develooper Front page | perl.perl6.language | Postings from July 2005

Re: SMD is for weenies

Thread Previous
From:
Yuval Kogman
Date:
July 6, 2005 07:52
Subject:
Re: SMD is for weenies
Message ID:
20050706145219.GA31653@woobling.org
On Wed, Jul 06, 2005 at 12:58:44 +0100, Piers Cawley wrote:

> Then write yourself a module, call it 'multiplicity' say, which would allow you
> to say  
> 
>     use multiplicity;
> 
>     sub foo (...) {...} # foo is a multimethod, even if there's already a 'SMD'
>                         # foo in existence.
> 
> It shouldn't even be that hard, just macroize sub/method/whatever to become
> multis that first check if there's already a singly dispatched sub with the
> same name and promoting to multi status if possible. 
> 
> Of course, if you use something like that, you're taking the risks on your own
> head, but you knew that as soon as you typed 'use multiplicity'. 
> 
> The important thing is that the dispatch and reflection system should be
> flexible enough to allow you to write something like this.

The issue is cultural, not technical.

If people expect SMD, use it, rely on it, MMD is just another
esotheric feature. Newbies' code will not exploit. Most of CPAN will
not be ready for it.

I won't write me such a module because it'll be more headache than
benefit - explaining to everyone that in my code I like everything
MMD.

What I'm claiming is that MMD like behavior should be the norm. When
it's not appended with true multiness, it's functionally identical
to SMD.

The issue is that extending another person's module with a
multimethod, and using type/parameter dispatch in order to
help code evolve better over time will never be a "good" or normal
thing to do if it feels kludgy.

My claim is that it doesn't need to feel kludgy.

A macro library kludging over a kludge is twice as kludgy as it was
before.

-- 
 ()  Yuval Kogman <nothingmuch@woobling.org> 0xEBD27418  perl hacker &
 /\  kung foo master: /me does a karate-chop-flip: neeyah!!!!!!!!!!!!!!


Thread Previous


nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About