From: "trans.  (T. Onoma)" <transami@...>
Date: 2005-01-14T07:12:04+09:00
Subject: Method Dispatching

I've touched on this before with the idea of a "pre" method missing, but it 
has come up again for me (AOP) and I really would like to get some general 
input on the subject.

The idea is essentially that if a #method_dispatch callback method were 
defined, then calls would be routed through it. For example:

  class C
    def method_dispatch(method, *args)
      case method
      when 'hi', 'hey'
        hello(*args)
      else
        send(method, *args)
      end
    end
    def hello(name)
      puts "Hello, #{name}."
    end
  end

  C.new.hi("Bob")  #=> Hello, Bob.

#send of course must bypass #method_dispatch, or perhaps there would be a 
variant method for this.

The questions I have about this:

  1. Might this be a generally useful/powerful mechanism?
  2. What kind of problems might this create?

Something like this certainly is useful for AOP, though I don't think the lack 
of it is necessarily a show stopper. But that's why I'm wondering about its 
more general implications.

Thanks,
trans.