> On 27 Jun 2017, at 20:23, Dave DeLong via swift-evolution > <swift-evolution@swift.org> wrote: > > Also a +1 from me. This is something I always put in to my code. > > I agree that having `Never` as a bottom type is interesting, but even if that > were the case, the proposed “!!” operator is still useful, because it > short-circuits having to fatalError() myself. IE: > > let last = array.last ?? fatalError(“array must not be empty”)
The above solution with Never is the better solution IMHO: No new operator More flexible: what if you want something else than a fatalError? For example, I might want to define a logAndFatalError() function which stores the error to a log file before trapping. > vs > > let last = array.last !! “Array must not be empty" > > I also think having it “fatalError” in shipping code is fine, because it’s > equivalent to what would happen if you incorrect force-unwrap. > > Dave > >> On Jun 27, 2017, at 12:08 PM, Zach Waldowski via swift-evolution >> <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: >> >> Big +1. >> >> Using `!` is widely seen as a smell. However, the need for it still arises; >> they are preconditions, of a sort. It has become prevalent in my teams’ >> codebases to do “guard else preconditionFailure”. >> >> I like `!!` over something like `?!`; it follows the pattern that almost >> every `?` in the language has an equivalent `!`. >> >> The implementation details are ultimately not relevant to me. I’m a fan of >> `Never` being a bottom type for more reasons than just this. I also see no >> reason why operator funcs couldn’t accept file and line as extra arguments >> on the rhs. >> >> Best, >> Zachary Waldowski >> z...@waldowski.me <mailto:z...@waldowski.me> >> >> On Tue, Jun 27, 2017, at 01:16 PM, Erica Sadun via swift-evolution wrote: >>> Using an operator to provide feedback on the context of a failed unwrap has >>> become a commonly implemented approach in the Swift developer Community. >>> What are your thoughts about adopting this widely-used operator into the >>> standard library? >>> >>> guard !lastItem.isEmpty else { return } >>> let lastItem = array.last !! "Array must be non-empty" >>> >>> Details here: >>> https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b >>> <https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b> >>> >>> Thank you for your thoughtful feedback, -- E >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> swift-evolution@swift.org <mailto:swift-evolution@swift.org> >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> <https://lists.swift.org/mailman/listinfo/swift-evolution> >> >> _______________________________________________ >> swift-evolution mailing list >> swift-evolution@swift.org <mailto: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
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