<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=""><div class="">Not to mention - mutating (in my limited and aged math knowledge) is NOT mathematical (computer simulations might use math in simulations which simulating something that mutates)</div><div class=""><br class=""></div><div class="">Mathematicians (typically) don’t mutate - they might be mutants…. but they don’t mutate their equations.</div><div class=""><br class=""></div><div class="">When was the last time you saw a mutating equation? If equations mutate then it makes it much more difficult to prove correctness.</div><div class=""><span style="color: rgb(64, 64, 64); font-family: 'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 13px; line-height: 19.994px; widows: 1; background-color: rgb(255, 255, 255);" class=""><br class=""></span></div><div style="widows: 1;" class=""><font color="#404040" face="Open Sans, Helvetica Neue, Helvetica, Arial, sans-serif" size="2" class=""><span style="background-color: rgb(255, 255, 255);" class="">Probably why even OO programming languages don’t allow you to mutate an Integer or Decimal ….. bad things can happen.</span></font></div><div class=""><br class=""></div><div class="">Union and intersection have more in common with operations like + and - which also do not mutate the values.</div><div class=""><br class=""></div><div class="">:p</div><div class=""><br class=""><blockquote type="cite" class=""><div dir="auto" class=""><blockquote type="cite" class=""><div class=""><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 <i class="">act as verbs</i> 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. </div></div></blockquote></div></blockquote></div><div class=""><div dir="auto" class=""><blockquote type="cite" class=""><div class=""><div class=""><br class=""></div></div></blockquote><br class=""></div></div><div dir="auto" class=""><br class=""></div><div class=""><div class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class=""><br class=""></div></div></div></div><div class=""><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class=""><br class=""></div></div></div><div><blockquote type="cite" class=""><div class="">On 2016-02-12, at 22:20:01, Thorsten Seitz 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="">I beg to disagree with your reasoning.</div><div class="">I think "union" is more commonly used as a noun and "intersection" certainly is not a verb. Your example sounded weird for me (but maybe that's because I'm not a native speaker) and I would rather expect the question to be "What is the union of A and B?"</div><div class=""><br class=""></div><div class="">-Thorsten </div><div class=""><br class="">Am 11.02.2016 um 20:09 schrieb Erica Sadun via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>>:<br class=""><br class=""></div><blockquote type="cite" class=""><div class=""><meta http-equiv="Content-Type" content="text/html charset=us-ascii" class=""><div class="">My expectations is that the standard operators act upon a set, changing the set. </div><div class=""><br class=""></div><div class=""><font face="Menlo" class="">set1.union(with: set2)</font> tells set1 to perform the union. </div><div class=""><font face="Menlo" class="">set1.unioned(with: set2)</font> 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. </div><div class=""><b class="">Mutating</b>: union, intersection, exclusiveOr. </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 <i class="">act as verbs</i> 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. </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, 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 class=""><blockquote type="cite" class=""><div class="">On Feb 11, 2016, at 9:52 AM, Dave Abrahams 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=""><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. We are planning to apply the changes shown here<br class=""><<a href="https://gist.github.com/dabrahams/d872556291a3cb797bd5" class="">https://gist.github.com/dabrahams/d872556291a3cb797bd5</a>> 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=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></div></blockquote></div><br class=""></div></blockquote><blockquote type="cite" class=""><div class=""><span class="">_______________________________________________</span><br class=""><span class="">swift-evolution mailing list</span><br class=""><span class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a></span><br class=""><span class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br class=""></div></blockquote></div>_______________________________________________<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></blockquote></div><br class=""></body></html>