From: gabriele renzi <surrender_it@...1.vip.ukl.yahoo.com>
Date: 2003-12-16T00:41:59+09:00
Subject: Re: Subclassing Array

il 15 Dec 2003 14:50:51 GMT, firstname@lastname.net (Hans Fugal) ha
scritto::

>I have a simple observer-like module:

>I'm hoping that most of the changing methods of Array are actually
>implemented in terms of a couple of fundamental methods, e.g. insert and
>delete. So I would do:
>
>class NotifyingArray
>    include Notifier
>    def insert(o)
>	super(o)
>	notify
>    end
>    def delete(o)
>	super(o)
>	notify
>    end
>end
>
>Am I on the right track? Does anyone know which methods I would have to
>override?

A possible alternative may be something like this:

class SimilArray
 def initialize(ary)
  @ary=ary
 end
 include Notifier
 def method_missing(:method,*args,&blk)
  @ary.send(:method,*args,&blk)
 end
end

This is a strange kind of "side inherithance", but it may work.
BTW, do you know that an observer module already exist in the standard
ruby lib ?