I'd like to see this, particularly in initialisers. Objective C can have '- (instanceType) init' and '- (instanceType) initWithQualifier', where Swift can only have 'init()'.
On Wed, Feb 22, 2017 at 10:24 AM, Patrick Pijnappel via swift-evolution < swift-evolution@swift.org> wrote: > I'd like to discuss allowing a trailing 'argument label' without an actual > argument: > > func adding(_ other: Self, reportingOverflow) -> … // Actual case in > SE-104 where this came up > func tableView(_ tableView: UITableView, numberOfSections) -> Int // > Referenced as tableView(_:numberOfSections) > > As illustrated above, the way we reference functions extends very > naturally to include these. > > This would be very useful for several cases: > • Delegate methods, which currently all start with the same prefix, except > for some odd cases that really actually just needed a trailing argument > label. > • Cases where the function is a more specialized version of one with the > same name, but can't use a flag because the return type is different (e.g. > reportingOverflow), or the extra flag check is just undesirable. The > standard library now uses some workarounds to achieve this (e.g. having a > trailing argument of type void). > • Function names that just work more naturally with some additional words > after the last argument. If we allow trailing argument labels, you can form > any sentence, rounding out the syntax. > > Overall, I think this could be the final missing piece to complete Swift's > functions-as-sentences approach. > > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution > >
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