Class UntypedAtomizingIterator

  • All Implemented Interfaces:, java.lang.AutoCloseable, LastPositionFinder, SequenceIterator, LookaheadIterator

    public class UntypedAtomizingIterator
    extends java.lang.Object
    implements SequenceIterator, LastPositionFinder, LookaheadIterator
    AtomizingIterator returns the atomization of an underlying sequence supplied as an iterator. We use a specialist class rather than a general-purpose MappingIterator for performance, especially as the relationship of items in the result sequence to those in the base sequence is often one-to-one.

    This UntypedAtomizingIterator is used only when it is known that the input sequence consists entirely of nodes, and that all nodes will be untyped.

    • Constructor Detail

      • UntypedAtomizingIterator

        public UntypedAtomizingIterator​(SequenceIterator base)
        Construct an AtomizingIterator that will atomize the values returned by the base iterator.
        base - the base iterator
    • Method Detail

      • next

        public AtomicValue next()
                         throws XPathException
        Description copied from interface: SequenceIterator
        Get the next item in the sequence. This method changes the state of the iterator.
        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
        Description copied from interface: LastPositionFinder
        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
      • hasNext

        public boolean hasNext()
        Description copied from interface: LookaheadIterator
        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.

        This method must not be called unless the result of getProperties() on the iterator includes the property SequenceIterator.Property.LOOKAHEAD

        Specified by:
        hasNext in interface LookaheadIterator
        true if there are more items in the sequence