austinzheng

import Foundation

// Build this as an OS X command line project, then run it. It should never terminate.

enum Value<T> {
  case Nil
  case Cons(T, LinkedList<T>)
}

final class LinkedList<T> {

austinzheng

// Released under the terms of the MIT license.

struct PrefixedPostfixedSequence<T : SequenceType, U where U == T.Generator.Element> : SequenceType {
  private let sequence : T
  private let initial : U?
  private let final : U?

  init(_ sequence: T, initial: U? = nil, final: U? = nil) {
    self.sequence = sequence
    self.initial = initial

austinzheng

import UIKit

/// A very simple example view that can accept keyboard input and add or delete text from an enclosed label.
class CustomTextInputView : UIControl, UIKeyInput {

  var label : UILabel?

  override func canBecomeFirstResponder() -> Bool {
    return true
  }

austinzheng

import UIKit

// Running on Xcode 7.0 beta (7A121l)
// All running in a playground
// Open console (View -> Debug Area -> Show Debug Area)

// Define a non-generic free fn taking 1 arg
func notGeneric(x: String) {
  print("notGeneric called")
}

austinzheng

//
//  ExampleCode.swift
//

import UIKit

// MARK: - Protocol

protocol SearchQueryProviderProtocol : class {    // 'class' means only class types can implement it
  func searchQueryData() -> String

austinzheng

   PROMOTION                         DEMOTION
    (init?)                           (init)
[~~~~~~~~~~~AnyRandomAccessCollection~~~~~~~~~~~]
    ^       ^                       |       |
    |       |                       |       |
    |       |                       v       |
    |    [~~AnyBidirectionalCollection~~]   |
    |       ^                       |       |
    |       |                       |       |
    |       |                       v       v    

austinzheng

import Foundation

func main() {
  print("Starting")

  // GCD works by dispatching chunks of code (represented by closures, and called 'blocks') onto things called 'dispatch
  // queues'. These queues run the blocks, either on the main thread or in a background thread. (Queues don't correspond
  // to threads on a one-to-one basis; GCD is responsible for spinning up threads to service queues.)

  // Here's a variable representing shared state I want to manipulate from different threads.

austinzheng

(Source: https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160229/011666.html)

Introduction

The “Complete Generics” goal for Swift 3 has been fairly ill-defined thus fair, with just this short blurb in the list of goals:

Complete generics: Generics are used pervasively in a number of Swift libraries, especially the standard library. However, there are a number of generics features the standard library requires to fully realize its vision, including recursive protocol constraints, the ability to make a constrained extension conform to a new protocol (i.e., an array of Equatable elements is Equatable), and so on. Swift 3.0 should provide those generics features needed by the standard library, because they affect the standard library's ABI.

This message expands upon the notion of “completing generics”. It is not a plan for Swift 3, nor an official core team communication, but it collects the results of numerous discussions among the core team and Swift developers, both of the compiler an

austinzheng

func compare(a: Any, b: Any) -> Bool {
  if let a = a as? Equatable, a openas T {
    if let b = b as? Equatable, b openas T {
      return a == b
    }
  }
  fatalError("a and b aren't comparable")
}

austinzheng

/// A statically typed view into a get-only property.
struct TypedGetPropertyView<T> {
	/// The name of the property, as a string.
	let name : String
	
	/// The actual metatype of the property.
	let metatype : T.Type
	
	/// Get the value of the property.
	func get() -> T