fn:function-lookup

Determines whether a function with a given name and arity is available in the context, and if so, returns a function item that can be used to call the function. The function is useful to allow fallback action when a function is not available: for example, when calling an XPath 3.0 function, the code can be conditional on whether the function is or is not available.

function-lookup($name as xs:QName, $arity as xs:integer) ➔ function(*)?

Namespace

http://www.w3.org/2005/xpath-functions

Links to W3C specifications

XPath 3.1 Functions and Operators

Notes on the Saxon implementation

Available in Saxon-HE since 10; in Saxon-PE/EE since 9.6.