Addition to 'Review of existing Languages'

[Peter Van Roy]

Dear Faré,

I'm not sure who to send this message to. I have a few comments on your
Review.  First, I would like to point your attention to the Oz
language, which grew from roots in the logic programming community to
become one of the few successful multiparadigm languages (see
http://www.mozart.oz.org).  That is, it has combined the paradigms in a
deep way, not just through feature stacking.  Please take a look at the
article:

  http://www.info.ucl.ac.be/people/PVR/tut120500.ps

Don't be fooled by the title; the article goes much beyond logic
programming.  In particular, Sections 7 and 9 should be of particular
interest to you.

Second, I would like to comment on Mercury, which you mention.  I have
a long background in logic programming, although I have not done any
work in this area since 1995.  Yet, I understand it well enough to have
a strong opinion on the Mercury project.  I think it is completely
misguided.  They have thrown out the baby with the bathwater.  That is,
they sacrifice Prolog's only real strength (computing with partial
information) on the altar of static typing.  The result is a functional
language with Horn clause syntax--not very original nor useful, in my
view.

Sincerely yours,

Peter Van Roy

Département d'Ingénierie Informatique
(Department of Computing Science and Engineering)
Université catholique de Louvain
B-1348 Louvain-la-Neuve, Belgium

Email: pvr@info.ucl.ac.be
Tel: (+32) (10) 47.83.74
Web: http://www.info.ucl.ac.be/~pvr/
Mozart: http://www.mozart-oz.org