Re: Proposal: XML helper functions

On tis, 2010-01-05 at 11:50 -0800, Scott Bailey wrote:
> > There has been talk about adding something like xpath_string,
> > xpath_number, xpath_boolean for fetching xpath expressions that
> don't
> > return nodesets.  I think that would fit your use case.
> 
> The first two sound very much like what I'm looking for. I'm unsure 
> about the third. Is it's purpose to extract the scalar value of an 
> expression and cast to bool as the other two do, or is it to identify
> if the xpath expression returned any nodes like xmlexists?

XPath as a language has four data types: nodeset, string, number,
boolean.  So an XPath expression could return any of those types.  Then,
I suppose, the xpath_foo() function would evaluate the expression and
return the result as type foo, possibly raising an error if the types
don't match.

Details to be determined.