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

java.lang.Object
  extended by net.sf.saxon.tree.iter.AxisIteratorImpl
      extended by net.sf.saxon.tree.util.Navigator.AxisFilter
All Implemented Interfaces:
SequenceIterator, AxisIterator, UnfailingIterator
Enclosing class:
Navigator

public static class Navigator.AxisFilter
extends AxisIteratorImpl

AxisFilter is an iterator that applies a NodeTest filter to the nodes returned by an underlying AxisIterator.


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.AxisFilter(AxisIterator base, NodeTest test)
          Construct a AxisFilter
 
Method Summary
 SequenceIterator getAnother()
          Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.
 Item next()
          Get the next item in the sequence.
 
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.AxisFilter

public Navigator.AxisFilter(AxisIterator base,
                            NodeTest test)
Construct a AxisFilter

Parameters:
base - the underlying iterator that returns all the nodes on a required axis. This must not be an atomizing iterator!
test - a NodeTest that is applied to each node returned by the underlying AxisIterator; only those nodes that pass the NodeTest are returned by the AxisFilter
Method Detail

next

public Item next()
Description copied from interface: SequenceIterator
Get the next item in the sequence. This method changes the state of the iterator, in particular it affects the result of subsequent calls of position() and current().

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.

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.

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


Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.