From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2002-02-01T10:54:18+09:00
Subject: using extend dynamically

Let's say I've got the following:

module MyMixin
  def foo
    puts "MyMixin::foo"
  end
end

class MyClass
  def initialize(mixin)
    self.extend(mixin)
  end
end

obj = MyClass.new(:MyMixin)
obj.foo

This raises the following error:

hierarchy.rb:29:in `extend': wrong argument type MyMixin (expected Module) 
(TypeError)
        from hierarchy.rb:29:in `initialize'
        from hierarchy.rb:33:in `new'
        from hierarchy.rb:33

So, it doesn't like the 'self.extend(:MyMixin)'
Is there any other way of doing this without using some kind of case 
statement:

class MyClass
  def initialize(mixin)
    case mixin
      when "MyMixin"
         self.extend(MyMixin)
      ...
    end
  end
end

Phil