How to implement PIN input with attempts about reactivecocoa HOT 1 CLOSED

extension SignalProducer {
    public func repeatWhile(upTo: Int, predicate: @escaping (Self.Value) -> Bool) -> SignalProducer<Self.Value, Self.Error> {
        return flatMap(.latest) { (value) -> SignalProducer<Self.Value, Error> in
            if predicate(value) && upTo > 0 {
                return self.producer.repeatWhile(upTo: upTo - 1, predicate: predicate)
            } else {
                return .init(result: .success(value))
            }
        }
    }
}

    /// Ask the user for the PIN and verify against the device up to 3 times
    /// - Returns: A producer for the pair of PIN and Verification
    func askUpToThreeTimesOrCorrectPIN() -> SignalProducer<PINVerification, Error> {
        return askAndVerify()
            .repeatWhile(upTo: 3, predicate: { (pinVerification) -> Bool in
                return pinVerification.1 != .correctPIN
            })
    }