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

Decorator pattern


Though it is easier to write quality Go code--than quality Java code--without an understanding of the GOF design patterns, it doesn't mean that we, as Go developers, cannot benefit from GOF's insight.

We'll soon see how we can put the Decorator pattern to good use in Go.

Type hierarchy UML

This is the type hierarchy UML that we might have created while designing the Decorator pattern back in the day that we used object-oriented languages:

This is the design work needed to represent the same Decorator pattern using Go:

"Less is exponentially more"

- Rob Pike

 

How Procedural design compares to functional Inversion of Control (IoC)

The client request is wrapped by the Authorization, LoadBalancing, Logging, and FaultTolerance decorators. When a client request is executed, the functionality in those decorators will be injected into the flow by our Decorator framework, as shown in the following diagram:

In procedural programming, the main() function would be in control of the flow of...