Class Sum

    • Constructor Detail

      • Sum

        public Sum()
    • Method Detail

      • getImplementationMethod

        public int getImplementationMethod()
        Get implementation method
        Overrides:
        getImplementationMethod in class SystemFunction
        Returns:
        a value that indicates this function is capable of being streamed
      • getItemType

        public ItemType getItemType​(TypeHierarchy th)
        Description copied from class: SystemFunction
        Determine the item type of the value returned by the function
        Overrides:
        getItemType in class SystemFunction
        Parameters:
        th - the type hierarchy cache
        Returns:
        a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known at compile time)
      • evaluateItem

        public Item evaluateItem​(XPathContext context)
                          throws XPathException
        Evaluate the function
        Overrides:
        evaluateItem in class Expression
        Parameters:
        context - The context in which the expression is to be evaluated
        Returns:
        the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression
      • total

        public static AtomicValue total​(SequenceIterator iter,
                                        XPathContext context,
                                        javax.xml.transform.SourceLocator location)
                                 throws XPathException
        Calculate the total of a sequence.
        Parameters:
        iter - iterator over the items to be totalled
        context - the XPath dynamic context
        location - location of the expression in the source for diagnostics
        Returns:
        the total, according to the rules of the XPath sum() function, but returning null if the sequence is empty. (It's then up to the caller to decide what the correct result is for an empty sequence.
        Throws:
        XPathException