Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Learning Functional Programming in Go

You're reading from   Learning Functional Programming in Go Change the way you approach your applications using functional programming in Go

Arrow left icon
Product type Paperback
Published in Nov 2017
Publisher Packt
ISBN-13 9781787281394
Length 670 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Lex Sheehan Lex Sheehan
Author Profile Icon Lex Sheehan
Lex Sheehan
Arrow right icon
View More author details
Toc

Table of Contents (13) Chapters Close

Preface 1. Pure Functional Programming in Go 2. Manipulating Collections FREE CHAPTER 3. Using High-Order Functions 4. SOLID Design in Go 5. Adding Functionality with Decoration 6. Applying FP at the Architectural Level 7. Functional Parameters 8. Increasing Performance Using Pipelining 9. Functors, Monoids, and Generics 10. Monads, Type Classes, and Generics 11. Category Theory That Applies 12. Miscellaneous Information and How-Tos

Monoids


Monoids are the most basic way to combine any values. A monoid is algebra that is closed under an associative binary operation and has an identity element.

We can think of a monoid as a design pattern that allows us to quickly reduce (or fold) on a collection of a single type in a parallel way.

Monoid rules

A monoid is anything that satisfies the following rules:

  • Closure rule
  • Associativity rule
  • Identity rule

Let's discuss these rules in brief.

Closure rule

“If you combine two values of same type, you get another value of the same type.” 

Given two inputs of the same type, a monoid returns one value of the same type as the input.

Closure rule examples

1 + 2 = 3, and 3 is an integer.

1 + 2 + 3 also equals an integer.

1 + 2 + 3 + 4 also equals an integer.

Our binary operation has been extended into an operation that works on lists!

Closure axiom

If a, b ∈ S, then a + b ∈ S.

That says, if a and b are any two values in the set S of integers and if we apply the binary operation + to any two values, then...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime