From: Sean O'Halpin <sean.ohalpin@...>
Date: 2006-07-17T12:20:24+09:00
Subject: Re: Alternate initializers or alternate class?

On 7/16/06, transfire@gmail.com <transfire@gmail.com> wrote:
>
> Sean O'Halpin wrote:
>
> > +1 - having cake and eating it is a thing devoutly to be wished for ;)
>
> Well, it seemed all well and good but now I find myself having to
> create Auto versions of every other subclass of Hash. I have a few, so
> that start's to get ugly. hmm....
>
> T.
>
You don't have to write the code yourself! :)

def make_auto(*classes)
  classes.each do |klass|
    new_class = Class.new klass do
      def initialize(*args)
        super(*args){ |h,k| h[k] = self.class.new }
      end
    end
    Object.const_set("Auto#{klass}", new_class)
  end
end

class OrderedHash < Hash
  # do something here
end

make_auto Hash, OrderedHash

ah = AutoHash.new
aoh = AutoOrderedHash.new

p ah[:a]
p aoh[:b]
__END__
{}
{}

Regards,
Sean