From: Christoffer Sawicki <christoffer.sawicki@...>
Date: 2006-05-20T00:34:43+09:00
Subject: Re: Mixing-in the inherited method

Hello Joel,

> A is not a subclass of Class, it's an instance of Class.

Indeed.

> Also, you need to use extend rather than include, so that the instance
> methods of Foobar (particularly, #inherited) become methods of A.
> Otherwise, the instance methods of Foobar become instance methods of
> _instances_ of A.
>
> These two examples both print "A":
>
> /.../

I understand your examples and your argument, but you seem to be
missing my point (if I have one). Instance methods of class Class
become class methods of Class instances, so why doesn't the mixed-in
inherited() work? Comparing these two examples, why is the output of
the second different?

= Example 1

class Class
  def inherited(klass)
    p klass
  end

  def test!
    p "test!"
  end
end

class A; end
A.test!

== Output

A
"test!"

= Example 2

module Foo
  def inherited(klass)
    p klass
  end

  def test!
    p "test!"
  end
end

class Class
  include Foo
end

class A; end
A.test!

== Output

"test!"

Thanks,

-- 
Christoffer Sawicki