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

Sample HOF application


Let’s build a sample app that will demonstrate the benefits of applying functional programming concepts to Go.

Our app will read from the following cars.csv file:

"Honda Accord"
"Honda Accord ES2"
"Lexus IS250"
"Honda CR-V"
"Lexus SC 430"
"Ford F-150"
"Toyota Highlander"
"Toyota RAV4"
"GM Hummer H2"
"GM Hummer H3"

We will apply high-order functions and various functional programming constructs to the list of cars to filter, map, reduce, and transform it to our heart's content. Our project is structured as follows:

$ tree
.
├── README.md
└── chapter4
 ├── 01_hof
 │ ├── cars.csv
 │ ├── cars.go
 │ ├── generator.go
 │ ├── more_cars.csv
 │ ├── restful.go
 │ ├── types.go
 │ └── utils.go
 └── main.go

At the root of the chapter4 directory is our main.go file. Since we plan to build a Go executable from main.go and run it, we use the package name of main and include a main() function.

The other files will be in a subdirectory named 01_hof, where hof stands for high-order functions...