Programming Crystal: Create High-Performance, Safe, Concurrent Apps

by Ivo Balbaert, Simon St. Laurent

Crystal is for Ruby programmers who want more performance or for developers who enjoy working in a high-level scripting environment. Crystal combines native execution speed and concurrency with Ruby-like syntax, so you will feel right at home. This book, the first available on Crystal, shows you how to write applications that have the beauty and elegance of a modern language, combined with the power of types and modern concurrency tooling. Now you can write beautiful code that runs faster, scales better, and is a breeze to deploy.

Crystal is elegant to read and easy to program like Ruby, allowing full object-oriented development. Its compiler is powerful enough to nearly always infer the type of your variables. So you get the benefits of a statically typed language: more robust code, safety, and execution speed while still reaching high productivity in development. Null pointer exceptions as in JavaScript, Java, or C#, are a thing of the past: Crystal annihilates them, just like Rust.

Explore the building blocks and design of the language and how you can use the Crystal tool-chain to build and manage powerful applications. Harness the power of the macro system, as well as how to work with fibers and channels, making concurrency as easy as possible. Learn how to use the Kemal web framework and access databases and how to tap the potential of existing Crystal libraries. Find the spot that Crystal fills in today’s software world with real-world examples.

With Crystal, you can combine the best of both worlds: the high-level coding of dynamic languages and the safety and blazing performance of a natively compiled language.

Genres: Programming

230 pages, ebook

Published January 10, 2019

Reviews

[Stefan Kanev · Rating 2 out of 5]

Read this book if you're looking for an overly long tutorial that does not help you grok the language, while interrupting you with uninformative interviews that you're unlikely to care about. It's kinda worth reading it if you already have access to it through O'Reilly Online Learning, but it's totally not worth the money or the time otherwise.

It explains the language partially, it doesn't get into anything interesting, and it covers even less than the already brief docs on crystal-lang.org.

As with pretty much any recent Pragmatic Bookshelf book on a programming language, you're better of not bothering and learning through something else. Sadly, there isn't a good alternative as of the time of writing of this review :)

[Andrew · Rating 2 out of 5]

As an introduction to Crystal, it’s about what you’d expect for a new language. But the review of the ecosystem, company interviews, and near constant comparison comparison to Ruby, Go, and Elixir reads like filler text. I didn’t need a sales pitch as much as an introduction to the language in book format.

[Tbueno · Rating 3 out of 5]

The book wastes too much time comparing it with Ruby instead of talking about Crystal's strengths. For example, the concurrency features are described in a 3 page section, while dozens of pages are used for interviews with completely unknown companies, which ended up emphasizing how premature the community was when the book was written.

[Dang-Khoa Le Tan · Rating 3 out of 5]

The book itself is boring and I skipped all interviews in the end of each chapter. However, the language is really interesting and hooked me due to its conciseness and performance.