Package com.saxonica.functions.extfn

Class Leading

java.lang.Object
net.sf.saxon.functions.AbstractFunction
net.sf.saxon.functions.SystemFunction
com.saxonica.functions.extfn.Leading
All Implemented Interfaces:
Callable, FunctionItem, GroundedValue, Item, Sequence
public class Leading extends SystemFunction
This class implements the saxon:leading() extension functions.

The first argument is a sequence S, the second a function F (defaulting to fn:data). The function returns the item or items I in the input sequence S up to and excluding the first one for which F(I) returns false.

  • Constructor Details

    • Leading

      public Leading()

  • Method Details

    • call

      public Sequence call(XPathContext context, Sequence[] arguments) throws XPathException
      Evaluate this function call at run-time
      Parameters:
      context - The XPath dynamic evaluation context
      arguments - The values of the arguments to the function call. Each argument value (which is in general a sequence) is supplied in the form of an iterator over the items in the sequence. If required, the supplied sequence can be materialized by calling, for example, new SequenceExtent(arguments[i]). If the argument is always a singleton, then the single item may be obtained by calling arguments[i].next(). The implementation is not obliged to read all the items in each SequenceIterator if they are not required to compute the result; but if any SequenceIterator is not read to completion, it is good practice to call its close() method.
      Returns:
      an iterator over the results of the function. If the result is a single item, it can be returned in the form of a SingletonIterator. If the result is an empty sequence, the method should return EmptyIterator.getInstance()
      Throws:
      XPathException - if a dynamic error occurs during evaluation of the function. The Saxon run-time code will add information about the error location.