[XeTeX] XeTeX in lshort

[Philip Taylor (Webmaster, Ret'd)]

Philipp Stephani wrote:

> Yes, but is that really "structure"? Of course it's basically a question of definition, but if you look at other technologies that are supposed to be able to express structure (e.g. XML), then you'll find data modeling, schema, transformation and querying languages, all of which are nonexistent in the TeX world. What I want to say is that macros can give a pretty good *simulation* of structure, but that simulation is leaky. In the middle of a LaTeX document you can say
>
> \let\chapter\section
>
> and all subsequent sections turn into chapters. This lack of referential transparency makes LaTeX documents pretty complex and hard to process compared to XML languages.

Agreed.  Because TeX is not only a declarative language but also
a procedural language, one can abuse it to change the semantics
of one's markup mid-stream.  That one should not so do is by
the by : one can.  However, TeX purists such as myself prefer
to keep the declarative and procedural aspects entirely separate,
whence the fact that my own documents are frequently marked up
using a totally different syntax to Don's backslash and braces :
I prefer an SGML/HTML/XML-like syntax that I have described elsewhere
as "ATML" or "XTML" ({A|eXtensible} TeX Markup Language).

In giving the world TeX, Don gave us a loaded gun; it is
up to us to use it wisely.

** Phil.