The Erlanger Playbook

The Erlanger Playbook is an upcoming book written by Loïc Hoguin, author of Cowboy, Ranch, Gun, and other Erlang/OTP projects. It provides a general exploration of Erlang/OTP; advice on writing Erlang code, writing tests and documentation and provide other Erlang-related insights.

In the Erlang section of the book, we learn about the building blocks of the Erlang language; we introspect a running Erlang/OTP system to understand how it functions; we learn about behaviors by writing our own gen_server and supervisor modules; we explore gen_statem; and we build and discuss process regitries and process groups.

In the Code section of the book we learn how to start a project; we discuss version control, project structure, code style and best practices; we delve into various technical topics such as the "enter loop" mechanism, special processes, IOLists and the process dictionary; and we discuss how to deal with compilation warnings across Erlang/OTP versions.

In the Tests section we cover success typing analysis, manual testing, unit testing and functional testing; we also learn what to do about timeouts when testing an application and how to write client/server tests.

In the Documentation section we gain insight on how to write better tutorials, user guides, manuals and README files.

The Design section covers public interfaces, REST APIs and other lessons learned. The Workflow and Selling Erlang sections end this book with short, non-technical advice.

The book is roughly:

  • 80 pages for the Erlang section
  • 60 pages for the Code section
  • 70 pages for the Tests section
  • 20 pages for the Documentation section
  • 20 pages for the Design section
  • 10 pages for the final two sections

You may currently buy lifetime access to the book's git repository. This lifetime access will give you access to the pre-release builds and to any future release of the book.

The plan is to continue to add content to this book for a long time after its initial release, and to occasionally produce a proper edition of the book. The First Edition will feature the same content as is currently available in the most recent pre-release build. The First Edition will be released after an editing pass has been done.

The First Edition and any subsequent editions will be available both as an ebook and on a print-on-demand service. It will be possible to buy the First Edition at a price lower than the lifetime access, though the price remains to be determined.

Buyers of the lifetime access of the book will receive all releases and pre-releases as ebook versions. A coupon code will also be provided on demand for those that want to print the book. The coupon will reduce the price to the printing costs (you do not have to buy the content twice).

The lifetime access costs 50€ (EUR) and may be bought using Paypal:

There will be a delay between payment and delivery of the credentials to access the git repository and download pages for the book. This process is currently manual.

As the book is a pre-release, feedback is more than welcome. You can send your comments to the contact address at the top of this website.

Like my work? Donate!

Donate to Loïc Hoguin because his work on Cowboy, Ranch, Gun and is fantastic:

Recurring payment options are also available via GitHub Sponsors. These funds are used to cover the recurring expenses like food, dedicated servers or domain names.