Crystal Programming: A project-based introduction to building efficient, safe, and readable web and CLI applications

The ultimate guide to Crystal programming covering all its fundamental concepts such as OOP and concurrent programming to help you write readable and safe code and build fast applications

Key Features

• The book uses an example-based approach for a better demonstration of the underlying concepts
• Develop a thorough appreciation of the roles of the macro API and annotations
• Leverage supportive tools – spec, documentation, deployment, and automation

Book Description

Crystal is a programming language with a concise and user-friendly syntax, along with a seamless system and a performant core, reaching C-like speed. This book will help you gain a deep understanding of the fundamental concepts of Crystal and show you how to apply them to create various types of applications.

This book comes packed with step-by-step explanations of essential concepts and practical examples. You'll learn how to use Crystal’s features to create complex and organized projects relying on OOP and its most common design patterns. As you progress, you'll gain a solid understanding of both the basic and advanced features of Crystal. This will enable you to build any application, including command-line interface (CLI) programs and web applications using IOs, concurrency and C bindings, HTTP servers, and the JSON API.

By the end of this programming book, you’ll be equipped with the skills you need to use Crystal programming for building and understanding any application you come across.

What you will learn

• Explore how Crystal combines the merits of other languages
• Understand how to leverage existing C libraries without writing any C
• Focus on zero-cost abstractions with compile-time macros
• Use an example-based approach to demonstrate language features
• Develop a variety of Crystal applications, such as web and CLI apps
• Gain an understanding of the macro API and annotations

Who this book is for

Developers who want to learn Crystal programming or anyone looking to improve their ability to solve real-world problems using the language will find this book helpful. Experience in application development using any other programming language is expected. However, prior knowledge of Crystal is not required.

Table of Contents

1. An Introduction to Crystal
2. Basics Semantics and Features of Crystal
3. Object-Oriented Programming
4. Exploring Crystal via Writing a Command-Line Interface
5. Input/Output Operations
6. Concurrency
7. C Interoperability
8. Using External Libraries
9. Creating a Web Application with Athena
10. Working with Macros
11. Introducing Annotations
12. Leveraging Compile-Time Type Introspection
13. Advanced Macro Usages
14. Testing
15. Documenting Code
16. Deploying Code
17. Automation
18. Tooling Setup
19. The Future of Crystal

George Dietrich is a software engineer, open-source aficionado, and Crystal community moderator. He holds a Master of Science degree in internet information systems and a Bachelor of Science degree in information sciences.

Guilherme Bernal is the chief technology officer at Cubos Tecnologia. He holds a bachelor's degree in TI management. Guilherme co-founded a software development company and several tech start-ups, including one that focused on teaching programming skills to a new generation of developers. He is also a two-time world finalist in the coding competition, ACM ICPC.