Path: utzoo!attcan!uunet!grand!day
From: day@grand.UUCP (Dave Yost)
Newsgroups: comp.lang.postscript
Subject: Re: Want Laser Prep walkthrough
Keywords: PostSCript, LaserPrep
Message-ID: <458@grand.UUCP>
Date: 17 Dec 88 07:27:42 GMT
References: <456@grand.UUCP> <3265@bgsuvax.UUCP> <788@sequent.cs.qmc.ac.uk>
Reply-To: day@grand.COM (Dave Yost)
Organization: Grand Software, Inc., Los Angels, CA 213-650-1089
Lines: 33
Summary:postscript pages should be independent

In article <788@sequent.cs.qmc.ac.uk>
 liam@cs.qmc.ac.uk (William Roberts) writes:
>The Adobe Document Structuring Conventions specs say that every page
>should be independent of every other page: LaserPrep 67 ... conforms almost
>to the letter of the document structuring conventions whilst being utterly
>against the spirit!

The LaserPrep behavior you are complaining about is perhaps not as
bad as another way in which some program-generated PostScript code
violates the notion of page independence.  The violation to which
I refer consists of doing a save before a %%Page comment, and then
doing a matching restore after that %%Page comment.  This makes it
impossible to do some interesting postprocessing of PostScript
document files, such as printing 2 pages of output per sheet.

Please, you PostScript people out there, if you have anything to do
with a program that outputs PostScript, see to it that the output
passes the following acid test of page independence: your page code
should work inside a save-restore pair, like this:

    %%Page:
    /struct_crucible save def       % added to test independence of page code

    [ page code ]

    struct_crucible restore         % added to test independence of page code
    %%Page:

Surprisingly, some very popular, excellent programs from important,
major software vendors do not pass this test.  In all the cases I have
seen, the deficiency would be easy to correct.

 --dave yost