<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="">This would make sense as an operator (or actually it would have to be a keywod):</div><div class=""><br class=""></div><div class="">return not self.lanes[...].contains(.Gap)</div><div class=""><br class=""></div><div class="">Or if you don't mind having { } around the expression it could be defined as a function:</div><div class=""><br class=""></div><div class="">func not(@noescape block: (Void) -> Bool) rethrows -> Bool { return !block() }</div><div class=""><br class=""></div><div class="">Then you can have</div><div class=""><br class=""></div><div class="">return not { self.lanes[...].contains(.Gap) }</div><div class=""><br class=""></div><div class="">But I am personally not a fan of this.</div><div class=""><br class=""></div><div class="">Charlie</div><br class=""><div><blockquote type="cite" class=""><div class="">On May 21, 2016, at 4:50 PM, Антон Миронов 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 style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">I found negation operator (!) the least detectable among the code. So I’ve decided to add property “not” to BooleanType (Swift 2.2) or Boolean on 3.0 with extension:<div class=""><br class=""></div><div class="">extension BooleanType {</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>var not: Bool { return !self.boolValue }</div><div class="">}<br class=""><div class=""><div class=""><br class=""></div><div class="">This is code with negation operator:</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>return !self.lanes[position.y][currentLaneRange].contains(.Gap)</div></div></div><div class=""><div class=""><div class=""><br class=""></div><div class="">As I sad before negation operation is hard to spot. Moreover at first it looks like I’m trying to negate self for some reason.</div><div class=""><br class=""></div><div class="">This is code with “not” property:</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>return self.lanes[position.y][currentLaneRange].contains(.Gap).not</div></div></div><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;" class=""><div class=""><br class=""></div></blockquote><div class=""><div class="">Now it is easy to spot the statement I am actually getting negation of.</div><div class="">On my experience negation operator can occasionally be missed while reading code. This happens less often with “not” property. So I’m proposing to add this property to standard library and prefer it in most cases.</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Anton Mironov</div></div><div class=""><br class=""></div></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>