Book Image

Crystal Programming

By : George Dietrich, Guilherme Bernal
Book Image

Crystal Programming

By: George Dietrich, Guilherme Bernal

Overview of this book

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.
Table of Contents (26 chapters)
1
Part 1: Getting Started
5
Part 2: Learning by Doing – CLI
10
Part 3: Learn by Doing – Web Application
13
Part 4: Metaprogramming
18
Part 5: Supporting Tools

Linting code

Static analysis is the act of analyzing the source code of a program in order to identify code issues without needing to actually execute the program. This process is primarily used to detect security, stylistic, or non-idiomatic code issues.

These static analysis tools are nothing new to programming languages. However, the typed nature of Crystal handles most of what an external static analysis tool would handle, without needing anything other than the compiler itself. While the compiler would catch type-related errors, it would not catch more idiomatic issues, such as code smells or using non-optimal methods.

In Crystal, the go-to static analysis tool is https://github.com/crystal-ameba/ameba. This tool is usually installed as a development dependency by adding this to your shard.yml file and then running shards install:

development_dependencies:
  ameba:
    github: crystal-ameba/ameba
version: ~> 1.0

When installed, Ameba...