From: Piers Cawley <pdcawley@...>
Date: 2001-08-08T16:20:32+09:00
Subject: [ruby-talk:19357] Re: Perl/Python/Ruby common backend (Parrot, can Ruby play too?)

Ned Konz <ned@bike-nomad.com> writes:

> On Tuesday 07 August 2001 10:37 pm, Mathieu wrote:
> 
> > Ruby has this thing called "mixins" that afaik is not in Python (unless
> > it's quite recent) and is not in Perl. In Perl you have multiple
> > inheritance, but the dispatch is C++-style, so calling SUPER looks
> > always upwards. Ruby backtracks in the method lookup. (Damian wants that
> > in Perl6)
> 
> I don't understand what you mean. In Perl, the method lookup is
> first in the current class, and then depth-first through the @ISA
> (parent) list. Calling, say, $self->SUPER::method merely skips the
> current class (and only works if written in the namespace (package)
> of the class that's being defined, not dynamically as I've wanted it
> to). 

Don't get me started on this. See the debate on the subject I had with
perl5porters about a month back. And which, having looked up the
SmallTalk way of doing it, I may be returning too.

Annoyingly, there seems to be no way of implementing a reliable
SUPER.pm which will do the right 'dynamic' thing, because perl doesn't
cache the appropriate information when it makes the function call.

> I could see wanting to do a breadth-first search through @ISA,
> or make SUPER work outside of the original namespace.

Take a look at Damian's 'NEXT' module.

-- 
Piers Cawley
www.iterative-software.com