Welcome!

Welcome to the Ruby closures book! You have taken a very important step toward becoming a better Ruby developer.

Closures are used everywhere in Ruby, from simple scripts to the most popular web frameworks. You might have even been using closures without knowing it.

However, once you become familiar with closures and their features, they will start jumping out at you, and you’ll appreciate the ways in which closures enable expressive and beautiful programs. But closures do more than that, especially in Ruby. Closures allow you to extend the language by enabling you to write your own domain-specific languages, or DSLs.

This book will take you from being a consumer of beautiful libraries, APIs, and DSLs, to someone who understands, appreciates, and produces the same beautiful code that only comes with close study and experimentation.