From: Dan Doel <djd15@...>
Date: 2003-08-25T18:12:26+09:00
Subject: Re: Class variables - a surprising result

Alan Chen wrote:

>The beauty of ruby is that you can clean this up if you 
>really want. 
>
>class Module
>  # generate "static" variables more like C++ or Java
>  def attr_reader_static(*syms)
>    syms.each { |sym|
>      module_eval( %Q[def self.#{sym}; @#{sym}; end] )
>    }
>  end
>
>  def attr_writer_static(*syms)
>    syms.each { |sym|
>      module_eval( %Q[def self.#{sym}=(val); @#{sym} = val; end] )
>    }
>  end
>
>  def attr_accessor_static(*syms)
>    attr_reader_static(syms)
>    attr_writer_static(syms)
>  end
>end
>
>
>class Foo
>  attr_accessor_static :staticvar
>end
>
>Foo.staticvar = 11
>p Foo.staticvar  => 11
>

Actually, this should be simpler (to read, anyway):

class Object
    def singleton_class
       class << self
          self
       end
    end
end

class Module
    def attr_reader_static(*syms)
       singleton_class.class_eval { attr_reader *syms }
    end

    def attr_writer_static(*syms)
       singleton_class.class_eval { attr_writer *syms }
    end

    def attr_accessor_static(*syms)
       singleton_class.class_eval { attr_accessor *syms }
    end
end

If you want class instance variables, anyway.

If you want static variables that act like Java/C++ static variables, I 
did that in a
post elsewhere in this thread (I could look it up if pressed :) ).

- Dan