From: Joel VanderWerf <vjoel@...>
Date: 2006-06-12T06:00:34+09:00
Subject: Re: Dynamic class change?

Mark Noworolski wrote:
> As time passes, when I hear a new MAC start talking, I dynamically
> create a corresponding object. So, if the first thing I hear is
> something a Nic says, a Nic object can spring into existence, ditto
> for Nic2, etc. So far, seems reasonable.
> 
> However, the similar things will sometimes appear as a Nic, then say
> something new and exciting that indicates that they are actually Nic2
> objects (or Nic3, for example).

It sounds like you could get away with something like htis:

class Nic
  attr_accessor :mac
end

module Nic2
  def do_nic2_stuff
    puts "nic2 at #{mac}!"
  end
end

module Nic3
end

# when you first hear it
nic = Nic.new
nic.mac = "12:23..."

# later when you have more info
nic.extend Nic2
nic.do_nic2_stuff   # ==> nic2 at 12:23...!


This will work as long as the information you get about these objects is
_monotone_: you never have to back out of extending a nic instance with
modules.

-- 
      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407