<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Tue, Dec 15, 2015 at 6:29 PM, Dave Abrahams via swift-evolution <span dir="ltr"><<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><div>I’d like to suggest a different implementation approach that not only handles the bidirectional issue but also probably reduces the amount of code involved: create a generic <font face="Menlo">CollectionOfZeroOrOne<T></font> that wraps a <font face="Menlo">T?</font>, and implement the <font face="Menlo">x.flatmap(f)</font> where <font face="Menlo">f</font> returns an optional as <font face="Menlo">x.flatmap { CollectionOfZeroOrOne(f($0)) }</font></div></div></blockquote><div><br></div><div>What's the advantage? Why would we want to have a type that is isomorphic to Optional, except that conforms to CollectionType?</div><div><br></div><div>Dmitri </div></div><div><br></div>-- <br><div class="gmail_signature">main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if<br>(j){printf("%d\n",i);}}} /*Dmitri Gribenko <<a href="mailto:gribozavr@gmail.com" target="_blank">gribozavr@gmail.com</a>>*/</div>
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