Newsgroups: comp.lang.apl
Path: watmath!watserv1!utgpu!cs.utexas.edu!wupost!uwm.edu!linac!att!cbfsb!cbnewsc!jwd
From: jwd@cbnewsc.cb.att.com (joseph.w.davison)
Subject: Re: Programming in J
Organization: AT&T Bell Laboratories
Distribution: na
Date: Tue, 5 Nov 1991 23:40:44 GMT
Message-ID: <1991Nov5.234044.3676@cbnewsc.cb.att.com>
Keywords: J
References: <1991Nov5.212542.20160@apollo.hp.com>
Lines: 69

In article <1991Nov5.212542.20160@apollo.hp.com> keil@apollo.hp.com (Mark Keil) writes:
...
>Even so, I still feel that I'm missing something. I just can't
>put my finger on it. Maybe it's the terseness of the language
>description, or maybe it's the labels of nouns/verbs/pronouns/etc
>that are throwing me. Maybe it is assumed knowledge that I don't have.
>I have done a number of the examples, and they work, and give me
>insite into their operation, but I feel that I am missing the big
>picture somehow. I suspect that there is an unexclaimed substructure
>to the language that, if I could see it, would make it all(?) clear.
>
>I suspect that hearing the "WHY" for many aspects of the language,
>would also help me to understand.
>
>I would appreciate any enlightenment that you other J folks could give me.
>
>Thanks, Mark
>

Well, this won't be too enlightening, but it may prompt a reply that
will be.

I share these feelings.  I was a novice APLer for a while, and was impressed,
but found the need for the special characters a hindrance.  I was therefore
pleased to stumble across J in this newsgroup, quite by accident.  I
picked up a mac version and have attempted to learn it, but haven't yet
gotten the book.  One of the difficulties I encountered was the
differences from APL, and mail about "hook" and "fork" and other
amazing but obscure references.  Searching about, I found an article in
Vector (by Iverson?) that talked about J.  Unfortunately, I don't have
the information handy, so I can't give you a good pointer, but I think
it was March '90 or '91.  Anyway, it was helpful in pointing out why it
differs from APL and some of what the goal of the work is.  Perhaps
some of the J cogniscenti would provide a better reference, or even
make a copy available via FTP.

And now, for something completely different: 

I find getting a toe-hold on the language very difficult -- climbing a
glass mountain.  The tutorial on my mac isn't too helpful because
when I try the tutorial it doesn't act the way I expect, and I usually
can't guess what the magic incantations are going to do before they're
gone.  With no english description of what I'm seeing, I see a line of
magic (the incantation) followed by a bunch of numbers:

a $%&.:##@! b

1 2  3
    - - -
6 4 | 7 |
    - - -


Huh?  Where's the bun?

If I'd not played with APL before, I'd have absolutely no idea what was
going on!  And my APL (STSC APL*PLUS on an XT-clone) didn't have boxed
arrays, I don't think, so it took awhile to figure out what they were.

It looks fascinating and really powerful, but I don't know if I want to
drop some of my gold and take the spell book  -- maybe my character is
geared to strength and agility, not to intelligence and dexterity.  Who
knows, the book might even be cursed!  ( "The book is stuck to your
hand, you are unable to put it down." or worse: "Your mind is filled
with wondrous visions, pushing out all else -- you no longer recognize
your spouse and children!")  

-- 
 Joe Davison      jwd@ihlpk.att.com 
