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Programming Ruby: The Pragmatic Programmers' Guide
If you're not familiar with it, Ruby is a very fun and elegant scripting language that has been described as "more powerful than Perl and more object oriented than Python." I won't start a language war by defending that statement, but I will tell you what makes Ruby very attractive to me: Extremely object oriented, super clean syntax, and a smooth blending of iterators and code blocks for straightforward, concise solutions. If that sounds like a language you would like to know more about, Programming Ruby is the book for you.
At 830 pages, this edition is considerably larger than the first. It represents an expansion on many topics originally covered, in addition to all new coverage on topics like unit testing, RDoc documentation for Ruby source code, and more. Better still, "Duck Typing," a topic central to Ruby philosophy, receives its own enlightening chapter. This volume covers the very latest release of the language, often highlighting new features and even giving tips for things to watch for in future versions.
Programming Ruby is divided into four distinct sections. "Part I - Facets of Ruby" is a tutorial on the Ruby Programming Language. It's very effective, but I probably better give a warning here: This book teaches you how to program in Ruby, not how to program. You likely won't feel comfortable, even in this tutorial section, unless you have some experience with other programming languages. As an example, Ruby is object oriented on a scale with languages like Smalltalk, so you'll need to know object oriented programming. This book makes no attempt to teach such concepts, excepting how they apply to Ruby. As long as you come with the proper background, this section will get you on your feet with Ruby in under 200 pages. It's very well thought out.
"Part II - Ruby in its Setting" is a mixed-bag tour on the many places Ruby sees use. Web programming, command-line hacking, using TK to build GUIs, and Windows programming are just some of the covered topics. Other chapters in here focus on elements unique to Ruby, like the earlier mentioned RDoc or "irb," the interactive Ruby shell. There's even a chapter in here on package management with RubyGems.
When you're ready, "Part III - Ruby Crystallized" will take you deep into the core of Ruby syntax and functionality. This section tells you all the details about how Ruby reads your code, and how it runs. I think few people could soak in all the tidbits in here in one scan. I've read it twice now and learned about as much both times. There's a lot of great Ruby knowledge waiting to be mined out of here.
Finally, "Part IV - Ruby Library Reference" is the best Ruby reference I've yet run across. It covers every class, module, method and constant in core Ruby. The descriptions for these entities tell you exactly what you need to know, the examples, though short, are inspiring, and the comments sneak in subtle hints that are more than useful. Following this, the book gives an overview of all Standard Libraries included with Ruby. This section really opened my eyes to the tools I've been missing out on simply because I didn't know they were there. Be warned: These Standard Library summaries won't teach you every feature available. They just tell you what they're for so you'll know where to look for the information you need. The last great feature in this section is a terrific index. I care about the index and a book that has a bad one will really bother me. Luckily, that couldn't be further from the truth here.
Programming Ruby isn't perfect, of course. Some of the chapters are not as thorough as you wish they could be, simply because of the amount of information that needs to be covered. The chapter on threads is probably the biggest example of this, but remember that entire volumes have been written on threading. Another minor point is that some of the examples are quite contrived. This bothers some people, but I don't feel it's too much trouble for the book's target audience. As I've said, you're expected to know how to program going into this book, just not how to program in Ruby.
Programming Ruby at least touches on most things central to the Ruby Programming Language, and goes into considerable detail more often than not. There's something for all levels here. You can learn Ruby from the tutorial, as I did with the first edition, but you'll keep coming back to the wonderful reference and to go deeper into specific areas of interest. That's a lot of great mileage for one book. I'm willing to bet most Ruby Gurus keep it in arm's reach, because Ruby wouldn't be half as much fun without it.
You can purchase Programming Ruby from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
http://www.rubycentral.com/book/
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
...it was written twice. Chad Fowler wrote it the first time while he was on vacation in Europe. Then he had to rewrite it after his Powerbook was stolen on his trip home. Argh!
More on Ruby Gems here.
The Army reading list
Ruby is like the glue that holds alot of my programs together.
:)
The first edition of this book came in really handy in college, when I'd have to find creative ways to do something (especially text manip), where C++ or Java just seemed to get in the way.
Ruby is quick to learn, and Dave Thomas from Pragmatic is a great teacher...he came to my school for a little lecture/speech one day, and talked on the merits of Ruby, which is how I got introduced to it.
The network aspects of Ruby are great too. Small concise ruby programs can do a whole lot
Why didn't reviewer say 'Brilliant, but slightly flawed'.
Who could hang a name on you
Oh come on someone had to do it.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
...thanks to Ruby Central for sponsoring it.
A BitTorrent of the presentations is available here.
The Army reading list
It comes from the pick and axe on the front cover of the book :-)
Many of us, Rubyists, have been introduced to Ruby by the very first version of this book. And the first version is online and is still handy for consulting:
http://www.ruby-doc.org/find/pickaxe
But this new version covers all the changes from Ruby 1.6 to Ruby 1.8; making this book a must have.
As far as I know, it's available as PDF and as paper, and I'm gonna have both.
Thanks Dave for helping the occident know Ruby and Matz for creating the must inspiring language for me.
Cheers!
I'm not sure what you mean by platform or "just runs". If you mean, do you need a certain OS? No. Do you need Apache in particular? No, though Apache and Ruby work very well together. Do you need any external web server? No. One of the standard libraries that comes with Ruby is WEBrick, which is a standalone webserver. You can get Ruby running web apps using WEBrick on any OS, no other software required.
Along those lines, let me throw in a quick plug for Ruby on Rails. Rails makes web application using the MVC model very quick and easy. The default setup includes a WEBrick servlet so you can have your application listening for requests minutes after installation, literally.
Visit #ruby-lang and #rubyonrails on freenode for more information about Ruby in general or Rails.
Jacob Fugal
> Ruby is a better fit for this problem?
There's a good C2 Wiki page on this - PythonVsRuby.
The Army reading list
We have built an extremely robust distributed testing framework for a Java-based multi-agent system completely implemented in Ruby (see Cougaar for more on the project and the ACME testing framework). We were told on starting this project (at DARPA) that it would never work...I really like proving people wrong ;-) My company is using its Ruby expertise as a differentiator in the market and getting very good reception.
Why's Poignant Guide to Ruby has got to be the most entertaining Ruby read out there....
Tweet, tweet.
I can live with Python's having no statement terminator (";" in C, C++, Perl, Java).
What I find unacceptable in Python is that whitespace (tabs) determine the logical flow. I once wrote a script on Windows and moved it to UNIX; the UNIX editor handled tabs differently, and my script wouldn't work without a few hours of attention just to set the spacing right.
Ruby has Pascal-like blocking. That alone makes it superior to Python. And for all other situations that do not require a good OO implementation, there is Perl.
Rich And Stupid is not so bad as Working For Rich And Stupid.
No, there is a difference. It's a mistaken notion that Ruby is like Python meets Perl.
It's more like Smalltalk + Regular Expression + Incidental Other Goodies + Culture.
I've tried both, and I like Ruby far more than Python. Ruby is an incredible language that tends to enable really simple, yet sophisticated code. When people talk about the Ruby Way, they aren't kidding. Ruby is endearing to me in ways that Python never was.
Ruby and Python are both drinking from the smalltalk fountain, but they are still very different. Ruby plows head-on into more functional-programming types of paradigms while still using objects.
Gentoo Sucks
Can I get any advice? Is Ruby really "more powerful than Perl
That's really difficult to quantify. How do you define 'more powerful'?
Personally, I prefer Ruby's clean syntax to Perl's (especially when compared to OO programming in Perl, which is just a disaster from an aesthetic viewpoint, as well as the amount of work that is required from the Perl programmer to do OO). There are a few features that Ruby has that Perl doesn't: continuations, code blocks and exceptions.
and more object oriented than Python" - is this what I'm looking for, or should I put it off and learn Python first?
This tends to be an area where there is a lot of dispute between the two camps. I've already revealed my bias toward Ruby, so take that into consideration regarding the following comments: In Python I get the feeling that object orientation was tacked on. Granted it was tacked on much earlier in the language's development than it was in Perl where OO programming is essentially a do-it-yourself project. There are a couple of nagging issues in Python which give me this idea:
1) why do I need to include 'self' as the first parameter of each method definition?
2) In Python people tend to prefer, for example, to find the length of an array by saying:
length( array ) instead of array.length (the latter being the way you would do it in Ruby). Of course Pythonistas are now screaming that you can also say: array.__length__ (or something similar) in Python as well.
Python now also has something similar to Ruby's iterators (though they're a bit different), but something to keep in mind is that Ruby's standard libraries and built-in classes were built from the ground up with iterators in mind - I think that's a big advantage that Ruby has over Python.
I suggest that you try to write a smallish program in each language (pick a project that might take an hour or two) and see how each language 'fits' with the way you think. I find Ruby fits my way of thinking much better than Python does, but as they say, YMMV.
Could you give some examples? I'd love to fix stuff. if it's broken.
Why not e-mail me directly as well as posting here: dave pragprog.com
Cheers
Dave
Ruby has first-class functions; you just have to disambiguate them syntactically, since bare property access (like foo.bar) is actually calling method bar on the object foo. So, if you want to reference the method explicitly, you have to write foo.method(:foo), which returns a Method instance which can be invoked or used like any other scalar value.
...the Ruby idiom would be one of the following:
...you would use this:
So, while in Python, you might write something like this:
controller.set_handler('some_action', myObject.handle_some_action)
controller.set_handler('some_action', myObject.method(:handle_some_action))
-or-
controller.set_handler('some_action') { myObject.handle_some_action }
The extra method(...) syntax is needed to ensure that all communication between objects is via method calls, rather than direct property access. Python allows you to directly assign to and read from object attributes, much like public members in C++ or Java classes. Ruby forces all attribute access to be wrapped in get/set methods, but provides a lot of support to make implementing those methods effectively automatic.
The latter example also uses a code block, cover many cases where first-class functions would be otherwise -- they're basically a compact syntax for lambda expressions, and prevent you from needed sugar like list comprehensions in most situations.
For example, instead of the following Python list comprehension:
[x*2 for x in myArrayOfValues if x % 3 == 0]
myArrayOfValues.map {|x| x*2}.find_all {|x| x % 3 == 0}
Blocks are also a general idiom used throughout the standard library and most Ruby code in the wild. You can use them to write callbacks, query databases, and even to build domain-specific languages (another traditional stronghold of functional languages).
Really, though, neither Ruby or Python is a truly functional language; both borrow from the more "academic" languages those features and concepts they find useful, and leave behind those that the maintainers and users don't want, need, or understand. (Except for continuations, of course -- Ruby has those, and I would guess that only a very small percentage of Ruby coders ever grok them.)
The comp.lang.functional FAQ says Actually Ruby only has expressions, so it seems to be a pretty good candidate. You can also create functional objects and use them as arguments:The same in Common LISP, also a functional programming language:Doesn't look so different, does it?
There are several kinds of programmers, at least when it comes to the language selection:
The first kind gives us applications that cannot be easily ported to other OSes or platforms, because everything is so low-level that it is tied to the underlying architecture. The second kind gives us duplicated effort and software that becomes unmantained whenever the main developer quits, since few other programmers know the language in which the project is written. The third kind gives us solutions that make sane people scream, like shell scripts that start with #!/usr/bin/php -q.
It's fun to learn other programming languages, and contribute to the development of new ones, but in the open-source environment it is also very important to remember that you a) do not and should not work in a vacuum, b) that there are freaks who will probably try to run your software on bizarre setups, and c) that there is always a chance that circumstances will require that you quit working on that project.
This is the reason why when picking a development environment for a project it is important to consider things like portability, maintainability, and suitability for the purpose. I'm not sure I can justify writing something in Ruby at this point, seeing as its adoption is far below Python, while its advantages over Python are slim to questionable.
If you open yourself to the foo, You and foo become one.
What really struck me about Ruby is how it "solved" many of the issues that had been bugging me about other languages (and I've used a bunch). Such as:
* In many languages, a built-in method will either mutate an object "in-place", or it will work on a copy of the object and return that, leaving the original untouched. Sometimes pretty arbitrarily. But in Ruby, there's a convention like in Scheme (and maybe others): methods ending in "!", like "array.sort!" will sort the array in-place, and the other methods return a new sorted copy. Nice! One annoying issue solved.
And booleans end in "?" which is nice too. instead of "is_foo" you write "foo?".
* In many languages, you can have fields on objects, and you can have methods. So when you have "attributes" (like "first_name", "last_name" on a customer object), do you use fields which are simple and straightforward with natural syntax:
object.first_name = "Joe"
or do you use methods, which can be refactored:
object.setFirstName("Joe")
So, do you go for the awkward syntax, keep the fields private, and allow refactoring? Or do you expose the field, and rewrite all the code later when the requirements say "name must default to 'Anonymous Coward' when no name set"? Or do you convolute your code around the issue?
Ruby solves this elegantly. There are NO PUBLIC FIELDS! Instead, you always use methods:And no goofy "set_first_name"
AND you don't even have to create the basic getter/setters! Ruby classes have a built-in class method that creates them dynamically:Very elegant! Well-written programs are very clean and light.
* No need to use exceptions for non-local flow control.
Ruby has exceptions, but sometimes you want to jump out of a deep tree search (for instance), and an exception is what you need: "raise SearchFinishedException" or something like that.
But is that a good idea? Using "exceptions" for flow control? No because exceptions are, well, *exceptional*, they don't occur normally.
Ruby helps me here too. It has catch()/throw() which is a simple alternative to exceptions, designed for nonlocal flow control. And of course you can write your *OWN* flow control because it has continuations (encapsulate program flow into an object for later return).
Anyway Ruby is such an amazingly elegant language, and the pickaxe book is the appropriate companion! Buy a copy now, even if you don't use Ruby, it's very clear and easy to read (not just because of the language, but because of the enthusiastic and talented authors).
i own the first edition, it's a good tutorial-type ruby book
Ever notice that there's tons of Perl, PHP, and Ruby snippents all over the web but very few Python snippets? It's because you really can't copy Python from the browser and paste it into a text editor! The whitespace gets changed and the program breaks in very hard-to-diagnose ways. It's rather funny.
There are many features of Python that will be adopted by future languages, but I doubt that significant whitespace is among them.
Python will require me to go line by line and insert spaces or tabs.
No offense, but that's a load of crap and evidence that you've never actually coded anything in Python. If you had, you'd know that Python comes with a fully functional editor called IDLE, which includes auto-indentation. You can also select whole chunks of code and press ctrl+] to indent or ctrl+[ to unindent. Explicit scope declarators serve no purpose but to frustrate the programmer who forgets to declare that last '}' of 'end' statement. All Python forces you to do is write clean, readable code.