Hi,

I joined the list not so long ago with the main intension of lurking,
as I don't feel qualified enough for more technical discussions. This
thread, however, is more general and touches upon some very important
questions, so I decided to chime in for this one time.

For those who don't know me, I'm mostly just another LaTeX user and
since recently also a member of the TeX Live development team. I'm
also quite interested in developments happening in LaTeX space.

As I understand, the main criticism of LaTeX3 project given by J.F. is
the choice of TeX macro language for its implementation. Although the
issue of named vs numbered arguments (given as an example) seems to me
largely a nitpicking, I too wonder if the LaTeX3 team does not
prematurely put a cap on project's potential by using TeX macros for
all programming.

Now, I don't want to start a discussion on programming languages and
their virtues, but rather I want to focus on one question: are there
any clear limitations of what can be accomplished with TeX macros in
the context of broadly taken document preparation?

Of course TeX is Turing complete, yadda yadda, but I want to look at
this from a practical rather than theoretical point of view.

Some features that I would like to see in LaTeX3 include:
* document model (a well defined data structure with programmatic
access to all document elements),
* ability to flexibly manipulate/transform those elements and operate
on the document as a whole,
* ability to store and reuse the results of those manipulations and
not only to proceed down the TeX guts to produce typeset output.

Can the above be reasonably accomplished with TeX macro language?

In another thread (subject: xparse) a possibility of using some kind
of a preprocessor was mentioned to do the complex data processing
prior to the typesetting step. I find the idea quite interesting as it
widens the solution space significantly. Has this option been
considered?

Cheers,

Tomek