From: matz@... (Yukihiro Matsumoto)
Date: 2001-08-23T10:16:41+09:00
Subject: [ruby-talk:20141] Re: Another Possible RCR - Wrappers via Mixins

Hi,

In message "[ruby-talk:20127] Another Possible RCR - Wrappers via Mixins"
    on 01/08/23, Stephen White <spwhite@chariot.net.au> writes:

|The main difference between mix-ins and multiple inheritence is (to my understanding) that parent classes do not call child code, but mix-ins do.

Well, it's not the difference.  The difference between Multiple
inheritance and Mix-in is that Mix-in module cannot have instance,
that's all.  Mix-in is merely restricted MI.


|Given this, perhaps mix-ins are a good place to do AOP style wrappers? If a mix-in has a method with the same name as the class being mixed into, then the mix-in code gets called then super's up.

But I think your proposal is interesting.  I was going to accomplish
it (if I do), by using method combination ala CLOS.

Note it's just an idea, syntax is not fixed:

  module WrapFred
    def fred :before
      puts "1"
    end
    def fred :after
      puts "2"
    end
  end

  include WrapFred

  def fred
    puts "hello"
  end

will print

  1
  hello
  2
							matz.