Package net.sf.saxon.tree.iter

Class ArrayIterator

java.lang.Object

net.sf.saxon.tree.iter.ArrayIterator

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, LastPositionFinder, FocusIterator, SequenceIterator, GroundedIterator, LookaheadIterator, ReversibleIterator

Direct Known Subclasses:

ArrayIterator.Of

public abstract class ArrayIterator
extends java.lang.Object
implements SequenceIterator, FocusIterator, LastPositionFinder, LookaheadIterator, GroundedIterator, ReversibleIterator

ArrayIterator is used to enumerate items held in an array. The items are always held in the correct sorted order for the sequence. The challenge here is getting the generics right, especially in a way that works for C#, which is less tolerant of generic abuse. The solution is to have a non-generic ArrayIterator class, with ArrayIterator.Of<T extends Item> as a subclass. A further subtlety is that we need an ArrayIterator of nodes to implement AxisIterator, so we have another subclass ArrayIterator.OfNodes<N extends NodeInfo> for that purpose.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ArrayIterator.Of<T extends Item>	Parameterised subclass to accept items of a particular item type
static class	ArrayIterator.OfNodes<N extends NodeInfo>	ArrayIterator.OfNodes is a subclass of ArrayIterator where the array always contains Nodes; it therefore implements the AxisIterator interface.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	end
protected int	index
protected int	start

Constructor Summary

Constructors

Constructor	Description
ArrayIterator()

Method Summary

Modifier and Type	Method	Description
int	getLength()	Get the position of the last item in the sequence
boolean	isActuallyGrounded()	Ask if the iterator is actually grounded.
abstract SequenceIterator	makeSliceIterator(int min, int max)	Create a new ArrayIterator over the same items, with a different start point and end point
int	position()	Get the current position.
boolean	supportsHasNext()	Ask whether the hasNext() method can be called.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.saxon.om.FocusIterator

current

Methods inherited from interface net.sf.saxon.tree.iter.GroundedIterator

getResidue, materialize

Methods inherited from interface net.sf.saxon.expr.LastPositionFinder

supportsGetLength

Methods inherited from interface net.sf.saxon.tree.iter.LookaheadIterator

hasNext

Methods inherited from interface net.sf.saxon.tree.iter.ReversibleIterator

getReverseIterator

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

close, next

Field Detail

index

protected int index

start

protected int start

end

protected int end

Constructor Detail

ArrayIterator

public ArrayIterator()

Method Detail

makeSliceIterator

public abstract SequenceIterator makeSliceIterator(int min,
                                                   int max)

Create a new ArrayIterator over the same items, with a different start point and end point

Parameters:

min - the start position (1-based) of the new ArrayIterator relative to the original

max - the end position (1-based) of the last item to be delivered by the new ArrayIterator, relative to the original. For example, min=2, max=3 delivers the two items ($base[2], $base[3]). Set this to Integer.MAX_VALUE if there is no end limit.

Returns:

an iterator over the items between the min and max positions

isActuallyGrounded

public boolean isActuallyGrounded()

Description copied from interface: GroundedIterator

Ask if the iterator is actually grounded. This method must be called before calling GroundedIterator.materialize() or GroundedIterator.getResidue(), because the iterator might be grounded under some conditions and not others (usually when it delegates to another iterator)

Specified by:

isActuallyGrounded in interface GroundedIterator

Returns:

true if this iterator is grounded

supportsHasNext

public boolean supportsHasNext()

Description copied from interface: LookaheadIterator

Ask whether the hasNext() method can be called. This method must be called before calling hasNext(), because some iterators implement this interface, but only support look-ahead under particular circumstances (this is usually because they delegate to another iterator)

Specified by:

supportsHasNext in interface LookaheadIterator

Returns:

true if the LookaheadIterator.hasNext() method is available

position

public int position()

Description copied from interface: FocusIterator

Get the current position. This will usually be zero before the first call on next(), otherwise it will be the number of times that next() has been called. Once next() has returned null, the preferred action is for subsequent calls on position() to return -1, but not all existing implementations follow this practice. (In particular, the EmptyIterator is stateless, and always returns 0 as the value of position(), whether or not next() has been called.)

This method does not change the state of the iterator.

Specified by:

position in interface FocusIterator

Returns:

the current position, the position of the item returned by the most recent call of next(). This is 1 after next() has been successfully called once, 2 after it has been called twice, and so on. If next() has never been called, the method returns zero. If the end of the sequence has been reached, the value returned will always be <= 0; the preferred value is -1.

getLength

public int getLength()

Description copied from interface: FocusIterator

Get the position of the last item in the sequence

Specified by:

getLength in interface FocusIterator

Specified by:

getLength in interface LastPositionFinder

Returns:

the position of the last item