Class AccumulatorFn

    • Constructor Detail

      • AccumulatorFn

        public AccumulatorFn()
    • Method Detail

      • getResultItemType

        public ItemType getResultItemType​(Expression[] args)
        Get the return type, given knowledge of the actual arguments
        Overrides:
        getResultItemType in class SystemFunction
        Parameters:
        args - the actual arguments supplied
        Returns:
        the best available item type that the function will return
      • getCardinality

        public int getCardinality​(Expression[] args)
        Get the cardinality, given knowledge of the actual arguments
        Overrides:
        getCardinality in class SystemFunction
        Parameters:
        args - the actual arguments supplied
        Returns:
        the most precise available cardinality that the function will return
      • call

        public Sequence call​(XPathContext context,
                             Sequence[] arguments)
                      throws XPathException
        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 methd 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