levibostian

import CoreData
import Foundation

protocol CoreDataManager {
    var uiContext: NSManagedObjectContext { get }
    func newBackgroundContext() -> NSManagedObjectContext
    func performBackgroundTaskOnUI(_ block: @escaping (NSManagedObjectContext) -> Void)
    func performBackgroundTask(_ block: @escaping (NSManagedObjectContext) -> Void)
    func loadStore(completionHandler: ((Error?) -> Void)?)
}

PaulWoodIII

//: [Previous](@previous)

import Foundation
import SwiftUI
import Combine

//: Current Value Subject is a value, a publisher and a subscriber all in one
let currentValueSubject = CurrentValueSubject<Bool, Never>(true)

print(currentValueSubject.value)

Sorix

//  Created by Vasily Ulianov on 09.02.17, updated in 2019.
//  License: MIT

import Foundation

/// Subclass of `Operation` that adds support of asynchronous operations.
/// 1. Call `super.main()` when override `main` method.
/// 2. When operation is finished or cancelled set `state = .finished` or `finish()`
open class AsynchronousOperation: Operation {
    public override var isAsynchronous: Bool {

olgakogan

extension Dictionary {

    func get(key: Key, defaultValue: Value) -> Value {
        /**
          Returns the value for the given key (if exists), otherwise returns the default value.
        */
        if let value = self[key] {
            return value
        } else {

andymatuschak

//
//  CollectionViewDataSource.swift
//  Khan Academy
//
//  Created by Andy Matuschak on 10/14/14.
//  Copyright (c) 2014 Khan Academy. All rights reserved.
//

import UIKit

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

ijoshsmith

import Foundation

extension Array
{
    /** Randomizes the order of an array's elements. */
    mutating func shuffle()
    {
        for _ in 0..<10
        {
            sort { (_,_) in arc4random() < arc4random() }