macbellingrath

import Foundation

extension String {

    /// Returns true if a string is a valid palindrome.
    var isPalindrome: Bool {
        let scalars = utf16

        if scalars.count < 2  { return true }

macbellingrath

extension Optional {
    func flatMapWith<T, U>(_ other: T?, _ transform: (Wrapped, T) -> U?) -> U? {
        guard case .some(let `self`) = self else {
            return nil
        }
        
        guard let element = other else {
            return nil
        }
        

macbellingrath

import UIKit
import PlaygroundSupport

class FirstTable: UITableViewController, UIViewControllerTransitioningDelegate {
    
    lazy var animator = TransitionAnimator()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "reuseID")

macbellingrath

let pushTopicSubscriptionStates = ["Sports": true, "News": false]

// an array of topics that user is subscribed to
let subscribedUserTopics = pushTopicSubscriptionStates.filter {  (_, subscribed) in  subscribed }
                                                      .map { (topic, _) in topic
}

macbellingrath

/* RAC*/
let userNameStrings = userNameTextfield
                     .rac_textSignal()
                     .toSignalProducer()
                     .map { text in text as! String }
        
let passwordStrings = passwordTextfield.rac_textSignal()
                    .toSignalProducer()
                    .map { password in password as! String }