Swift与Objective－C中的闭包

Swift Code:

    func makeIncrementor(forIncrement amount: Int) -> (() -> Int,() -> Int) {

        var runningTotal = 

        func incrementor() -> Int {

            runningTotal += amount

            return runningTotal

        }

        func decrementor()->Int{

            runningTotal -= amount

            return runningTotal

        }

        runningTotal += ;

        return (incrementor,decrementor)

    }

    let counter = makeIncrementor(forIncrement: );

    let a1 = counter.();

    assert(a1==, "a1")

    let a2 = counter.();

    assert(a2==, "a2")

    let a3 = counter.();

    assert(a3==, "a3")

    let c1 = counter.();

    assert(c1==, "c1")

Objective-C Code:

        __block int runningTotal = ;

        int (^incrementor)() = ^(){
            return ++runningTotal;
        };

        int (^decrementor)() = ^(){
            return --runningTotal;
        };
        runningTotal=;
        int a1 = incrementor();
        int a2 = incrementor();
        int a3 = incrementor();
        int c1 = decrementor();