Tool development: by Perl-wrapped XQuery

[David A. Lee]

>
> Now my questions: 
> - would you recommend alternatives for rapid tool development? 
> - if taking a similar approach - would you like to recommend special details, perhaps the script language actually used, or other aspect?
>   
In my opinion the problem with doing this in perl is that unless the 
xquery implementation itself is in perl or atleast runs within the same 
process you will run into horrible performance problems.   See my (with 
Norm Walsh's) paper :

http://www.balisage.net/Proceedings/vol4/author-pkg/Lee01/BalisageVol4-Lee01.html

What we found is that for our test cases there is a 100-200x (yes 10000 
% - 20000 % ) performance penalty of using a scripting language to call 
xml processing programs.   This *can* be optimized but the exact use 
cases of using a off-the-shelf scripting language to do this kind of 
thing is typically by the audience of people who do not want to spend 
the extra effort to optimize it, or who are not experts in the type of 
software development/languages required to  do it, or both. i.e its 
exactly why they are using scripting - so they don't have to do all that 
extra work.

This is the primary reason xmlsh was invented instead of re-using an 
existing scripting language.   I took a "toy" program in a scripting 
language it worked great.
But when I loaded up all the files I needed it to run it died a horrible 
death.   This is what I call "The Brick Wall" and why scripting XML 
processes fail so many of us.   The presentation cited above has some 
good charts and figures as well as the full test case code.

This is why I suggest either (both)

* Use a scripting language that already is 'in process' with all the XML 
core languages you want to use (xquery, xslt etc)
 -> examples XProc, xmlsh

* Encourage scripting languages developers to embed these XML languages 
directly into the scripting languages (say perl).
-> This is hard work and may in fact involve re-implementing many of the 
core tools from scratch.
-> Some of the work is done but is incomplete ... I've seen references 
to XSLT implementions native in perl where the author quoted  something like
   "This isnt a complete implementation of XSLT 1.0 but it works pretty 
good for me".


-- 
David A. Lee
http://x-query.com/mailman/listinfo/talk  
http://www.calldei.com
http://www.xmlsh.org
812-482-5224