margin-top:0px;margin-bottom:0px;font-stretch:normal;line-height:1.45;word-wrap:normal;padding:16px;overflow:auto;background-color:rgb(246,248,250);border-radius:3px;word-break:normal"><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">extension</span> <span class="m_-2247452335458820292gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)"><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Strideable</span></span> <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">where</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Stride</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">:</span> <span class="m_-2247452335458820292gmail-pl-e" style="box-sizing:border-box;color:rgb(121,93,163)"><span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Integer</span></span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">func</span> <span class="m_-2247452335458820292gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-en" style="box-sizing:border-box;color:rgb(121,93,163)">to</span> <span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">range</span>: <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Range</span><<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Self</span>>) <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">-></span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">Self</span> {
<span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">return</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">clamped</span>(<span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">to</span>: range.<span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">lowerBound</span><span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">...</span>(range.<span class="m_-2247452335458820292gmail-pl-smi" style="box-sizing:border-box;color:rgb(51,51,51)">uppe<wbr>rBound</span> <span class="m_-2247452335458820292gmail-pl-k" style="box-sizing:border-box;color:rgb(167,29,93)">-</span> <span class="m_-2247452335458820292gmail-pl-c1" style="box-sizing:border-box;color:rgb(0,134,179)">1</span>))
}
}</pre></div><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-source-compatibility" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#source-compatibility" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Source compatibility</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">This feature is purely additive; it has no effect on source compatibility.</p><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-effect-on-abi-stability" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#effect-on-abi-stability" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Effect on ABI stability</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">This feature is purely additive; it has no effect on ABI stability.</p><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-effect-on-api-resilience" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#effect-on-api-resilience" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Effect on API resilience</h2><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The proposed function would become part of the API but purely additive.</p><h2 style="box-sizing:border-box;margin-top:24px;margin-bottom:16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(234,236,239);color:rgb(36,41,46);font-family:-apple-system,system-ui,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol""><a id="m_-2247452335458820292gmail-user-content-alternatives-considered" class="m_-2247452335458820292gmail-anchor" href="https://github.com/Nirma/swift-evolution/blob/clamp_function/proposals/NNNN-add-clamp-function.md#alternatives-considered" style="box-sizing:border-box;background-color:transparent;color:rgb(3,102,214);text-decoration:none;float:left;padding-right:4px;line-height:1" target="_blank"></a>Alternatives considered</h2><div style="box-sizing:border-box;margin-top:0px;color:rgb(36,41,46);font-family:-apple-system,system-ui,'segoe ui',helvetica,arial,sans-serif,'apple color emoji','segoe ui emoji','segoe ui symbol';font-size:16px;margin-bottom:0px">Aside from doing nothing, no other alternatives were considered.</div></div></div>
______________________________<wbr>_________________<br>swift-evolution mailing list<br><a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a><br><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank">https://lists.swift.org/<wbr>mailman/listinfo/swift-<wbr>evolution</a><br></div></blockquote></div><br></div>______________________________<wbr>_________________<br>swift-evolution mailing list<br><a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a><br><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank">https://lists.swift.org/<wbr>mailman/listinfo/swift-<wbr>evolution</a><br></div></blockquote></div></div></div><br></div></blockquote></div><br></div>