Newsgroups: comp.lang.apl
Path: watmath!watserv1!utgpu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!nntp-server.caltech.edu!tesla!ssr
From: ssr@tesla.caltech.edu (Steve Roy)
Subject: Newbie questions
Message-ID: <1992Feb11.024018.15440@cco.caltech.edu>
Sender: news@cco.caltech.edu
Nntp-Posting-Host: tesla.ama.caltech.edu
Organization: Caltech Applied Mathematics
Date: Tue, 11 Feb 1992 02:40:18 GMT
Lines: 35

Howdy J land.

I've been looking around at scientific programming environments and
came across J recently and I had a couple of questions.  Any help
would be greatly appreciated.

Anybody got some more documentation?  I recognize that it is sort of a
fun puzzle to pick through what there is on watserv1.uwaterloo.ca and
figure out how to use this thing, but I have things I want to use this
for and would rather get right to it.  More than a single word
explaination of 'm~   evoke    evoke' would be nice.

Anybody got a verbose dictionary?  I personally don't mind writing
'Sqrt' rather than '%:' (or is it :%).  If I were Stephen Hawking I
would probably want to minimize keystrokes, but my typing skills are
pretty good and the limiting factor for writing and understanding
programs is not number of keystrokes.

I'm new to J and don't really know much about its internals.  How
efficient is it?  I see in the 4.1 source there are some interface
routines that could presumably let you use all this stuff from C.  Is
there a writeup on how arrays and all that are stored.  Yes, I could
spend the time to figure it out, just wondering if someone else has
done it and written it down somewhere.  How about an interface to
linpack?

Can a list/array hold heterogeneous objects?  That is, can I build a
tree-type structure?  Can I build things like linked lists?  Is this
written up somewhere?

There are more questions, but that is a place to start.  Thanks for
giving some help to a newbie.

Steve Roy
ssr@ama.caltech.edu
