Book Image

Learning Functional Programming in Go

By : Lex Sheehan
Book Image

Learning Functional Programming in Go

By: Lex Sheehan

Overview of this book

Lex Sheehan begins slowly, using easy-to-understand illustrations and working Go code to teach core functional programming (FP) principles such as referential transparency, laziness, recursion, currying, and chaining continuations. This book is a tutorial for programmers looking to learn FP and apply it to write better code. Lex guides readers from basic techniques to advanced topics in a logical, concise, and clear progression. The book is divided into four modules. The first module explains the functional style of programming: pure functional programming, manipulating collections, and using higher-order functions. In the second module, you will learn design patterns that you can use to build FP-style applications. In the next module, you will learn FP techniques that you can use to improve your API signatures, increase performance, and build better cloud-native applications. The last module covers Category Theory, Functors, Monoids, Monads, Type classes and Generics. By the end of the book, you will be adept at building applications the FP way.
Table of Contents (21 chapters)
Title Page
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Summary


In this chapter, we saw how to use bad design using inheritance in Java and contrasted that solution to using composition in Go.

The Gang of Four's (GoF) epic book, Design Patterns: Elements of Reusable Object-Oriented Software, discussed design patterns that addressed design flaws in the object oriented languages like Java. For example, in the Putting Reuse Mechanisms to Work section, the GoF book states, Favor object composition over class inheritance.

This design principle is not even applicable to Go. Go does not support inheritance. No extra thought or work is required for Go developers. Go promotes composition out-of-the-box.

"These compositional techniques are what give Go its flavor, which is profoundly different from the flavor of C++ or Java programs." 

- Rob Pike

Composition is a software design pattern we should use to build better APIs.

We start by breaking our system into small parts: single responsibility interfaces. We can then put the pieces back together again. When we...