<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>I agree with you.</div><div><br></div><div>On the other hand the partial functions cannot exist outside of a total closure so I'm wondering whether it makes sense giving that concept a name. It might keep the door open to make partial functions explicit in the future, though (although I'm still not convinced we need them due to Swift's lightweight optional syntax).</div><div><br></div><div>-Thorsten </div><div><br>Am 20.01.2016 um 08:23 schrieb Craig Cruden <<a href="mailto:ccruden@novafore.com">ccruden@novafore.com</a>>:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=utf-8">Yes and No.<div class=""><br class=""></div><div class="">A single case in the closure is a partial function. The fact that you have to union them with other partial functions before you can use them inside a closure. So the closure is total, but it is composed of a union of partial functions. </div><div class=""><br class=""></div><div class="">NOTE: not necessarily union if the partials overlap but I could not think of another word.</div><div class=""><br class=""></div><div class=""><div><blockquote type="cite" class=""><div class="">On 2016-01-20, at 13:07:00, Thorsten Seitz <<a href="mailto:tseitz42@icloud.com" class="">tseitz42@icloud.com</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="">Sorry, I meant "partial function", not "partial closure".</div><div class="">In Scala that term makes sense as the partiality is exposed there. In the proposal it is not used, because totality is required. So I was thinking about dropping the term from the proposal. The alternatives section might note that Scala's partial functions were considered but that exhaustiveness checks were considered more important and partial functions might easily be simulated be returning an optional.</div><div class="">But you are right that some catching term would be needed. Hmm, maybe "case closures"?</div><div class=""><br class=""></div><div class="">-Thorsten </div><div class=""><br class=""></div><div class=""><br class="">Am 20.01.2016 um 06:32 schrieb Craig Cruden <<a href="mailto:ccruden@novafore.com" class="">ccruden@novafore.com</a>>:<br class=""><br class=""></div><blockquote type="cite" class=""><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class="">“partial closure” might not be the best term, but so far I I don’t think any of the terminology that I have heard is as short or catchy …. <div class=""><br class=""></div><div class="">But I will think about it.<br class=""><div class=""><blockquote type="cite" class=""><div class="">On 2016-01-20, at 6:10:59, Thorsten Seitz <<a href="mailto:tseitz42@icloud.com" class="">tseitz42@icloud.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;">Actually I’m not sure about introducing the term "partial closure“ because the proposal does not make use of their partiality in any way (like Scala does with the method isDefinedAt() or the chaining methods) and on the contrary requires their combination to be a total function (which is a good thing IMO). As I already wrote in another mail a couple of days before I think in Swift partial functions can simply be formulated by making the return type an optional which I think fits Swift nicely because of its lightweight syntax of optionals.</div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;">So I don’t think there is a need for partial functions in Swift and therefore I probably would not introduce that term but instead propose a new lightweight syntax for defining unary closures where</div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class="">{ x in </font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class=""> switch x {</font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class=""> case pattern: return expr</font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class=""> default: return expr</font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class=""> }</font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class="">}</font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;">can simply be written as</div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><font face="Menlo" class="">{ </font></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><div class=""><font face="Menlo" class=""> case pattern: expr</font></div><div class=""><font face="Menlo" class=""> default: expr</font></div><div class=""><font face="Menlo" class="">}</font></div></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;">Does that make sense?</div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;"><br class=""></div><div class="" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: 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;">-Thorsten</div></div></blockquote></div><br class=""></div></div></blockquote></div></div></blockquote></div><br class=""></div></div></blockquote></body></html>