[Oz] Factoring Mozart's Record Construct

[BOWERY,JIM Non-HP-Cupertino,ex1]

A significant number of the type labels could be removed without loss of
clarity.  In too many cases the record label is just one more thing to
remember and get wrong.  There is enough of substance to learn with Mozart
already -- it doesn't need less substantive features getting in the way of
acceptance.  If my experience is any indication this may be turning a lot
more people away from Mozart in their initial impressions than you are
likely to discover unless you do some careful outreach.  People don't have
time to mess with every new technology that comes along -- and Mozart's
record syntax is a big piece of its initial impression.  If it _appears_ it
_might_ have thinking behind it, people will simply ditch it and not bother
analyzing why they ditched it, let alone bothering to tell you the reasons
why they ditched it.  This is particularly true of technologies that fresh
from the lab.

-----Original Message-----
From: Peter Van Roy [mailto:pvr at info.ucl.ac.be]
Sent: Wednesday, March 15, 2000 4:11 AM
To: BOWERY,JIM (Non-HP-Cupertino, ex1)
Cc: users at mozart-oz.org
Subject: Re: [Oz] Factoring Mozart's Record Construct 

[Jim Bowery wrote]
> Perhaps the most obvious symptom of confusion is the way record labels
> frequently end up as redundant annoyances.  Has there been any
consideration
> given to factoring the record construct into primitives that would include
> unlabeled feature lists to which labels may be afixed by operators?  Might
> record labels then be more seamlessly unified with the names of
> features/attributes?

You are right; records could indeed be factored in this way.  We have not
done
so because the record label plays the role of a type identifier.  This makes
it
easier to avoid confusing one record type for another: just give them
different
labels.  You can give all records the same label, but this is not considered
good style.

Two data types related to records are dictionaries and record constraints.
Dictionaries have no labels and are the recommended data type to use when
the mapping changes.  Record constraints allow to give partial information
about records, for example, that two features are known but that the label
is not known yet.  Record constraints are intended for constraint
applications, for example, natural language processing.

Peter

-
Please send submissions to users at mozart-oz.org
and administriva mail to users-request at mozart-oz.org.
The Mozart Oz web site is at http://www.mozart-oz.org/.
-
Please send submissions to users at mozart-oz.org
and administriva mail to users-request at mozart-oz.org.
The Mozart Oz web site is at http://www.mozart-oz.org/.