behaviours

[Vlad Dumitrescu]

----- Original Message ----- 
From: "Thomas Lindgren" <thomasl_erlang@REDACTED>
> --- Fredrik Linder <fredrik.linder@REDACTED>
> wrote:
>
> > Good point. Versioning is definitely desired,
> > perhaps something like:
> >
> > behaviour_info(callbacks) -> [{Function, Arity}];
> > behaviour_info(version) -> Version;
> > behaviour_info(_) -> undefined.
>
> It would be nice to integrate behaviour versions with
> applications and releases too. I'm not sure what's
> right, though. It might be straightforward. (Simply
> take the vsn attribute?)
>
> A complicating case: several versions active in the
> system at the same time (due to use of legacy code,
> say).

I think this is why COM and CORBA (I think) had to resort to incomprehensible
unique identifiers that change with the slightest change of the interface... One
can't just say "I implement interface X", but "interface X version Y" and with
several developers it gets easily out of hand. And what if someone doesn't
update the version? Ouch!

This isn't easy.
Regards,
Vlad