<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">My expectations is that the standard operators act upon a set, changing the set.&nbsp;</div><div class=""><br class=""></div><div class=""><font face="Menlo" class="">set1.union(with: set2)</font> tells set1 to perform the union.&nbsp;</div><div class=""><font face="Menlo" class="">set1.unioned(with: set2)</font>&nbsp;creates a new instance where set1 has been unioned with set 2.</div><div class=""><br class=""></div><div class=""><b class="">Naming</b>: intersected, unioned, and exclusiveOred over intersecting, unioning, exclusiveOring.&nbsp;</div><div class=""><b class="">Mutating</b>: union, intersection, exclusiveOr.&nbsp;</div><div class=""><b class="">Non-Mutating, returning new value</b>: unioned(with), intersected(with), exclusiveOred(with)</div><div class=""><br class=""></div><div class="">Reasoning:</div><div class=""><br class=""></div><div class="">* <b class="">I think the -ing endings sound unnatural, stilted, and unmathematical. </b>They make me wince.</div><div class="">* <b class="">I think you have the nature of the words mis-assigned</b>. In my opinion in this rare case, union, intersection, and exclusiveOr&nbsp;<i class="">act as verbs</i>&nbsp;as they are mathematical set operations. For example, "what is the result of A union B?" is a reasonable thing to say to a math person or put on an exam question, etc.&nbsp;</div><div class=""><br class=""></div><div class="">Importantly, they produce significant side effects, and should be treated as verbs that operate upon the receiver, updating the receiver, establishing their use for mutating ops.</div><div class=""><br class=""></div><div class="">Dave wrote:</div><div class=""><blockquote type="cite" class="" style="font-family: Palatino-Roman;"><div class=""><blockquote type="cite" class=""><blockquote type="cite" class="">- use nouns for methods with no side effects (or only incidental ones,&nbsp; like logging)<br class="">- use verbs for methods with significant side-effects</blockquote></blockquote></div></blockquote></div><div class=""><br class=""></div><div class="">-- E</div><div class=""><br class=""></div><div><blockquote type="cite" class=""><div class="">On Feb 11, 2016, at 9:52 AM, Dave Abrahams via swift-evolution &lt;<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>&gt; wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><br class="">Hi All,<br class=""><br class="">The API guidelines working group took up the issue of the InPlace suffix<br class="">yesterday, and decided that it was not to be used anywhere in the<br class="">standard library. &nbsp;We are planning to apply the changes shown here<br class="">&lt;<a href="https://gist.github.com/dabrahams/d872556291a3cb797bd5" class="">https://gist.github.com/dabrahams/d872556291a3cb797bd5</a>&gt; to the API of<br class="">SetAlgebra (and consequently Set) to make it conform to the guidelines<br class="">under development.<br class=""><br class="">Comments welcome as usual,<br class=""><br class="">-- <br class="">-Dave<br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""></div></div></blockquote></div><br class=""></body></html>