Lex Sheehan - Learning Functional Programming in Go: Change the way you approach your applications using functional programming in Go

BIRMINGHAM - MUMBAI

Copyright 2017 Packt Publishing

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First published: November 2017

Production reference: 1221117

ISBN 978-1-78728-139-4

www.packtpub.com

Lex Sheehan has a B.S. in Computer Science from Auburn University, resides in Atlanta, GA, and works as a senior software engineer with over 20 years of experience. He has a deep understanding of functional programming; His first encounter was using high-order functions in Ruby, Scala, JavaScript, Haskell, Java, and Go.

Lex worked for IBM Software Group and IBM Global Business Services, designing and building various enterprise business systems. He is the author of eight US patents (IT security and data transformations) and he writes a blog titled Application Development with Lex Sheehan.

Lex is available to consult and meet with your CTO, or provide in-house training on the information in this book.

I would like to acknowledge the people who helped me during the writing of this book.

Thank you, Rohit, for editing my writing and providing your insight, guidance, and words of encouragement.

Thank you, John and Wayne, for reviewing this book for technical accuracy. Thank you to all other reviewers who helped improve the quality of this book's content.

Thank you, Mac, for being my wise counsel.

Thank you, Marty, for being my sounding board.

Thank you, Erik, for providing legal counsel regarding the Forgetful Functor.

Thank you all who lifted me up in your prayers during this endeavor.

Thank you, Salim, for your support. Your leadership style has earned my trust and loyalty.

Thank you, to the one who would say, "Lex Brilliance". That was and still is a great source of inspiration. Words matter.

We are all given talents. Some fear failure and suffer for it; others invest their talents.

This book is dedicated to those who invest in themselves and go on to help others.

John Pradeep is a software engineer with over 10 years of experience in designing and developing various applications in an agile way.

After working on multiple languages (Lisp being his favorite), he has recently started using Go for its clear set of design goals and simplicity. Now, Go has become his language of choice for most projects that he works on.

He loves finding simple solutions to complex problems, and he is also a huge fan of methodologies that help build elegant systems such as functional programming, domain-driven design, CQRS, reactive architectures, and so on.

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Until recently, the message has been Go and functional programmingdon't do it.

Functional programming (FP) is a perfect fit for multicore, parallel processing. Go is a concurrency baller (with Goroutines, channels, and so on) and already runs on every available CPU core. FP reduces complexity; simplicity is one of Go's biggest strengths.

So, what can FP bring to Go that will actually improve our software applications? Here's what it offers:

• Composition