public class MappingIterator extends java.lang.Object implements SequenceIterator
This is a powerful class. It is used, with different mapping functions, in a great variety of ways. It underpins the way that "for" expressions and path expressions are evaluated, as well as sequence expressions. It is also used in the implementation of the document(), key(), and id() functions.
ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD
Constructor and Description |
---|
MappingIterator(SequenceIterator base,
MappingFunction action)
Construct a MappingIterator that will apply a specified MappingFunction to
each Item returned by the base iterator.
|
Modifier and Type | Method and Description |
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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.
|
public MappingIterator(SequenceIterator base, MappingFunction action)
base
- the base iterator, which must deliver items of type Faction
- the mapping function to be appliedpublic Item next() throws XPathException
SequenceIterator
next
in interface SequenceIterator
XPathException
- if an error occurs retrieving the next itempublic void close()
SequenceIterator
(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.)
close
in interface SequenceIterator
public int getProperties()
getProperties
in interface SequenceIterator
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.Copyright (c) 2004-2018 Saxonica Limited. All rights reserved.