[ssax-sxml] XPath over S-expressions

[Oleg A. P. <ol...@us...>]

Hello,

I'd like to pre-announce the diploma work of Evgeni Milenin
(Saint-Petersburg State University, 2007):

XPath over S-expressions
The title describes the work in full

The diploma text (sorry, only in Russian):
http://xmlhack.ru/protva/Xpath_over_Sexp.pdf

A short English readme file, together with the library, can be found in
the directory "ffi-sexp" in the Generative XPath distribution package:

http://sourceforge.net/project/showfiles.php?group_id=138946&package_id=235034

At the moment, the library works under Guile only. But with small
additions to cond-expand, it should work under any R5RS-compliant Scheme
implementation, which supports integers of arbitrary length.

The work is based on Generative XPath:

``Generative XPath is an XPath 1.0 implementation, which can be adapted
to different hierarchical memory structures and different programming
languages. It is based on a small, easy to implement virtual machine,
which is already available for different platforms, including plain C,
Java and .NET.''

XML Prague 2007 paper, slides, download:

http://xmlhack.ru/protva/prague07-generative-xpath.pdf
http://xmlhack.ru/protva/prague07-generative-xpath-slides.pdf
http://sourceforge.net/project/showfiles.php?group_id=138946&package_id=235034

How does work compare with SXML?

The main difference between the approaches:

* SXML represents XML as S-expressions and processes XML using Scheme,

* The work maps arbitrary S-expressions to a virtual XML and uses XML
XPath standard to query the S-epxressions.

With the library, it's possible to execute XPath over SXML.However, it's
just a coincide, and some cases require attention. For example, what is
"elem/@attr" in SXPath, that should be written as "elem/@/attr".

Performance study said that the library is twice slower as SXPath/txpath.
However, there is a lot of opportunities for optimization. In short,
there is a lot of topics for a lot of students. :)



-- 
Oleg Parashchenko  olpa@ http://uucode.com/
http://uucode.com/blog/  Generative Programming, XML, TeX, Scheme
http://tohtml.com/       Online syntax highlighting