Go Programming Blueprints

Author: Mat Ryer
Publisher: Packt Publishing Ltd
ISBN: 9781786462473
Release Date: 2016-10-27
Genre: Computers

Build real-world, production-ready solutions in Go using cutting-edge technology and techniques About This Book Get up to date with Go and write code capable of delivering massive world-class scale performance and availability Learn to apply the nuances of the Go language, and get to know the open source community that surrounds it to implement a wide range of start-up quality projects Write interesting and clever but simple code, and learn skills and techniques that are directly transferrable to your own projects Who This Book Is For If you are familiar with Go and are want to put your knowledge to work, then this is the book for you. Go programming knowledge is a must. What You Will Learn Build quirky and fun projects from scratch while exploring patterns, practices, and techniques, as well as a range of different technologies Create websites and data services capable of massive scale using Go's net/http package, exploring RESTful patterns as well as low-latency WebSocket APIs Interact with a variety of remote web services to consume capabilities ranging from authentication and authorization to a fully functioning thesaurus Develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go's in-built concurrency mechanisms Build microservices for larger organizations using the Go Kit library Implement a modern document database as well as high-throughput messaging queue technology to put together an architecture that is truly ready to scale Write concurrent programs and gracefully manage the execution of them and communication by smartly using channels Get a feel for app deployment using Docker and Google App Engine In Detail Go is the language of the Internet age, and the latest version of Go comes with major architectural changes. Implementation of the language, runtime, and libraries has changed significantly. The compiler and runtime are now written entirely in Go. The garbage collector is now concurrent and provides dramatically lower pause times by running in parallel with other Go routines when possible. This book will show you how to leverage all the latest features and much more. This book shows you how to build powerful systems and drops you into real-world situations. You will learn to develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go's in-built concurrency mechanisms. Scale, performance, and high availability lie at the heart of our projects, and the lessons learned throughout this book 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. Style and approach This book provides fun projects that involve building applications from scratch. These projects will teach you to build chat applications, a distributed system, and a recommendation system.

Go Programming Blueprints

Author: Mat Ryer
Publisher: Packt Publishing Ltd
ISBN: 9781783988037
Release Date: 2015-01-23
Genre: Computers

Intended for seasoned Go programmers who want to put their expertise in Go to use to solve big, real-world, modern problems. With a basic understanding of channels and goroutines, you will hone your skills to build tools and programs that are quick and simple. You need not be an expert in distributed systems or technologies in order to deliver solutions capable of great scale. It is assumed that you are familiar with the basic concepts of Go.

Go Programming Blueprints

Author: Mat Ryer
Publisher: Packt Pub Limited
ISBN: 1783988029
Release Date: 2015-01-23
Genre: Computers

Intended for seasoned Go programmers who want to put their expertise in Go to use to solve big, real-world, modern problems. With a basic understanding of channels and goroutines, you will hone your skills to build tools and programs that are quick and simple. You need not be an expert in distributed systems or technologies in order to deliver solutions capable of great scale. It is assumed that you are familiar with the basic concepts of Go.

Go Programming Blueprints Second Edition

Author: Mat Ryer
Publisher:
ISBN: 1786468948
Release Date: 2016-12-30
Genre:

Build real-world, production-ready solutions in Go using cutting-edge technology and techniquesAbout This Book* Get up to date with Go and write code capable of delivering massive world-class scale performance and availability* Learn to apply the nuances of the Go language, and get to know the open source community that surrounds it to implement a wide range of start-up quality projects* Write interesting and clever but simple code, and learn skills and techniques that are directly transferrable to your own projectsWho This Book Is ForIf you are familiar with Go and are want to put your knowledge to work, then this is the book for you. Go programming knowledge is a must.What You Will Learn* Build quirky and fun projects from scratch while exploring patterns, practices, and techniques, as well as a range of different technologies* Create websites and data services capable of massive scale using Go's net/http package, exploring RESTful patterns as well as low-latency WebSocket APIs* Interact with a variety of remote web services to consume capabilities ranging from authentication and authorization to a fully functioning thesaurus* Develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go's in-built concurrency mechanisms* Build microservices for larger organizations using the Go Kit library* Implement a modern document database as well as high-throughput messaging queue technology to put together an architecture that is truly ready to scale* Write concurrent programs and gracefully manage the execution of them and communication by smartly using channels* Get a feel for app deployment using Docker and Google App EngineIn DetailGo is the language of the Internet age, and the latest version of Go comes with major architectural changes. Implementation of the language, runtime, and libraries has changed significantly. The compiler and runtime are now written entirely in Go. The garbage collector is now concurrent and provides dramatically lower pause times by running in parallel with other goroutines when possible.This book will show you how to leverage all the latest features and much more. This book shows you how to build powerful systems and drops you into real-world situations. Scale, performance, and high availability lie at the heart of our projects, and the lessons learned throughout this book will arm you with everything you need to build world-class solutions. Each project could form the basis of a start-up, which means they are directly applicable to modern software markets.

Go Programming Blueprints

Author: Mat Ryer
Publisher: Packt Publishing Ltd
ISBN: 9781786462473
Release Date: 2016-10-27
Genre: Computers

Build real-world, production-ready solutions in Go using cutting-edge technology and techniques About This Book Get up to date with Go and write code capable of delivering massive world-class scale performance and availability Learn to apply the nuances of the Go language, and get to know the open source community that surrounds it to implement a wide range of start-up quality projects Write interesting and clever but simple code, and learn skills and techniques that are directly transferrable to your own projects Who This Book Is For If you are familiar with Go and are want to put your knowledge to work, then this is the book for you. Go programming knowledge is a must. What You Will Learn Build quirky and fun projects from scratch while exploring patterns, practices, and techniques, as well as a range of different technologies Create websites and data services capable of massive scale using Go's net/http package, exploring RESTful patterns as well as low-latency WebSocket APIs Interact with a variety of remote web services to consume capabilities ranging from authentication and authorization to a fully functioning thesaurus Develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go's in-built concurrency mechanisms Build microservices for larger organizations using the Go Kit library Implement a modern document database as well as high-throughput messaging queue technology to put together an architecture that is truly ready to scale Write concurrent programs and gracefully manage the execution of them and communication by smartly using channels Get a feel for app deployment using Docker and Google App Engine In Detail Go is the language of the Internet age, and the latest version of Go comes with major architectural changes. Implementation of the language, runtime, and libraries has changed significantly. The compiler and runtime are now written entirely in Go. The garbage collector is now concurrent and provides dramatically lower pause times by running in parallel with other Go routines when possible. This book will show you how to leverage all the latest features and much more. This book shows you how to build powerful systems and drops you into real-world situations. You will learn to develop high-quality command-line tools that utilize the powerful shell capabilities and perform well using Go's in-built concurrency mechanisms. Scale, performance, and high availability lie at the heart of our projects, and the lessons learned throughout this book 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. Style and approach This book provides fun projects that involve building applications from scratch. These projects will teach you to build chat applications, a distributed system, and a recommendation system.

The Go Programming Language Phrasebook

Author: David Chisnall
Publisher: Pearson Education
ISBN: 9780321817143
Release Date: 2012
Genre: Computers

A guide to Go describes how the programming language is structured and provides examples of code that demonstrate every stage of Go development, from creating a simple program to debugging and distributing code.

Programming in Go

Author: Mark Summerfield
Publisher: Addison-Wesley
ISBN: 9780132764094
Release Date: 2012-05-01
Genre: Computers

Your Hands-On Guide to Go, the Revolutionary New Language Designed for Concurrency, Multicore Hardware, and Programmer Convenience Today’s most exciting new programming language, Go, is designed from the ground up to help you easily leverage all the power of today’s multicore hardware. With this guide, pioneering Go programmer Mark Summerfield shows how to write code that takes full advantage of Go’s breakthrough features and idioms. Both a tutorial and a language reference, Programming in Go brings together all the knowledge you need to evaluate Go, think in Go, and write high-performance software with Go. Summerfield presents multiple idiom comparisons showing exactly how Go improves upon older languages, calling special attention to Go’s key innovations. Along the way, he explains everything from the absolute basics through Go’s lock-free channel-based concurrency and its flexible and unusual duck-typing type-safe approach to object-orientation. Throughout, Summerfield’s approach is thoroughly practical. Each chapter offers multiple live code examples designed to encourage experimentation and help you quickly develop mastery. Wherever possible, complete programs and packages are presented to provide realistic use cases, as well as exercises. Coverage includes Quickly getting and installing Go, and building and running Go programs Exploring Go’s syntax, features, and extensive standard library Programming Boolean values, expressions, and numeric types Creating, comparing, indexing, slicing, and formatting strings Understanding Go’s highly efficient built-in collection types: slices and maps Using Go as a procedural programming language Discovering Go’s unusual and flexible approach to object orientation Mastering Go’s unique, simple, and natural approach to fine-grained concurrency Reading and writing binary, text, JSON, and XML files Importing and using standard library packages, custom packages, and third-party packages Creating, documenting, unit testing, and benchmarking custom packages

Python Programming Blueprints

Author: Daniel Furtado
Publisher: Packt Publishing Ltd
ISBN: 9781786464903
Release Date: 2018-02-27
Genre: Computers

How to build useful, real-world applications in the Python programming language Key Features Deliver scalable and high-performing applications in Python. Delve into the great ecosystem of Python frameworks and libraries through projects that you will build with this book. This comprehensive guide will help you demonstrate the power of Python by building practical projects. Book Description Python is a very powerful, high-level, object-oriented programming language. It's known for its simplicity and huge community support. Python Programming Blueprints will help you build useful, real-world applications using Python. In this book, we will cover some of the most common tasks that Python developers face on a daily basis, including performance optimization and making web applications more secure. We will familiarize ourselves with the associated software stack and master asynchronous features in Python. We will build a weather application using command-line parsing. We will then move on to create a Spotify remote control where we'll use OAuth and the Spotify Web API. The next project will cover reactive extensions by teaching you how to cast votes on Twitter the Python way. We will also focus on web development by using the famous Django framework to create an online game store. We will then create a web-based messenger using the new Nameko microservice framework. We will cover topics like authenticating users and, storing messages in Redis. By the end of the book, you will have gained hands-on experience in coding with Python. What you will learn Learn object-oriented and functional programming concepts while developing projects The dos and don'ts of storing passwords in a database Develop a fully functional website using the popular Django framework Use the Beautiful Soup library to perform web scrapping Get started with cloud computing by building microservice and serverless applications in AWS Develop scalable and cohesive microservices using the Nameko framework Create service dependencies for Redis and PostgreSQL Who this book is for This book is for software developers who are familiar with Python and want to gain hands-on experience with web and software development projects. A basic knowledge of Python programming is required.

Go Building Web Applications

Author: Nathan Kozyra
Publisher: Packt Publishing Ltd
ISBN: 9781787126596
Release Date: 2016-08-31
Genre: Computers

Build real-world, production-ready solutions by harnessing the powerful features of Go About This Book An easy-to-follow guide that provides everything a developer needs to know to build end-to-end web applications in Go Write interesting and clever, but simple code, and learn skills and techniques that are directly transferable to your own projects A practical approach to utilize application scaffolding to design highly scalable programs that are deeply rooted in go routines and channels Who This Book Is For This book is intended for developers who are new to Go, but have previous experience of building web applications and APIs. What You Will Learn Build a fully featured REST API to enable client-side single page apps Utilize TLS to build reliable and secure sites Learn to apply the nuances of the Go language to implement a wide range of start-up quality projects Create websites and data services capable of massive scale using Go's net/http package, exploring RESTful patterns as well as low-latency WebSocket APIs Interact with a variety of remote web services to consume capabilities ranging from authentication and authorization to a fully functioning thesaurus Explore the core syntaxes and language features that enable concurrency in Go Understand when and where to use concurrency to keep data consistent and applications non-blocking, responsive, and reliable Utilize advanced concurrency patterns and best practices to stay low-level without compromising the simplicity of Go itself In Detail Go is an open source programming language that makes it easy to build simple, reliable, and efficient software. It is a statically typed language with syntax loosely derived from that of C, adding garbage collection, type safety, some dynamic-typing capabilities, additional built-in types such as variable-length arrays and key-value maps, and a large standard library. This course starts with a walkthrough of the topics most critical to anyone building a new web application. Whether it's keeping your application secure, connecting to your database, enabling token-based authentication, or utilizing logic-less templates, this course has you covered. Scale, performance, and high availability lie at the heart of the projects, and the lessons learned throughout this course will arm you with everything you need to build world-class solutions. It will also take you through the history of concurrency, how Go utilizes it, how Go differs from other languages, and the features and structures of Go's concurrency core. It will make you feel comfortable designing a safe, data-consistent, and high-performance concurrent application in Go. This course is an invaluable resource to help you understand Go's powerful features to build simple, reliable, secure, and efficient web applications. Style and approach This course is a step-by-step guide, which starts off with the basics of go programming to build web applications and will gradually move on to cover intermediate and advanced topics. You will be going through this smooth transition by building interesting projects along with the authors, discussing significant options, and decisions at each stage, while keeping the programs lean, uncluttered, and as simple as possible.

Go Design Patterns for Real World Projects

Author: Vladimir Vivien
Publisher: Packt Publishing Ltd
ISBN: 9781788392877
Release Date: 2017-06-12
Genre: Computers

An insightful guide to learning the Go programming language About This Book Get insightful coverage of Go programming syntax, constructs, and idioms to help you understand Go code Get a full explanation of all the known GoF design patterns in Go, including comprehensive theory and examples Learn to apply the nuances of the Go language, and get to know the open source community that surrounds it to implement a wide range of start-up quality projects Who This Book Is For Beginners to Go who are comfortable in other OOP languages like Java, C#, or Python will find this course interesting and beneficial. What You Will Learn Install and configure the Go development environment to quickly get started with your first program Use the basic elements of the language including source code structure, variables, constants, and control flow primitives Get to know all the basic syntax and tools you need to start coding in Go Create unique instances that cannot be duplicated within a program Build quirky and fun projects from scratch while exploring patterns, practices, and techniques, as well as a range of different technologies Create websites and data services capable of massive scaling using Go's net/http package, Explore RESTful patterns as well as low-latency WebSocket APIs Interact with a variety of remote web services to consume capabilities, ranging from authentication and authorization to a fully functioning thesaurus In Detail 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: Learning Go Programming Go Design Patterns Go Programming Blueprints, Second Edition Style and approach Full of real-world, practical examples, this course teaches you the widely used design patterns and best practices in Go in a step-by-step manner. It also provides fun projects that involve building applications from scratch.

Learning Go Programming

Author: Vladimir Vivien
Publisher: Packt Publishing Ltd
ISBN: 9781784392338
Release Date: 2016-10-26
Genre: Computers

An insightful guide to learning the Go programming language About This Book Insightful coverage of Go programming syntax, constructs, and idioms to help you understand Go code effectively Push your Go skills, with topics such as, data types, channels, concurrency, object-oriented Go, testing, and network programming Each chapter provides working code samples that are designed to help reader quickly understand respective topic Who This Book Is For If you have prior exposure to programming and are interested in learning the Go programming language, this book is designed for you. It will quickly run you through the basics of programming to let you exploit a number of features offered by Go programming language. What You Will Learn Install and configure the Go development environment to quickly get started with your first program. Use the basic elements of the language including source code structure, variables, constants, and control flow primitives to quickly get started with Go Gain practical insight into the use of Go's type system including basic and composite types such as maps, slices, and structs. Use interface types and techniques such as embedding to create idiomatic object-oriented programs in Go. Develop effective functions that are encapsulated in well-organized package structures with support for error handling and panic recovery. Implement goroutine, channels, and other concurrency primitives to write highly-concurrent and safe Go code Write tested and benchmarked code using Go's built test tools Access OS resources by calling C libraries and interact with program environment at runtime In Detail 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. Style and approach The book is written to serve as a reader-friendly step-by-step guide to learning the Go programming language. Each topic is sequentially introduced to build on previous materials covered. Every concept is introduced with easy-to-follow code examples that focus on maximizing the understanding of the topic at hand.

PHP 7 Programming Blueprints

Author: Jose Palala
Publisher: Packt Publishing Ltd
ISBN: 9781785885242
Release Date: 2016-10-07
Genre: Computers

Learn how to exploit the impressive power of PHP 7 with this collection of practical project blueprints – begin building better applications for the web today! About This Book Don't just learn PHP 7 – follow a diverse range of practical knowledge to get started quickly Take advantage of PHP 7's newest features – and find out how to use them to solve real development challenges Put PHP to work for performance and scalability – we'll show you how, you do it! Who This Book Is For The book is for web developers, PHP consultants, and anyone who is working on multiple projects with PHP. Basic knowledge of PHP programming is assumed. What You Will Learn Build versatile projects using the newest features PHP 7 has to offer Learn how to use PHP 7's event-driven asynchronous features Find out how to improve the performance of your code with effective techniques and design patterns Get to grips with backend development and find out how to optimize session handling Learn how to use the PHP 7 Abstract Syntax Tree to improve the quality of your code and make it more maintainable Find out how to build a RESTful web service Build your own asynchronous microservice In Detail When it comes to modern web development, performance is everything. The latest version of PHP has been improvised and updated to make it easier to build for performance, improved engine execution, better memory usage, and a new and extended set of tools. If you're a web developer, what's not to love? This guide will show you how to make full use of PHP 7 with a range of practical projects that will not only teach you the principles, but also show you how to put them into practice. It will push and extend your skills, helping you to become a more confident and fluent PHP developer. You'll find out how to build a social newsletter service, a simple blog with a search capability using Elasticsearch, as well as a chat application. We'll also show you how to create a RESTful web service, a database class to manage a shopping cart on an e-commerce site and how to build an asynchronous microservice architecture. With further guidance on using reactive extensions in PHP, we're sure that you'll find everything you need to take full advantage of PHP 7. So dive in now! Style and approach This product focuses on helping developers build projects from scratch. But more than that, each project will help the reader to learn a new facet or feature of PHP 7 – it means the reader really will 'learn by doing.'

Mastering Concurrency in Go

Author: Nathan Kozyra
Publisher: Packt Publishing Ltd
ISBN: 9781783983490
Release Date: 2014-07-23
Genre: Computers

A practical approach covering everything you need to know to get up and running with Go, starting with the basics and imparting increasingly more detail as the examples and topics become more complicated. The book utilizes a casual, conversational style, rife with actual code and historical anecdotes for perspective, as well as usable and extensible example applications. This book is intended for systems developers and programmers with some experience in either Go and/or concurrent programming who wish to become fluent in building high-performance applications that scale by leveraging single-core, multicore, or distributed concurrency.

Go Design Patterns

Author: Mario Castro Contreras
Publisher: Packt Publishing Ltd
ISBN: 9781786461902
Release Date: 2017-02-24
Genre: Computers

Learn idiomatic, efficient, clean, and extensible Go design and concurrency patterns by using TDD About This Book A highly practical guide filled with numerous examples unleashing the power of design patterns with Go. Discover an introduction of the CSP concurrency model by explaining GoRoutines and channels. Get a full explanation, including comprehensive text and examples, of all known GoF design patterns in Go. Who This Book Is For The target audience is both beginner- and advanced-level developers in the Go programming language. No knowledge of design patterns is expected. What You Will Learn All basic syntax and tools needed to start coding in Go Encapsulate the creation of complex objects in an idiomatic way in Go Create unique instances that cannot be duplicated within a program Understand the importance of object encapsulation to provide clarity and maintainability Prepare cost-effective actions so that different parts of the program aren't affected by expensive tasks Deal with channels and GoRoutines within the Go context to build concurrent application in Go in an idiomatic way In Detail 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. Style and approach This book will teach widely used design patterns and best practices with Go in a step-by-step manner. The code will have detailed examples, to allow programmers to apply design patterns in their day-to-day coding.

The Go Programming Language

Author: Alan A. A. Donovan
Publisher: Addison-Wesley Professional
ISBN: 9780134190563
Release Date: 2015-11-16
Genre: Computers

The Go Programming Language is the authoritative resource for any programmer who wants to learn Go. It shows how to write clear and idiomatic Go to solve real-world problems. The book does not assume prior knowledge of Go nor experience with any specific language, so you’ll find it accessible whether you’re most comfortable with JavaScript, Ruby, Python, Java, or C++. The first chapter is a tutorial on the basic concepts of Go, introduced through programs for file I/O and text processing, simple graphics, and web clients and servers. Early chapters cover the structural elements of Go programs: syntax, control flow, data types, and the organization of a program into packages, files, and functions. The examples illustrate many packages from the standard library and show how to create new ones of your own. Later chapters explain the package mechanism in more detail, and how to build, test, and maintain projects using the go tool. The chapters on methods and interfaces introduce Go’s unconventional approach to object-oriented programming, in which methods can be declared on any type and interfaces are implicitly satisfied. They explain the key principles of encapsulation, composition, and substitutability using realistic examples. Two chapters on concurrency present in-depth approaches to this increasingly important topic. The first, which covers the basic mechanisms of goroutines and channels, illustrates the style known as communicating sequential processes for which Go is renowned. The second covers more traditional aspects of concurrency with shared variables. These chapters provide a solid foundation for programmers encountering concurrency for the first time. The final two chapters explore lower-level features of Go. One covers the art of metaprogramming using reflection. The other shows how to use the unsafe package to step outside the type system for special situations, and how to use the cgo tool to create Go bindings for C libraries. The book features hundreds of interesting and practical examples of well-written Go code that cover the whole language, its most important packages, and a wide range of applications. Each chapter has exercises to test your understanding and explore extensions and alternatives. Source code is freely available for download from http://gopl.io/ and may be conveniently fetched, built, and installed using the go get command.