Combine Subscriber for Medium

gistfile1.txt

final class StringSubscriber: Subscriber {
    typealias Input = [Character]
    typealias Failure = Error

    var subscription: Subscription?
    var count = 0

    func receive(subscription: Subscription) {
        self.subscription = subscription
        self.subscription?.request(.max(1))
    }

    func receive(_ input: Input) -> Subscribers.Demand {
        input.forEach({ print(count == 0 ? "Chars:" : " ", $0, terminator: ""); self.count += 1 })
        subscription?.request(.max(1))
        return .max(1)
    }

    func receive(completion: Subscribers.Completion<Failure>) {
        print("\nSubscriber completion: \(completion)")
        self.subscription = nil
    }
}