The Science of Functional Programming, Part II: A tutorial, with examples in Scala

This book is a pedagogical in-depth tutorial and reference on the functional programming paradigm. Starting from issues found in practical coding, the book builds up the theoretical intuition, knowledge, and techniques that functional programmers use for for rigorous reasoning about types and code. The second part of the book focuses on working with laws, structural analysis, and code for functors, monads, and other typeclasses, as well as the required techniques of symbolic derivation and proof. Detailed explanations and derivations are accompanied by solved examples tested in the Scala interpreter, as well as exercises and discussions that further build upon each chapter's material. The difficulty of this book's mathematical material is at the level of undergraduate multivariate calculus.