From: matt@... (matt neuburg)
Date: 2006-11-01T02:20:13+09:00
Subject: Re: Class inheriting from class within the namespace

Gavin Kistner <gavin.kistner@anark.com> wrote:

> Tree structures are interesting. Often the root of the tree is used as a
> handle for the tree itself. However, the tree often has additional
> methods beyond that of the root node.
> 
> I couldn't figure out how to do this simply via inheritance due to
> chicken-and-egg problems with namespacing:
> 
>   class Tree < Tree::Node
>     class Node
>     end
>   end
>   #=> chicken-and-egg.rb:1: uninitialized constant Tree (NameError)

Why wouldn't you do this?

module TreeStuff
  class Node
  end
  class Tree < Node
  end
end

A tree does more than a node (you say), so a tree is a subclass of node
("a node and then some"). The pair are wrapped up in a module to isolate
their namespace.

Of course I could be missing some other desideratum. m.

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