Class FunctionLookup

  • All Implemented Interfaces:
    Callable, Function, GroundedValue, Item, Sequence

    public class FunctionLookup
    extends ContextAccessorFunction
    This class supports the function-lookup() function in XPath 3.0. It takes as arguments a function name (QName) and arity, and returns a function item representing that function if found, or an empty sequence if not found.
    • Constructor Detail

      • FunctionLookup

        public FunctionLookup()
    • Method Detail

      • makeFunctionCall

        public Expression makeFunctionCall​(Expression... arguments)
        Description copied from class: SystemFunction
        Make an expression that either calls this function, or that is equivalent to a call on this function
        makeFunctionCall in class SystemFunction
        arguments - the supplied arguments to the function call
        either a function call on this function, or an expression that delivers the same result
      • equals

        public boolean equals​(java.lang.Object o)
        Determine whether two expressions are equivalent
        equals in class SystemFunction
      • bindContext

        public Function bindContext​(XPathContext context)
        Bind a context item to appear as part of the function's closure. If this method has been called, the supplied context item will be used in preference to the context item at the point where the function is actually called.
        Specified by:
        bindContext in class ContextAccessorFunction
        context - the context to which the function applies. Must not be null.
      • call

        public Sequence call​(XPathContext context,
                             Sequence[] arguments)
                      throws XPathException
        Evaluate the expression
        Specified by:
        call in interface Callable
        call in class ContextAccessorFunction
        context - the dynamic evaluation context
        arguments - the values of the arguments, supplied as SequenceIterators
        the result of the evaluation, in the form of a SequenceIterator
        XPathException - if a dynamic error occurs during the evaluation of the expression