Original iOS application before separating library

RandomGeneratorXor128.swift

//
//  RandomGeneratorXor128.swift
//  EFTest
//
//  Created by KodamaYoshinori on 2016/10/22.
//  Copyright © 2016 Yoshinori Kodama. All rights reserved.
//

class RandomGeneratorXor128 {
    static var seed: Int = 19937
    static var generator: () -> RandomGeneratorXor128 = {
        return RandomGeneratorXor128(seed: RandomGeneratorXor128.seed)
    }
    
    var seed: UInt64
    
    var x: UInt64
    var y: UInt64
    var z: UInt64
    var w: UInt64
        
    private init(seed: Int) {
        self.seed = UInt64.init(abs(seed))
        self.x = 123456789
        self.y = 362436069
        self.z = 521288629
        self.w = 88675123
//        print("seed used: \(seed)")
        self.z ^= self.seed
        self.z ^= z >> 21; z ^= z << 35; z ^= z >> 4
        self.z = self.z &* 2685821657736338717
//        print("and z is initialized to: \(z)")
    }
    
    func xor128() -> UInt64 {
        let t = x ^ (x << 11)
        x = y; y = z; z = w;
        w = (w ^ (w >> 19)) ^ (t ^ (t >> 8))
        
//        print("\(x), \(y), \(z), \(w)")     // debug print
        
        return w
    }
    
    func getNextRandomUInt() -> UInt {
        return UInt.init(truncatingBitPattern: xor128())
    }
    
    func getNextRandomInt() -> Int {
        return Int.init(truncatingBitPattern: xor128())
    }
}

ViewController.swift

//
//  ViewController.swift
//  EF_Test
//
//  Created by KodamaYoshinori on 2016/10/24.
//  Copyright © 2016 Yoshinori Kodama. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var randomButton: UIButton!
    
    var randHelper: RandomGeneratorXor128? = nil

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let seed = Date().hashValue
        RandomGeneratorXor128.seed = seed
        print("Seed set: \(seed)")
        randHelper = RandomGeneratorXor128.generator()
        _ = randHelper!.getNextRandomInt()
        _ = randHelper!.getNextRandomInt()
        _ = randHelper!.getNextRandomInt()
        _ = randHelper!.getNextRandomInt()

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func randomButtonPressed(_ sender: AnyObject) {
        let rand = randHelper!.getNextRandomUInt()
        randomButton.setTitle("\(rand)", for: .normal)
    }

}