RxSwift触ってみた ref: http://qiita.com/jollyjoester/items/c4013c60acd453ea7248

file1.sh

$ pod install
...
Installing RxBlocking (2.4)
Installing RxCocoa (2.4)
Installing RxSwift (2.4)
Installing RxTests (2.4)
...

file2.txt

Xcode
Version 7.3 (7D175)

pod --version
0.39.0

Podfile

use_frameworks!

target 'RxSwiftSample' do
    pod 'RxSwift',    '~> 2.0'
    pod 'RxCocoa',    '~> 2.0'
end

# RxTests and RxBlocking have most sense in the context of unit/integration tests
target 'RxSwiftSampleTest' do
    pod 'RxBlocking', '~> 2.0'
    pod 'RxTests',    '~> 2.0'
end

UITextField+Rx.swift

extension UITextField {
    /**
    Reactive wrapper for `text` property.
    */
    public var rx_text: ControlProperty<String> {
        return UIControl.rx_value(
            self,
            getter: { textField in
                textField.text ?? ""
            }, setter: { textField, value in
                textField.text = value
            }
        )
    }
}

ViewController.swift

import UIKit

class ViewController: UIViewController {

    // for existing impl
    @IBOutlet weak var label2: UILabel!
    @IBOutlet weak var textField2: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()

        // for existing impl
        label2.text = "「」"
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(UITextInputDelegate.textDidChange(_:)), name: UITextFieldTextDidChangeNotification, object: self.textField2)
    }

    // ...  

    func textDidChange(notification: NSNotification) {
        if let text = textField2.text {
            label2.text = "「\(text)」"
        }
    }

    deinit {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }
}