net.sf.saxon.tree.iter

Class NodeWrappingAxisIterator<B>

java.lang.Object

net.sf.saxon.tree.iter.NodeWrappingAxisIterator<B>

All Implemented Interfaces:

SequenceIterator, AxisIterator, LookaheadIterator, UnfailingIterator

public abstract class NodeWrappingAxisIterator<B>
extends Object
implements AxisIterator, LookaheadIterator

An AxisIterator that wraps a Java Iterator. This is an abstract class, because the Java iterator does not hold enough information to support the getAnother() method, needed to implement the XPath last() function

Field Summary

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

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor and Description
NodeWrappingAxisIterator(Iterator<B> base, NodeWrappingFunction<B,NodeInfo> wrappingFunction) Create a SequenceIterator over a given iterator

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the iterator.
abstract AxisIterator	getAnother() Get another iterator over the same sequence of items, positioned at the start of the sequence.
Iterator<B>	getBaseIterator()
NodeWrappingFunction<B,NodeInfo>	getNodeWrappingFunction()
int	getProperties() Get properties of this iterator, as a bit-significant integer.
boolean	hasNext() Determine whether there are more items to come.
boolean	isIgnorable(B node)
NodeInfo	next() Get the next item in the sequence.

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeWrappingAxisIterator

public NodeWrappingAxisIterator(Iterator<B> base,
                        NodeWrappingFunction<B,NodeInfo> wrappingFunction)

Create a SequenceIterator over a given iterator

Parameters:

base - the base Iterator

wrappingFunction - a function that wraps objects of type B in a Saxon NodeInfo

Method Detail

getBaseIterator

public Iterator<B> getBaseIterator()

getNodeWrappingFunction

public NodeWrappingFunction<B,NodeInfo> getNodeWrappingFunction()

hasNext

public boolean hasNext()

Description copied from interface: LookaheadIterator

Determine whether there are more items to come. Note that this operation is stateless and it is not necessary (or usual) to call it before calling next(). It is used only when there is an explicit need to tell if we are at the last element.

This method must not be called unless the result of getProperties() on the iterator includes the bit setting SequenceIterator.LOOKAHEAD

Specified by:

hasNext in interface LookaheadIterator

Returns:

true if there are more items in the sequence

next

public NodeInfo next()

Description copied from interface: UnfailingIterator

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.

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

isIgnorable

public boolean isIgnorable(B node)

getAnother

public abstract AxisIterator getAnother()

Description copied from interface: UnfailingIterator

Get another iterator over the same sequence of items, positioned at the start of the sequence. It must be possible to call this method at any time, whether none, some, or all of the items in the original iterator have been read. The method is non-destructive: it does not change the state of the original iterator.

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.