<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=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div class=""><br class=""></div><div class="">On Apr 12, 2017, at 6:20 PM, Brent Royal-Gordon via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class=""></div><blockquote type="cite" class=""><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div class="">Wow, maybe I shouldn't have slept.</div></div></blockquote><div class=""><br class=""></div>LOL. <div class=""><br class=""></div><div class="">My thoughts so far:</div><div class=""><br class=""></div><div class="">• If and only if the opening """ is followed by a newline then strip it.</div><div class="">• Don't strip the trailing newline.</div><div class=""><br class=""></div><div class="">Example:</div><div class=""><br class=""></div><div class=""><div class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class=""><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;"><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(62, 30, 129);">print</span><span class="" style="font-variant-ligatures: no-common-ligatures;">( """</span></div><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);"><span class="" style="font-variant-ligatures: no-common-ligatures;"> Usage: myapp <options></span></div><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27); min-height: 13px;"><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><br class="webkit-block-placeholder"></div><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);"><span class="" style="font-variant-ligatures: no-common-ligatures;"> Run myapp to do mything</span></div><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27); min-height: 13px;"><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><br class="webkit-block-placeholder"></div><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);"><span class="" style="font-variant-ligatures: no-common-ligatures;"> Options:</span></div><div class="" style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);"><span class="" style="font-variant-ligatures: no-common-ligatures;"> -myoption - an option</span></div><div class="" style="margin: 0px; line-height: normal;"><span class="" style="font-variant-ligatures: no-common-ligatures;"><font color="#d12f1b" face="Menlo" class=""><span style="font-size: 11px;" class=""> </span></font><font face="Menlo" class=""><span style="font-size: 11px;" class="">"</span></font></span><span class="" style="font-variant-ligatures: no-common-ligatures;"><font face="Menlo" class=""><span style="font-size: 11px;" class="">""</span></font><font face="Menlo" class=""><span style="color: rgb(209, 47, 27); font-size: 11px;" class=""> </span><span style="font-size: 11px;" class="">)</span></font></span></div></div></div></div><br class=""></div><div class="">Additionally, allow the string to start immediately after the opening """. In this scenario the indentation stripping is performed starting with the second line:</div><div class=""><br class=""></div><div class=""><div class=""><div class=""><font face="Menlo" class=""><span style="font-size: 11px;" class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>case .isExprSameType(let from, let to):</span></font></div></div><div class=""><div class=""><font face="Menlo" class=""><span style="font-size: 11px;" class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>return """</span><font color="#d12f1b" class=""><span style="font-size: 11px;" class="">checking a value with optional type </span></font><font color="#1a04ff" style="font-size: 11px;" class="">\(</font><font style="font-size: 11px;" color="#00ab00" class=""><b class="">from</b></font><font color="#1a04ff" class=""><span style="font-size: 11px;" class="">)</span></font><span style="font-size: 11px;" class=""> </span></font><span style="color: rgb(26, 4, 255); font-family: Menlo; font-size: 11px;" class="">\</span></div><div class=""><span class="Apple-tab-span" style="font-family: Menlo; font-size: 11px; white-space: pre;"> </span><span style="font-family: Menlo; font-size: 11px;" class=""> </span><font color="#d12f1b" style="font-family: Menlo;" class=""><span style="font-size: 11px;" class="">against dynamic type</span></font><span style="font-family: Menlo; font-size: 11px;" class=""> </span><font color="#1a04ff" style="font-family: Menlo;" class=""><span style="font-size: 11px;" class="">\(</span></font><font color="#00ab00" style="font-family: Menlo; font-size: 11px;" class=""><b class="">to</b></font><font color="#1a04ff" style="font-family: Menlo;" class=""><span style="font-size: 11px;" class="">) \</span></font></div><div class=""><font face="Menlo" class=""><span class="Apple-tab-span" style="font-size: 11px; white-space: pre;"> </span><span style="font-size: 11px;" class=""> </span><font color="#d12f1b" class=""><span style="font-size: 11px;" class="">succeeds whenever the value is non-'nil'; </span></font></font><span style="color: rgb(26, 4, 255); font-family: Menlo; font-size: 11px;" class="">\</span></div><div class=""><span class="Apple-tab-span" style="font-family: Menlo; font-size: 11px; white-space: pre;"> </span><span style="font-family: Menlo; font-size: 11px;" class=""> </span><font face="Menlo" class=""><font color="#d12f1b" class=""><span style="font-size: 11px;" class="">did you mean to use '!= nil'?</span></font></font><span style="color: rgb(26, 4, 255); font-family: Menlo; font-size: 11px;" class="">\</span></div><div class=""><span class="Apple-tab-span" style="font-family: Menlo; font-size: 11px; white-space: pre;"> </span><span style="font-family: Menlo; font-size: 11px;" class=""> </span><span style="font-family: Menlo; font-size: 11px;" class="">"""</span></div></div></div><div class=""><div class=""><div class=""><br class=""></div><div class="">And definitely something like this too:</div><div class=""><br class=""></div><div class=""><font face="Menlo" class=""><span style="font-size: 11px;" class="">let html = """</span><span style="color: rgb(209, 47, 27); font-size: 11px;" class=""><a href="</span><font color="#1a04ff" class=""><span style="font-size: 11px;" class="">\(</span></font><font color="#00ab00" class=""><span style="font-size: 11px;" class=""><b class="">url</b></span></font><font color="#1a04ff" class=""><span style="font-size: 11px;" class="">)</span></font><span style="color: rgb(209, 47, 27); font-size: 11px;" class="">" id="link</span><font color="#1a04ff" class=""><span style="font-size: 11px;" class="">\(</span></font><font color="#00ab00" class=""><span style="font-size: 11px;" class=""><b class="">i</b></span></font><font color="#1a04ff" class=""><span style="font-size: 11px;" class="">)</span></font><span style="color: rgb(209, 47, 27); font-size: 11px;" class="">" class="link"></span><span style="font-size: 11px;" class="">"""</span></font></div><div class=""><br class=""></div><div class="">Again, the string literal is allowed to start immediately after the opening """. And No newline stripping is required here because the closing """ is not on a line by itself.</div><div class=""><br class=""></div><div class=""><br class=""></div></div></div><div class=""><blockquote type="cite" class=""><div class=""><div class="">Okay, let's deal with trailing newline first. I'm *very* confident that trailing newlines should be kept by default. This opinion comes from lots of practical experience with multiline string features in other languages. In practice, if you're generating files in a line-oriented way, you're usually generating them a line at a time. It's pretty rare that you want to generate half a line and then add more to it in another statement; it's more likely you'll interpolate the data. I'm not saying it doesn't happen, of course, but it happens a lot less often than you would think just sitting by the fire, drinking whiskey and musing over strings.</div><div class=""><br class=""></div><div class="">I know that, if you're pushing for this feature, it's not satisfying to have the answer be "trust me, it's not what you want". But trust me, it's not what you want.</div><div class=""><br class=""></div><div class="">Moving to the other end, I think we could do a leading newline strip *if* we're willing to create multiline and non-multiline modes—that is, newlines are _not allowed at all_ unless the opening delimiter ends its line and the closing delimiter starts its line (modulo indentation). But I'm reluctant to do that because, well, it's weird and complicated. I also get the feeling that, if there's a single-line mode and a multi-line mode, we ought to treat them as truly orthogonal features and allow `"`-delimited strings to use multi-line mode, but I'm really not convinced that's a good idea.</div><div class=""><br class=""></div><div class="">(Note, by the way, that heredocs—a *really* common multiline string design—always strip the leading newline but not the trailing one.)</div><div class=""><br class=""></div><div class="">Adrian cited this example, where I agree that you really don't want the string to be on the same line as the leading delimiter:</div><div class=""><br class=""></div><div class=""><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>let myReallyLongXMLConstantName = """<?xml version="1.0"?></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> <catalog></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> <book id="bk101" empty=""></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> <author>John Doe</author></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> <title>XML Developer's Guide</title></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> <genre>Computer</genre></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> <price>44.95</price></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> </book></div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> </catalog>\</div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> """ </div><br class="Apple-interchange-newline">But there are lots of places where it works fine. Is there a good reason to force an additional newline in this?</div><div class=""><br class=""></div><div class=""><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>case .isExprSameType(let from, let to):</div></div><div class=""><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>return """checking a value with optional type \(from) against dynamic type \(to) \</div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> succeeds whenever the value is non-'nil'; did you mean to use '!= nil'?\</div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span> """</div></div><div class=""><br class=""></div><div class="">I mean, we certainly could, but I'm not convinced we should. At least, not yet.</div><div class=""><br class=""></div><div class="">In any case, trailing newline definitely stays. Leading newline, I'm still thinking about.</div><div class=""><br class=""></div><div class="">As for other things:</div><div class=""><br class=""></div><div class="">* I see zero reason to fiddle with trailing whitespace. If it's there, it might be significant or it might not be. If we strip it by default and we shouldn't, the developer has no way to protect it. Let's trust the developer. (And their tooling—Xcode, I believe Git, and most linters already have trailing whitespace features. We don't need them too.)</div><div class=""><br class=""></div><div class="">* Somebody asked about `"""`-delimited heredocs. I think it's a pretty syntax, but it's not compatible with single-line use of `"""`, and I think that's probably more important. We can always add heredocs in another way if we decide we want them. (I think `#to(END)` is another very Swifty syntax we could use for heredocs--less lightweight, but it gives us a Google-able keyword.)</div><div class=""><br class=""></div><div class="">* Literal spaces and tabs cannot be backslashed. This is really important because, if you see a backslash after the last visible character in a line, you can't tell just by looking whether the next character is a space, tab, or newline. So the solution is, if it's not a newline, it's not valid at all.</div><div class=""><br class=""></div><div class="">I'll respond to Jarod separately.</div><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Apr 12, 2017, at 12:07 PM, John Holdsworth <<a href="mailto:mac@johnholdsworth.com" class="">mac@johnholdsworth.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">Finally.. a <a href="http://johnholdsworth.com/swift-LOCAL-2017-04-12-a-osx.tar.gz" class="">new Xcode toolchain</a> is available largely in sync with the proposal as is.</div><div class="">(You need to restart Xcode after selecting the toolchain to restart SourceKit)</div><div class=""><br class=""></div><div class="">I personally am undecided whether to remove the first line if it is empty. The new</div><div class="">rules are more consistent but somehow less practical. A blank initial line is almost</div><div class="">never what a user would want and I would tend towards removing it automatically.</div><div class="">This is almost what a user would it expect it to do.</div><div class=""><br class=""></div><div class="">I’m less sure the same applies to the trailing newline. If this is a syntax for</div><div class="">multi-line strings, I'd argue that they should normally be complete lines -</div><div class="">particularly since the final newline can so easily be escaped.</div><div class=""><br class=""></div><div class=""><span style="font-family: Menlo; font-size: 11px; font-variant-ligatures: no-common-ligatures;" class=""> </span><span style="font-family: Menlo; font-size: 11px; font-variant-ligatures: no-common-ligatures; color: rgb(186, 45, 162);" class="">let</span><span style="font-family: Menlo; font-size: 11px; font-variant-ligatures: no-common-ligatures;" class=""> longstring = ""</span><span style="font-family: Menlo; font-size: 11px; font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"\</span></div><div class=""><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod \</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, \</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.\</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> "</span><span style="font-variant-ligatures: no-common-ligatures;" class="">""</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #3e1e81" class="">print</span><span style="font-variant-ligatures: no-common-ligatures" class="">( ""</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"\</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Usage: myapp <options></span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><br class="webkit-block-placeholder"></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Run myapp to do mything</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><br class="webkit-block-placeholder"></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Options:</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> -myoption - an option</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(209, 47, 27);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> "</span><span style="font-variant-ligatures: no-common-ligatures;" class="">"" )</span></div></div><div class=""><span style="font-variant-ligatures: no-common-ligatures;" class=""><br class=""></span></div><div class="">(An explicit “\n" in the string should never be stripped btw)</div><div class=""><br class=""></div><div class="">Can we have a straw poll for the three alternatives:</div><div class=""><br class=""></div><div class="">1) Proposal as it stands - no magic removal of leading/training blank lines.</div><div class="">2) Removal of a leading blank line when indent stripping is being applied.</div><div class="">3) Removal of leading blank line and trailing newline when indent stripping is being applied.</div><div class=""><br class=""></div><div class="">My vote is for the pragmatic path: 2)</div><div class=""><br class=""></div><div class="">(The main intent of this revision was actually removing the link between how the</div><div class="">string started and whether indent stripping was applied which was unnecessary.)</div><br class=""><div class=""><blockquote type="cite" class=""><div class="">On 12 Apr 2017, at 17:48, Xiaodi Wu 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=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">Agree. I prefer the new rules over the old, but considering common use cases, stripping the leading and trailing newline makes for a more pleasant experience than not stripping either of them.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">I think that is generally worth prioritizing over a simpler algorithm or even accommodating more styles. Moreover, a user who wants a trailing or leading newline merely types an extra one if there is newline stripping, so no use cases are made difficult, only a very common one is made more ergonomic.</span></div></blockquote></div><br class=""></div></div></blockquote></div><br class=""><div class="">
<span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; border-spacing: 0px;"><div class=""><div style="font-size: 12px; " class="">-- </div><div style="font-size: 12px; " class="">Brent Royal-Gordon</div><div style="font-size: 12px; " class="">Architechies</div></div></span>
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<br class=""></div></blockquote><blockquote type="cite" class=""><div class=""><span class="">_______________________________________________</span><br class=""><span class="">swift-evolution mailing list</span><br class=""><span class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a></span><br class=""><span class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br class=""></div></blockquote></div></div></body></html>