Book Image

Go: Design Patterns for Real-World Projects

By : Vladimir Vivien, Mario Castro Contreras, Mat Ryer
Book Image

Go: Design Patterns for Real-World Projects

By: Vladimir Vivien, Mario Castro Contreras, Mat Ryer

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 lets programmers write correct and predictable code using concurrency idioms and a full-featured standard library. This practical guide is full of real-world examples to help you get started with Go in no time at all. You’ll start by understanding the fundamentals of Go, then get a detailed description of the Go data types, program structures, and Maps. After that, you’ll learn how to use Go concurrency idioms to avoid pitfalls and create programs that are exact in expected behavior. Next, you will get familiar with the tools and libraries that are available in Go to write and exercise tests, benchmarking, and code coverage. After that, 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. Then you’ll start applying your skills to build some amazing projects in Go. You will learn to develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go’s built-in concurrency mechanisms. Scale, performance, and high availability lie at the heart of our projects, and the lessons learned throughout the sections will arm you with everything you need to build world-class solutions. You will get a feel for app deployment using Docker and Google App Engine. Each project could form the basis of a start-up, which means they are directly applicable to modern software markets. With these skills in hand, you will be able to conquer all your fears of application development and go on to build large, robust and succinct apps in Go. This Learning Path combines some of the best that Packt has to offer in one complete, curated package. It includes content from the following Packt products: 1. Learning Go Programming 2. Go Design Patterns 3. Go Programming Blueprints, Second Edition
Table of Contents (38 chapters)
Go: Design Patterns for Real-World Projects
Credits
Preface
Bibliography

Function panic and recovery


Earlier in the chapter, it was stated that Go does not have the traditional exception mechanism offered by other languages. Nevertheless, in Go, there is a way to abruptly exit an executing function known as function panic. Conversely, when a program is panicking, Go provides a way of recovering and regaining control of the execution flow.

Function panic

During execution, a function may panic because of any one of following:

  • Explicitly calling the panic built-in function

  • Using a source code package that panics due to an abnormal state

  • Accessing a nil value or an out-of-bound array element

  • Concurrency deadlock

When a function panics, it aborts and executes its deferred calls. Then its caller panics, causing a chain reaction as illustrated in the following figure:

The panic sequence continues all the way up the call stack until the main function is reached and the program exits (crashes). The following source code snippet shows a version of the anagram program that will...