Preface: What’s an étude?

An étude, according to Wikipedia, is "an instrumental musical composition, usually short and of considerable difficulty, usually designed to provide practice material for perfecting a particular musical skill."

What are Études for Erlang?

In this book, you will find descriptions of programs that you can compose (write) in Erlang. The programs will usually be short, and each one has been designed to provide practice material for a particular Erlang programming concept. Unlike musical études, these programs have not been designed to be of considerable difficulty, though they may ask you to stretch a bit beyond the immediate material and examples that you find in the book Introducing Erlang.

How This Book was Written

While reading the early release version of Introducing Erlang, I began by copying the examples in the book. (This always helps me learn the material better.) I then began experimenting with small programs of my own to make sure I really understood the concepts. As I continued writing my own examples, I thought they might be useful to other people as well. I contacted Simon St. Laurent, the author of Introducing Erlang, and he liked the idea of having these companion exercises and suggested naming them études. At some point, the études took on a life of their own, and you are reading the result now.

I was learning Erlang as I was creating the solutions to the études, following the philosophy that "the first way that works is the right way." Therefore, don’t be surprised if you see some fairly naïve code that an expert Erlang programmer would never write.

Working with Other Books

Although this was based on Introducing Erlang, you can use it with other Erlang books. A note at the beginning of each chapter will point you to relevant sections in other books. The books listed through are:


Many thanks to Simon St. Laurent, who wrote Introducing Erlang. His book not only got me to begin to understand functional programming, but also made me realize that it was a lot of fun. Simon also felt that the exercises I was writing for myself could be useful to others, and he encouraged me to continue developing them.