Erik Flores erikfloresq

Async/Await for Swift

Proposal: SE-XXXX
Authors: Chris Lattner, Joe Groff

Introduction

Modern Cocoa development involves a lot of asynchronous programming using closures and completion handlers, but these APIs are hard to use. This gets particularly problematic when many asynchronous operations are used, error handling is required, or control flow between asynchronous calls gets complicated. This proposal describes a language extension to make this a lot more natural and less error prone.

This paper introduces a first class Coroutine model to Swift. Functions can opt into to being async, allowing the programmer to compose complex logic involving asynchronous operations, leaving the compiler in charge of producing the necessary closures and state machines to implement that logic.

NOTE (2022-07-09): Xcode finally added this functionality in Xcode 14, please see release notes here:

New Features in Xcode 14 Beta 3
When editing code, the Edit > Duplicate menu item and its corresponding keyboard shortcut now duplicate the selected text — or the line that currently contains the insertion point, if no text is selected. (8614499) (FB5618491)

Xcode line duplicate

Bind keys to duplicate lines in Xcode

Async semantics proposal for Swift

Modern Cocoa development involves a lot of asynchronous programming using blocks and NSOperations. A lot of APIs are exposing blocks and they are more natural to write a lot of logic, so we'll only focus on block-based APIs.

Block-based APIs are hard to use when number of operations grows and dependencies between them become more complicated. In this paper I introduce asynchronous semantics and Promise type to Swift language (borrowing ideas from design of throw-try-catch and optionals). Functions can opt-in to become async, programmer can compose complex logic involving asynchronous operations while compiler produces necessary closures to implement that logic. This proposal does not propose new runtime model, nor "actors" or "coroutines".

Videos

Introduction to Functional Programming Johannes Weiß - https://vimeo.com/100786088
ReactiveCocoa at MobiDevDay Andrew Sardone - https://vimeo.com/65637501
The Future Of ReactiveCocoa Justin Spahr-Summers - https://www.youtube.com/watch?v=ICNjRS2X8WM
Enemy of the State Justin Spahr-Summers - https://www.youtube.com/watch?v=7AqXBuJOJkY
WWDC 2014 Session 229 - Advanced iOS Application Architecture and Patterns Andy Matuschak - https://developer.apple.com/videos/play/wwdc2014/229/
Functioning as a Functionalist Andy Matuschak - https://www.youtube.com/watch?v=rJosPrqBqrA
Controlling Complexity in Swift Andy Matuschak - https://realm.io/news/andy-matuschak-controlling-complexity/

	import UIKit

	/// Represents a single `NSLayoutConstraint`
	enum LayoutAnchor {
	case constant(attribute: NSLayoutConstraint.Attribute,
	relation: NSLayoutConstraint.Relation,
	constant: CGFloat)

	case relative(attribute: NSLayoutConstraint.Attribute,
	relation: NSLayoutConstraint.Relation,

	// First, install InjectionIII.app from the Mac AppStore
	// https://apps.apple.com/us/app/injectioniii/id1380446739?mt=12

	// Make these changes to your code:

	// add the following to application(didFinishLaunchingWithOptions:)
	#if DEBUG
	Bundle(path: "/Applications/InjectionIII.app/Contents/Resources/iOSInjection.bundle")?.load()
	#endif

	#!/usr/bin/env ruby

	print "What is the URL of your Apple Downloads resource?\nURL:"
	url = gets.strip

	print "What is the ADCDownloadAuth cookie token:\nADCDownloadAuth: "
	token = gets.strip

	command = "aria2c --header \"Host: adcdownload.apple.com\" --header \"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8\" --header \"Upgrade-Insecure-Requests: 1\" --header \"Cookie: ADCDownloadAuth=#{token}\" --header \"User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 10_1 like Mac OS X) AppleWebKit/602.2.14 (KHTML, like Gecko) Version/10.0 Mobile/14B72 Safari/602.1\" --header \"Accept-Language: en-us\" -x 16 -s 16 #{url} -d ~/Downloads"

	//: Playground - noun: a place where people can play

	import UIKit

	protocol SectionModel {
	var count: Int { get }

	func cell(at: Int) -> UITableViewCell
	func selected(at: Int)
	}

	@IBDesignable
	class UIPaddedLabel:UILabel {
	@IBInspectable var topPadding:CGFloat = 0 {
	didSet {
	updatePadding()
	}
	}

	@IBInspectable var leftPadding:CGFloat = 0 {
	didSet {

Erik Flores erikfloresq

Async/Await for Swift

Introduction

Xcode line duplicate

Bind keys to duplicate lines in Xcode

Async semantics proposal for Swift

Table of contents

Videos

English learning

Books

Desktop / Mobile apps

Word Pronunciation