From: Justin Collins <justincollins@...>
Date: 2009-08-01T02:42:19+09:00
Subject: Re: Modifying Struct members

Yossef Mendelssohn wrote:
> Is it possible to modify the members of a Struct class once it's been
> created, yet retain all other behavior?
>
> An example:
>
>    Thing = Struct.new(:a, :b, :c) do
>      def some_method
>      end
>    end
>
> Is there a way to modify Thing so it behaves as if it were effectively
> created like so?
>
>    Thing = Struct.new(:a, :b, :c, :d) do
>      def some_method
>      end
>    end
>
> Re-assigning Thing to a new Struct obviously doesn't work because then
> the behavior is lost.
> Altering Thing.members seemed promising, but that didn't work either.
> Adding attr_accessor for :d isn't good because I need Thing.new['d']
> to work.
>
> Thoughts?
>
> --
> -yossef
>
>   

OpenStruct might be what you want: 
http://ruby-doc.org/core/classes/OpenStruct.html

-Justin