<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="">Le 24 janv. 2017 à 04:31, Brent Royal-Gordon via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> a écrit :</div><br class="Apple-interchange-newline"><div class=""><div class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><blockquote type="cite" class="">The operands and sense of the comparison are kind of lost in all this garbage. You really want to see `foo < bar` in this code somewhere, but you don't.<br class=""></blockquote><br class="">Yeah, we thought about trying to build a DSL for that, but failed. I think the best possible option would be something like:<br class=""><br class=""> foo.comparison(case: .insensitive, locale: .current) < bar<br class=""><br class="">The biggest problem is that you can build things like<br class=""><br class=""> fu = foo.comparison(case: .insensitive, locale: .current)<br class=""> br = bar.comparison(case: .sensitive)<br class=""> fu < br // what does this mean?<br class=""><br class="">We could even prevent such nonsense from compiling, but the cost in library API surface area is quite large.<br class=""></blockquote><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">Is it? I think we're talking, for each category of operation that can be localized like this:</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">* One type to carry an operand and its options.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">* One method to construct this type.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">* One alternate version of each operator which accepts an operand+options parameter. (I'm thinking it should always be the right-hand side, so the long stuff ends up at the end; Larry Wall noted this follows an "end-weight principle" in natural languages.)</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; 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; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">I suspect that most solutions will at least require some sort of overload on the comparison operators, so this may be as parsimonious as we can get.<span class="Apple-converted-space"> </span></span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""></div></div></blockquote></div><br class=""><div class="">SQL has the `collate` keyword:</div><div class=""><br class=""></div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>-- sort users by email, case insensitive</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>select * from users order by email collate nocase</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>-- look for a specific email, in a case insensitive way</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>select * from users where email = '<a href="mailto:foo@example.com" class="">foo@example.com</a>' collate nocase</div><div class=""><br class=""></div><div class="">It is used as a decorator that modifies an existing sql snippet (a sort descriptor first, and a comparison last)</div><div class=""><br class=""></div><div class="">When designing an SQL building to Swift, I chose the `nameColumn.collating(.nocase)` approach, because it allowed a common Swift syntax for both use cases:</div><div class=""><br class=""></div><div class=""><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>// sort users by email, case insensitive</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>User.order(nameColumn.collating(.nocase))</div><div class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>// look for a specific email, in a case insensitive way</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>User.filter(nameColumn.collating(.nocase) == "<a href="mailto:foo@example.com" class="">foo@example.com</a>")</div><div class=""><br class=""></div></div><div class="">Yes, it comes with extra operators so that nonsensical comparison are avoided.</div><div class=""><br class=""></div><div class="">But it just works.</div><div class=""><br class=""></div><div class="">Gwendal</div><div class=""><br class=""></div></body></html>