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, LookaheadIterator

public class GroupStartingIterator
extends GroupMatchingIterator
implements LookaheadIterator, 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, nextItem, pattern, population, position, runningContext, select

Constructor Summary

Constructors

Constructor	Description
GroupStartingIterator(PullEvaluator 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).
boolean	supportsGetLength()	Ask whether this iterator supports use of the LastPositionFinder.getLength() method.

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

close, currentGroup, getCurrentGroupingKey, getSnapShot, hasNext, next, supportsHasNext

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

currentGroup, getCurrentGroupingKey, getSnapShot

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

hasNext, supportsHasNext

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

close, next

Constructor Details

GroupStartingIterator

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

Throws:

XPathException

Method Details

supportsGetLength

public boolean supportsGetLength()

Description copied from interface: LastPositionFinder

Ask whether this iterator supports use of the LastPositionFinder.getLength() method. This method should always be called before calling LastPositionFinder.getLength(), because an iterator that implements this interface may support use of LastPositionFinder.getLength() in some situations and not in others

Specified by:

supportsGetLength in interface LastPositionFinder

Returns:

true if the LastPositionFinder.getLength() method can be called to determine the length of the underlying sequence.

getLength

public int getLength()

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 LastPositionFinder.supportsGetLength() has been called and has returned true.

Specified by:

getLength in interface LastPositionFinder

Returns:

the number of items in the sequence

advance

protected void advance()
                throws XPathException

Specified by:

advance in class GroupMatchingIterator

Throws:

XPathException