I heart Ruby
A friend of mine pointed out an article on lj a while ago, Why Python, and asked for a response… so now you're all getting it.
I'm pretty sure that I would have been (almost) as impressed with Python as I have been with Ruby… I just happened to run into Ruby first. Both these languages are so wonderful to use because of their dynamic nature.
Notice that "almost" up there? Ruby does have a few really neat tricks that (if used correctly) can be really useful. Granted, most of the time they aren't gonna be used correctly. Here's a good example, though (found throughout the net):
fib = Hash.new do |h,n|
if n <= 1
h[n] = n
else
h[n] = fib[n-1] + fib[n-2]
end
end
fib[10] # returns Fibonacci of 10 (55)
The Hash object can take a block of code during instantiation that it will execute if you reference a non-existent index. So the code above computes the fibonacci sequence using caching (or memoization or dynamic programming, depending on what pretentious fuck you're talking to). Meaning that the next time I ask for $fib[10], it's already been computed. That's the simplest way to do memoization that I've ever seen.
Since Ruby is a functional language, you can also do neat (but uselessly obscure) things like:
puts case
when x < 0; "x < 0"
when 0 <= x && x < 1; "x in interval [0,1)"
when 1 <= x && x < 2; "x in interval [1,2)"
when 2 <= x; "x >= 2"
end
Which puts (like print) the results of the case statement. Like all things geeky, this can be used for good or evil :)
Ruby seems to take all the best parts of LISP, but bringing them into an easy to use and modern language.
Finally, I agree whole heartedly with everything ESR said about perl. It's amazing to me that Citysearch (and many other large sites) are built entirely out of perl code. How do they manage to keep their sanity?