Book Image

Mastering macOS Programming.

By : Stuart Grimshaw, Gregory Casamento
Book Image

Mastering macOS Programming.

By: Stuart Grimshaw, Gregory Casamento

Overview of this book

macOS continues to lead the way in desktop operating systems, with its tight integration across the Apple ecosystem of platforms and devices. With this book, you will get an in-depth knowledge of working on macOS, enabling you to unleash the full potential of the latest version using Swift 3 to build applications. This book will help you broaden your horizons by taking your programming skills to next level. The initial chapters will show you all about the environment that surrounds a developer at the start of a project. It introduces you to the new features that Swift 3 and Xcode 8 offers and also covers the common design patterns that you need to know for planning anything more than trivial projects. You will then learn the advanced Swift programming concepts, including memory management, generics, protocol orientated and functional programming and with this knowledge you will be able to tackle the next several chapters that deal with Apple’s own Cocoa frameworks. It also covers AppKit, Foundation, and Core Data in detail which is a part of the Cocoa umbrella framework. The rest of the book will cover the challenges posed by asynchronous programming, error handling, debugging, and many other areas that are an indispensable part of producing software in a professional environment. By the end of this book, you will be well acquainted with Swift, Cocoa, and AppKit, as well as a plethora of other essential tools, and you will be ready to tackle much more complex and advanced software projects.
Table of Contents (28 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface
18
LLDB and the Command Line

Logging with special literals


Among the reserved keywords of Swift are a small number of what Apple calls special literals. These are keywords that are substituted at compile time, and four of them are very useful for debugging purposes. They are as follows:

  • #function, which is converted into a String of the name of the function in which the literal is used
  • #file, which is converted into a String containing the path to the file in which the literal is used, starting with:
      /Users/...
  • #line and #column are converted to an Int of the line and column number at which they appear

For any kind of ad-hoc debugging, or custom debugging classes, these are an essential tool. Add the following code to the AppDelegate.swift file's applicationDidFinishLaunching method (or anywhere else, for that matter):

    print("Function: \(#function)") 
    print("File: \(#file)") 
    print("Line: \(#line)") 
    print("Column: \(#column)") 

The output from this code will look something like the following:

Function...