From: dblack@...
Date: 2003-10-02T21:46:24+09:00
Subject: Re: Instance- and class-variables (was Re: mixing in class methods)

Hi --

On Thu, 2 Oct 2003, Gavin Sinclair wrote:

> I initially tried to code my example like this:
>
>   class Project
>     class << Project
>       attr_accessor :implemented_methods
>     end
>
>     def implement(_method)
>       # some checking
>       yield
>       # some checking
>       Project.implemented_methods << _method
>     end
>   end
>
> Note in both examples, the idea is to be able to call
>
>   Project.implemented_methods
>
> after calling Project#implement a number of times.  However, the second
> case (using a class instance variable instead of a class variable) did not
> work.  I think the array always came back empty.  Now I may have done
> something simple wrong, but I think I've demonstrated enough anyway. :)
> Well, I hope so.

Ummm, what array? :-)  I think you'd need something like:

  class Project
    class << self
      attr_reader :implemented_methods
      def implemented_methods
        @method_list ||= []
      end
    end

    def implement(method)
      Project.implemented_methods << method
    end
  end


David

-- 
David Alan Black
home: dblack@superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav