RE: [xsl] general purpose filter stylesheet

["Michael Kay" <michael dot h dot kay at ntlworld dot com>]

> How can I do this query resolving with XSLT?
> (I need this for an java xml wrapper, that can submit queries
> to given docs
> without knowing a lot of their structure)
>
> My query is an boolean expression:
> ###########################
>
> ((author='Date' or title='Database Systems') and number='1')
> PROBLEM: 'number' is not part of the same parent as 'author'
>
You seem to have invented your own query language. If you want this to work
when "number" and "author" are not siblings, then you're assuming some
semantics that are different from the XPath semantics. If you want to invent
your own query language, then you will have to define its syntax and
semantics, and write a translator that converts it into an XPath expression.
You can then pass the resulting XPath expression to a suitable dynamic XPath
execution engine - for example the xx:evaluate() function in Saxon or Xalan.

I don't know what the intended semantics of your expression are. Perhaps
it's equivalent to the XPath expression

  ((//author='Date' or //title='Database Systems') and //number='1')

in which case doing the translation into XPath might not be too difficult.

Michael Kay
Software AG
home: Michael.H.Kay@ntlworld.com
work: Michael.Kay@softwareag.com


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