locationManager.rx_didRangeBeaconsInRegion
    .sample(interval(5, MainScheduler.sharedInstance))
    .subscribeNext { (tuple: ([CLBeacon]!, CLBeaconRegion!)) in
        debugPrint("beacons: \(tuple.0), region: \(tuple.1)")
    }
    .addDisposableTo(disposeBag)

import Foundation
import UIKit
import ReactiveCocoa

class MyViewModel {
    let (changed, sink) = Signal<Void, NoError>.pipe()

    func doAction() {
        // do something
        sendNext(sink, ())
    }
}


class MyViewController : UIViewController {
    let viewModel = MyViewModel()

    override func viewDidLoad() {
        super.viewDidLoad()

        viewModel.changed |> observe(next: debugPrintln)

        viewModel.doAction()
    }
}

import Dollar

extension $ {
    class func each<T: SequenceType>(array: T, callback: (T.Generator.Element) -> ()) -> T {
        for elem in array {
            callback(elem)
        }
        return array
    }
}

$.each(["a", "b", "c"]) { (s: String) in println(s) }
$.each(["key": "val"]) { (e: (String, String)) in println("\(e.0) = \(e.1)") }
// a
// b
// c
// key = val