<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body 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 Jul 22, 2016, at 9:10 PM, Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" class="">xiaodi.wu@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">On Fri, Jul 22, 2016 at 9:08 PM, Matthew Johnson <span dir="ltr" class=""><<a href="mailto:matthew@anandabits.com" target="_blank" class="">matthew@anandabits.com</a>></span> wrote:<br class=""><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><br class=""><div class=""><span class=""><blockquote type="cite" class=""><div class="">On Jul 22, 2016, at 9:04 PM, Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" target="_blank" class="">xiaodi.wu@gmail.com</a>> wrote:</div><br class=""><div class=""><div dir="ltr" style="font-family:Helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class="">On Fri, Jul 22, 2016 at 8:57 PM, Matthew Johnson<span class=""> </span><span dir="ltr" class=""><<a href="mailto:matthew@anandabits.com" target="_blank" class="">matthew@anandabits.com</a>></span><span class=""> </span>wrote:<br class=""><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><br class=""><div class=""><span class=""><blockquote type="cite" class=""><div class="">On Jul 22, 2016, at 8:54 PM, Xiaodi Wu via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:</div><br class=""><div class=""><div dir="ltr" class="">On Fri, Jul 22, 2016 at 8:52 PM, Jaden Geller via swift-evolution<span class=""> </span><span dir="ltr" class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>></span><span class=""> </span>wrote:<br class=""><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div style="word-wrap:break-word" class="">"The totalOrder predicate will order these cases, and it also distinguishes between different representations of NaNs and between the same decimal floating point number encoded in different ways."<div class="">- [Wikipedia](<a href="https://en.wikipedia.org/wiki/IEEE_floating_point#Total-ordering_predicate" target="_blank" class="">https://en.wikipedia.org/wiki/IEEE_floating_point#Total-ordering_predicate</a>)<br class=""><div class=""><br class=""></div><div class="">Sounds like `===` should not return `true` for zeros of different signs, then.</div></div></div></blockquote><div class=""><br class=""></div><div class="">Fair enough; the result of that will be, as Pyry noted above, that:</div><div class=""><br class=""></div><div class="">```</div><div class=""><span style="font-size:13px" class="">[-0.0, 1.0, .nan, 0.0].firstIndex(of: 0.0)</span> <span style="font-size:13px" class="">//=> 3, not 0</span></div><div class=""><span style="font-size:13px" class="">```</span></div></div></div></div></div></blockquote><div class=""><br class=""></div></span><div class="">Maybe we need floating point specific implementations of some algorithms to resolve this problem?</div><div class=""><br class=""></div><div class="">It doesn’t seem like there is a way to provide the semantics required by generic algorithms and still provide the expected behavior for floating point values. </div></div></div></blockquote><div class=""><br class=""></div><div class="">Well, what I'm trying to say is that generic algorithms such as `index(of:)` require only an equivalence relation. For floating point types, there are three ways to slice it:</div><div class=""><br class=""></div><div class="">1. NaN != NaN and +0 == -0 [what the traditional comparison operators are constrained to do]</div><div class="">2. NaN == NaN, +0 == -0, and the same number encoded different ways compare equal</div><div class="">3. NaN == NaN, +0 != -0, and the same number encoded different ways compare not equal</div><div class=""><br class=""></div><div class="">Both #2 and #3 can fall out of valid equivalence relations; if `===` behaved like #2 for FloatingPoint types, then generic algorithms work just fine. If we insist on using a total ordering defined by `<=>` all the time, then we've got problems.</div></div></div></div></div></blockquote><div class=""><br class=""></div></span><div class="">And if we don’t then we’re back to 3 different concepts of equality. There is definitely a tradeoff no matter what we choose.</div></div></div></blockquote><div class=""><br class=""></div><div class="">If some types have three concepts of equality, each with their particular use, why must we eliminate one of them?</div></div></div></div></div></blockquote><div><br class=""></div><div>This isn’t about eliminating concepts of equality for a type. They can have 42 if they want. </div><div><br class=""></div><div>This is about the right way to define the semantics of specific protocols. It says nothing about additional notions of equality a type may have available.</div><div><br class=""></div><div>The difficulty is finding a design for the protocols that makes sense with floating point types because we want them to be able to conform to the protocols.</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote"><div class=""> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><div class=""><div class=""><div class="h5"><blockquote type="cite" class=""><div class=""><div dir="ltr" style="font-family:Helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><div class=""><div class=""><div class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><div class=""><div class=""><div class=""><div class=""><div class=""><blockquote type="cite" class=""><div class="">On Jul 22, 2016, at 6:48 PM, Dave Abrahams via swift-evolution <<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:</div><br class=""><div class=""><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">on Fri Jul 22 2016, Jaden Geller <</span><a href="mailto:swift-evolution@swift.org" style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank" class="">swift-evolution@swift.org</a><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">> wrote:</span><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><blockquote type="cite" style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><blockquote type="cite" class="">For floating point, I'd hope that `a === b` if `(a <=> b) == .same`<br class="">*but not iff*. This is to satisfy IEEE 754: "Comparisons shall<br class="">ignore the sign of zero (so +0 = −0)".<br class=""></blockquote><br class="">I don't see why both `(+0) === (-0)` and `(+0) <=> (-0)` can't return<br class="">`true` and `.same`, respectively. This doesn't break the total<br class="">ordering of values. `===` doesn't do raw memory comparison. They're<br class="">"identical", so it ought to return `true`.<br class=""></blockquote><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">It ought to do whatever IEEE-754 specifies that its total ordering test</span><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">does. That is, IEEE-754 gets to decide whether the difference between</span><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">+0 and -0 is “essential” to IEEE-754 floating point types, or not.</span><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><blockquote type="cite" style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><br class=""><blockquote type="cite" class="">On Jul 22, 2016, at 6:37 PM, Xiaodi Wu via swift-evolution<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class="">On Fri, Jul 22, 2016 at 8:20 PM, Dave Abrahams via swift-evolution<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class="">wrote:<br class=""><br class="">on Fri Jul 22 2016, Daniel Duan <<a href="http://daniel-at-duan.org/" target="_blank" class="">daniel-AT-duan.org</a>> wrote:<br class=""><br class=""><blockquote type="cite" class=""><blockquote type="cite" class="">On Jul 22, 2016, at 3:00 PM, Dave Abrahams via swift-evolution<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class="">wrote:<br class=""><br class=""><br class="">on Fri Jul 22 2016, Daniel Duan<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>>><br class="">wrote:<br class=""><br class=""></blockquote><br class=""><blockquote type="cite" class=""><blockquote type="cite" class=""><blockquote type="cite" class="">On Jul 22, 2016, at 11:05 AM, Dave Abrahams via swift-evolution<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>>><br class="">wrote:<br class=""><br class=""><br class="">on Thu Jul 21 2016, Duan<br class=""></blockquote><br class=""><blockquote type="cite" class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>>>><br class="">wrote:<br class=""><br class=""><blockquote type="cite" class="">Great proposal. I want to second that areSame may mislead user to<br class="">think this is about identity.<br class=""><br class="">I like areEquivalent() but there may be better names.<br class=""></blockquote><br class="">It really *is* about identity as I posted in a previous message. But<br class="">that doesn't change the fact that areEquivalent might be a better name.<br class="">It's one of the things we considered; it just seemed long for no real<br class="">benefit.<br class=""><br class=""></blockquote><br class="">If the addresses of the arguments aren’t being used, then we don’t consider<br class="">them part of their *identity*. I can follow this logic. My fear is most users<br class="">won’t make this leap on their own and get the same initial impression as I did.<br class="">It's entirely possible this fear is unfounded. Some educated bikesheding<br class="">wouldn't hurt here IMO :)<br class=""></blockquote><br class="">Well, it's still a very real question whether we ought to have the<br class="">additional API surface implied by areSame, or wether we should collapse<br class="">it with ===.<br class=""><br class=""></blockquote><br class="">To spell this out (because I had to think about it for a second): === will be derived from<br class=""><=>,<br class="">but also becomes default implementation for ==, which remains open for<br class="">customization.<br class=""></blockquote><br class="">I was imagining roughly this (untested):<br class=""><br class=""> /// Two references are identical if they refer to the same<br class=""> /// instance.<br class=""> ///<br class=""> /// - Note: Classes with a more-refined notion of “identical”<br class=""> /// should conform to `Identifiable` and implement `===`.<br class=""> func ===(lhs: AnyObject, rhs: AnyObject) -> Bool {<br class=""> ObjectIdentifier(lhs) == ObjectIdentifier(rhs)<br class=""> }<br class=""><br class=""> /// Supports testing that two values of `Self` are identical<br class=""> ///<br class=""> /// If `a` and `b` are of type `Self`, `a === b` means that<br class=""> /// `a` and `b` are interchangeable in most code. A conforming<br class=""> /// type can document that specific observable characteristics<br class=""> /// (such as the `capacity` of an `Array`) are inessential and<br class=""> /// thus not to be considered as part of the interchangeability<br class=""> /// guarantee.<br class=""> ///<br class=""> /// - Requires: `===` induces an equivalence relation over<br class=""> /// instances.<br class=""> /// - Note: conforming types will gain an `==` operator that<br class=""> /// forwards to `===`.<br class=""> /// - Note: Types that require domain-specific `==`<br class=""> /// implementations with different semantics (e.g. floating<br class=""> /// point) should define a more-specific overload of `==`,<br class=""> /// which will be used in contexts where the static type is<br class=""> /// known to the compiler.<br class=""> /// - Note: Generic code should usually use `==` to compare<br class=""> /// conforming instances; that will always dispatch to `===`<br class=""> /// and will be unaffected by more specific overloads of<br class=""> /// `==`.<br class=""> protocol Identifiable { // née Equatable name is negotiable<br class=""> func ===(_: Self, _: aSelf) -> Bool<br class=""> }<br class=""><br class=""> /// Default definition of `==` for Identifiable types.<br class=""> func ==<T: Identifiable>(lhs: T, rhs: T) -> Bool {<br class=""> return lhs === rhs<br class=""> }<br class=""><br class=""> /// Conforming types have a default total ordering.<br class=""> ///<br class=""> /// If `a` and `b` are of type `Self`, `a <=> b` means that<br class=""> /// `a` and `b` are interchangeable in most code. A conforming<br class=""> /// type can document that specific observable characteristics<br class=""> /// (such as the `capacity` of an `Array`) are inessential and<br class=""> /// thus not to be considered as part of the interchangeability<br class=""> /// guarantee.<br class=""> ///<br class=""> /// - Requires: `<=>` induces a total ordering over<br class=""> /// instances.<br class=""> /// - Requires: the semantics of `<=>` are consistent with<br class=""> /// those of `===`. That is, `(a <=> b) == .equivalent`<br class=""> /// iff `a === b`.<br class=""><br class="">For floating point, I'd hope that `a === b` if `(a <=> b) == .same` *but not iff*. This is to satisfy IEEE 754: "Comparisons shall ignore the sign of zero (so +0 = −0)".<br class=""><br class=""> /// - Note: conforming types will gain `<`, `<=`, `>`, and `>=`<br class=""> /// operators defined in terms of `<=>`.<br class=""> /// - Note: Types that require domain-specific `<`, etc.<br class=""> /// implementations with different semantics (e.g. floating<br class=""> /// point) should define more-specific overloads of those<br class=""> /// operators, which will be used in contexts where the<br class=""> /// static type is known to the compiler.<br class=""> /// - Note: Generic code can freely use `<=>` or the traditional<br class=""> /// comparison operators to compare conforming instances;<br class=""> /// the result will always be supplied by `<=>`<br class=""> /// and will be unaffected by more specific overloads of<br class=""> /// the other operators.<br class=""> protocol Comparable : Identifiable {<br class=""> func <=> (lhs: Self, rhs: Self) -> Ordering<br class=""> }<br class=""><br class=""> /// Default implementations of `<`, `<=`, `>`, and `>=`.<br class=""> extension Comparable {<br class=""> static func <(lhs: Self, rhs: Self) -> Bool {<br class=""> return (lhs <=> rhs) == .ascending<br class=""> }<br class=""> static func <=(lhs: Self, rhs: Self) -> Bool {<br class=""> return (rhs <=> lhs) != .ascending<br class=""> }<br class=""> static func >(lhs: Self, rhs: Self) -> Bool {<br class=""> return (lhs <=> rhs) == .descending<br class=""> }<br class=""> static func >=(lhs: Self, rhs: Self) -> Bool {<br class=""> return (rhs <=> lhs) != .descending<br class=""> }<br class=""> }<br class=""><br class=""><blockquote type="cite" class="">I like this idea. If we keep === as a separate thing, now users have 3 “opportunities” to define<br class="">equality. The must be few, if any, use cases for this.<br class=""><br class="">Would love to see if anyone on the list can give us an example. Otherwise we should make<br class="">areSame === again™!<br class=""><br class=""><blockquote type="cite" class=""><blockquote type="cite" class=""><br class=""><blockquote type="cite" class=""><blockquote type="cite" class="">Daniel Duan<br class="">Sent from my iPhone<br class=""><br class=""><blockquote type="cite" class="">On Jul 21, 2016, at 6:32 PM, Robert Widmann via swift-evolution<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class="">wrote:<br class=""><br class=""><br class=""><blockquote type="cite" class="">On Jul 21, 2016, at 6:19 PM, Xiaodi Wu<br class=""><<a href="mailto:xiaodi.wu@gmail.com" target="_blank" class="">xiaodi.wu@gmail.com</a><br class=""><<a href="mailto:xiaodi.wu@gmail.com" target="_blank" class="">mailto:xiaodi.wu@gmail.com</a>>><br class="">wrote:<br class=""><br class="">This is nice. Is `areSame()` being proposed because static `==` is<br class="">the status quo and you're trying to make the point that `==` in the<br class="">future need not guarantee the same semantics?<br class=""></blockquote><br class="">Yep! Equivalence and equality are strictly very different things.<br class=""><br class=""><blockquote type="cite" class=""><br class="">Nit: I think the more common term in stdlib would be<br class="">`areEquivalent()`. Do you think `same` in that context (independent<br class="">of the word "ordering") might erroneously suggest identity?<br class=""></blockquote><br class="">There is room for improvement here. Keep ‘em coming.<br class=""><br class=""><blockquote type="cite" class=""><br class=""><br class=""><blockquote type="cite" class="">On Thu, Jul 21, 2016 at 8:11 PM, Robert Widmann via<br class="">swift-evolution<br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class="">wrote:<br class="">Hello Swift Community,<br class=""><br class="">Harlan Haskins, Jaden Geller, and I have been working on a<br class="">proposal to clean up the semantics of ordering relations in the<br class="">standard library. We have a draft that you can get as a gist.<br class="">Any feedback you might have about this proposal helps - though<br class="">please keeps your comments on Swift-Evolution and not on the gist.<br class=""><br class="">Cheers,<br class=""><br class="">~Robert Widmann<br class=""><br class=""><br class=""><br class=""><br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><br class=""></blockquote><br class=""></blockquote><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""></blockquote>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><br class=""></blockquote><br class="">--<br class="">Dave<br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>>><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>>>><br class=""></blockquote>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>>><br class=""><br class=""></blockquote><br class="">--<br class="">Dave<br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>>><br class=""></blockquote></blockquote><br class="">--<br class="">Dave<br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><<a href="mailto:swift-evolution@swift.org" target="_blank" class="">mailto:swift-evolution@swift.org</a>><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a>><br class=""></blockquote>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><br class=""></blockquote><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">--<span class=""> </span></span><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span 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style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><span style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline" class="">swift-evolution mailing list</span><br style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" class=""><a href="mailto:swift-evolution@swift.org" style="font-family:helvetica;font-size:12px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank" class="">swift-evolution@swift.org</a><br 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class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""><br class=""></blockquote></div><br class=""></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" target="_blank" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" target="_blank" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></div></blockquote></div></div></div></div></blockquote></div></div></div></div></blockquote></div></div></div><br class=""></div></blockquote></div><br class=""></div></div>
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