From: Austin Ziegler <halostatue@...>
Date: 2005-04-05T23:05:28+09:00
Subject: Re: [EVALUATION] - E03b - The Ruby Object Model

On Apr 5, 2005 8:34 AM, Ilias Lazaridis <ilias@lazaridis.com> wrote:
> The existing documentation seems at least missleading, if not
> wrong:

It's neither misleading nor wrong. It is complex.

> this can be drawn like this:


> i've played within IRB, but:
> I cannot access any of the metaclasses
> the same in the documentation: no metaclasses

  puts Class.id                       # => 20927668
  puts class << Class; self.id; end   # => 20927632
  puts Object.id                      # => 20927692
  puts class << Object; self.id; end  # => 20927656

The class "Class" has an object ID that is different than its
metaclass. The same with class "Object". Objects, too, can have
metaclasses, like:

  foo = Object.new
  puts foo.id                         # => 22734748
  puts class << foo; self.id; end     # => 22725040

I've modified your diagram; ocObject* is an instance of otherClass,
and the (ocObject)* metaclass is the metaclass for this instance,
and it is a different metaclass than any other instance of
otherClass.

    ocObject*---->(ocObject)*
           |         |
           |         |
           v         v
    otherClass--->(OtherClass)
           |         |
           |         |
           v         v
        Object--->(Object)
           ^        ^^
           |        ||
           |       / |
           |      /  |
           |     /   |
           |    /    |
        Module--->(Module)
           ^  /      ^
           | /       |
           |/        |
         Class---->(Class)

-austin
-- 
Austin Ziegler * halostatue@gmail.com
               * Alternate: austin@halostatue.ca