As a developer, you’ve probably heard that functional programming techniques help manage the complexities of today’s real-world, concurrent systems. You’re also investigating designs that help you maximize uptime and manage security. This book is your guide to Elixir, a modern, functional, and concurrent programming language. Because Elixir runs on the Erlang VM, and uses the underlying Erlang/OTP architecture, it benefits from almost 20 years of research into high performance, highly parallel, and seriously robust applications. Elixir brings a lot that’s new: a modern, Ruby-like, extendable syntax, compile and runtime evaluation, a hygienic macro system, and more. But, just as importantly, Elixir brings a sense of enjoyment to parallel, functional programming. Your applications become fun to work with, and the language encourages you to experiment. Part 1 covers the basics of writing sequential Elixir programs. We’ll look at the language, the tools, and the conventions. Part 2 uses these skills to start writing concurrent code—applications that use all the cores on your machine, or all the machines on your network! And we do it both with and without OTP. And Part 3 looks at the more advanced features of the language, from DSLs and code generation to extending the syntax. By the end of this book, you’ll understand Elixir, and know how to apply it to solve your complex, modern problems.

在了解 Elixir 前，在网上看到一些评论说， Elixir 其实就是用 Ruby 的语法来编写 Erlang 程序。其实不然。真正玩了 Elixir 之后，就会发现这纯属幻觉。因为 Elixir 相对于 Ruby 使用了截然不同的语言范式——函数式编程。两者在编程思想上相距甚远。如果说它看似 Ruby ，也仅仅是 Elixir 设计者 José Valim ，一个 Ruby 开发者的情怀使然罢了。 Elixir 只是在 Erlang 之上加入的一层语法糖，在不改变 Erlang 开发实践的基础上，还能重用已有的 Erlang 代码。然而这层小小的语法糖却给内心坚若磐石但语法苦涩难懂的 Erlang 增添了一副平易近人的外表。虽然函数式编程并非新鲜事物，而 Elixir 则让函数式编程更现代化。 原著作者就是 15 年前编写了 Programming Ruby ，将 Ruby 带入大众视野的 Dave Thomas 。他延续了一贯的写作风格，以一个拥有面向对象的开发经历但并未接触过函数式编程的开发者的角度切入，循序渐进地带领读者进入 Elixir 的奇妙世界。通过一步步的实验探索，引导读者逐步跳出已有的编程思维模式，以全新的函数式编程方式来思考及寻找解决实际问题的办法。然而本书并不像 Programming Ruby 那样面面俱到，而是通过给读者讲述基本的 Elixir 语法和编程思想，同时提供许多有用的资源，启发读者继续深入探索。这才是学习一门新语言的乐趣所在。

Erlang is a development platform, proven in large systems for more than two decades, that offers highly-efficient concurrency, scalability, and fault-tolerance. Elixir is a modern programming language that takes advantage of the Erlang Virtual Machine without the complex syntax and conventions of the Erlang language. The Elixir language offers Ruby-like elegance along with the power to develop bulletproof scalable, fault tolerant, distributed server systems that can handle massive numbers of simultaneous clients and run with almost no downtime. Elixir in Action teaches you to apply the new Elixir programming language to practical problems associated with scalability, concurrency, fault-tolerance, and high-availability. This book starts with a quick overview of the Elixir language, mapping familiar language concepts to the Elixir syntax. Then, you'll learn to think about problems from the Elixir mindset, which builds on the model of functional-style programming. With a solid foundation, you'll confidently explore Elixir's seamless integration with the Erlang Virtual Machine and supporting OTP library that offers battle-tested, industry proven abstractions you can use immediately in your applications. Finally, the book provides guidance on how to create deployable releases, distribute the system over multiple machines, and control the running system in production.

Don't accept the compromise between fast and beautiful: you can have it all. Phoenix creator Chris McCord, Elixir creator Jose Valim, and award-winning author Bruce Tate walk you through building an application that's fast and reliable. At every step, you'll learn from the Phoenix creators not just what to do, but why. Packed with insider insights and completely updated for Phoenix 1.3, this definitive guide will be your constant companion in your journey from Phoenix novice to expert, as you build the next generation of web applications. Phoenix is the long-awaited web framework based on Elixir, the highly concurrent language that combines a beautiful syntax with rich metaprogramming. The best way to learn Phoenix is to code, and you'll get to attack some interesting problems. Start working with controllers, views, and templates within the first few pages. Build an in-memory context, and then back it with an Ecto database layer, complete with changesets and constraints that keep readers informed and your database integrity intact. Craft your own interactive application based on the channels API for the real-time applications that this ecosystem made famous. Write your own authentication plugs, and use the OTP layer for supervised services. Organize code with modular umbrella projects. This edition is fully updated for Phoenix 1.3, Elixir 1.3, and Ecto 2.1, with a new chapter on using Channel Presence to find out who's connected, even on a distributed application. Use the new generators and the new ExUnit features to organize tests and make Ecto tests concurrent. This is a book by developers and for developers, and we know how to help you ramp up quickly. Any book can tell you what to do. When you've finished this one, you'll also know why to do it.