From: Adriano Ferreira <a.r.ferreira@...>
Date: 2005-05-06T02:07:24+09:00
Subject: Re: Whats so different about a Hash?

> Hm, I'm okay with the last part (checking if all pairs are shared), but
> I'd replace the h1, h2 stuff with self.size == other.size.

Agreed. That was unnecessarily complicated. That should do it:

class Hash
  def eql?(b)
    return (self.size==b.size) && self.all? { | k, v | v.eql?(b[k]) } 
  end

  def hash
    return self.inject(0) { | h, k, v | h ^ k.hash ^ v.hash }
  end
end

The Hash#hash is a suggestion for a hash method which obeys
h1.hash==h2.hash if h1.eql?(h2). None of the methods above rely on
sorting and other expensive operations, even though traversing the
hash and possibly recursion (if there are hashes inside hashes) is
expensive enough.

Regards,
Adriano.