Package net.sf.saxon.tree.iter

Class PrependSequenceIterator

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, SequenceIterator
    Direct Known Subclasses:
    PrependAxisIterator
    public class PrependSequenceIterator
extends java.lang.Object
implements SequenceIterator
    An iterator over nodes, that prepends a given node to the nodes returned by another iterator. Used to modify an iterator over axis A to one that iterates over A-OR-SELF.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Close the iterator.
      void discharge()
      Calling this method instructs the iterator to release any resources it holds, while still remaining able to deliver the remaining items in the sequence.
      Item next()
      Get the next item in the sequence.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

    • Method Detail

      • next

        public Item next()
        Get the next item in the sequence.
        Specified by:
        next in interface SequenceIterator
        Returns:
        the next Item. If there are no more items, return null.

      • 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.

        Closing an iterator is not necessary if the iterator is read to completion: if a call on SequenceIterator.next() returns null, the iterator will be closed automatically. An explicit call on SequenceIterator.close() is needed only when iteration is abandoned prematurely.

        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in interface SequenceIterator

      • discharge

        public void discharge()
        Description copied from interface: SequenceIterator
        Calling this method instructs the iterator to release any resources it holds, while still remaining able to deliver the remaining items in the sequence. This may require the iterator to calculate the rest of the sequence eagerly. The method is called by a client if it anticipates that it might not read the iterator to completion, but it cannot guarantee that SequenceIterator.close() will be called when no more items are needed.
        Specified by:
        discharge in interface SequenceIterator