Read-only and non-computed variable properties in Swift

Question

I\'m trying to figure out something with the new Apple Swift language. Let\'s say I used to do something like the following in Objective-C. I have readonly prop

Answer 1

Since there are no access controls (meaning that you can't make an access contract that differs depending on who the caller is), here's what I would do for now:

class Clock {
    struct Counter {
        var hours = 0;
        var minutes = 0;
        var seconds = 0;
        mutating func inc () {
            if ++seconds >= 60 {
                seconds = 0
                if ++minutes >= 60 {
                    minutes = 0
                    ++hours
                }
            }
        }
    }
    var counter = Counter()
    var hours : Int { return counter.hours }
    var minutes : Int { return counter.minutes }
    var seconds : Int { return counter.seconds }
    func incrementTime () { self.counter.inc() }
}

This merely adds a level of indirection, as it were, to direct access to the counter; another class can make a Clock and then access its counter directly. But the idea — i.e., the contract we're trying to make — is that another class should use the Clock's top-level properties and methods only. We can't enforce that contract, but actually it was pretty much impossible to enforce in Objective-C too.