Package net.sf.saxon.om

Class ReverseArrayIterator

java.lang.Object
net.sf.saxon.om.ReverseArrayIterator
All Implemented Interfaces:
LastPositionFinder, ReversibleIterator, LookaheadIterator, SequenceIterator, UnfailingIterator
Direct Known Subclasses:
ReverseNodeArrayIterator
public class ReverseArrayIterator extends Object implements UnfailingIterator, ReversibleIterator, LookaheadIterator, LastPositionFinder
ReverseArrayIterator is used to enumerate items held in an array in reverse order.
Author:
Michael H. Kay

  • Constructor Details

    • ReverseArrayIterator

      public ReverseArrayIterator(Item[] items, int start, int end)
      Create an iterator a slice of an array
      Parameters:
      items - The array of items
      start - The first item in the array to be be used (this will be the last one in the resulting iteration). Zero-based.
      end - The item after the last one in the array to be used (this will be the first one to be returned by the iterator). Zero-based.

  • Method Details

    • 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

    • next

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

    • current

      public Item current()
      Description copied from interface: UnfailingIterator
      Get the current item in the sequence.
      Specified by:
      current in interface SequenceIterator
      Specified by:
      current in interface UnfailingIterator
      Returns:
      the current item, that is, the item most recently returned by next()

    • position

      public int position()
      Description copied from interface: UnfailingIterator
      Get 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

    • getLastPosition

      public int getLastPosition()
      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.LAST_POSITION_FINDER
      Specified by:
      getLastPosition in interface LastPositionFinder

    • 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

    • getAnother

      public SequenceIterator getAnother()
      Description copied from interface: UnfailingIterator
      Get another iterator over the same sequence of items, positioned at the start of the sequence. It must be possible to call this method at any time, whether none, some, or all of the items in the original iterator have been read. The method is non-destructive: it does not change the state of the original iterator.
      Specified by:
      getAnother in interface SequenceIterator
      Specified by:
      getAnother in interface UnfailingIterator
      Returns:
      a new iterator over the same sequence

    • getProperties

      public int getProperties()
      Get properties of this iterator, as a bit-significant integer.
      Specified by:
      getProperties in interface SequenceIterator
      Returns:
      the properties of this iterator. This will be some combination of properties such as SequenceIterator.GROUNDED, SequenceIterator.LAST_POSITION_FINDER, and SequenceIterator.LOOKAHEAD. It is always acceptable to return the value zero, indicating that there are no known special properties. It is acceptable for the properties of the iterator to change depending on its state.

    • getReverseIterator

      public SequenceIterator getReverseIterator()
      Get an iterator that processes the same items in reverse order. Since this iterator is processing the items backwards, this method returns an ArrayIterator that processes them forwards.
      Specified by:
      getReverseIterator in interface ReversibleIterator
      Returns:
      a new ArrayIterator