Everything you need to know about Macros.

About the Book

This book explores everything you need to know about Macros and how to write them.

Examples are mainly written in Elixir ( but there is also smatterings of Clojure and other languages that do interesting things with Macros.

The Macro concepts explored are useful to to all implementations of Macros.

About the Author

Joseph Wilk
Joseph Wilk

Joseph Wilk works as an Engineer at SoundCloud helping infuse Clojure and Elixir into the organisation.


Twitter: @josephwilk

Table of Contents

  • The Sharp knife
  • What are Macros?
  • Why Macros?
    • Compile time lazy evaluation
    • Macros vs Metaprogramming
  • Macro Basics
    • Quote
    • Unquote
    • Building Functions
    • Unquote Splicing
    • Macro Escaping
    • Eval quoted
    • Hygiene & Macros
    • Unhygienic
    • Unquoting outside of macros
  • Common mistakes
    • Calling macros with runtime arguments
    • Breaking syntax
    • Manually parsing quoted code
    • Unquoting multiple times
  • Macro Development Style
    • Minimize Footprint
    • Looking inside the Macro
    • Lead by an Example
    • Comparing Abstract Syntax Trees
    • Meaningful stacktraces
  • Types of Macros
    • Anonymous Macros
    • Anaphoric Macros
    • Reader Macros
  • References
  • Appendix 1: Elixir’s AST

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