From: "Hal E. Fulton" <hal9000@...>
Date: 2003-01-14T09:43:03+09:00
Subject: Re: Array_Of(AClass)

----- Original Message ----- 
From: "Gavin Sinclair" <gsinclair@soyabean.com.au>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Monday, January 13, 2003 6:39 PM
Subject: Re: Array_Of(AClass)


> On Tuesday, January 14, 2003, 9:59:44 AM, dblack wrote:
> 
> > Technique #2 is not a drop-in replacement for technique #1, though.
> > For example, if you want to "listen in" on what a method is doing,
> > you might do:
> 
> >   class String
> >     alias :oldsplit :split
> >     def split(*a)
> >       puts "args are #{a.join(', ')}"
> >       oldsplit(*a)
> >     end
> >   end
> 
> > I don't think there's an equivalent way to do this by modifying the
> > object's singleton class.
> 
> If it's just a single object, surely you can:
> 
> class << the_str
>   def split(*args)
>     puts "args are #{args.join(', ')}"
>     super
>   end
> end
> 
> Which, again, is much nicer than aliasing.  However, it only works on
> one String instance, not all of them.  Which was probably your point.

I think eventually we're going to get some kind
of mechanism like LISP's defadvice (I seem to
recall a rumor like that).

Not that I know LISP or understand defadvice -- 
but it sounds a little like AOP to me. It came
up once when I suggested a "prior" keyword.

Hal