Class PedigreeFn

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

    public class PedigreeFn
    extends SystemFunction
    The saxon:pedigree function, new in Saxon 9.9.

    The function is applied to a map or array that has a pedigree, typically because it was selected by downwards selection within a tree where pedigrees are maintained. It returns information about the pedigree of the map or array, that is, information about its position within the containing tree.

    This information is returned in the form of a map that contains the following entries.

    container - the containing map or array, or an empty sequence if the supplied map or array is the root of the pedigree tree

    index - if the container is an array, this entry is an integer holding the 1-based index of the supplied map or array within the containing array

    key - if the container is a map, this entry is an atomic value holding the key of the entry in this map that contains the supplied map or array.

    • Constructor Detail

      • PedigreeFn

        public PedigreeFn()
    • Method Detail

      • call

        public Sequence call​(XPathContext context,
                             Sequence[] arguments)
                      throws XPathException
        Description copied from interface: Callable
        Call the Callable.
        Parameters:
        context - the dynamic evaluation context
        arguments - the values of the arguments, supplied as Sequences.

        Generally it is advisable, if calling iterate() to process a supplied sequence, to call it only once; if the value is required more than once, it should first be converted to a GroundedValue by calling the utility method SequenceTool.toGroundedValue().

        If the expected value is a single item, the item should be obtained by calling Sequence.head(): it cannot be assumed that the item will be passed as an instance of Item or AtomicValue.

        It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.

        Returns:
        the result of the evaluation, in the form of a Sequence. It is the responsibility of the callee to ensure that the type of result conforms to the expected result type.
        Throws:
        XPathException - if a dynamic error occurs during the evaluation of the expression