Book Image

Swift High Performance

By : Kostiantyn Koval
Book Image

Swift High Performance

By: Kostiantyn Koval

Overview of this book

Swift is one of the most popular and powerful programming languages for building iOS and Mac OS applications, and continues to evolve with new features and capabilities. Swift is considered a replacement to Objective-C and has performance advantages over Objective-C and Python. Swift adopts safe programming patterns and adds modern features to make programming easier, more flexible, and more fun. Develop Swift and discover best practices that allow you to build solid applications and optimize their performance. First, a few of performance characteristics of Swift will be explained. You will implement new tools available in Swift, including Playgrounds and REPL. These will improve your code efficiency, enable you to analyse Swift code, and enhance performance. Next, the importance of building solid applications using multithreading concurrency and multi-core device architecture is covered, before moving on to best practices and techniques that you should utilize when building high performance applications, such as concurrency and lazy-loading. Finally, you will explore the underlying structure of Swift further, and learn how to disassemble and compile Swift code.
Table of Contents (15 chapters)
Swift High Performance
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Swift command line tools


In this book, we have already worked with a terminal tool—a Swift REPL console. We start it by entering the xcrun swift command in the terminal. It starts the REPL, and we can enter Swift code and evaluate it.

xcrun

To start a REPL, we actually used two tools: xcrun and swift. xcrun is an Xcode command-line tool runner. It helps you run a command-line tool by its name from the active developer directory. When you have installed many versions of Xcode, you can select which one to use while executing a command-line tool. You can do this in Xcode by going to Xcode | Preference | Locations | Command Line Tools, or by running the xcode-select command from the terminal. In this way, xcrun allows you to avoid specifying the full path in the command-line tool you want to run, and makes the process of running it much simpler.

xcrun has a few more interesting options, and you should experiment with them. To get help, run the xcrun -h help command, which is usually available...