From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2004-02-14T09:04:54+09:00
Subject: accessing constants from class methods


what i would like to accomplish would be something like this:


  class Abstract 
    class << self
      def x
        # defined?(self::X)  ? self::X : nil
      end
    end
  end

  class Concrete < Abstract 
    X = 42
  end

  # p Base.x    # => nil
  # p Derived.x # => 42


does this make sense?  in essence i want an abstract class method with the
semantics of "iff a concrete class has defined a certain constant, return it"

the problem is that 'self::X' above tries to reference 'Class::X', if i
replace 'self' with 'Abstract' then i will be referencing the incorrect 'X'...

how does one say 'the constant of the current class' from within a class
method?

-a
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