Class MemoSequence.ProgressiveIterator

    • Constructor Detail

      • ProgressiveIterator

        public ProgressiveIterator()
        Create a ProgressiveIterator
    • Method Detail

      • getMemoSequence

        public MemoSequence getMemoSequence()
        Get the containing MemoSequence
      • next

        public Item 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
        Returns:
        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.
        Throws:
        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 java.io.Closeable
        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)
        Specified by:
        getLength in interface LastPositionFinder
        Returns:
        the number of items in the sequence
        Throws:
        XPathException - if an error occurs evaluating the sequence in order to determine the number of items
      • getResidue

        public GroundedValue getResidue()
                                 throws XPathException
        Description copied from interface: GroundedIterator
        Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position. This should be an "in-memory" value, not a Closure. This method does not change the state of the iterator (in particular, it does not consume the iterator).
        Specified by:
        getResidue in interface GroundedIterator
        Returns:
        the corresponding Value
        Throws:
        XPathException - in the cases of subclasses (such as the iterator over a MemoClosure) which cause evaluation of expressions while materializing the value.