From: "David A. Black" <dblack@...>
Date: 2005-11-14T23:48:48+09:00
Subject: Re: Heirarchy Troubles

Hi --

On Mon, 14 Nov 2005, CBlair1986 wrote:

> Hello all. I've got a somewhat unique problem, I think. I have a list
> of classes planned out, with the attributes needed for them and
> everything else, but I want to figure out how the classes should relate
> to one another, so that I don't need to needlessly repeat myself.

That's unique?! :-)

> For instance, say I have the classes planned as such:
> class Apple
>  attr_accessor :taste, :type, :flavor, :flesh, ...
> end
> class Orange
>  attr_accessor :taste, :type, :flavor, :peel, ...
> end
> and so on.
>
> How would I go about fitting these together, so that I could have more
> general classes such as Fruit and Vegetable and so on?

You could encapsulate the non-shared behaviors (or even the shared
ones, if you wanted) in modules:

   module Peelable
     attr_accessor :peel
   end

   module Fleshy
     attr_accessor :flesh
   end

   class Fruit
     attr_accessor :taste, :type
   end

   class Apple < Fruit
     include Fleshy
   end

   class Orange < Fruit
     include Peelable
   end

etc.  That way, if you had more than one peelable class, and the
nature of peelability changed, you could change it all in one place.


David
-- 
David A. Black
dblack@wobblini.net