Re: [xml] Return type of the xpath query during the compilation of xpath

[Umesh Chandak <umeshc gslab com>]

Daniel Veillard wrote:
> On Thu, May 29, 2008 at 09:57:06AM +0530, Umesh Chandak wrote:
>   
> > Hi ,
> >     I want to know is there any way in libxml xpath to come to know the 
> > return type of the xpath query. I know that there is a way to determine 
> > the return type of the  xpath query after evaluation but for my purpose 
> > I want to know this return type at compilation time .
> >     If there is no way then can any point to me how it can be done in 
> > libxml xpath.
> >     
>
>   There is no way in libxml2, we didn't try to provide this informations.
> I also don't think it's possible in all cases since XPath alllows the
> support for vairables. See the introduction of the spec:
>
>  "The value of a variable is an object, which can be of any of the types
>   that are possible for the value of an expression, and may also be of
>   additional types not specified here."
>
>   "$foo" is a correct XPath expression, you can't determine its type
> statically at compile time since variable definitions are available only
> during evaluation.
>
>   Without variable this is probably possible, nobody asked for it so far,
> and this is not present in libxml2.
>
> Daniel
>
>   
Thanks for the reply. Can you provide me some pointers for how I can do 
this without the variable in xpath.
Basically I want to determine the return type of xpath query is boolean, 
string , number or nodeset without the variable in xpath queries.

Thanks.
Regards,
Umesh