Message-ID:  <009BB6D1.D6B5A400.247@triumf.ca>
Reply-To: Mailing list for the LaTeX3 project
              <LATEX-L@RELAY.URZ.UNI-HEIDELBERG.DE>
Date:         Tue, 7 Oct 1997 17:49:35 PST
From: Donald Arseneau <asnd@TRIUMF.CA>
Sender: Mailing list for the LaTeX3 project
              <LATEX-L@RELAY.URZ.UNI-HEIDELBERG.DE>
To: Multiple recipients of list LATEX-L
              <LATEX-L@RELAY.URZ.UNI-HEIDELBERG.DE>
Subject:      Re: Extended include
Status: R

David Carlisle <david@DCARLISLE.DEMON.CO.UK> wrote:
%
% > add reason 2A) for using \include: To produce a partial document
% > that is identical to part of the whole document.
%
% Yes that as well, but to be reliable for that use the pages generated
% have to be *exactly* correct and it is always difficult to be sure of
% that with an include system.

This is the primary use of \include.  Yes, the most *common* (correct)
use is for quicker latex runs at the draft stage, but in that case the
cross-references are unlikely to be correct and nobody really cares.

The primary function of the \include mechanism is to make minor changes
to a completed final copy.  For this use, the \clearpage is practically
essential!  Without it, and with unincluded parts sharing pages with
included parts, just about any change at all would require reprocessing
the entire document, as adding just one line will change all the ensuing
page breaks.  When \clearpage separates sections, it is rare (but possible)
for a small change to affect pagination after the included section.

% So you \includeonly{chapter3} but the
% first page of chapter3 `should' start with a float from chapter2,
% (which is now allowed because we assume an improved system with no
% \clearpage)

I am always amazed by the difference between dialects of English.
In North America, "improve" means "make better", not "ruin"!

Floats should not be allowed to wander very far for reasons of
good typesetting, not just for technical convenience.  So an extended
include should begin (and end) with a \FloatBarrier or equivalent
(placeins.sty).

Still, I don't see any case where a non-page-breaking include would
be beneficial;  when sections run one into the other, you must process
the entire document to get the locations right after any change.

I will have to look at Matt's work.  I believe a non-breaking \include
is possible (but not useful imho).  It requires:

abolish \immediate writes (no problem)
Either:  write to only the main aux file (goodbye chapterbib) with
         tags to gobble sections of it when interested in just a part.
Or:      abolish \immediate \openout.  Easy!
\FloatBarrier
checkpoint \pagetotal etc.

Donald Arseneau                         asnd@triumf.ca