From: Daniel DeLorme <dan-ml@...42.com>
Date: 2007-06-05T13:47:16+09:00
Subject: Re: Reverse-range alternatives?

Kenneth McDonald wrote:
> Since a reverse range (eg. 4...1) is functionally almost the same as an 
> empty range, is there an alternative in the standard library, where 
> .each would actually iterate over the elements from first to last, in 
> this case 4, 3, 2?

I can't resist this one...

class Range
   def reverse
     r = dup
     def r.each(&block)
       last.downto(first, &block)
     end
     r
   end
end

 >> (1..9).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
 >> (1..9).reverse.to_a
=> [9, 8, 7, 6, 5, 4, 3, 2, 1]

:-D

Daniel