DaVinci wrote:
> Hello friends.
>
> I have a rpoblem with object orientation. Intention is to define
> instances usable from all classes. For example:
>
> 	class Configuration
>		attr_reader :size
>	
>		def initialize(size)
>			@size = size
>		end
>	end
>
>	class Foo
>		def initialize
>			puts @conf.size
>		end
>	end
>
>	attr_reader :conf
>	@conf = Configuration.new(100)
>	Foo.new
>
>	exit(0)
>
> Why I can not use attr_reader form base class?. Might I use a global
> variable to define instance?.
>
> I need your ideas about "best way of doing it" :)

I'm not sure quite what you're aiming for. 
Perhaps something like this? [Disclaimer: I typed 
it into email, and haven't run it through Ruby, 
so beware of typos!]

###############
class Configuration
  attr_reader :size

  def initialize(size)
    @size = size
  end
end

class Foo < Configuration
  def initialize
    super(100)
    puts size
  end
end

Foo.new
###############

Kevin