Class TreeEnumeration

    • Constructor Detail

      • TreeEnumeration

        public TreeEnumeration​(NodeImpl origin,
                               NodeTest nodeTest)
        Create an axis enumeration for a given type and name of node, from a given origin node
        Parameters:
        origin - the node from which the axis originates
        nodeTest - test to be satisfied by the returned nodes, or null if all nodes are to be returned.
    • Method Detail

      • conforms

        protected boolean conforms​(NodeImpl node)
        Test whether a node conforms to the node type and name constraints. Note that this returns true if the supplied node is null, this is a way of terminating a loop.
        Parameters:
        node - the node to be tested
        Returns:
        true if the node matches the requested node type and name
      • advance

        protected final void advance()
        Advance along the axis until a node is found that matches the required criteria
      • step

        protected abstract void step()
        Advance one step along the axis: the resulting node might not meet the required criteria for inclusion
      • hasNext

        public boolean hasNext()
        Determine whether there are more items to come. Note that this operation is stateless and it is not necessary (or usual) to call it before calling next(). It is used only when there is an explicit need to tell if we are at the last element.
        Specified by:
        hasNext in interface LookaheadIterator
        Returns:
        true if there are more items in the sequence
      • moveNext

        public boolean moveNext()
        Move to the next node, without returning it. Returns true if there is a next node, false if the end of the sequence has been reached. After calling this method, the current node may be retrieved using the current() function.
        Specified by:
        moveNext in interface AxisIterator
        Returns:
        true if there is a next node, false if the end of the sequence has been reached
      • position

        public final int position()
        Return the current position
        Specified by:
        position in interface SequenceIterator
        Specified by:
        position in interface UnfailingIterator
        Returns:
        the position of the current item (the item most recently returned by next()), starting at 1 for the first node
      • close

        public void close()
        Description copied from interface: SequenceIterator
        Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

        (Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)

        Specified by:
        close in interface SequenceIterator
      • iterateAxis

        public AxisIterator iterateAxis​(byte axis,
                                        NodeTest test)
        Return an iterator over an axis, starting at the current node.
        Specified by:
        iterateAxis in interface AxisIterator
        Parameters:
        axis - the axis to iterate over, using a constant such as Axis.CHILD
        test - a predicate to apply to the nodes before returning them.
        Returns:
        an iterator over an axis, starting at the current node
        Throws:
        java.lang.NullPointerException - if there is no current node
      • atomize

        public Value atomize()
                      throws XPathException
        Return the atomized value of the current node.
        Specified by:
        atomize in interface AxisIterator
        Returns:
        the atomized value.
        Throws:
        java.lang.NullPointerException - if there is no current node
        XPathException - if the current node cannot be atomized, for example because it is an element node with element-only content.
      • getStringValue

        public java.lang.CharSequence getStringValue()
        Return the string value of the current node.
        Specified by:
        getStringValue in interface AxisIterator
        Returns:
        the string value, as an instance of CharSequence.
        Throws:
        java.lang.NullPointerException - if there is no current node