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

Using mathematics and category theory to gain understanding


Let's work with something we can relate to soccer!

How can we know the position of a ball in the air as it moves from Messi's foot into the goal?

Note that due to spin on the ball and the imbalance of air pressure, when in the air, the ball may curve left to right and up and sharply down.

Suppose we have a small soccer field with the dimensions of 50 yards X 100 yards and a net that is 8 feet tall. The height of the goal is the z dimension:

If the sun is directly overhead and makes a shadow on the field, then we can know the x, y coordinates. If we can also measure the height of the ball as it moves, then we know the z coordinate. Combining both of those pieces of information, we can know the ball's position in the three-dimensional space.

The following diagram says that if we know A and B...