From: dblack@...
Date: 2003-05-13T23:42:47+09:00
Subject: Re: Scope of modules and classes

Hi --

On Tue, 13 May 2003, Bernhard Weitzhofer wrote:

> Hello Ruby-community
>
> I am writing a set of classes to be used in a mod_ruby environment, and
> I decided to group them together in a module:
[...]
> So far so good - but then I wanted to get rid of all those "M::"s:
>
> module M2
>      include M
>
>      class K3 < K1
>          def initialize
>              @a = K2.new
>              @b = K2.new
>          end
>      end
>
>      ...
> end
>
> does not work (K2 is unknown in the scope of K3), and:
>
> module M2
>      class K3 < M::K1
>          include M
>          def initialize
>              @a = K2.new
>              @b = K2.new
>          end
>      end
>
>      ...
> end
>
> seems a little bit ugly to me since I have to include M in every class of M2
>
> Is there a better way, should I stick to the "M::"s, or is it just bad
> design that I am doing here?

Looking at the design aspect of it, you could put M2 inside M (since
it seems to want to be there :-) if it makes sense in the larger
picture.

  module M
    class K1
    end

    class K2
      def initialize
	puts "Initializing a #{self.class}!"
      end
    end

    module M2
      class K3 < K1
	def initialize
	  @a = K2.new
	end
      end
    end
  end

  include M
  M2::K3.new

(For those last two lines you could also do

  include M::M2
  K3.new

or just

  M::M2::K3.new

)


David

-- 
David Alan Black
home: dblack@superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav