Bind feature with Swift from scratch

Bindable.swift

import UIKit

public class Variable<T: Equatable> {
    public var value: T {
        didSet {
            obserbers.forEach {
                $0(value)
            }
        }
    }
    
    public init(_ value: T) {
        self.value = value
    }
    
    public func update(_ value: T) {
        self.value = value
    }
    
    public typealias Observer = (T) -> ()
    var obserbers: [Observer] = []
    public func observe(_ observer: @escaping Observer) {
        obserbers.append(observer)
    }
}

public class UIControlObserver <T: UIControl & Bindable>: NSObject {
    deinit {
        subscribers.forEach { (subscriber) in
            value.removeTarget(self, action: #selector(handle(control:)), for: subscriber.events)
        }
    }
    
    public let value: T
    public init(_ value: T) {
        self.value = value
        super.init()
    }
    
    public typealias Subscriber = (events: UIControlEvents, handler: (T) -> ())
    
    var subscribers: [Subscriber] = []
    
    public func observe(for events: UIControlEvents, and handler: @escaping (T) -> ()) {
        value.addTarget(self, action: #selector(handle(control:)), for: events)
        subscribers.append((events, handler))
        value.sendActions(for: events)
    }
    
    public func bind(to variable: Variable<T.BindingType>, events: UIControlEvents = .allEditingEvents) {
        self.observe(for: events) { [weak variable] (value) in
            variable?.update(value.observingValue())
        }
    }
    
    @objc private func handle(control: UIControl) {
        subscribers.forEach { (subscriber) in
            subscriber.handler(value)
        }
    }
}

public protocol Bindable: NSObjectProtocol {
    associatedtype BindingType: Equatable
    func observingValue() -> BindingType
    func updateValue(with value: BindingType)
}

extension UITextField : Bindable {
    public typealias BindingType = String
    
    public func observingValue() -> String {
        return self.text ?? ""
    }
    
    public func updateValue(with value: String) {
        self.text = value
    }
}

extension UITextView : Bindable {
    public typealias BindingType = String
    
    public func observingValue() -> String {
        return self.text
    }
    
    public func updateValue(with value: String) {
        self.text = value
    }
}

extension UISwitch : Bindable {
    public typealias BindingType = Bool
    
    public func observingValue() -> Bool {
        return self.isOn
    }
    
    public func updateValue(with value: Bool) {
        self.isOn = value
    }
}

extension UISlider : Bindable {
    public typealias BindingType = Float
    
    public func observingValue() -> Float {
        return self.value
    }
    
    public func updateValue(with value: Float) {
        self.value = value
    }
}

extension UIStepper : Bindable {
    public typealias BindingType = Double
    
    public func observingValue() -> Double {
        return self.value
    }
    
    public func updateValue(with value: Double) {
        self.value = value
    }
}

let textField = UIControlObserver<UITextField>(UITextField())
let text = Variable<String>("")
textField.bind(to: text)

textField.value.text = "hello"
textField.value.sendActions(for: .editingChanged)
textField.value.text = "world"
textField.value.sendActions(for: .editingChanged)

text.value