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(*)?
Arguments | |||
| $name | xs:QName | The name of the requested function |
| $arity | xs:integer | The arity of the requested function (number of arguments) |
Result | function(*)? | ||
Namespace
http://www.w3.org/2005/xpath-functions