net.sf.saxon.tree.iter

Class ListIterator

java.lang.Object

net.sf.saxon.tree.iter.ListIterator

All Implemented Interfaces:

LastPositionFinder, SequenceIterator, GroundedIterator, LookaheadIterator, ReversibleIterator, UnfailingIterator

Direct Known Subclasses:

ListIterator.Atomic

public class ListIterator
extends Object
implements UnfailingIterator, LastPositionFinder, LookaheadIterator, GroundedIterator, ReversibleIterator

Class ListIterator, iterates over a sequence of items held in a Java List

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ListIterator.Atomic

Field Summary

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

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor and Description
ListIterator(List<? extends Item> list) Create a ListIterator over a given List
ListIterator(List<? extends Item> list, int length) Create a ListIterator over the leading part of a given List

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the iterator.
ListIterator	getAnother() Get another iterator over the same sequence of items, positioned at the start of the sequence.
int	getLength() Get the last position (that is, the number of items in the sequence).
int	getProperties() Get properties of this iterator, as a bit-significant integer.
SequenceIterator	getReverseIterator() Get a new SequenceIterator that returns the same items in reverse order.
boolean	hasNext() Determine whether there are more items to come.
GroundedValue	materialize() Return a SequenceValue containing all the items in the sequence returned by this SequenceIterator
Item	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

ListIterator

public ListIterator(List<? extends Item> list)

Create a ListIterator over a given List

Parameters:

list - the list: all objects in the list must be instances of Item

ListIterator

public ListIterator(List<? extends Item> list,
            int length)

Create a ListIterator over the leading part of a given List

Parameters:

list - the list: all objects in the list must be instances of Item

length - the number of items to be included

Method Detail

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 Item next()

Description copied from interface: UnfailingIterator

Get the next item in the sequence.

Specified by:

next in interface SequenceIterator

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

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 result of getProperties() on the iterator includes the bit setting SequenceIterator.LAST_POSITION_FINDER

Specified by:

getLength in interface LastPositionFinder

Returns:

the number of items in the sequence

getAnother

public ListIterator 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 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.

materialize

public GroundedValue materialize()

Return a SequenceValue containing all the items in the sequence returned by this SequenceIterator

Specified by:

materialize in interface GroundedIterator

Returns:

the corresponding SequenceValue

getReverseIterator

public SequenceIterator getReverseIterator()

Description copied from interface: ReversibleIterator

Get a new SequenceIterator that returns the same items in reverse order. If this SequenceIterator is an AxisIterator, then the returned SequenceIterator must also be an AxisIterator.

Specified by:

getReverseIterator in interface ReversibleIterator

Returns:

an iterator over the items in reverse order