Programming Ruby

While Ruby isn't new, it's one scripting-and-everything else language which has yet to break out (in the U.S. at least) the way Perl and Python have. Chromatic may help buck that non-trend -- he says that Ruby is one polished gem of a language, and below he introduces a book on Ruby that he compares in importance with the O'Reilly Camel book.

Programming Ruby
author	David Thomasand Andrew Hunt
pages	564
publisher	Addison-Wesley
rating	9
reviewer	chromatic
ISBN	0-201-71089-7
summary	A no-nonsense, clear guide that's as clean and usable as Ruby itself.

The Scoop

Ruby is a growing language that combines the power and conciseness of Perl with the Smalltalk object model. Though popular in Japan, it hasn't reached its potential in English speaking countries, lacking appropriate documentation. Enter Dave Thomas and Andy Hunt. On the heels of The Pragmatic Programmer, they've produced the Ruby equivalent of Perl's Camel.

What's to Like?

Programming Ruby starts with a general language overview. A dozen short and sweet chapters form this tutorial. Readers with no programming background won't feel too out of place, though they will need to be comfortable with terminology explained once and used throughout the rest of the book. Topics range from language basics to multithreading and using the debugger. Rather than starting from syntax rules, the authors introduce concepts as their context dictates. There is some conceptual overlap between chapters, but this approach is preferable to discussing one topic at a time, referring briefly to future chapters.

The next section shows how to connect Ruby to other languages and tools. Besides information on Ruby modules and the command line, chapters include CGI programming, Ruby GUI programming with Tk, and automating Windows. The chapter on embedding Ruby in C is short but comprehensive. Within the 200 pages of these two sections, experienced programmers will have learned enough Ruby to be quite productive.

Section three expands further on the core language. Though covering the same areas as the tutorial, these chapters delve into the gory details. (As gory as Ruby gets, which is to say, surprisingly little spit and bailing wire.) Thomas and Hunt write with the authority of language designers producing a standard reference. Chapter 19, Classes and Objects, particularly stands out. It describes Ruby's simple object model, using a handful of well-chosen examples and clean diagrams to punctuate the point.

The final section takes up nearly half of the book. This library reference lists Ruby's built-in and common classes and objects. Each class has a description, a named parent, and a list of mixins and class and instance methods where appropriate. Modules fare similarly. Most explanations include common usage examples.

Four appendices and an impressive index round things out.

What's to Consider?

Ruby itself makes a fine starting language. To get the most benefit from the book, it's handy to have experience with OO programming and a similar scripting language. (Python and Perl hackers will have little trouble, Smalltalk coders will feel right at home, and Java and C++ fans will do well.) Beginning programmers won't have their hands held for very long.

A handful of advanced concepts are mentioned but not explained. This is only a minor gripe -- techniques like runtime code generation are beyond the scope of the average hacker's needs. The flexibility of Ruby's object model and the loose distinction between compile-time and run-time obviate the need for much of this trickery anyhow.

Some might find the class reference section slightly hard on the eyes. The repeated horizontal lines are visually distracting -- indentation would improve readability. On the positive side, the class, library, and module sections are arranged alphabetically, with a tabbed margins to improve navigation.

The Summary

This attractive tome ought to be on the desk of any serious Ruby programmer -- and Ruby itself deserves consideration as a clean and powerful development language. Aimed at moderately experienced programmers, Programming Ruby is a great introduction and a handy reference. Read it online here!

Table of Contents

1. Roadmap

1. Facets of Ruby
2. 1. Ruby.New
   2. Classes, Objects, and Variables
   3. Containers, Blocks, and Iterators
   4. Standard Types
   5. More About Methods
   6. Expressions
   7. Exceptions, Catch, and Throw
   8. Modules
   9. Basic Input and Output
   10. Threads and Processes
   11. When Trouble Starts
3. Ruby in Its Setting
4. 1. Ruby and Its World
   2. Ruby and the Web
   3. Ruby Tk
   4. Ruby and Microsoft Windows
   5. Extending Ruby
5. Ruby Crystallized
6. 1. The Ruby Language
   2. Classes and Objects
   3. Locking Ruby in the Safe
   4. Reflection, ObjectSpace, and Distributed Ruby
7. Ruby Library Reference
8. 1. Built-in Classes
   2. Built-in Modules
   3. Standard Library
   4. Object-Oriented Design Libraries
   5. Network and Web Libraries
   6. Microsoft Windows Support
9. Appendices
10. 1. Embedded Documentation
    2. Interactive Ruby Shell
    3. Support
    4. Bibliography

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Besides reading online, you can purchase this book at ThinkGeek

why Ruby hasn't broken out

I don't think Ruby's lack of documentation has anything to do with why it hasn't broken out. After all, Ruby's web site has tons of perfectly good documentation that any competent programmer shouldn't have any problems making heads or tails of.

Ruby's main problem is it doesn't offer clear benefits over the existing solutions. For instance, take a look at Ruby's comparison page. It's improvements over Perl are: nicer syntax, different default scoping, cleaner integration of object-orientedness. Those are hardly decisive. Compare Ruby to Python and you'll find a similarly non-compelling argument.

Re:Where does ruby sparkle? (languages are languag

PHP (perl for people to stupid to perl)

While I tend to find some things about PHP annoying in comparison to perl -- PHP is, in most things, just a little less convenient, and I'm used to perl -- I think that comment is just way off. Much better, I think, is Mark Jason-Dominus' view [perl.com].

"In my world, PHP can be a good solution, and Perl can be a good solution, because maybe a problem can have more than one good solution. In my world you use what works, and using PHP can't possibly reflect badly on Perl."

as Objective C does to C++

Now I know you're smoking crack. For years, a small group of people called NeXT programmers wrote serious software with ease and speed the rest of the world -- especially the C++ world -- only dreamed of. Yes, back when (and perhaps before) perl was still in version 4.

And the functional and logical paradigms are VERY useful in the right problem domains (and/or with the right mindset). Which can be said of just about every language. Yes, perl is cool, and multiparadigmatic, and it is the swiss army chainsaw it's touted as, but that doesn't mean that other languages are all useless. There's more than one way to do it.

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Re:Where does ruby sparkle?

I am afraid you don't know ruby, Ruby is what Python should have been + 100. I say this as a passionate python lover, I have known about ruby for sometime, and really respect it tho I haven't adopted it fulltime yet. Your comment is exactly what some people said about Python, dare you say that anymore? In Japan, people/companies are doing lots of productive work with Ruby, you need to grow up, Man, even functional languages are being used to solve real problems. I suggest you go to ruby's site, read up on the tutorial, there was an article on dr dobbs journal a month or two ago on ruby, read that too, and perhaps you will eat your words.

From #ruby-lang

"i've been programming for 18 months now and i don't see why we need another programming language. i'd write more, but my mother's calling."

-- David Thomas, in response to the comments in this article

Ruby is really nice...

I'm sure there will be a raft of "do we need another script language -- isn't python/perl enough?" comments.

The answer is yes we do -- if it is ruby. Ruby offers a much better OO model than either Python or (gahk) Perl, with much clearer syntax for things like instance variables (non of this execrable 'self' gunk that python forces upon you). Ruby is so OO that it is scary, whereas Python and Perl always feel like procedural scripting languages with some OO bolted on.

And iterators -- baby, they are the coolest. Forget for loops and while loops for counting, just use the iterators. They are used throughout the language and make your code both small and readable.

The main barrier for ruby i the lack of online docs for the library -- the original docs are in Japanese. I ended up having to carry my "Programming Ruby" book in my laptop case for reference. That is what I miss most from my python days -- online reference docs.

Re:too many tools?

I don't think so. Different languages do the same things in different ways, and learning new languages can broaden the way you think about solving problems.
As long as those unsung (and often sung) heroes go on developing new languages, I'll eagerly try to learn about at least some of them.


-beme

Re:too many tools?

do we really need to have a choice of almost a dozen languages to do just a small variety of tasks?

I don't know about you, but I haven't had a "small variety" of programming tasks since the mid-80s.

Programming Ruby has been on my book want list [petdance.com] for a while, but based on this review I can tell I'm going to have to move it up in priority.

I especially look forward to commentary from those /.ers who have used it.
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Re:Which reminds me... Modula-2

Modula-2 is a very different kind of language. It has two basic properties:

• It's really hard to get your program to compile, because the language is so strict.
• Once your program compiles, there's a good chance it will run the first time.

Hackers hate that.

Re:..and there's CPAN

There is the "ruby application archive" at http://www.ruby-lang.org/en/raa.html.

Yes, CPAN is great and no other language comes close to the support found on CPAN. Of course, there's only one way to remedy that problem and that is to join the Ruby community and actually contribute.

Not what I expected

Thanks for the review. I might have picked up this book by accident!

I was expecting a book by the mafia and/or the CIA about brainwashing a Dallas stripclub owner named Jack.

..and there's CPAN

For me the best thing about perl is the huge CPAN library...just about anything you could think of, all categorised and indexed...and the cpan.pm module makes everything really easy to download and install too. i don't see that newer scripting languages like Ruby can take off unless they have a similar centralised mass of ready to go modules...a clean object model can only get you so far when you have to code everything yourself 'cos there's no huge library of modules. does anyone know what the state of the supporting Ruby modules are like? anything approaching CPAN yet?

Re:why Ruby hasn't broken out

I looked into this, the threads arent native, they are implemented inside the ruby interpreter, so you do get the advantage of coding threads, but you wont get any of the advantages of executing threads, like you would want for tweaking performance on multi-cpu machines, or working around blocking calls in a server. Proof if this is that ruby threads work even in DOS

don't forget about CPAN

For me the best thing about perl is the huge CPAN library...just about anything you could think of, all categorised and indexed...and the cpan.pm module makes everything really easy to download and install too. i don't see that newer scripting languages like Ruby can take off unless they have a similar centralised mass of ready to go modules...a clean object model can only get you so far when you have to code everything yourself 'cos there's no huge library of modules. does anyone know what the state of the supporting Ruby modules are like? anything approaching CPAN yet?


Yours,
Bob