What about calling a framework variadic function that I could not re-declare? like print
> 在 2017年12月2日，上午1:26，Tino Heth <[email protected] <mailto:[email protected]>> 写道： > > There has been a solution to the same problem that’s imho much nicer, because > instead of adding fundamental new syntax, it removes a piece of C-legacy: > > Basically,instead of > func f(args: Int…) > you would just declare > func f(args: @variadic [Int]) > or even > func f(args: [Int]) > and interpret any argument that’s a comma-separated list as an array — or, > and that’s imho another useful aspect, something else that can be expressed > with an array literal > func f(args: Set<Int>) > > So you would not only make the language surface smaller, but also add new > abilities that basically come for free (they would still have to be > implemented, though ;-) > >> Am 30.11.2017 um 22:13 schrieb Cao, Jiannan via swift-evolution >> <[email protected] <mailto:[email protected]>>: >> >> What happened with this proposal? This looks easy to implement. >> >> func sumOf(numbers: Int...) -> Int { >> ... >> } >> typealias Function = [Int] -> Int >> let sumOfArray = unsafeBitCast(sumOf, Function.self) >> sumOfArray([1, 2, 3]) >> >>> Hello everyone. >>> >>> I understand that topic has already been discussed in the past, but I >>> failed to get any information on its current state of affairs. >>> >>> I guess the subject of this mail is explicit, but to make sure I’m clear, >>> here's a small snippet that illustrates the problem: >>> >>> func f(args: Int…) { >>> // Some implementation ... >>> } >>> // Now it's impossible to call f without explicitly naming its parameters. >>> >>> For many use-cases, this problem can be solved by overloading f so that it >>> explicitly accepts an array. >>> >>> func f(_ args: [Int]) { >>> // Some implementation ... >>> } >>> >>> func f(_ args: Int…) { >>> f(args) >>> } >>> >>> Some people also advocate (myself generally included) that one should >>> prefer the signature explicitly marking args as an array, as the syntactic >>> overhead of wrapping the arguments with “[]” when calling f is arguably >>> bearable. However, in some other situations, this approach might not be >>> applicable. For instance, one may simply not be able to modify the original >>> function. Another use-case may be a function that should forward its own >>> variadic parameters. >>> >>> In a variety of other languages, there exists a way to do this. For >>> instance, Python can “unpack” (or splat) a list into function arguments by >>> prefixing it with *: >>> >>> def f(*args): >>> # Some implementation … >>> >>> f(*[1, 2, 3]) # == f(1, 2, 3) >>> >>> I was wondering if such feature could be supported by Swift, and if not, >>> why. >>> >>> Syntactically, I like the use of “…”, which would mirror function >>> signatures: >>> >>> f(…[1, 2, 3]) // == f(1, 2, 3) >>> >>> Thanks. >>> >>> -- >>> Dimitri Racordon >> >> _______________________________________________ >> swift-evolution mailing list >> [email protected] <mailto:[email protected]> >> https://lists.swift.org/mailman/listinfo/swift-evolution >> <https://lists.swift.org/mailman/listinfo/swift-evolution> >
_______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
