Eloquent Ruby [Paperback]

This book is so easy to read yet so useful and informative that I read it in its entirety within 24 hours (across 2 distinct days admittedly ;-)).

Eloquent Ruby is a book published by Addison Wesley and written by Russ Olsen (who also wrote Design Patterns in Ruby a few years ago). It clocks in at around 400 pages and has 31 chapters clocking in at around a punchy 10 pages each. Each chapter is titled as a guideline you should follow to write "eloquent" Ruby - things like Create Classes That Understand Equality and Write Code That Looks Like Ruby - and typically the claim is explained, some code examples shown and discussed, some real world examples pointed to, and that's it. As with Design Patterns in Ruby, Russ adopts a chatty, familiar tone. Reading this book is like reading a book specifically written for you by a friend. He doesn't shoot off on many unnecessary tangents and he keeps the stories short and sweet but this book certainly couldn't be called dry.

The book is also notably short of egregious errors or omissions. Even when I don't read something with a fine-toothed comb on standby, I can usually pick out a laundry list of factual and grammatical errors or omissions (as both Obie Fernandez and my wife will attest) but Eloquent Ruby gave me little to chew on. I can only bring to mind a few spacing and formatting issues and only one true "error": a > instead of a < in a class definition on a single example.

Russ tries to remain neutral with his choice of Ruby implementations but the book seems to focus primarily on Ruby 1.9 (Ruby 1.9.1 specifically but that's just due to when he wrote it) while providing useful footnotes in the cases where there are differences to Ruby 1.8. No matter what Ruby implementation you're using, there's little to confuse you as most of it is very non-implementation and non-version specific.

I wholeheartedly recommend this book to anyone except those who, well, could have written a similar book themselves. The short punchy chapters make it a delight to read and gives the option of reading it merely 10 minutes at a time before bed or similar. The short chapters also make it useful as a reference if you forget how to do a certain thing like, say, use method_missing, even though it's not put together as a reference book at all. Lastly, this book is a must read if you're not confident with Ruby idioms and the best way to structure and lay out your code - Russ's approaches reinforce the current "standard" way to write Ruby and this alone is worth the price of admission.

For better or worse the vast majority of my work life journey has been travelled with Java as my vehicle of expression. However, by nature I have a burning desire to learn new languages and at one point or another I discovered Russ Olsen's (also the author of Eloquent Ruby) "Design Patterns in Ruby". Having at one time counted myself as a true-believer in everything pattern-esque, I was excited for the opportunity to learn Ruby under the aegis of The Gang of Four. However, what I found was something else entirely. I absolutely loved "Design Patterns in Ruby" for reasons that I was not expecting. That is, what I found was an extremely interesting book that was playful and as a nice side-effect *actually taught me how Ruby's powerful features make many design patterns unnecessary*.

Olsen, with his latest effort has mastered the art of writing a book that is extremely interesting, fun, and informative. As an author myself, I greatly admire the ability in other authors to take what many would consider dry and bland, a programming language book, and create something that is truly special. Let me not give the impression that "Eloquent Ruby" is filled with fluff however; on the contrary, of any Ruby book that I've read I have learn the most from Mr. Olsen's masterpiece.

"Eloquent Ruby" is written for the programmer like me: someone with previous programming experience, but with only a passing understanding of Ruby itself. The structure of the book will help guide the Ruby neophyte toward a stronger understanding of not only the language constructs and idioms, but also the Ruby culture. As an outsider to said culture, I've always viewed the Ruby community as merely a collection of characters, but Olsen's book helps to illustrate that (almost universally) Ruby practitioners first and foremost strive to create correct and robust solutions. As a proponent of the Lisp family of languages, I tend to look askance at languages falling into the ALGOL family, but "Eloquent Ruby" has succeeded in convincing me that with the right approach and mindset then Ruby can be a stunningly beautiful language. And this is really the key point to take away from Mr. Olsen's book. That is, he guides the reader through the Ruby mindset to drive home the point that Ruby's features -- from its powerful and fluent blocks and modules, to the mind-bending metaprogramming facilities, to its to its humble symbol, and through its philosophy of "Objects all the way down" -- play together in such a way as to foster ... well, elegance.

The highlight of the book is of course its dénouement that succeeds in pulling together all of the lessons presented throughout the book into explaining the role that Domain-Specific Languages (DSL) serve in solving programming problems with Ruby. I can't possibly do justice in summarizing this important technique, but the punch-line is that Ruby's features foster the creation of powerful and expressive DSLs used to simplify the development of complex solutions by allowing the language itself to be molded into a form that is highly expressive to said solution! It takes a while to see the power in this technique, but "Eloquent Ruby" makes a compelling case indeed.

Russ Olsen has helped me to gain more experience points in Ruby, and I must say that I am excited to learn more. If you too wish to learn more about Ruby, then you would be hard-pressed to find a better book than "Eloquent Ruby" in helping you to do so.

I can't even begin to imagine how difficult it would be to write a book covering such an in-depth topic as the Ruby Programming language. Add to that a target audience with a widely diverse range of skills and the tasks seems to be out right impossible. Fortunately for us mere mortals Russ Olsen has taken on this challenge and surpassed my high expectations in his second book, Eloquent Ruby.

The first part of the book is for the Ruby newbies, but takes an interesting deviation from most programming books. Instead of focusing simply on the syntax and language libraries, Eloquent Ruby focuses on the community aspect of the Ruby programming language. Each programming community has its own style and norms and without a lot of direction and practice, these style and norms can be difficult to learn. The Ruby community is heavily opinionated and Russ's book does a great job of explaining these opinions and their manifestation in many Ruby codebases.

In Part Two of Eloquent Ruby, Olsen dives into the core concepts and building blocks of the Ruby programming language. This section of the book covers the everyday usage patterns and common best practices when working with Ruby's classes, iterators, blocks, and modules.

The power and flexibility of Ruby is put on full display in Part Three of Russ's book. Newcomers to Ruby are often mystified by Ruby code that appears to be doing magical things like dynamically adding methods to a class. In this section, Russ pulls back the curtain and explains the magic that is metaprogramming. Those unfamiliar with the concept may find the topic confusing at first, but Olsen breaks it down in a way that is easy to understand. This section thoroughly covers Ruby's method_missing hook and how to open classes to add your own customizations.

In the last section Russ ties a lot of the concepts of the book together through a discussion on how Ruby can be used to create Domain Specific Languages (DSLs). As a bonus Russ finishes the book with a chapter on how to package your code into a gem (Ruby library) and a chapter on the different Ruby Implementations.

At almost 400 pages I feared Eloquent Ruby would take a while to read, but I was pleasantly surprised at the pace at which I made it through the book. Even though the book was a quick read it still felt as if I had gained a lot of new knowledge after its completion. I credit the speed reading and depth of understanding to Olsen's writing style. The book is broken up into 30 concise chapters that each focus on a specific topic. This makes the book's information very easy to digest.

Following a similar pattern from his first book, Design Patterns in Ruby, each chapter of Eloquent Ruby describes code examples "In the Wild" where Olsen discusses code snippets from open source projects using the topics covered within that chapter. In my opinion giving "real world" code examples was a great way to prove the relevance of the information covered in the book. Overall, Eloquent Ruby was a great read and I'd highly recommend it to Rubyist at all skill levels.