com.saxonica.ee.stream

Class ManualGroupIterator

java.lang.Object

net.sf.saxon.tree.iter.ManualIterator

com.saxonica.ee.stream.ManualGroupIterator

All Implemented Interfaces:

LastPositionFinder, GroupIterator, FocusIterator, SequenceIterator, GroundedIterator, LookaheadIterator, ReversibleIterator, UnfailingIterator

Direct Known Subclasses:

GroupByIterator.ManualGroupByIterator, MergeGroupingIterator.ManualMergeGroupingIterator

public class ManualGroupIterator
extends ManualIterator
implements GroupIterator

The class ManualGroupIterator represents an iterator that is never repositioned, but can be used to represent the focus in the dynamic context. It is used as a snapshot copy of a real grouping iterator for use when asynchronous threads are forked, as in xsl:result-document; the purpose of taking a snapshot is to ensure that changes to the base iterator in one thread do not affect the focus of another thread.

Field Summary

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

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor and Description
ManualGroupIterator(Item item, int position) Create a manual grouping iterator

Method Summary

Methods

Modifier and Type	Method and Description
AtomicSequence	getCurrentGroupingKey() Get the grouping key of the current group
ManualGroupIterator	getSnapShot(XPathContext context) Get a sequence which is a snapshot of this sequence at the current position
boolean	hasCurrentGroup() Ask whether this iterator has a current group
boolean	hasCurrentGroupingKey() Ask whether this iterator has a current grouping key
SequenceIterator	iterateCurrentGroup() Get an iterator over the members of the current group, in population order.
void	setCurrentGroup(Sequence group)
void	setCurrentGroupingKey(AtomicSequence key)

Methods inherited from class net.sf.saxon.tree.iter.ManualIterator

close, current, getAnother, getLength, getProperties, getReverseIterator, hasNext, incrementPosition, materialize, next, position, setContextItem, setLastPositionFinder, setPosition

Methods inherited from class java.lang.Object

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

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

close, getAnother, getProperties, next

Constructor Detail

ManualGroupIterator

public ManualGroupIterator(Item item,
                   int position)

Create a manual grouping iterator

Parameters:

item - the context item

position - the context position

Method Detail

hasCurrentGroup

public boolean hasCurrentGroup()

Description copied from interface: GroupIterator

Ask whether this iterator has a current group

Specified by:

hasCurrentGroup in interface GroupIterator

Returns:

false if the controlling xsl:for-each-group element binds a group variable, true if it delivers results using the current-group() function

hasCurrentGroupingKey

public boolean hasCurrentGroupingKey()

Description copied from interface: GroupIterator

Ask whether this iterator has a current grouping key

Specified by:

hasCurrentGroupingKey in interface GroupIterator

Returns:

false if the controlling xsl:for-each-group element binds a grouping-key variable, true if it delivers results using the current-grouping-key() function

getSnapShot

public ManualGroupIterator getSnapShot(XPathContext context)
                                throws XPathException

Description copied from interface: GroupIterator

Get a sequence which is a snapshot of this sequence at the current position

Specified by:

getSnapShot in interface GroupIterator

Throws:

XPathException

setCurrentGroupingKey

public void setCurrentGroupingKey(AtomicSequence key)

getCurrentGroupingKey

public AtomicSequence getCurrentGroupingKey()

Description copied from interface: GroupIterator

Get the grouping key of the current group

Specified by:

getCurrentGroupingKey in interface GroupIterator

Returns:

the current grouping key in the case of group-by or group-adjacent, or null in the case of group-starting-with and group-ending-with

setCurrentGroup

public void setCurrentGroup(Sequence group)

iterateCurrentGroup

public SequenceIterator iterateCurrentGroup()
                                     throws XPathException

Description copied from interface: GroupIterator

Get an iterator over the members of the current group, in population order. This must always be a clean iterator, that is, an iterator that starts at the first item of the group.

Specified by:

iterateCurrentGroup in interface GroupIterator

Returns:

an iterator over all the members of the current group, in population order.

Throws:

XPathException - if a dynamic error occurs