net.sf.saxon.expr

Class IntersectionEnumeration

java.lang.Object

net.sf.saxon.expr.IntersectionEnumeration

All Implemented Interfaces:

SequenceIterator

public class IntersectionEnumeration
extends java.lang.Object
implements SequenceIterator

An enumeration representing a nodeset that is an intersection of two other NodeSets. This implements the XPath 2.0 operator "intersect".

Field Summary

Fields inherited from interface net.sf.saxon.om.SequenceIterator

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor and Description
IntersectionEnumeration(SequenceIterator p1, SequenceIterator p2, ItemOrderComparer comparer) Form an enumeration of the intersection of the nodes in two nodesets

Method Summary

Modifier and Type	Method and Description
void	close() Close the iterator.
int	getProperties() Get properties of this iterator, as a bit-significant integer.
NodeInfo	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

IntersectionEnumeration

public IntersectionEnumeration(SequenceIterator p1,
                               SequenceIterator p2,
                               ItemOrderComparer comparer)
                        throws XPathException

Form an enumeration of the intersection of the nodes in two nodesets

Parameters:

p1 - the first operand: must be in document order

p2 - the second operand: must be in document order

comparer - Comparer to be used for putting nodes in document order

Throws:

XPathException - if an error occurs, for example reading from the input sequence

Method Detail

next

public NodeInfo 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.

(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

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.