[tex-k] teTeX-beta 20021116 and source specials and the syntax package

Olaf Weber olaf@infovore.xs4all.nl
09 Dec 2002 18:27:05 +0100

Kai Gro▀johann writes:

> I used to use TeXlive 7 which grokked source specials fine.

It didn't.  There are two changes in TeXlive 7 w.r.t. source specials.
One ensures that a source special will be inserted using an "internal"
special token, so that they cannot be affected by a redefinition of

The other fiddled with the location of the every_par source special.
My log entry for this reads:

        Delay the generation of everypar source specials until after
        the \everypar processing has been done, because they could be
        easily "captured" otherwise

This is what made it into TeX-live 7.  It turned out to have major
undesirable side effects on the formatting of documents, and was
backed out because the previous situation was judged to be the least
of two evils.  That log entry reads as follows:

        Back out the change that moved the generation of src_specials.
        It in turn led to markedly different results in "normal" input
        that is considerably more common than the constructions that
        prompted the change.  The upshot is that at present I know of
        _no_ non-intrusive way to implement source specials, and
        enabling them may break your documents in unexpected ways.

The upshot is that source specials are incompatible with certain
packages, and fixing that requires changes that would be far more
invasive of the TeX internals than the implementation is.

Olaf Weber

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