net.sf.saxon.tree.iter

Class AtomizingIterator

java.lang.Object

net.sf.saxon.tree.iter.AtomizingIterator

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, SequenceIterator<AtomicValue>

public class AtomizingIterator
extends java.lang.Object
implements SequenceIterator<AtomicValue>

AtomizingIterator returns the atomization of an underlying sequence supplied as an iterator. We use a specialist class rather than a general-purpose MappingIterator for performance, especially as the relationship of items in the result sequence to those in the base sequence is often one-to-one.

This AtomizingIterator is capable of handling list-typed nodes whose atomized value is a sequence of more than one item. When it is known that all input will be untyped, an UntypedAtomizingIterator is used in preference.

Field Summary

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

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor and Description
AtomizingIterator(SequenceIterator base) Construct an AtomizingIterator that will atomize the values returned by the base iterator.

Method Summary

Modifier and Type	Method and Description
void	close() Close the iterator.
int	getProperties() Get properties of this iterator, as a bit-significant integer.
AtomicValue	next() Get the next item in the sequence.
void	setRoleDiagnostic(RoleDiagnostic role)

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.SequenceIterator

forEachOrFail, materialize

Constructor Detail

AtomizingIterator

public AtomizingIterator(SequenceIterator base)

Construct an AtomizingIterator that will atomize the values returned by the base iterator.

Parameters:

base - the base iterator

Method Detail

setRoleDiagnostic

public void setRoleDiagnostic(RoleDiagnostic role)

next

public AtomicValue next()
                 throws XPathException

Description copied from interface: SequenceIterator

Get the next item in the sequence. This method changes the state of the iterator.

Specified by:

next in interface SequenceIterator<AtomicValue>

Returns:

the next item, or null if there are no more items. Once a call on next() has returned null, no further calls should be made. The preferred action for an iterator if subsequent calls on next() are made is to return null again, and all implementations within Saxon follow this rule.

Throws:

XPathException - if an error occurs retrieving the next item

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.

For example, the iterator returned by the unparsed-text-lines() function has a close() method that causes the underlying input stream to be closed, whether or not the file has been read to completion.

Closing an iterator is important 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 java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface SequenceIterator<AtomicValue>

getProperties

public int getProperties()

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

Specified by:

getProperties in interface SequenceIterator<AtomicValue>

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.