Has someone put in something to squeak to allow multiple dispatch? I thought
I heard this was not supported in Smalltalk in general, but is there
something in Squeak to do it?

Thanks!

-joel



----- Original Message ----- 
From: "Brian T Rice" <water at tunes.org>
To: "The general-purpose Squeak developers list"
<squeak-dev at lists.squeakfoundation.org>
Sent: Monday, June 09, 2003 2:04 AM
Subject: Re: Object: Identity vs. Environment


> I'm glad that someone eventually mentioned something related to multiple
> dispatch. Slate's is: seems to work rather well for this case. ;)
>
> You can also override is: for ad hoc pretending on a pair of arguments,
> and the original method is reallyIs: and is not overridden.
>
> On Mon, 9 Jun 2003, Joel Shellman wrote:
>
> > Ah, I think what you're referring to is double dispatch, isn't it?
> >
> > http://c2.com/cgi/wiki?DoubleDispatch
> >
> > Which so far as I understand it makes good sense.
> >
> > -joel
> >
> > ----- Original Message -----
> > From: "Andres Valloud" <sqrmax at comcast.net>
> > To: "The general-purpose Squeak developers list"
> > <squeak-dev at lists.squeakfoundation.org>
> > Sent: Monday, June 09, 2003 12:04 AM
> > Subject: Re: Object: Identity vs. Environment
> >
> >
> > > > But you might have a dozen methods with isFoo + ifTrue/ifFalse.
> > > > Then you would need Object>>fooAction1, Object>>fooAction2, etc.
> > >
> > > The dozen actions will get written one way or the other, either inside
> > > ifTrue/ifFalse blocks or in messages.  As far as the amount of code is
> > > concerned, fooActions are at least as compact - if not more since you
> > > don't need ifTrue/ifFalse.
> > >
> > > The key issue here is that the ifTrue/ifFalse actions should be in
> > > messages the receivers of isXYZ understand.  Otherwise, the context in
> > > which you write the ifTrue/ifFalse actions has to grow larger to
provide
> > > meaning to the actions.  You end up as if you had used a traditional
> > > programming language: the receivers of isXYZ are more value holders
than
> > > behaviorful distinctions as far as the context of usage is concerned.
> > >
> > > Disclaimer: these arguments apply only to the "isKindOf:" kind of
isXYZ
> > > messages.
> > >
> > > Andres.
>
> -- 
> Brian T. Rice
> LOGOS Research and Development
> http://tunes.org/~water/
>