From: "Ball, Donald A Jr (Library)" <donald.ball@...>
Date: 2007-05-02T06:33:57+09:00
Subject: Re: simple subclass question

Thanks to you and Robert for the quick answers. I think I get it now; I
was a little fuzzy on the notion of class instance variables before. I
now use a construct like so:

class A
  class << self
    attr_accessor :var
  end
end

class B < A
  class << self
    def var
      @var || superclass.var
    end
  end
end

to allow subclasses's instance variables to default to their
superclass's until and unless overridden. I'll admit the class << self
syntax continues to mystify somewhat; can anyone proffer an explanation
that would help me grok it fully?

- donald