From: Ara.T.Howard@...
Date: 2005-05-04T11:45:04+09:00
Subject: Re: un_metaclass

On Tue, 3 May 2005 dave.burt@gmail.com wrote:

> # This is how to do it:
>
> class Module
>  def instances
>    result = []
>    ObjectSpace.each_object do |obj|
>      result << obj if obj.is_a? self
>    end
>    result
>  end
> end

it seems to miss much of the time?


   class Module
     def instance_class
       m = %r/^(?:#<Class:)+(.*?)(>+)$/io.match inspect
       if m
         klass_name, brackets = m[1], m[2]
         n = brackets.size - 1
         klass = const_get klass_name
         n.times{ klass = class << klass; self; end }
         klass
       else
         superclass
       end
     end
     def instances
       result = []
       ObjectSpace.each_object do |obj|
         result << obj if obj.is_a? self
       end
       result
     end
     def both
       [ instance_class, instances ]
     end
   end

   class C
     p both
     class << self
       p both
       class << self
         p both
         class << self
           p both
         end
       end
     end
   end

   class K < C
     p both
     class << self
       p both
       class << self
         p both
         class << self
           p both
         end
       end
     end
   end

   jib:~/eg/ruby > ruby a.rb
   [Object, []]
   [C, [C]]
   [#<Class:C>, []]
   [#<Class:#<Class:C>>, []]
   [C, []]
   [K, [K]]
   [#<Class:K>, []]
   [#<Class:#<Class:K>>, []]


cheers.

-a
-- 
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