pub fn dispatch<I: DocIndexLike>(
ns_uri: &str,
name: &str,
args: Vec<Value>,
idx: &I,
) -> Option<Result<Value, XmlError>>Expand description
Dispatch an XPath function call to the matching EXSLT family.
Returns Some(result) when ns_uri matches one of the EXSLT
namespace URIs and the family recognises name; otherwise
None, so the caller can fall through to its own table or
surface “unregistered function.”
Generic over the doc index because some EXSLT functions (e.g.
set:distinct, str:tokenize when given a nodeset) need to
read string-values of nodes.