Class SubsequenceIterator

    • Method Detail

      • make

        public static <T extends ItemSequenceIterator make​(SequenceIterator base,
                                                             int min,
                                                             int max)
                                                      throws XPathException
        Static factory method. Creates a SubsequenceIterator, unless for example the base Iterator is an ArrayIterator, in which case it optimizes by creating a new ArrayIterator directly over the underlying array. This optimization is important when doing recursion over a node-set using repeated calls of $nodes[position()>1]
        base - An iteration of the items to be filtered
        min - The position of the first item to be included (base 1)
        max - The position of the last item to be included (base 1)
        an iterator over the requested subsequence
        XPathException - if a dynamic error occurs
      • hasNext

        public boolean hasNext()
        Test whether there are any more items available in the sequence
        Specified by:
        hasNext in interface LookaheadIterator
        true if there are more items in the sequence
      • next

        public Item next()
                  throws XPathException
        Get the next item if there is one
        Specified by:
        next in interface SequenceIterator
        the next item, or null if there are no more items. Once a call on next() has returned null, no further calls should be made. The preferred action for an iterator if subsequent calls on next() are made is to return null again, and all implementations within Saxon follow this rule.
        XPathException - if an error occurs retrieving the next item
      • 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.

        For example, the iterator returned by the unparsed-text-lines() function has a close() method that causes the underlying input stream to be closed, whether or not the file has been read to completion.

        Closing an iterator is important 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 java.lang.AutoCloseable
        Specified by:
        close in interface
        Specified by:
        close in interface SequenceIterator
      • getLength

        public int getLength()
                      throws XPathException
        Get the last position (that is, the number of items in the sequence). This method is non-destructive: it does not change the state of the iterator. The result is undefined if the next() method of the iterator has already returned null. This method must not be called unless the result of getProperties() on the iterator includes the bit setting SequenceIterator.Property.LAST_POSITION_FINDER
        Specified by:
        getLength in interface LastPositionFinder
        the number of items in the sequence
        XPathException - if an error occurs evaluating the sequence in order to determine the number of items