Write code that writes code with Elixir macros. Macros make metaprogramming possible and define the language itself. In this book youll learn how to use macros to extend the language with fast maintainable code and share functionality in ways you never thought possible. Youll discover how to extend Elixir with your own firstclass features optimize performance and create domainspecific languages. Metaprogramming is one of Elixirs greatest features. Maybe youve played with the basics or written a few macros. Now you want to take it to the next level. This book is a guided series of metaprogramming tutorials that take you step by step to metaprogramming mastery. Youll extend Elixir with powerful features and write faster more maintainable programs in ways unmatched by other languages. Youll start with the basics of Elixirs metaprogramming system and find out how macros interact with Elixirs abstract format. Then youll extend Elixir with your own firstclass features write a testing framework and discover how Elixir treats source code as building blocks rather than rote lines of instructions. Youll continue your journey by using advanced code generation to create essential libraries in strikingly few lines of code. Finally youll create domainspecific languages and learn when and where to apply your skills effectively. When youre done you will have mastered metaprogramming gained insights into Elixirs internals and have the confidence to leverage macros to their full potential in your own projects.