Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!batcomputer!itsgw!steinmetz!uunet!grand!day
From: day@grand.UUCP (Dave Yost)
Newsgroups: comp.lang.postscript
Subject: Re: Large postscript files to a laserwriter
Summary: how to use save/restore pairs to bracket pages
Message-ID: <483@grand.UUCP>
Date: 27 Feb 89 06:52:30 GMT
References: <1936@goanna.oz> <3660@cidam.rmit.oz> <1175@softway.oz>
Reply-To: day@grand.COM (Dave Yost)
Organization: Grand Software, Inc., Los Angels, CA 213-650-1089
Lines: 54

In article <1175@softway.oz> chris@softway.oz (Chris Maltby) writes:
>The best generic solution is to embed each page of text between a
>restore/save pair, and save the empty environment at start time.  By
>restoring to the empty saved environment and then saving it again you can
>cause the VM garbage collection to work much better.

I think this advice should be stated more
explicitly.  Your advice as given could be
construed to support a very bad practice
that I have seen used in Pagemaker which
should be banished because it is bad news for
PostScript postprocessor programs.  (I hope
someone from Aldus is listening.)

I suggest this statement:

A PostScript document program should start
each page of text with a save and end it with
a restore.  In addition to guaranteeing total
page independence, this practice causes the
interpreter's VM garbage collection to work
much better.

    DO THIS:

    ...
%%Page: 1 1
    /x save def
    ...
    x restore
%%Page: 2 2
    /x save def
    ...
    x restore
%%Trailer

The bad Pagemaker trick looks like this:

   DO NOT DO THIS:

    /x save def
%%Page: 1 1
    x restore
    ...
    x restore
    ...
%%Page: 2 2
    x restore
    ...
    x restore
    ...
%%Trailer

 --dave yost