From: Trans <transfire@...>
Date: 2008-11-18T17:23:42+09:00
Subject: Re: Subclassing Hash to enforce value uniqueness ala key uniqueness.



On Nov 17, 11:33 pm, Adam Gardner <adam.oddfel...@gmail.com> wrote:
> Anyway, if someone has either a) a prior implementation of this, or b)
> some suggestions on improving my implimentation, I'd love to hear it.

You may be able to save yourself some time with a little meta
programming. Eg.

  class HashSet < Hash

    Hash.instance_methods(false).each do |m|
      define_method(m, *a, &b)
        r = super
        fix
        r
      end
    end

    def fix
      self.replace(self.invert.invert)
    end

  end

You'll want to improve upon that code of course, probably limit it to
only certain methods. But you get the idea.

T.