[xquery-talk] flowrrr - how to structure a function?

Martin Probst martin at x-hive.com
Tue Oct 17 21:06:19 PDT 2006


> I wonder how other processors work. I read somewhere that you can  
> use Saxon as eXist's XQuery processor, which I intend to do for  
> validity and performance comparisons.
> Do other processors evaluate sequences in order?

X-Hive will currently evaluate the function calls in order, but we  
actively warn our customers that this might not always be the case.  
There is little reason to change the order of evaluation in this  
example, but in other examples the implementation might decide to  
change that.

I think having functions that have side effects is always a dangerous  
thing. Specifically when writing web applications this is a problem -  
people need all those "redirect" and "set cookie" things. My idea at  
solving that would be to rather return an XML document format that  
describes the whole HTTP response. E.g. have response:redirect($code,  
$uri) actually return a value, <?web-request redirect $code $uri ?>,  
and the wrapper around that should interpret the results. With XQJ  
and the servlet API, it might even be possible to write something  


Martin Probst
X-Hive Corporation
martin at x-hive.com

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