Available from Gumroad
"The Case of the Vanishing Bodies" is an introduction to the magic of freestanding and attached Swift Macros.
There's a fair amount of boilerplate code involved in so many of our everyday tasks as Swift programmers. Until Xcode 15, every time we created a new SwiftUI View we had to create the corresponding preview code. The struct and computed property weren't interesting in any way - they were just a necessary task we needed to perform to display a preview of our View. With the introduction of the #Preview macro, we now only need to provide the code required to create an instance of the view being displayed.
In this book you'll learn to create a variety of macros. You'll get a feel for when you should and shouldn't create them, which sort of macro you should create, and how to use SwiftSyntax to implement them. Your macros will accept parameters when appropriate and will always include tests. You'll even learn to create helpful diagnostics for your macros and even FixIts.
Updated for Xcode 15 and Swift 5.10 and tested on Apple Silicon.
Prelude: Before we Begin
Chapter 1: A Look Around
Perhaps we can give it a try
Tale of Two Macros
The Model Macro
The Xcode Macro Template
Road Map
Credits
Chapter 2: Our First Macro
Naming the Macro
Defining the Macro
Passing Tests
Adding a Second Parameter
Manipulating Strings
Accessing Values Using ASTs
Introducing SwiftSyntax
Chapter 3: Freestanding Macros
URL: You do it
Throwing Errors
Using Macros in Projects
Using Macros in Macros
Declaration Macros
Helper Methods
Diagnostics
Chapter 4: Our First Attached Macro
Explaining our goal
Seeing is not believing
Introducing an Attached Macro
Parameters for Expanding
Adding Flexibility to our Macro
More Diagnostics
FixIts
Chapter 5: More Attached Macros
Macros and the Three Bears
Extension Macros
Accessor Macros
Peer Macros
Identifying Stored Properties
Combining Macros
MemberAttribute Macros
Presenting Macros in Macros
