NetNews Usenet Archive 1992 #20/NN_1992_20.iso/spool/comp/lang/apl/1005

Text File | 1992-09-14 | 6.4 KB | 144 lines

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From: "BBS\APL (Murray Spencer)" <[e-mail]>
Subject:  CPCUG Presents a Workshop on J by Prof.  Donald B. McIntyre
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Organization: University of Waterloo
Date: Mon, 14 Sep 1992 13:23:16 GMT
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             Capital PC User Group SIG APL Presents

                         A WORKSHOP ON J

            October 10, 1992, from 9:30 a.m. to 4:00 p.m.
        and October 11, 1992, from 2:00 p.m. to 5:00 p.m.

                by Professor Donald B. McIntyre

And "Language as an Intellectual Tool:  From Hieroglyphics to J"
A talk by Professor McIntyre at the SIG APL meeting at 7:30 p.m.
on October 12, 1992.

J is an exciting development in computer languages, designed by
Turing Award winner Kenneth Iverson and his associate Roger Hui
in 1990, who also provided the elegant implementation.  It
appeals to all those whose interest in computing goes beyond the
use of packaged programs.  The implementation is shareware,
written in C, and the source code is available; it runs on a
variety of machines (Oa@DOS, Macintosh, Sun Sparc, Sun 3, MIPS,
SGI, Atari ST, NeXt, IBM RS 6000, ...).

J is a concise, consistent, symbolic notation that enables
programming in functional form, without explicit reference to
arguments.  Although J is very APL-like, it omits everything
Iverson was in doubt about in APL and adds many new features,
particularly new combining forms and control structures that
greatly increase its expressive power over that of APL.  It
requires only the ASCII font for program definition and
execution, discarding the special characters used in APL.  J
includes boxed arrays, complex arithmetic, composition and trains
of functions.  Its logic is clean and consistent, and its
straightforward syntax is ideally suited to parallel processing.

J is described in Iverson's Dictionary of J.  The dictionary
describes nouns (arrays), verbs (functions), adverbs (monadic
operators), and conjunctions (dyadic operators).  Names given to
stored nouns are pronouns (variables).

Like Topsy, mathematical notation just grew.  Through the
centuries its originators introduced additional symbols without
the benefit of hindsight that we enjoy.  As a result, there are
many inconsistencies.

J is a consistent mathematical notation that is executable on
most computers, and provides ready means for solving a great
variety of problems.  With its aid we can write programs (define
mathematical functions -- "verbs") much more concisely and
systematically than ever before.  We can write our programs in
what John Backus (in his Turing Award paper) called "functional
form", without explicit reference to the arguments.

Strings ("trains") of verbs ("hooks" and "forks") now have
meanings, and adverbs, conjunctions, and gerunds (verbal nouns)
are essential parts of the language.  Single-Instruction-
Multiple-Data (SIMD) is made simple by the use of the "rank"
conjunction; while the gerund makes possible Multiple-
Instruction-Multiple-Data (MIMD) and invites parallel processing.

Efficient code results from pre-parsing the definitions.  There
are shareware interpreters for J available for MS DOS, Macintosh,
and other systems.  The J source code is available and a J
compiler is under development.

Donald McIntyre has championed J from the start, with several
recent published papers and presentations to professional
societies, school teachers, and students.  Audiences know him as
a lively, entertaining, and informative speaker.  Moreover, a
personal, interactive tutorial from Donald's experience is a big
help in getting started with J's new concepts.  He has published
these papers:

     "Mastering J", APL Quote Quad 21, No. 6, (August 1991) p.
     264-273.  Presented at APL91, Stanford University, August
     1991

     "Language as an Intellectual Tool", IBM Systems Journal Vol.
     30, No. 4 (1991) p. 554-581

     "Hooks and Forks and the Teaching of Elementary Arithmetic",
     Vector, Vol. 8, No. 3 (January 1992) p. 101-123

     He has two other completed papers now in the publication
     cycle.

Donald McIntyre was educated in his native Scotland, receiving
B.Sc, Ph.D., and D.Sc. degrees from Edinburgh University where he
was a member of the faculty from 1948-1954.  From 1954 to 1989 he
was Professor of Geology at Pomona College.  He has been active
in computing for 30 years, and has received a Fulbright Award, a
John Simon Guggenheim Memorial Fellowship, and in 1985 was named
California College and University Professor of the Year.  He is
an honorary Fellow at the Universities of Edinburgh and St.
Andrews.

Workshop Details

The first aim of the workshop is to get people actually started
using J, rather than to show off the most remarkable features of
the language.  However, since this is a fairly long, multi-
session workshop, there should be time to explore many of the
remarkable features.

Professor McIntyre's foils will be projected on one screen, and a
live demonstration computer session will be projected on another
screen.

You are invited to bring a portable computer (MS DOS or
Macintosh) and a long extension cord to the workshop.  In the
first 30 minutes from 9:30 a.m. to 10:00 we will assist you in
getting the J software running on your computer.  You may wish to
bring a card table on which to work, as the meeting room does not
have tables for the audience.  If you have no computer to bring,
you may be able to work with someone who has one.

There is no charge for workshop or the J software.  You may find
learning easier if you purchase certain publications about J that
will be available.  You will have an opportunity to make a
contribution to defraying the cost of Professor McIntyre's
travel.  Each person provides his own lunch on Saturday, and
there will be a break that allows ample time for going out for
lunch, or you can bring a lunch.

Although there is no charge for the workshop, it is important
that you register your (firm or hopeful) intent to attend
(Saturday and Sunday; Saturday only; Sunday only) so that we can
inform you of additional details, or changes as the workshop time
approaches.  Please send a mailbox message to John Martin or
Murray Spencer on BBS\APL ([phone]), or to Internet
mail address [e-mail],  or, if that is not convenient,
call Murray Spencer at ([phone]).