Struct Extensions 

pub struct Extensions { /* private fields */ }

Ergonomic builder for the common case of registering a handful of closure-based extension functions keyed by (namespace, name).

Lookups are O(1) and don’t allocate per call (the &str argument is matched directly against the stored String keys via Borrow).

Implementations

impl Extensions

pub fn new() -> Self

pub fn register<F>( &mut self, ns_uri: impl Into<String>, name: impl Into<String>, f: F, ) -> &mut Self

where F: Fn(Vec<XPathValue>) -> Result<XPathValue, XmlError> + 'static,

Register f to handle ns_uri:name(...) calls. Re-registering the same (ns, name) pair replaces the previous closure.

Trait Implementations

impl Debug for Extensions

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Extensions

fn default() -> Extensions

Returns the “default value” for a type.

impl ExtensionFunctions for Extensions

fn call( &self, ns_uri: &str, name: &str, args: Vec<XPathValue>, ) -> Option<Result<XPathValue, XmlError>>

Try to invoke name in ns_uri with args. Return Some(Ok(value)) on success, Some(Err(_)) to surface a runtime error, or None if this implementation doesn’t handle the call (the engine will continue its fallback chain — native EXSLT, then “unknown function” error).