net.sf.saxon.tree.util
Class Navigator.PrecedingEnumeration

java.lang.Object
  net.sf.saxon.tree.iter.AxisIteratorImpl
      net.sf.saxon.tree.util.Navigator.BaseEnumeration
          net.sf.saxon.tree.util.Navigator.PrecedingEnumeration

All Implemented Interfaces:

SequenceIterator, AxisIterator, UnfailingIterator

Enclosing class:

Navigator

public static final class Navigator.PrecedingEnumeration
extends Navigator.BaseEnumeration

Helper method to iterate over the preceding axis, or Saxon's internal preceding-or-ancestor axis, by making use of the ancestor, descendant, and preceding-sibling axes.

Field Summary

Fields inherited from class net.sf.saxon.tree.iter.AxisIteratorImpl

current, position

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

GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Navigator.PrecedingEnumeration(NodeInfo start, boolean includeAncestors)
Create an iterator for the preceding or "preceding-or-ancestor" axis (the latter being used internall to support xsl:number)

Method Summary

void	advance() The advance() method must be provided in each concrete implementation.
SequenceIterator	getAnother() Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.

Methods inherited from class net.sf.saxon.tree.util.Navigator.BaseEnumeration

next

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

atomize, close, current, getProperties, getStringValue, iterateAxis, moveNext, position

Methods inherited from class java.lang.Object

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

Constructor Detail

Navigator.PrecedingEnumeration

public Navigator.PrecedingEnumeration(NodeInfo start,
                                      boolean includeAncestors)

Create an iterator for the preceding or "preceding-or-ancestor" axis (the latter being used internall to support xsl:number)

Parameters:

start - the initial context node

includeAncestors - true if ancestors of the initial context node are to be included in the result

Method Detail

advance

public void advance()

Description copied from class: Navigator.BaseEnumeration

The advance() method must be provided in each concrete implementation. It must leave the variable current set to the next node to be returned in the iteration, or to null if there are no more nodes to be returned.

Specified by:

advance in class Navigator.BaseEnumeration

getAnother

public SequenceIterator getAnother()

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.

This method allows access to all the items in the sequence without disturbing the current position of the iterator. Internally, its main use is in evaluating the last() function.

This method does not change the state of the iterator.

Specified by:

getAnother in interface SequenceIterator

Specified by:

getAnother in interface UnfailingIterator

Specified by:

getAnother in class Navigator.BaseEnumeration

Returns:

a SequenceIterator that iterates over the same items, positioned before the first item