Book Image

Learning Go Programming

Book Image

Learning Go Programming

Overview of this book

The Go programming language has firmly established itself as a favorite for building complex and scalable system applications. Go offers a direct and practical approach to programming that let programmers write correct and predictable code using concurrency idioms and a full-featured standard library. This is a step-by-step, practical guide full of real world examples to help you get started with Go in no time at all. We start off by understanding the fundamentals of Go, followed by a detailed description of the Go data types, program structures and Maps. After this, you learn how to use Go concurrency idioms to avoid pitfalls and create programs that are exact in expected behavior. Next, you will be familiarized with the tools and libraries that are available in Go for writing and exercising tests, benchmarking, and code coverage. Finally, you will be able to utilize some of the most important features of GO such as, Network Programming and OS integration to build efficient applications. All the concepts are explained in a crisp and concise manner and by the end of this book; you would be able to create highly efficient programs that you can deploy over cloud.
Table of Contents (18 chapters)
Learning Go Programming
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Package initialization


When a package is imported, it goes through a series of initialization sequences before its members are ready to be used. Package-level variables are initialized using dependency analysis that relies on lexical scope resolution, meaning variables are initialized based on their declaration order and their resolved transitive references to each other. For instance, in the following snippet, the resolved variable declaration order in package foo will be a, y, b, and x:

package foo 
var x = a + b(a) 
var a = 2 
var b = func(i int) int {return y * i} 
var y = 3 

Go also makes use of a special function named init that takes no arguments and returns no result values. It is used to encapsulate custom initialization logic that is invoked when the package is imported. For instance, the following source code shows an init function used in the resistor package to initialize function variable Rpi:

package resistor 
 
var Rpi func(float64, float64...