<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div><br></div><div>On Jan 17, 2017, at 03:40, Charlie Monroe via swift-evolution <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">I've come across multiple cases, where you simply know the array is never empty and hence the optionality on first, last and behavior of a few other members is slightly different. Also, there are cases where you want to declare that you shouldn't pass an empty array e.g. into an initializer.</div><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class=""><br class=""></div><div class="">I was wondering whether Swift could have a specialized NonEmptyArray that could be used throughout the stdlib - e.g. <span style="font-family: Menlo; font-size: 9px;" class="">String.components(separatedBy:)</span> would return NonEmptyArray.</div><div class=""><br class=""></div><div class="">Thoughts?</div></div></div></div></div></blockquote><br><div>I've tried to make such a type a few times... The struct itself isn't hard ("var first:T; var tail:[T]"), but I never could figure out how to make `NonEmptyArray` conform to `ExpressibleByArrayLiteral` (because the protocol doesn't allow for failable inits) without just crashing if there wasn't at least one element.</div><div><br></div><div>Anyway, I'm not opposed to adding it, as long as there's a non-crashy way to assign array literals to them.</div><div><br></div><div>- Dave Sweeris</div></body></html>