[comp.sys.next] Exception 1000

rbeach@mongo.uswest.com (Richard Beach) (06/10/91)

I'm posting this for a friend who is having trouble posting himself.
Please respond to mfriedel@slate.mines.colorado.edu   and NOT to me, thanks.

	I'm getting an uncuaght exception 1000 while playing with postscript,
and was wondering if anybody knew what it was or where I couldfind some
information about it. 
	Thanks in advance, Mike.

eps@toaster.SFSU.EDU (Eric P. Scott) (06/10/91)

In article <1991Jun9.194516.21651@cherokee.uswest.com>
	rbeach@mongo.uswest.com (Richard Beach) writes:
>Please respond to mfriedel@slate.mines.colorado.edu   and NOT to me, thanks.

>	I'm getting an uncuaght exception 1000 while playing with postscript,
>and was wondering if anybody knew what it was or where I couldfind some
>information about it. 

Exception 1000 is an untrapped standard PostScript language
interpreter error (you probably figured that out already, heh).
It's the numeric value of dps_err_ps, described in Display
PostScript System: Client Library Reference Manual, page 94, as
reproduced in Supplemental Documentation of the 2.0 Tech Docs.

Just about any of the PostScript errors listed in
/NextLibrary/Documentation/NextDev/Summaries/04_OpSummary/_Errors.rtf
will trigger this if you haven't made arrangements to deal with
them.

What to do depends on why there's an error condition; if the
error is something like typecheck, there's probably something
wrong with your code, and you should try testing it "separately"
with pft or Yap (or DisplayTalk if you have money to burn).

If it's something like rangecheck, you generally deal with it
in a "stopped context"--

	{ questionable code } stopped

If the questionable code completed successfully, this contruct
will leave false on top of the operand stack.

If a PostScript error occurs, the standard handlers will perform
$error /newerror true put
and execute stop, leaving true on top of the operand stack, and
a bunch of useful debugging information in the $error dictionary.

For client-side error handling, see the sample code in
/NextLibrary/Documentation/NextDev/Notes/ExceptHandling.rtfd/

More info:

	PostScript Language Reference Manual "red book"
	(published by Addison-Wesley)

	Extensions for the Display PostScript System
	(reproduced in Supplemental Documentation of 2.0 Tech
	 Docs)

					-=EPS=-