Package net.sf.saxon.om

Class ReverseArrayIterator

java.lang.Object

net.sf.saxon.om.ReverseArrayIterator

All Implemented Interfaces:

LastPositionFinder, ReversibleIterator, AxisIterator, LookaheadIterator, SequenceIterator

public final class ReverseArrayIterator
extends java.lang.Object
implements AxisIterator, ReversibleIterator, LookaheadIterator, LastPositionFinder

ReverseArrayIterator is used to enumerate items held in an array in reverse order.

Author:

Michael H. Kay

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Item	current
(package private) int	end
(package private) int	index
(package private) Item[]	items
(package private) int	start

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

ATOMIZABLE, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor	Description
ReverseArrayIterator(Item[] items, int start, int end)	Create an iterator a slice of an array

Method Summary

Modifier and Type	Method	Description
Item	current()	Get the current item in the sequence.
SequenceIterator	getAnother()	Get another iterator over the same sequence of items, positioned at the start of the sequence.
int	getLastPosition()	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 an iterator that processes the same items in reverse order.
boolean	hasNext()	Determine whether there are more items to come.
Item	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

Field Detail

items

Item[] items

index

int index

start

int start

end

int end

current

Item current

Constructor Detail

ReverseArrayIterator

public ReverseArrayIterator(Item[] items,
                            int start,
                            int end)

Create an iterator a slice of an array

Parameters:

items - The array of items

start - The first item in the array to be be used (this will be the last one in the resulting iteration). Zero-based.

end - The item after the last one in the array to be used (this will be the first one to be returned by the iterator). Zero-based.

Method Detail

hasNext

public boolean hasNext()

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.

Specified by:

hasNext in interface LookaheadIterator

Returns:

true if there are more items in the sequence

next

public Item next()

Description copied from interface: AxisIterator

Get the next item in the sequence.

Specified by:

next in interface AxisIterator

Specified by:

next in interface SequenceIterator

Returns:

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

current

public Item current()

Description copied from interface: AxisIterator

Get the current item in the sequence.

Specified by:

current in interface AxisIterator

Specified by:

current in interface SequenceIterator

Returns:

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

position

public int position()

Description copied from interface: AxisIterator

Get the current position

Specified by:

position in interface AxisIterator

Specified by:

position in interface SequenceIterator

Returns:

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

getLastPosition

public int getLastPosition()

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:

getLastPosition in interface LastPositionFinder

getAnother

public SequenceIterator getAnother()

Description copied from interface: AxisIterator

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 AxisIterator

Specified by:

getAnother in interface SequenceIterator

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.

getReverseIterator

public SequenceIterator getReverseIterator()

Get an iterator that processes the same items in reverse order. Since this iterator is processing the items backwards, this method returns an ArrayIterator that processes them forwards.

Specified by:

getReverseIterator in interface ReversibleIterator

Returns:

a new ArrayIterator