Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!ames!amdahl!kim
From: kim@amdahl.uts.amdahl.com (Kim DeVaughn)
Newsgroups: comp.sys.amiga
Subject: Re: Comments on Perfect Vision?
Message-ID: <22073@amdahl.uts.amdahl.com>
Date: 6 Feb 88 02:35:30 GMT
References: <5381@elroy.Jpl.Nasa.Gov>
Organization: Amdahl Corporation,  Sunnyvale, CA 94086
Lines: 92
Summary: programable control from other applications, ARexx

In article <5381@elroy.Jpl.Nasa.Gov>, rgd059@Mipl3.JPL.Nasa.Gov writes:
> 
> Someone in another message asked about using the digitizer from application
> programs.  The source code is not included (at least not currently).  If you
> need the digitizing code, call up SunRize and you can work something out.
> The source for Perfect Sound is provided with that package, so they don't
> have much problem with releasing such things.

This is a good example where an interface to Bill Hawes' ARexx package
could give you what is wanted.  Granted, both PerfectVision and the
other application need to support an ARexx interface, but that is quite
easy to do .. really!

I've added an ARexx interface to Matt's "dme" editor (v1.29), and the
basic interface code was only about 200 lines of code, and added about
1.5K to the executable.  Also, it only took maybe 20-25 lines of code
added to Matt's original sources to hook it in (which Matt has improved
on, I believe).

ARexx (in case you don't know), is a general purpose interpreter that
executes the REXX programming language, as defined by Colishaw (of IBM
Cambridge, as I recall).  Certain characteristics of the language make
it an ideal general purpose macro processor (any "command" in an ARexx
program file that the interpreter itself doesn't understand is passed
to a user specifiable "host" program for processing).

As such, it makes an excellent "exec" or "script" processor for any
application (such as a shell, or an editor, or any other application
that processes "commands" [which menu selections can also be thought
of]).  As an example of a very simple dme/ARexx macro, I've attached
"save.dme" to this posting.  Now when I want to save a file in dme, I
can just hit ESC, and type "save" or "save somefilename", and it
happens (I don't have to remember to use "saveold" and "saveas").

ARexx has several other useful capabilities besides being a macro
processor, such as providing easy access by any application to
user wirtten shared.libraries, but I haven't explored them as yet.


I don't intend for this to be an advertisement for ARexx (though it is
probably one of the best bargins available), but to point out how easy
it really is to provide an external interface into any application, that
any similarly interfaced application can take advantage of.  And one
that provides a *significant* increase in functionality quite cheaply.

Since you mention that v1.1 of the s/w is being worked on, I'd like to
suggest that you consider this approach.  This way *everyone* can have
access to PerfectVision's "innards", and you don't need to worry about
giving source out, etc.

As to who else is working with ARexx ... Charlie Heath has said that the
next release of TxEd will support the ARexx interface, and I know that
the developer of at least one commercial communications program is
considering it.  Also you may see a version of the VT100 program that
Tony Sumrall has been enhancing supporting it, and possible a version
of "shell".  Not to mention that Bill Hawes' own WShell/Conman program
will support it.  And it has been rumored that CBM and Bill have had
some discussion about having a future version of the Amiga OS support
the ARexx interface directly ...


Anyway, enough "preaching" about the virtues of ARexx, but I do think it
deserves your serious consideration (as well as consideration by any and
all Amiga developers).

/kim


Here's the "save.dme" example:

/*   Saves the file with the filename specified by the 1st argument.   */
/*   If no name is specified, the file is saved with it's original     */
/*   filename.  Arguments following the 1st one are ignored.           */
/*                                                                     */
/*   Kim DeVaughn  12/21/87                                            */

options failat 5
rc = 0

parse arg filename junk
if filename = ""
   then saveold
   else saveas  filename
exit rc


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