Debounce & Throttle 1

Debounce.swift

import Foundation

class Debounce: DelayWork {
    
    override func run() {
        self.workItem?.cancel()
        
        let workItem = DispatchWorkItem { [weak self] in
            self?.handler?(Date())
        }
        self.workItem = workItem
        
        DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(delay), execute: workItem)
    }
}

DelayWork.swift

import Foundation

class DelayWork {
    
    typealias Handler = ((Date) -> Void)
    
    var workItem: DispatchWorkItem?
    let delay: Int!
    let handler: Handler?
    
    init(milliseconds delay: Int, handler: Handler?) {
        self.delay = delay
        self.handler = handler
    }
    
    func run() {}
}

Throttle.swift

import Foundation

class Throttle: DelayWork {
    
    override func run() {
        if self.workItem == nil {
            handler?(Date())
            
            let workItem = DispatchWorkItem { [weak self] in
                self?.workItem?.cancel()
                self?.workItem = nil
            }
            self.workItem = workItem
            
            DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(delay), execute: workItem)
        }
    }
}