Package net.sf.saxon.expr.sort

Class GroupStartingIterator

java.lang.Object

net.sf.saxon.expr.sort.GroupMatchingIterator

net.sf.saxon.expr.sort.GroupStartingIterator

All Implemented Interfaces:

Closeable, AutoCloseable, LastPositionFinder, GroupIterator, SequenceIterator<Item<?>>, LookaheadIterator<Item<?>>

public class GroupStartingIterator
extends GroupMatchingIterator
implements LookaheadIterator<Item<?>>, GroupIterator

A GroupStartingIterator iterates over a sequence of groups defined by xsl:for-each-group group-starting-with="x". The groups are returned in order of first appearance.

Field Summary

Fields inherited from class net.sf.saxon.expr.sort.GroupMatchingIterator

baseContext, current, currentMembers, next, pattern, population, position, runningContext, select

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

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor	Description
GroupStartingIterator(Expression select, Pattern startPattern, XPathContext context)

Method Summary

Modifier and Type	Method	Description
protected void	advance()
int	getLength()	Get the last position (that is, the number of items in the sequence).

Methods inherited from class net.sf.saxon.expr.sort.GroupMatchingIterator

close, getCurrentGroupingKey, getProperties, hasNext, iterateCurrentGroup, next

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.expr.sort.GroupIterator

getCurrentGroupingKey, iterateCurrentGroup

Methods inherited from interface net.sf.saxon.tree.iter.LookaheadIterator

hasNext

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

close, forEachOrFail, getProperties, materialize, next

Constructor Details

GroupStartingIterator

public GroupStartingIterator(Expression select,
 Pattern startPattern,
 XPathContext context)
                      throws XPathException

Throws:

XPathException

Method Details

getLength

public int getLength()
              throws XPathException

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:

getLength in interface LastPositionFinder

Returns:

the number of items in the sequence

Throws:

XPathException - if an error occurs evaluating the sequence in order to determine the number of items

advance

protected void advance()
                throws XPathException

Specified by:

advance in class GroupMatchingIterator

Throws:

XPathException