console out

LearningCombine.playground

import UIKit
import PlaygroundSupport
import Combine

class MyViewController : UIViewController {
        
    var label: UILabel!
    var sub: AnyCancellable!
        
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white
        
        label = UILabel()
        label.frame = CGRect(x: 150, y: 200, width: 200, height: 20)
        label.text = "Hello World!"
        label.textColor = .black
        
        view.addSubview(label)
        
        let textField = UITextField()
        textField.frame = CGRect(x:150, y: 300, width: 200, height: 20)
        textField.text = "Hello World!"
        textField.textColor = .black
        
        sub = NotificationCenter.default
            .publisher(for: UITextField.textDidChangeNotification, object: textField)
            .map( { ($0.object as! UITextField).text ?? "" } )
            .filter( { $0!.unicodeScalars.allSatisfy({CharacterSet.alphanumerics.contains($0)}) } )
            .debounce(for: .milliseconds(500), scheduler: RunLoop.main)
            .receive(on: RunLoop.main)
            .assign(to: \MyViewController.label.text, on: self)
        
        view.addSubview(textField)
        
        self.view = view
    }
}
    
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()