<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 16 Aug 2016, at 20:24, Justin Jia via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div class=""></div><div class="">Thank you for the sharing how you solve this problem! It seems like the best workaround so far. </div><div class=""><br class=""></div><div class="">I wish $0 can be replaced by the actual name. (Maybe tuples?)</div><div class=""><br class=""></div><div class="">let a = (x: x, y: y)</div><div class="">let result = a.my_map { foo(x: $0.x, y: $0.y }</div><div class=""><br class=""></div><div class="">In my_map unwrap all variables inside tuple?</div><div class=""><br class=""></div><div class="">I agree that short-circuiting is an issue. But personally I still think the imperfect solution is good enough. But I'll try to find other possible solutions. </div></div></div></blockquote></div><br class=""><div class="">One technique around this is to introduce a set of generic library functions that try to unwrap all of their arguments and construct a tuple thereof if every argument evaluated to `.some(_)`. The evaluation of expressions can also be delayed with @autoclosure:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><div style="margin: 0px; line-height: normal;" class=""><div style="margin: 0px; line-height: normal;" class=""><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">func</span><span style="font-variant-ligatures: no-common-ligatures" class=""> unwrap<A, B>(</span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">_</span><span style="font-variant-ligatures: no-common-ligatures" class=""> a: </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">A</span><span style="font-variant-ligatures: no-common-ligatures" class="">?, </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">_</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b: </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">@autoclosure</span><span style="font-variant-ligatures: no-common-ligatures" class=""> () </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">throws</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">B</span><span style="font-variant-ligatures: no-common-ligatures" class="">?) </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">rethrows</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -> (</span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">A</span><span style="font-variant-ligatures: no-common-ligatures" class="">, </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">B</span><span style="font-variant-ligatures: no-common-ligatures" class="">)? {</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">guard</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> a = a, </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b = </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">try</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b() </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">else</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">nil</span><span style="font-variant-ligatures: no-common-ligatures" class=""> }</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> (a, b)</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> }</span></div><div style="margin: 0px; line-height: normal; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">func</span><span style="font-variant-ligatures: no-common-ligatures" class=""> unwrap<A, B, C>(</span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">_</span><span style="font-variant-ligatures: no-common-ligatures" class=""> a: </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">A</span><span style="font-variant-ligatures: no-common-ligatures" class="">?,</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">_</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b: </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">@autoclosure</span><span style="font-variant-ligatures: no-common-ligatures" class=""> () </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">throws</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">B</span><span style="font-variant-ligatures: no-common-ligatures" class="">?,</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">_</span><span style="font-variant-ligatures: no-common-ligatures" class=""> c: </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">@autoclosure</span><span style="font-variant-ligatures: no-common-ligatures" class=""> () </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">throws</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">C</span><span style="font-variant-ligatures: no-common-ligatures" class="">?) </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">rethrows</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -> (</span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">A</span><span style="font-variant-ligatures: no-common-ligatures" class="">, </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">B</span><span style="font-variant-ligatures: no-common-ligatures" class="">, </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">C</span><span style="font-variant-ligatures: no-common-ligatures" class="">)?</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> {</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">guard</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> a = a, </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b = </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">try</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b(), </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> c = </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">try</span><span style="font-variant-ligatures: no-common-ligatures" class=""> c() </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">else</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">nil</span><span style="font-variant-ligatures: no-common-ligatures" class=""> }</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> (a, b, c)</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> }</span></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div></div><div style="margin: 0px; line-height: normal; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">// ...etc, for higher arities than 3.</span></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div></div></div></div><div class="">Repetitive library code? Yes. But can be easily generated with a code generator such as swift.gyb, and you hardly need it for arities higher than a few.</div><div class=""><br class=""></div><div class="">You can use `unwrap()` together with `if let` or `guard let`:</div><div class=""><br class=""></div><div class=""><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: #bb2ca2" class="">if</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> (a, b, c) = </span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">unwrap</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"1"</span><span style="font-variant-ligatures: no-common-ligatures" class="">), </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Double</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"12"</span><span style="font-variant-ligatures: no-common-ligatures" class="">), </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Bool</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"true"</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;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">print</span><span style="font-variant-ligatures: no-common-ligatures" class="">(a, b, c) </span><span style="font-variant-ligatures: no-common-ligatures; color: #008400" class="">//=> 1 12.0 true</span></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></div></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div class="">Or even `.map()` if you like. This use is similar to Dave Sweeris' suggestion of `optionally()`:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">struct</span><span style="font-variant-ligatures: no-common-ligatures" class=""> User { </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(187, 44, 162);" class="">var</span><span style="font-variant-ligatures: no-common-ligatures;" class=""> username,</span><span style="font-variant-ligatures: no-common-ligatures;" class=""> language: </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(112, 61, 170);" class="">String </span>}</div><div style="margin: 0px; line-height: normal; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures;" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(187, 44, 162);" class="">let</span><span style="font-variant-ligatures: no-common-ligatures;" class=""> data = [</span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"u"</span><span style="font-variant-ligatures: no-common-ligatures;" class="">: </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"chris"</span><span style="font-variant-ligatures: no-common-ligatures;" class="">, </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"l"</span><span style="font-variant-ligatures: no-common-ligatures;" class="">: </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"swift"</span><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; line-height: normal; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures;" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(187, 44, 162);" class="">let</span><span style="font-variant-ligatures: no-common-ligatures;" class=""> user = </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(49, 89, 93);" class="">unwrap</span><span style="font-variant-ligatures: no-common-ligatures;" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(79, 129, 135);" class="">data</span><span style="font-variant-ligatures: no-common-ligatures;" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"u"</span><span style="font-variant-ligatures: no-common-ligatures;" class="">], </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(79, 129, 135);" class="">data</span><span style="font-variant-ligatures: no-common-ligatures;" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(209, 47, 27);" class="">"l"</span><span style="font-variant-ligatures: no-common-ligatures;" class="">]).</span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(61, 29, 129);" class="">map</span><span style="font-variant-ligatures: no-common-ligatures;" class=""> {u, l </span><span style="font-variant-ligatures: no-common-ligatures; color: rgb(187, 44, 162);" class="">in</span><span style="font-variant-ligatures: no-common-ligatures" class=""></span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">User</span><span style="font-variant-ligatures: no-common-ligatures" class="">(username: u, language: l)</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> }</span></div><div style="margin: 0px; line-height: normal;" class=""><div style="margin: 0px; line-height: normal; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">print</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">user</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class="">) </span><span style="font-variant-ligatures: no-common-ligatures" class="">//=> Optional(User(username: "chris", language: "swift"))</span></div></div></div></div><div class=""><br class=""></div><div class="">I guess that reads better than this equivalent with `.flatMap()` and `.map()`:</div><div class=""><br class=""></div><div class=""><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: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> user = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">data</span><span style="font-variant-ligatures: no-common-ligatures" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"u"</span><span style="font-variant-ligatures: no-common-ligatures" class="">].</span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">flatMap</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { u </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">in</span></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: #4f8187" class="">data</span><span style="font-variant-ligatures: no-common-ligatures" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"l"</span><span style="font-variant-ligatures: no-common-ligatures" class="">].</span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">map</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { l </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">in</span></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: #4f8187" class="">User</span><span style="font-variant-ligatures: no-common-ligatures" class="">(username: u, language: l)</span></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></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></div></div><div class=""><br class=""></div><div class="">OTOH, it isn't much better than either delayed `let` initialisation:</div><div class=""><br class=""></div><div class=""><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: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> user: </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">User</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;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">if</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> u = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">data</span><span style="font-variant-ligatures: no-common-ligatures" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"u"</span><span style="font-variant-ligatures: no-common-ligatures" class="">], </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> l = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">data</span><span style="font-variant-ligatures: no-common-ligatures" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"l"</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;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">user</span><span style="font-variant-ligatures: no-common-ligatures" class=""> = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">User</span><span style="font-variant-ligatures: no-common-ligatures" class="">(username: u, language: l)</span></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: #bb2ca2" class="">else</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;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">user</span><span style="font-variant-ligatures: no-common-ligatures" class=""> = </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">nil</span></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></div></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div class="">Or the use of a one-off closure like so:</div><div class=""><br class=""></div><div class=""><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: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> user: </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">User</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;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">guard</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> u = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">data</span><span style="font-variant-ligatures: no-common-ligatures" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"u"</span><span style="font-variant-ligatures: no-common-ligatures" class="">], </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> l = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">data</span><span style="font-variant-ligatures: no-common-ligatures" class="">[</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"l"</span><span style="font-variant-ligatures: no-common-ligatures" class="">] </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">else</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">nil</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;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">return</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">User</span><span style="font-variant-ligatures: no-common-ligatures" class="">(username: u, language: l)</span></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></div></div><div class=""><br class=""></div><div class="">— Pyry</div><div class=""><br class=""></div><div class=""><div class="">(Sorry for the sparing use of newlines in the examples above. Tried to keep it tight.)</div></div><div class=""><br class=""></div></body></html>