## net.sf.saxon.expr
Class DifferenceEnumeration

    java.lang.Object
      net.sf.saxon.expr.DifferenceEnumeration

All Implemented Interfaces:
  SequenceIterator

public class DifferenceEnumeration
extends java.lang.Object
implements SequenceIterator

An enumeration representing a nodeset that is teh difference of two other NodeSets. There is an "except" operator in XPath 2.0 to create such an expression.

Constructor Summary
`DifferenceEnumeration(SequenceIterator p1, SequenceIterator p2, NodeOrderComparer comparer)` Form an enumeration of the difference of two nodesets, that is, the nodes that are in p1 and that are not in p2.

Method Summary
`Item` `current()` Get the current value in the sequence (the one returned by the most recent call on next()).
`SequenceIterator` `getAnother()` Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.
`Item` `next()` Get the next item in the sequence.
`int` `position()` Get the current position.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### DifferenceEnumeration

    public DifferenceEnumeration(SequenceIterator p1,
                                 SequenceIterator p2,
                                 NodeOrderComparer comparer)
                          throws XPathException

  Form an enumeration of the difference of two nodesets, that is, the nodes that are in p1 and that are not in p2.

Parameters:
  `p1` - the first operand
  `p2` - the second operand
  `comparer` - the comparer

Method Detail

### next

    public Item next()
              throws XPathException

  Description copied from interface: `SequenceIterator`
  Get the next item in the sequence.

  Specified by:
    `next` in interface `SequenceIterator`
  Returns:
    the next item, or null if there are no more items.
  Throws:
    `XPathException` - if an error occurs retrieving the next item

### current

    public Item current()

  Description copied from interface: `SequenceIterator`
  Get the current value in the sequence (the one returned by the most recent call on next()). This will be null before the first call of next().

  Specified by:
    `current` in interface `SequenceIterator`
  Returns:
    the current item, the one most recently returned by a call on next(); or null, if next() has not been called, or if the end of the sequence has been reached.

### position

    public int position()

  Description copied from interface: `SequenceIterator`
  Get the current position. This will be zero before the first call on next(), otherwise it will be the number of times that next() has been called.

  Specified by:
    `position` in interface `SequenceIterator`
  Returns:
    the current position, the position of the item returned by the most recent call of next()

### getAnother

    public SequenceIterator getAnother()
                                throws XPathException

  Description copied from interface: `SequenceIterator`
  Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.

  Specified by:
    `getAnother` in interface `SequenceIterator`
  Returns:
    a SequenceIterator that iterates over the same items, positioned before the first item
  Throws:
    `XPathException` - if any error occurs