You could make a call with the document function (in a non-functional
way :) ) to a back end that uses a custom uri resolver that, when
receives a certain href, logs/writes the /real/ current-dateTime and
returns <nothing/>.


On Fri, 2008-04-18 at 10:24 -0400, Liam Quin wrote:
> On Fri, Apr 18, 2008 at 02:05:52PM +0100, Andrew Welch wrote:
> > It should be straightforward to write an extension function instead...
> 
> Actually no.  A conformant implementation is allowed to call an
> extension function only once for any given argument value, and
> to remember the results, to make it stable.  A give implementation
> might let you write such an extension function as you want, but
> there's no guarantee.
> 
> In addition, suppose you have a stylesheet that does, say
> 
>     xsl:for-each 1 to 1000
> 	value-of current-time
> 
> the implementation doesn't have to start at 1 and evaluate the
> "loop"  a thousand times.  Instead, this could be written as,
>     map the items in the sequence (1 ... 1000)
>     to the value of current-time
> with current-time being called once.
> 
> Or, the implementation could start at 1000 and work downwards,
> and as long as it ended at 1 and put the results in the right
> order, you coudn't tell.
> 
> And yes, there are implementations that do that sort of thing :-)
> at least for XQuery and quite possibly for XSLT.
> 
> So, best to think of XSLT as specifying a mapping, rather than
> in terms of procedural instructions.
> 
> Hppe this helps, although it's perhaps notwhat you want to hear.
> 
> Best,
> 
> Liam