pdftex primitives

[Hans Hagen]

Chris Rowley wrote:

> Although I can get people to attempt to test these empirically, or to
> look at the change file so as to work out what may be happening, this
> is very inefficient; moreover, it only helps to establish the actual
> semantics this week.  It is no help in trying to evaluate whether the
> code actually does what Thanh or anyone else intended it to do; and it
> is little help in evaluating whether the high-level design spec was
> optimal in the first place.
> 
> So please, please, please can we have something to read along these lines,
> before the merger with etex.

They have already merged mysteriously. Hurray!  

Concerning the specs I suppose Sebastian and I have to fill in that gap
because we're dealing with the manual now. In general pdftex extensions
are rather straightforward. The main point is synchronization, which is
rather new related to tex. Normally we do things in specials, and they
end up in the dvi file in the place we expect them. The only fuzzy thing
I can come up with in good old tex is marks: because they can migrate
from their current location. Some examples: 

\pdfobj       -> directly 'shipped' out
\pdfpageattr  -> content handled at ship out time 
\pdfliteral   -> handled like special 
\pdfpagewidth -> to be set before first shipout

Some of these differ rather fundamental from the \special case, in terms
of when the macropackage has to deal with them. 

I have plans to add these things to the manual. 

Hans

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