net.sf.saxon.tree.iter
Class PrependIterator

java.lang.Object
  net.sf.saxon.tree.iter.PrependIterator

All Implemented Interfaces:

SequenceIterator, AxisIterator, UnfailingIterator

public class PrependIterator
extends Object
implements AxisIterator

An iterator over nodes, that prepends a given node to the nodes returned by another iterator. Used to modify an iterator over axis A to one that iterates over A-OR-SELF.

Field Summary

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

GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

PrependIterator(NodeInfo start, AxisIterator base)

Method Summary

Value	atomize() Return the atomized value of the current node.
void	close() Close the iterator.
NodeInfo	current() Get the current item in the sequence.
AxisIterator	getAnother() Get another iterator over the same sequence of items, positioned at the start of the sequence
int	getProperties() Get properties of this iterator, as a bit-significant integer.
CharSequence	getStringValue() Return the string value of the current node.
AxisIterator	iterateAxis(byte axis, NodeTest test) Return an iterator over an axis, starting at the current node.
boolean	moveNext() Move to the next node, without returning it.
NodeInfo	next() Get the next item in the sequence.
int	position() Get the current position

Methods inherited from class java.lang.Object

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

Constructor Detail

PrependIterator

public PrependIterator(NodeInfo start,
                       AxisIterator base)

Method Detail

moveNext

public boolean moveNext()

Move to the next node, without returning it. Returns true if there is a next node, false if the end of the sequence has been reached. After calling this method, the current node may be retrieved using the current() function.

Specified by:

moveNext in interface AxisIterator

Returns:

true if there is a next node, false if the end of the sequence has been reached

next

public NodeInfo next()

Get the next item in the sequence.

Specified by:

next in interface SequenceIterator

Specified by:

next in interface AxisIterator

Specified by:

next in interface UnfailingIterator

Returns:

the next Item. If there are no more nodes, return null.

current

public NodeInfo current()

Get the current item in the sequence.

Specified by:

current in interface SequenceIterator

Specified by:

current in interface AxisIterator

Specified by:

current in interface UnfailingIterator

Returns:

the current item, that is, the item most recently returned by next()

position

public int position()

Get the current position

Specified by:

position in interface SequenceIterator

Specified by:

position in interface UnfailingIterator

Returns:

the position of the current item (the item most recently returned by next()), starting at 1 for the first node

close

public void close()

Description copied from interface: SequenceIterator

Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)

Specified by:

close in interface SequenceIterator

iterateAxis

public AxisIterator iterateAxis(byte axis,
                                NodeTest test)

Return an iterator over an axis, starting at the current node.

Specified by:

iterateAxis in interface AxisIterator

Parameters:

axis - the axis to iterate over, using a constant such as Axis.CHILD

test - a predicate to apply to the nodes before returning them.

Returns:

an iterator over an axis, starting at the current node

Throws:

NullPointerException - if there is no current node

atomize

public Value atomize()
              throws XPathException

Return the atomized value of the current node.

Specified by:

atomize in interface AxisIterator

Returns:

the atomized value.

Throws:

NullPointerException - if there is no current node

XPathException - if the current node cannot be atomized, for example because it is an element node with element-only content.

getStringValue

public CharSequence getStringValue()

Return the string value of the current node.

Specified by:

getStringValue in interface AxisIterator

Returns:

the string value, as an instance of CharSequence.

Throws:

NullPointerException - if there is no current node

getAnother

public AxisIterator getAnother()

Get another iterator over the same sequence of items, positioned at the start of the sequence

Specified by:

getAnother in interface SequenceIterator

Specified by:

getAnother in interface AxisIterator

Specified by:

getAnother in interface UnfailingIterator

Returns:

a new iterator over the same sequence

getProperties

public int getProperties()

Get properties of this iterator, as a bit-significant integer.

Specified by:

getProperties in interface SequenceIterator

Returns:

the properties of this iterator. This will be some combination of properties such as SequenceIterator.GROUNDED, SequenceIterator.LAST_POSITION_FINDER, and SequenceIterator.LOOKAHEAD. It is always acceptable to return the value zero, indicating that there are no known special properties. It is acceptable for the properties of the iterator to change depending on its state.