From: Ilias Lazaridis <ilias@...>
Date: 2005-04-21T21:39:32+09:00
Subject: [EVALUATION] - E03e - The Ruby Object Model (Summary)

[EVALUATION] - E03d - The Ruby Object Model (End Game)
http://groups-beta.google.com/group/comp.lang.ruby/msg/ea9da543dc256b42

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The above thread has led to this code:

class Class
    def Meta()
      @Meta ||= (class<<self;self;end)
    end
end

which is modified here to:

class Object
    def sso()
      @sso ||= (class<<self;self;end)  # see code below
    end
end

simplified:
    def sso()
      unless @sso
        @sso = (class<<self; self; end) #
      end
      @sso
    end

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sso = Specializing Singleton Object

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The sso contains definitions (methods, attributes, constants) which 
specialize the behaviour of its carrying object.

The "sso" of a "class object" is used to specialize the behaviour of the 
class (against Class).

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The sso's are essentially internal implementation details, although they 
are accessible (see code above).

The sso's are _not_ part of the Ruby Object Model (e.g. inheritance 
hierarchy).

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As stated before, the following documentation is false:

cmd:> ri Class

"Classes, modules, and objects are interrelated. In the diagram that
follows, the arrows represent inheritance, and the parentheses
meta-classes. All metaclasses are instances of the class `Class'."

                            +------------------+
                            |                  |
              Object---->(Object)              |
               ^  ^        ^  ^                |
               |  |        |  |                |
               |  |  +-----+  +---------+      |
               |  |  |                  |      |
               |  +-----------+         |      |
               |     |        |         |      |
        +------+     |     Module--->(Module)  |
        |            |        ^         ^      |
   OtherClass-->(OtherClass)  |         |      |
                              |         |      |
                            Class---->(Class)  |
                              ^                |
                              |                |
                              +----------------+

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a) The term "meta-classes" is false.
      Correction: "specializing-singleton-objects"

b) vertical arrows do not represent inheritance
      e.g.:       Object---->(Object)
      Correction: Object-----(Object)

c) the classes in "()" do not belong to the object model
      Correction: remove (showcase sso in seperate topic)

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My final questions are basicly:

  * Ruby is OO. Why is the sso not directly accessible?

  * Who has written the "ri Class" documentation?

  * Can I expect an apology for this false documentation?

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http://lazaridis.com/case/lang/ruby

..

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