From: Thomas Hafner <thomas@...>
Date: 2007-01-28T03:05:05+09:00
Subject: Re: cartesian product of arrays

Peter Szinek <peter@rubyrailways.com> wrote/schrieb <45B9E90C.7010106@rubyrailways.com>:

> Just a suggestion: it is also possible to reopen Enumerable and put your 
> code there - in this case, all enumerable types will have this 
> functionality (e.g. Sets), not only Arrays.

Does that follow your suggestion?:
#\\\
module Enumerable
  def cartprod(*args)
    result = [[]]
    ([self] + args).each do |b|
      t, result = result, []
      t.each do |a|
        b.each do |n|
          result << a + [n]
        end
      end
    end
    result
  end
end
#///

Example:
(1..2).cartprod((3..5), (6..8))

Regards
  Thomas