Re: "multiple inheritence" / behavior

[Adam Fedor]

But I think the problem remains that he has to IMPLEMENT the same code 
in both classes, which is not only a waste, but could lead to problems 
if they get out of sync (although I suppose you could play with #ifdef's 
and multiple compilations of the same file).

Behaviors, however, are one step further. They are a protocol with an 
implementation. behaviors are used at a fundamental level in 
gnustep-base, so I think they will continue to be supported in the 
future (They aren't supported on Darwin with the darwin compiler, though).

As long as you access all instance variables through a method and not 
directly, there should be no problem using them in classes with 
different layouts.


Mondragon, Ian wrote:
> ooops...don't forget to import the SecretMethods.h file ;-)
>
>
> > -----Original Message-----
> > From:	Mondragon, Ian 
> > Sent:	Friday, November 15, 2002 10:16 AM
> > To:     'Manuel Guesdon'; discuss-gnustep@gnu.org
> > Subject:        RE: "multiple inheritence" / behavior
> >
> > use a @protocol - that's exactly what they're for.  if you want all of
> > your classes to respond to everyoneDoThis and everyoneDoThat...
> >
> > --- SecretMethods.h ---
> >
> > @protocol
> >
> > - (void)everyoneDoThis;
> > - (void)everyoneDoThat;
> >
> > @end
> >
> > --- end ---
> >
> > then in each of your non-related classes, just declare them like so:
> >
> > --- WhateverClass.h ---
> >
> > @interface WhateverClass <SecretMethods>
> >
> > --- end ---
> >
> > then implement the methods.
> >
> > problem solved.  another hoo-rah for objc.
> >
> > - ian mondragon
> >
> > -----Original Message-----
> > From:   Manuel Guesdon [SMTP:ml@orange-concept.com]
> > Sent:   Friday, November 15, 2002 9:30 AM
> > To:     discuss-gnustep@gnu.org
> > Subject:        "multiple inheritence" / behavior
> >
> > MIME-Version: 1.0
> > Content-Type: text/plain; charset="us-ascii"
> > Content-Disposition: INLINE
> > Organization: Orange Concept
> > X-Mailer: Mahogany 0.64 'Sparc', compiled for Linux 2.4.3-12smp i686
> > Reply-To: ml@orange-concept.com
> >
> > Hi,
> >
> > I'dl like to have a common set of methods used by different objects but
> > without letting them inherit from the same class
> > and without adding a category to one of the common inherited class.
> > I've seen behavior methods which seems to be what I need but there are
> > warnings in behavior.h.
> > So, is there another method to make this ? If not, is behaviour will be
> > supported for a long time ? Is there any
> > problem if I add methods by this way in classes which don't have exactly
> > the same ivars (or ivars order) if I don't use
> > these ivars directly ?
> >
> > Thank you .
> >
> > Manuel
> >
> >
> >
> >
> > _______________________________________________
> > Discuss-gnustep mailing list
> > Discuss-gnustep@gnu.org
> > http://mail.gnu.org/mailman/listinfo/discuss-gnustep
>
>
>
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--
Adam Fedor, Digital Optics Corp.      | I'm glad I hate spinach, because
http://www.doc.com                    | if I didn't, I'd eat it, and you
                                      | know how I hate the stuff.