Book Image

Go Design Patterns

By : Mario Castro Contreras
Book Image

Go Design Patterns

By: Mario Castro Contreras

Overview of this book

Go is a multi-paradigm programming language that has built-in facilities to create concurrent applications. Design patterns allow developers to efficiently address common problems faced during developing applications. Go Design Patterns will provide readers with a reference point to software design patterns and CSP concurrency design patterns to help them build applications in a more idiomatic, robust, and convenient way in Go. The book starts with a brief introduction to Go programming essentials and quickly moves on to explain the idea behind the creation of design patterns and how they appeared in the 90’s as a common "language" between developers to solve common tasks in object-oriented programming languages. You will then learn how to apply the 23 Gang of Four (GoF) design patterns in Go and also learn about CSP concurrency patterns, the "killer feature" in Go that has helped Google develop software to maintain thousands of servers. With all of this the book will enable you to understand and apply design patterns in an idiomatic way that will produce concise, readable, and maintainable software.
Table of Contents (17 chapters)
Go Design Patterns
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Callbacks


Now that we know how to use WaitGroups, we can also introduce the concept of callbacks. If you have ever worked with languages like JavaScript that use them extensively, this section will be familiar to you. A callback is an anonymous function that will be executed within the context of a different function.

For example, we want to write a function to convert a string to uppercase, as well as making it asynchronous. How do we write this function so that we can work with callbacks? There's a little trick-we can have have a function that takes a string and returns a string:

func toUpperSync(word string) string { 
  //Code will go here 
} 

So take the returning type of this function (a string) and put it as the second parameter in an anonymous function, as shown here:

func toUpperSync(word string, f func(string)) { 
  //Code will go here 
} 

Now, the toUpperSync function returns nothing, but also takes a function that, by coincidence, also takes a string...