[XeTeX] XeTeX maintenance

[Philip Taylor]

Zdenek Wagner wrote:

> Formatting advices should better be present in processing instructions.
> You can type <?TeX something?> <?HTML something else ?> etc.

Why do you write "better", Zdeněk ?  They /can/ be expressed as
processing instructions, but that would require an augmented parser;
they can equally well be expressed as attributes or as a <pragmat> -- I
do not think that either is "better", they are simply different.  XML is
an /eXtensible/ Markup Language -- one should never hesitate to extend it.

> Such parsers already exist in luatex and ConTeXt. I only know about
> them, I have never used them. And FO may be processed by passiveTeX. And
> there are, of course,  numerous other tools.

All of which will typically have a steep learning curve.  In my
experience, it is usually better to write a tool for oneself; in that
way, not only does one have an innate understanding of how it works, one
can easily amend or augment it if it fails to deliver.  Other people's
tools, on the other hand, rarely deliver /exactly/ what is required, and
it is only too easy to blame the tool when one's own package fails to
deliver in turn, rather than attempt to fix a tool which is very easy to
exploit but very hard to modify.  Far too many example of this abound in
the real world for me to single out any one as an example, but suffice
to say that one does not need to look outside the TeX world in order to
find examples ...

** Phil.