Book Image

Swift 3 New Features

By : Keith Elliott
Book Image

Swift 3 New Features

By: Keith Elliott

Overview of this book

Since Swift was introduced by Apple in WWDC 2015, it has gone on to become one of the most beloved languages to develop iOS applications with. In the new version, the Swift team aimed to take its adoption to the next level by making it available for new platforms and audiences. This book will very quickly get you up to speed and productive with Swift 3. You will begin by understanding the process of submitting new feature requests for future versions of Swift. Swift 3 allows you to develop and run your applications on a Linux machine. Using this feature, you will write your first Linux application using the debugger in Linux. Using Swift migrator, you will initiate a conversion from Swift 2.2 to Swift 3. Further on, you will learn how to interact with Cocoa libraries when importing Objective C to Swift. You will explore the function and operator changes new to Swift 3, followed by Collection and Closure changes. You will also see the changes in Swift 3 that allow you write tests easier with XCTest and debug your running code better with new formats as well. Finally, you will have a running server written completely in Swift on a Linux box. By the end of the book, you will know everything you need to know to dive into Swift 3 and build successful projects.
Table of Contents (16 chapters)
Swift 3 New Features
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
5
Function and Operator Changes – New Ways to Get Things Done

A new model for collections and indices [SE-0065]


Swift 3 introduces a new model for collections that moves the responsibility of the index traversal from the index to the collection itself. To make this a reality for collections, the Swift team introduced four areas of change:

  • The Index property of a collection can be any type that implements the Comparable protocol

  • Swift removes any distinction between intervals and ranges; leaving just ranges

  • Private index traversal methods are now public

  • Changes to ranges make closed ranges work without the potential for errors

Note

You can read the proposal at the following link https://github.com/apple/swift-evolution/blob/master/proposals/0065-collections-move-indices.md

Introducing the Collection protocol

In Swift 3, Foundation collection types such as Arrays, Dictionaries, and Sets are generic types that implement the newly created Collection protocol. This change was needed in order to support traversal on the collection. If you want to create custom...