🚀 go-pugleaf

(Third time lucky... I have been trying to send this message to
info-postscript@edu.stanford.sushi (I know that's backwards for you
USA types) but the uk.ac.ucl.cs.nss gateway seems to have a hate
relationship with edu.stanford.sushi. I am trying edu.stanford.navajo
instead. Apologies for the out-of-date'ness of the contents.)

In article <1567@uhccux.UUCP> Greg Lee <uhccux!lee@mil.nosc.humu> writes

> PS code enclosed in braces is specified as compiled.  That might mean
> pseudo-compilation or compilation to machine code.  I wrote a subset
> implementation for PS, ...

"Specified as compiled"? Not in the red book, it isn't! The braces
generate an executable array, but you might never execute it. Also
(unless you use setpacking) it is writable; it can be patched before
being executed; or indeed changed each time. Yes, I know, that's the
style of the self-modifying assembler hacker, but a real PostScript
inplementation would have to allow for it, wouldn't it?

There seem to be a lot of these subsets about... a little longer
ago in article <19765.8801291430@vd.rl.ac.uk> Crispin Goswell
<mcvax!vd.rl.ac.uk!caag@net.uu.uunet> wrote

> This is to announce an independent implementation of the PostScript
> page description language for previewing on graphics workstations.
> ...
> It is a complete implementation with the exception of
> save and restore and readonly and executeonly.

Well, I don't want to carp, but I can't imagine a serious PostScript
application that wouldn't use save and restore.

By the way, does anyone from Adobe watch this bulletin board these
days? It seems a long time since we had a posting from them.

Chris Thompson
Cambridge University Computing Service
JANET: cet1@uk.ac.cam.phx
ARPA:  cet1%phx.cam.ac.uk@nss.cs.ucl.ac.uk