Re: where to "put" a unification algorithm...

Hello Chris.

I need a unification algorithm in Squeak to solve simple constraint 
problems.
What is the current state of your project for implementing a unification 
algorithm ?

BTW, does anybody known whether or not the SOUL package on squeaksource 
is stable.

Thanks a lot.

Guillaume Grondin

Chris Wright wrote:
> On 2/16/07, Roel Wuyts <Roel.Wuyts@xxxxxxxxx> wrote:
> > You can put it there, yes.
> >
> > But there is an important design question lurking there. If you put
> > the unification method on these classes, what you are really saying
> > is: this Smalltalk object can be unified with that Smalltalk object.
> > So you are then extending the Smalltalk language with unification.
>
> That's exactly right
>
> > The alternative is to only have unification methods un your own
> > 'unifiable objects' hierarchy. In that hierarchy you will probably
> > have a class called: CWNumber, which represents numbers in your
> > language and which will hold a Smalltalk number.
> >
> > Which alternative to choose depends on whether, and how deep, you
> > want to integrate Smalltalk and your own language. Unless you really
> > want to mingle Smalltalk objects within your language, or want
> > unification directly accessible at the Smalltalk level without having
> > to pass through your language, I would advise the second option.
>
> I understand. If I did choose the second option (make my own classes -
> CWNumber, CWString, CSList etc), would I then have to use a tool like
> SmaCC to construct instances. The advantage of extending the existing
> classes ("extending the language") seems to me that no parsing /
> compiling is required to make
>
> 5 unifiesWith: 5 in: emptyEnv
>
> work.
>
> I would be very interested in your work on this subject.
>
> Thanks again for the help.

--
Guillaume Grondin
Ph.D candidate in Computer Science
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