public interface SequenceIterator
Item
.
The interface to SequenceIterator is changed in Saxon 9.6 to drop support for the
current() and position() methods. Internal iterators no longer need to maintain the values
of the current item or the current position. This information is needed (in general) only
for an iterator that acts as the current focus; that is, an iterator stored as the current
iterator in an XPathContext. SequenceIterators than maintain the value of position()
and last() are represented by the interface FocusIterator
.Modifier and Type | Field and Description |
---|---|
static int |
ATOMIZING
Property value: the iterator can deliver an atomized result.
|
static int |
GROUNDED
Property value: the iterator is "grounded".
|
static int |
LAST_POSITION_FINDER
Property value: the iterator knows the number of items that it will deliver.
|
static int |
LOOKAHEAD
Property value: the iterator knows whether there are more items still to come.
|
Modifier and Type | Method and Description |
---|---|
void |
close()
Close the iterator.
|
int |
getProperties()
Get properties of this iterator, as a bit-significant integer.
|
Item |
next()
Get the next item in the sequence.
|
static final int GROUNDED
GroundedIterator
, and (b) the
implementation of the materialize() method must be efficient (in particular,
it should not involve the creation of new objects)static final int LAST_POSITION_FINDER
LastPositionFinder
,
and (b) the implementation of the getLastPosition() method must be efficient (in particular,
it should take constant time, rather than time proportional to the length of the sequence)static final int LOOKAHEAD
LookaheadIterator
, and (b) the
implementation of the hasNext() method must be efficient (more efficient than the client doing
it)static final int ATOMIZING
Item next() throws XPathException
XPathException
- if an error occurs retrieving the next itemvoid close()
(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.)
int getProperties()
GROUNDED
, LAST_POSITION_FINDER
,
and 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.Copyright (c) 2004-2018 Saxonica Limited. All rights reserved.