Okay, at least I can deduce the following:
Peter and Kevin insist on having their approach.
Denys insists on having his approach.
So, guys, as there seems no way of reaching consensus what do we do. The
obvious thing is to do nothing (safe but not very satisfying).
As well as Peter I am sick of it.
Christian
"Peter Van Roy" <pvr@info.ucl.ac.be> wrote in message
news:<3D059FAD.7AFEA41@info.ucl.ac.be>...
> Christian Schulte wrote:
> >
> > So where are we currently.
> >
> > I'd vote for Denys approach, mostly because I find the explanation
> > more appealing, and, as far as I understand, it lacks one minor
> > problem.
>
> I completely disagree, for the following reasons:
>
> 1. '@' has no independent meaning in the Denys proposal, whereas in
the
> P&K proposal it is an operation ('Access'). Writing @A:=@A+1 for
all
> object attributes and cells A is completely surrealistic. What
does
> '@A' mean here? And no, a literary solution does not satisfy me.
> @ is a type marker that seems to mean 'the next expression must
evaluate
> to a cell'. This makes it a new concept in Oz! We don't need this
new
> concept. I am not going to twist myself into a knot explaining
this to
> students.
>
> 2. The primitive semantic concept is a cell, not a mapping. A mapping
is a
> derived concept. Defining a cell as a simple case of mapping is
> completely
> against scientific method. Usually, complex concepts are derived
> from simple
> ones, not the other way around.
>
> 3. We should clearly distinguish two levels:
> - semantic level: cells and records, assign and access. Simple!
> - mapping level: a linguistic abstraction, using the '.', to
facilitate
> calculating with mappings. Simple!
> Why does it need to be more complex than this? Why do we need a
> full-blown
> theory of mappings? (I have nothing against such a theory, as long
as it
> fits inside the mapping level. The basic semantics of the language
> should
> *not* be based on such a theory.)
>
> 4. Our proposal makes calculating with dictionaries, arrays, and
records
> syntactically simple. However, our proposal has the ``glitch''
that
> calculating with 'records of cells' needs an @ when accessing the
record
> element. And why should it not? If you define a record of cells
> then you
> *explicitly* use the cell concept, which is not the case when
calculating
> with dictionaries and records. So an @ to access when using
records of
> cells is perfectly ok.
>
> Finally, a meta-comment. This discussion has been going on for too
> long. For the future, we need a clear procedure for designing and
> implementing language changes.
>
> Peter
> -
> Please send submissions to hackers@mozart-oz.org
> and administriva mail to hackers-request@mozart-oz.org.
> The Mozart Oz web site is at http://www.mozart-oz.org/.
-
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