From: "T. Onoma" <transami@...>
Date: 2003-11-27T15:38:59+09:00
Subject: Re: Method wrapping

On Thursday 27 November 2003 04:00 am, Hal Fulton wrote:
> Since I have already opened this issue, I will clarify by asking
> two more specific questions:
>
> 1. If I want to redefine a "secondary" method (or whatever I should
> call it), can I do so? It seems that an attempt to redefine
> foo:pre would simply add a new foo:pre.

I doubt we should be able to redine secondary methods. If you do this they 
will have to be indexed in someway, and a means for referencing those indexes 
becomes neccessary. Because the indexes have no semantic value, they would 
not be generally usable. For example, if I had a class using 3 wraps, and you 
created a subclass of it that redinfined wrap #2, if I later "improved" my 
class by placing another warp before #2, your subclass would no longer work. 
(Similiar to below)

> 2. If the primary method is redefined, do the "secondary" methods
> get cancelled? Or do they simply remain in place?

Using just def to redefine method will neccessarily destroy all wraps 
otherwise, you run into this:

  class A  # An external library class
    def riot
      print "P"
    end
  end

  class B < A  # My subclass
    def riot
      print "Q"
    end
  end

If later, the library maintainer decided to add an AOP method:

  class A  # An external library class
    def riot
      print "P"
    end
    def riot:wrap
      print "*"
    end
  end

B class will no longer work as expected.

-t0