Path: utzoo!utgpu!watmath!att!ucbvax!decwrl!shlump.nac.dec.com!level.dec.com!batcheldern
From: batcheldern@level.dec.com (Ned Batchelder)
Newsgroups: comp.lang.postscript
Subject: Re: Colours of books, etc.
Message-ID: <3772@shlump.nac.dec.com>
Date: 26 Jul 89 20:37:31 GMT
References: <1360@crdgw1.crd.ge.com> <1276@crdgw1.crd.ge.com>
Sender: news@shlump.nac.dec.com
Lines: 30

Distribution: world
Keywords: red blue green Addison-Wesley print them
Organization: DEC

In article <1360@crdgw1.crd.ge.com>, barnett@crdgw1.crd.ge.com (Bruce Barnett)
states essentially that Inside PostScript has given him greater understanding
of the inner workings of PostScript implementations, and has helped him in
writing his own code that must act in ways similar to the PostScript code found
burned into the ROMs of printers.

I think this is a reasonable way to approach this book, but please, be careful.
It can be extremely tricky to keep separate the implementation and the
language definition. Many people would do very poorly on a quiz that
asked what PostScript facilities were guaranteed by the Red Book. I have
known even Adobe people to get questions of that nature wrong.

The fact is that if you examine a reasonable number of instances of a
thing, and they all have a feature in common, then even when you are
told that other instances may not have that feature, you deep down
believe that it either does or should.

For example, I've seen programs that make use of a variable named
"=string". Is this wise? No. Will it work on all the printers made so
far? Maybe. So why not do it? Because you have no guarantee that it will
continue to work.

So, go ahead and enjoy Inside PostScript. Just don't fall into the trap
of thinking that its cover is red.

Ned Batchelder, Digital Equipment Corp., BatchelderN@Hannah.DEC.com