Newsgroups: comp.lang.apl
Path: watmath!watserv2.uwaterloo.ca!mach1!torn!cs.utexas.edu!qt.cs.utexas.edu!yale.edu!ira.uka.de!Sirius.dfn.de!tubsibr!infbssys!neitzel
From: neitzel@ips.cs.tu-bs.de (Martin Neitzel)
Subject: Re: Weaning  myself from Matlab: is APL a viable alternative for scientific programming and signal processing?
Message-ID: <1993Jan29.133601.7385@ips.cs.tu-bs.de>
Sender: neitzel@ips.cs.tu-bs.de (Martin Neitzel)
Organization: Inst. f. Informatik, TU Braunschweig, FRG
References: <WEG.93Jan19140548@mace.cc.purdue.edu> <1502@kepler1.rentec.com> <WEG.93Jan26115205@mace.cc.purdue.edu>
Date: Fri, 29 Jan 1993 13:36:01 GMT
Lines: 22

> We read and write but do not pipe.  Is this an instance of
> J's insulation?

Yes.  Also the fact that the host execution verbs (0!:0 and 0!:1)
require that unix commands return exit state 0.  That is, you can't
invoke programs like "mail -e" which uses the exit state to indicate
the presence of mail and similar programs.  (The whole point of exit
codes is to support a functional style of program interconnection but
the J implementation prefers to ignore that.)

It's sad to see efforts wasted on things like built-in graphics
featurisms instead of much simpler and more general capabilities
like cooperation with external processes.  Looks like another instance
of the all-in-one approach.

I am very happy that ISI has made the source available.

						Martin Neitzel

[Hey, at least they *did* think along the right lines once.  Remember
the "gnuplot" example, eg. from "Programming in J", Chapter 1, "Host
facilities"?]
