From: Robert Klemme <shortcutter@...>
Date: 2008-01-29T22:16:09+09:00
Subject: Re: Adding instance variables using module include

2008/1/28, me@mikehogan.net <me@mikehogan.net>:
> Hi there,
>
> If I have a module and class like this:
>
> module VisitMemory
>     def mark_visited(method)
>         @methods_visited << method.my_declaration_signature
>     end
>
>     def already_visited?(method)
>         @methods_visited.include?(method.my_declaration_signature)
>     end
> end
>
> module Guff
>     module JavaSource
>         class Class
>             include VisitMemory
>         end
>     end
> end
>
> How can i ensure that all instances of Guff::JavaSource::Class is
> going to have the instance variable @methods_visited ?

require 'set'

module VisitMemory
   def mark_visited(method)
       (@methods_visited ||= Set.new) << method.my_declaration_signature
   end

   def already_visited?(method)
       @methods_visited and
@methods_visited.include?(method.my_declaration_signature)
   end
end

> So that this will work:
>
> Guff::JavaSource::Class.new.already_visited?(something)

Cheers

robert

-- 
use.inject do |as, often| as.you_can - without end