CountDown.swift

import Foundation

public typealias CompletionHandler = () -> Void

protocol CountDown: NSObjectProtocol {
    // 1
    var timeElapsed: TimeInterval {get set}
    var timeLimit: TimeInterval {get set}
    
    // 2 
    var isFinished: Bool {get}
    var isRunning: Bool {get}
    
    // 3
    /// Executed on completion
    var completion: CompletionHandler? {get set}
    /// Executed every iteration
    var repeatingTask: CompletionHandler? {get set}
    
    // 4
    func start()
    func stop()
    func reset()
    func restart()
}