myell0w

/// Used to identify traits of the current UI Environment - especially useful for cross-platform code
public struct MNCUITraits: Withable {

    /// Does *not* identify the device type, but the idiom of the layout to apply
    /// This means that e.g. on iPad the layoutIdiom can be `.phone`, if run in Split Screen or SlideOver
    public enum LayoutIdiom {
        case phone(hasRoundCorners: Bool)
        case pad(hasRoundCorners: Bool)
        case mac
    }

timonus

- (UIImage *)dynamicImage
{
    UITraitCollection *const baseTraitCollection = /* an existing trait collection */;
    UITraitCollection *const lightTraitCollection = [UITraitCollection traitCollectionWithTraitsFromCollections:@[baseTraitCollection, [UITraitCollection traitCollectionWithUserInterfaceStyle:UIUserInterfaceStyleLight]]];
    UITraitCollection *const purelyDarkTraitCollection = [UITraitCollection traitCollectionWithUserInterfaceStyle:UIUserInterfaceStyleDark];
    UITraitCollection *const darkTraitCollection = [UITraitCollection traitCollectionWithTraitsFromCollections:@[baseTraitCollection, purelyDarkTraitCollection]];
    
    __block UIImage *lightImage;
    [lightTraitCollection performAsCurrentTraitCollection:^{
        lightImage = /* draw image */;

dennisvennink

extension Sequence {
  var headAndTail: (head: Element, tail: SubSequence)? {
    var head: Element?

    let tail = drop {
      if head == nil {
        head = $0

        return true
      } else {

AdamLantz

//Swift 4 modifications for this gist: https://gist.github.com/krooked/9c4c81557fc85bc61e51c0b4f3301e6e
import Foundation
import UIKit

extension UIImage {
    func cropImageByAlpha() -> UIImage {
        let cgImage = self.cgImage
        let context = createARGBBitmapContextFromImage(inImage: cgImage!)
        let height = cgImage!.height
        let width = cgImage!.width

lattner

Swift Concurrency Manifesto

Author: Chris Lattner

Chinese Translation by Jason Yu

Contents

• Introduction
• Overall Vision

chriseidhof

import Foundation

// A lens is a getter and a setter combined
struct Lens<Whole, Part> {
    let get: (Whole) -> Part
    let set: (inout Whole, Part) -> ()
}

// We can create a lens from a key path
extension Lens {

alessaba

// Swift Playgrounds Beta 1.0
import AVFoundation
import AVKit
import Accelerate
import Accounts
import AudioToolbox
import AudioUnit
import CFNetwork
import CoreAudio
import CoreAudioKit

irace

/**
 *  A class that can be part of a tabbed navigational interface (expected to be a `UIViewController` but can also be a 
 *  coordinator that proxies through to an underlying controller).
 */
public protocol TabComponent {
    /// The tab metadata
    var tabItem: TabItem { get }

    var viewController: UIViewController { get }
}

andymatuschak

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

krzyzanowskim

// http://blog.krzyzanowskim.com

import Cocoa

struct ChunkSequence<Element>: SequenceType {
    let chunkSize: Array<Element>.Index
    let collection: Array<Element>

    func generate() -> AnyGenerator<ArraySlice<Element>> {
        var offset:Array<Element>.Index = collection.startIndex