About This Book

This book is for the typical Scala developer, probably with a Java background, who is both sceptical and curious about the Functional Programming (FP) paradigm. This book justifies every concept with practical examples, including writing a web application.

This book uses Scalaz 7.2, the most popular, stable, principled and comprehensive Functional Programming framework for Scala.

This book is designed to be read from cover to cover, in the order presented, with a rest between chapters. Earlier chapters encourage coding styles that we will later discredit: similar to how we learn Newton’s theory of gravity as children, and progress to Riemann / Einstein / Maxwell if we become students of physics.

A computer is not necessary to follow along, but studying the Scalaz source code is encouraged. Some of the more complex code snippets are available with the book’s source code and those who want practical exercises are encouraged to (re-)implement Scalaz (and the example application) using the partial descriptions presented in this book.

We also recommend The Red Book as further reading. It teaches how to write an FP library in Scala from first principles.