From: "Hal E. Fulton" <hal9000@...>
Date: 2003-05-21T12:42:48+09:00
Subject: super, aliases, defadvice, AOP, and so on

Hello, all.

I'm reopening an issue I brought up
once before, just to make sure it
isn't forgotten or under-explored.

Actually the thing I brought up 
opened up a wider field of discussion,
and that's what interests me.


Think for a moment about why we have
the keyword "super" -- it's a way of 
distinguishing between the current
method and the one in the parent, but
it's also a convenient shorthand that 
does not depend on the method name.

I once proposed a keyword "prior" that
would refer to the old definition of a
method that was being replaced. This
would make unnecessary the idiom of
explicitly creating an alias and then 
calling the old method by name.

But Matz replied (I'm paraphrasing)
that this was a part of a more general
problem, and that something like Lisp's
defadvice was the answer.

Disclaimer: I don't know Lisp and I know
little about AOP. But it seems likely to 
me that this is where AOP gets its odd
usage of the word "advice."

But this whole concept interests me. If
Ruby had suitable operations built in, it
could make AOP much easier, I think; not
to mention certain kinds of tools such as
debuggers and profilers.

I'm sure nothing like this will come about
until Rite at the earliest, however.

But I don't consider it too early to speculate.
So: How does Lisp's defadvice work? How should
something similar in Ruby work?

Matz, Dave, others?


Hal