Halliday S. Functional programming for mortals, with scalaz

Leanpub, 2018. — 336 p.This book is for the typical Scala developer, probably with a Java background, who is both skeptical 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.