Re: [xml-dev] How to specify null value and collection value as anXPATH

[Michael Kay <mike@saxonica.com>]

  On 08/10/2010 7:47 PM, Farrukh Najmi wrote:
>
> Is it possible to specify a null value to an XPATH function as a 
> parameter value?
>
> Also, is it possible to specify a collection (e.g. collection of 
> strings)  to an XPATH function as a parameter value?
>
> In my case, its an extension function, so I suppose anything is 
> possible but I am curious what are the rules.
>
> Thanks.
>

XPath 1.0 or XPath 2.0? - the data models are very different. But 
neither has a concept known by the name of "null". The nearest thing to 
null in XPath 1.0 is an empty node-set; the nearest thing in XPath 2.0 
is an empty sequence. Both, of course, can happily be used as arguments 
to a function call.

As for extension functions - there are no rules.

Michael Kay
Saxonica