From: Daniel DeLorme <dan-ml@...42.com>
Date: 2007-02-10T13:17:42+09:00
Subject: Re: Your favorite bit of ruby code?

Carl Lerche wrote:
> I'd like to see some of them!

This is one I particulary like from my personal library. It allows me to do 
stuff like:
   book.author.ergo.name
instead of:
   book.author && book.author.name


require "singleton"
class BlackHole
   include Singleton
   private
   def method_missing(*args); nil; end
   for m in public_instance_methods
     undef_method(m.to_sym) unless m =~ /^__.*__$/
   end
end

class NilClass
   def ergo
     BlackHole.instance
   end
end

class Object
   def ergo
     if block_given?
       yield(self)
     else
       self
     end
   end
end