Enum FunctionItem 

pub enum FunctionItem {
    Inline {
        params: Vec<String>,
        sig: Box<FunctionSig>,
        body: Expr,
        closure: Vec<(String, Value)>,
    },
    Named {
        name: String,
        ns: String,
        arity: usize,
        sig: Option<Box<FunctionSig>>,
    },
    Partial {
        base: Box<FunctionItem>,
        bound: Vec<Option<Value>>,
    },
}

A callable XPath 3.1 function item.

Variants

Inline

An inline function(...){...} — parameter names, the body expression, and the values of the free variables captured from the defining scope (static scoping).

Fields

params: Vec<String>

sig: Box<FunctionSig>

Declared signature, for function subtyping in instance of.

body: Expr

closure: Vec<(String, Value)>

Named

A reference to a named function (built-in or user-defined), name#arity, invoked by re-entering function dispatch. name is the lexical QName used for dispatch; ns is its resolved namespace URI (the default function namespace for an unprefixed name), captured at reference time so fn:function-name can rebuild the expanded QName without the defining scope.

Fields

name: String

ns: String

arity: usize

sig: Option<Box<FunctionSig>>

The function’s declared signature, captured at reference time for function subtyping (instance of function(…)). None when unknown (built-ins / extensions) — subtyping then falls back to arity-only matching.

Partial

A partial application: a base function with some arguments already bound; None slots are the remaining parameters.

Fields

base: Box<FunctionItem>

bound: Vec<Option<Value>>

Implementations

impl FunctionItem

pub fn arity(&self) -> usize

The function’s arity (number of parameters still to be supplied).

pub fn declared_sig(&self) -> Option<&FunctionSig>

The function’s declared signature, if captured (named user functions record it at reference time). None for inline, partial, and built-in items.

Trait Implementations

impl Clone for FunctionItem

fn clone(&self) -> FunctionItem

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FunctionItem

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

Formats the value using the given formatter.