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## Re: [Axiom-developer] Re: converting sexps to XML

 From: michel . lavaud Subject: Re: [Axiom-developer] Re: converting sexps to XML Date: Wed, 29 Jun 2005 11:48:54 +0200

Hello Bob,

On 28 Jun 2005 at 13:26, Bob McElrath wrote:

> I think these two ideas are very distinct.  A latex document is
> processed from top to bottom, once.  A change requires essentially a
> re-compile of the entire document.

I don't agree with you on that point : I have devised a software (AsTeX
assistant) that
allows to tune parts of TeX/LateX documents by selecting small portions of the
document and displaying it without compiling the whole document - for example
select
a formula or part of formula, or part of a table - and display only the
formula, or part of
the formula or table or etc.. You have just to select the portion of document
in your
favorite editor (Emacs, or any other editor, even Word), click on the Display
button of
AA, and the selected portion is displayed in the dvi viewing window. You can
even use
predefined commands such as \def\g{\gamma} defined outside the selected text
(say,
defined in a special file such as mymacros.tex), or commands defined in LaTeX
packages. For illustrations, cf.

http://www.univ-orleans.fr/EXT/ASTEX/astex/doc/fr/nouv31a/html/nouv31.htm

for part of a table + included figure + colored maths, and

http://www.univ-orleans.fr/EXT/ASTEX/astex/doc/fr/assist/html/aase7.htm

for part of a formula.

Of course, if one forces incorrect commands or undefined commands inside the
selected portion, the display is incorrect, in the same way as the result is
incorrect if
one forces an incorrect command or undefine variable in Axiom, or Maxima, or
other
interactive software. AA was presented at TUG2000 in Oxford, and various other
places.

> Syntactic validity cannot be
> ensured in a sub-document of latex.  (e.g. I could insert
> "\end{paragraph}" in the middle of my paragraph...causing the parser
> to totally barf)
> On the other hand XML has the concept of a DOM, which allows me to
> examine nodes individually, add/remove nodes, and modify the text
> inside a node, all in a self-contained manner.

I think one ought to compare what is comparable : it seems that you consider the
possibility to write an incorrect LaTeX document by omitting \end{paragraph} in
a
dumb editor (say notepad under Windows) ? Well, OK, but I cannot see what would
prevent me from writing an incorrect XML document with the same editor ? It
seems
to me that, either one uses a dumb editor and run an external software to check
the
validity of the TeX or XML document, or one uses a specialized editor for TeX
or XML
that prevents most or all errors. If one uses LyX, one cannot introduce
syntactic errors
such as trailing \end{paragraph} (except if one does it on purpose - but one
could
create a version that forbids it). If one uses Emacs with AUC-TeX, or any
editor +
AsTeX assistant to insert TeX/LaTeX commands, or other "intelligent editors",
one
gets a mostly syntactically correct document with the existing softwares
("mostly" in
the sense that errors would have a human origin, not because of TeX or the
editor
used). One could even have an always syntactically correct document with more
effort
(at least with AA, I had not the time to do it but the plan is there). And if
there are XML
constructions that do not exist in LaTeX, I suppose it could be possible to add
commands in LaTeX that implement them, in the same way LaTeX builds on Plain
TeX by adding \begin{} \end{}, \tableofcontents etc., and builds on PostScript
via
\special{} to implement color (although TeX knows only of B&W), or figures,
rotations,
etc. I would be very astonished if one could prove that it is impossible to
implement
the DOM concept, or other XML concepts,  in LaTeX ?

http://www.univ-orleans.fr/EXT/ASTEX
ftp://ftp.univ-orleans.fr/pub/tex/PC/AsTeX