From: Glenn Parker <glenn.parker@...>
Date: 2005-01-25T05:35:33+09:00
Subject: Re: Complex Library Object/Class and its Interface

Trans wrote:
> 
> It toke me some time to work this out in itself. And I thought I had
> finally gotten a fairly nice interface here. But to my dismay, I just
> discovered that I can't subclass Marker b/c I loose the definitions of
> the above attributes (ie. exclusive, start, stop).

What exactly do you mean when you say you "lose the definitions"?  The 
definitions for Marker will remain accessible via the Marker scope, but 
a derived class will start out with its own set of (empty) definitions. 
  Do you want auto-inherit for class instance variables?

class Parent
   class << self
     def set_name(n)
       @name = n
     end
     def name
       (defined? @name) ? @name : superclass.name
     end
   end
   set_name "Smith"
end

class Child < Parent
end

class Grandchild < Child
   set_name "Jones"
end

puts "Parent.name = #{Parent.name}"
puts "Child.name = #{Child.name}"
puts "Grandchild.name = #{Grandchild.name}"

Prints:

Parent.name = Smith
Child.name = Smith
Grandchild.name = Jones

-- 
Glenn Parker | glenn.parker-AT-comcast.net | <http://www.tetrafoil.com/>