I also avoid using ! for negation when possible, and `toggle` or `invert` will be helpful, but in many cases I think the negative case is better expressed directly. For example, I find that using `nonEmpty` instead of !isEmpty makes the code easier to read:
extension String { var nonEmpty: Bool { return !self.isEmpty } } if !string.isEmpty { … } if string.isEmpty.inverted() { … } if string.nonEmpty { … } For the case of `contains`, maybe define `lacks`? if !items.contains(item) { ... } if items.contains(item).inverted() { ... } if items.lacks(item) { ... } Anders Kierulf > On Jan 12, 2018, at 12:54 PM, Alejandro Martinez via swift-evolution > <swift-evolution@swift.org> wrote: > > I wouldn't go as far as to ask to fade out ! but in all my code I end > up doing == false just for readability. That ! knows who to hide > himself too well :P > > On Fri, Jan 12, 2018 at 10:13 AM, Adrian Zubarev via swift-evolution > <swift-evolution@swift.org> wrote: >> I’m not sure if this would be considered or not, but I would like if the >> negation operator `!` would fade out. >> >> If this is ever going to a review then I’d suggest that we add a pair of >> functions, one mutating and the other non-mutating. >> >> extension Bool { >> mutating func invert() { >> self = !self >> } >> >> func inverted() { >> return !self >> } >> } >> >> I’d rather use `inverted` instead of `!` because of the readability this >> function provides. >> >> if !items.contains(item) { ... } >> >> if items.contains(item).inverted() { ... } >> >> —— >> >> I personally have some other extensions like: >> >> extension Bool { >> @discardableResult >> func whenTrue<T>(execute closure: () throws -> T) rethrows -> T? { >> if self { return try closure() } >> return nil >> } >> >> @discardableResult >> func whenFalse<T>(execute closure: () throws -> T) rethrows -> T? { >> if !self { return try closure() } >> return nil >> } >> } >> >> But this is more a personal preference. >> >> —— >> >> That said, if the community is fine with the `invert/inverted` pair then I’d >> say go for it ;) >> >> Am 12. Januar 2018 um 09:14:22, Nate Cook via swift-evolution >> (swift-evolution@swift.org) schrieb: >> >> >> On Jan 12, 2018, at 12:15 AM, Chris Eidhof via swift-evolution >> <swift-evolution@swift.org> wrote: >> >> Hey SE! >> >> When we have a bunch of nested structs: >> >> struct Sample { >> var bar: Bar >> } >> >> struct Bar { >> var show: Bool >> } >> >> var foo = Sample(bar: Bar(show: false)) >> >> It can be repetitive to toggle a deeply nested boolean: >> >> foo.bar.show = !foo.bar.show // duplication >> >> I sometimes add a `toggle` extension on `Bool` >> >> extension Bool { >> mutating func toggle() { >> self = !self >> } >> } >> >> This allows you to write the same code without duplication, and makes the >> intent clearer: >> >> foo.bar.show.toggle() >> >> >> I like it! >> >> In other languages, I don't think the `toggle` would make as much sense, but >> the mutable self makes this very useful. >> >> After I posted it on Twitter, it turns out I'm not the only one: >> https://twitter.com/PublicExtension/status/730434956376346624 >> >> I would have gone straight to a proposal, but I think we can do some >> bikeshedding about the name of `toggle`? >> >> >> Another verb that could work is `invert`. >> >> The `!` operator that does this is the negation operator, but I think >> `negate` could sound to some like "make this false" rather than toggling. >> >> Nate >> _______________________________________________ >> swift-evolution mailing list >> swift-evolution@swift.org >> https://lists.swift.org/mailman/listinfo/swift-evolution >> >> >> _______________________________________________ >> swift-evolution mailing list >> swift-evolution@swift.org >> https://lists.swift.org/mailman/listinfo/swift-evolution >> > > > > -- > Alejandro Martinez > http://alejandromp.com > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution _______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution