Judging by the coverage in some computer journals, you might be forgiven for thinking that Rails is the only reason anyone programs in Ruby. Love and marriage, horse and carriage, Ruby on Rails – as the old song goes, “You can’t have one without the other”.
I beg to differ. Not only can you program in Ruby without Rails; there are many good reasons why you would want to program in Ruby without Rails. Don’t get me wrong – I’m not denigrating Rails. It’s a fine framework for developing interactive web applications. But it is not the be-all and end-all of Ruby. In short, while Rails can’t do anything without Ruby, Ruby can do a great deal without Rails.
Let me try to define the ‘special’ qualities of Ruby – the things that, to my mind, set it apart from other languages. Before I start I should say that some of these qualities can undoubtedly be claimed by other languages too – everything from Smalltalk (thorough OOP) to Pascal (clear syntax). But it’s the combination of the whole bunch of these qualities that really sets Ruby apart.
Terse
Can you get any simpler than a “Hello world” program in one line?
puts “Hello world”
Clear
It doesn’t look like C! Hurrah! More like Pascal, really, though without all the begins.
while i < arr.length
puts(arr[i])
i += 1
end
until i == arr.length
puts(arr[i])
i +=1
end
Type-free
Or, at least, not strictly typed – no type declarations; and a single var name can be instantiated from many different classes.
Here (see the code below) x and y are arrays. Then x becomes a string, then a number. x is appended ( << ) to the array y and its value is finally shown by p y, which prints: ["hello", " ", "world", 200]
x = y = ["hello", " "]
x = "world"
y << x
x = 200
y << x
p y
Thorough Object Orientation
Well, pretty thorough anyway: Ruby’s OOP is closer to Smalltalk than to C++ or Java.
Fast to develop
Write then run. No compiling or linking.
Dynamic Programming
Want to add executable code to a program while it’s still running? It’s this simple…
input = ""
until input == "q"
input = gets().chomp()
if input != "q" then eval( input ) end
end
The Name
OK, maybe that’s not a good enough reason to pick a programming language but I have to say that, to my mind, programming in Ruby sounds a heck of a lot more fun that programming in C++. And, as luck would have it, programming in Ruby really is a lot more fun than programming in C++. (But, then again, what isn’t…?).
Let me be honest, there are also things I don’t like about Ruby. In my view, there are simply too many ways in Ruby of doing the same thing – too many methods, too much alternative syntax; this not only makes a consistent coding style difficult to achieve but also hides a number of potential pitfalls such as the different behaviour of apparently identical constructs: the two ‘ors’ or and ||, for example, or the two types of block – { … } and do … end.
In fact, when you really get to know Ruby, you will find that some of the claims I made earlier – everything from its simple syntax to its thorough object orientation – are not entirely true. Some bits of Ruby syntax are, to be blunt, a bit gnarly. If you aren’t very careful indeed, “what you see” in Ruby code may not always be “what you get” when you run it. In that respect, it isn’t as clear – as unambiguous – as Pascal. And as for its object orientation – well, as I said, it’s pretty thorough, though there are a few little oddities such as blocks which aren’t objects and imperfect encapsulation (data hiding is not strictly enforced) which might come as a shock to a Smalltalk programmer.
One thing that makes Ruby particularly interesting at the moment is the simple fact that it is not only evolving as a language (Ruby 1.9, 2.0 and beyond) but is also inspiring all kinds of other projects: everything from IDEs (such as Ruby In Steel :-) to compilers such as the Gardens Point Ruby.NET, to alternative Rubylike implementations ranging from the highly Rubylike JRuby to the less Rubylike Groovy. Not to mention frameworks such as Rails and Nitro and CMS applications such as Radiant and Typo.
In short, even though Ruby itself has been around for a decade, there has never been a period of such active development as now. All in all, this is an exciting time to be programming in Ruby…
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