Package org.apache.xalan.xsltc.dom
Class MatchingIterator
java.lang.Object
org.apache.xml.dtm.ref.DTMAxisIteratorBase
org.apache.xalan.xsltc.dom.MatchingIterator
- All Implemented Interfaces:
Cloneable
,DTMAxisIterator
This is a special kind of iterator that takes a source iterator and a
node N. If initialized with a node M (the parent of N) it computes the
position of N amongst the children of M. This position can be obtained
by calling getPosition().
It is an iterator even though next() will never be called. It is used to
match patterns with a single predicate like:
BOOK[position() = last()]
In this example, the source iterator will return elements of type BOOK,
a call to position() will return the position of N. Notice that because
of the way the pattern matching is implemented, N will always be a node
in the source since (i) it is a BOOK or the test sequence would not be
considered and (ii) the source iterator is initialized with M which is
the parent of N. Also, and still in this example, a call to last() will
return the number of elements in the source (i.e. the number of BOOKs).
- Author:
- Jacek Ambroziak, Santiago Pericas-Geertsen
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Field Summary
Fields inherited from interface org.apache.xml.dtm.DTMAxisIterator
END
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionReturns a deep copy of this iterator.int
getLast()
Returns the position of the last node within the iteration, as defined by XPath.int
void
gotoMark()
Restores the current node remembered by setMark().int
next()
Get the next node in the iteration.reset()
Resets the iterator to the last start node.void
setMark()
Remembers the current node for the next call to gotoMark().void
setRestartable
(boolean isRestartable) Set if restartable.setStartNode
(int node) Set start to END should 'close' the iterator, i.e. subsequent call to next() should return END.Methods inherited from class org.apache.xml.dtm.ref.DTMAxisIteratorBase
getAxis, getNodeByPosition, getStartNode, includeSelf, isDocOrdered, isReverse
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Constructor Details
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MatchingIterator
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Method Details
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setRestartable
public void setRestartable(boolean isRestartable) Description copied from interface:DTMAxisIterator
Set if restartable.- Specified by:
setRestartable
in interfaceDTMAxisIterator
- Overrides:
setRestartable
in classDTMAxisIteratorBase
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cloneIterator
Description copied from class:DTMAxisIteratorBase
Returns a deep copy of this iterator. Cloned iterators may not be restartable. The iterator being cloned may or may not become non-restartable as a side effect of this operation.- Specified by:
cloneIterator
in interfaceDTMAxisIterator
- Overrides:
cloneIterator
in classDTMAxisIteratorBase
- Returns:
- a deep copy of this iterator.
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setStartNode
Description copied from interface:DTMAxisIterator
Set start to END should 'close' the iterator, i.e. subsequent call to next() should return END.- Parameters:
node
- Sets the root of the iteration.- Returns:
- A DTMAxisIterator set to the start of the iteration.
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reset
Description copied from interface:DTMAxisIterator
Resets the iterator to the last start node.- Specified by:
reset
in interfaceDTMAxisIterator
- Overrides:
reset
in classDTMAxisIteratorBase
- Returns:
- A DTMAxisIterator which has been reset to the start node, which may or may not be the same as this iterator.
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next
public int next()Description copied from interface:DTMAxisIterator
Get the next node in the iteration.- Returns:
- The next node handle in the iteration, or END.
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getLast
public int getLast()Description copied from class:DTMAxisIteratorBase
Returns the position of the last node within the iteration, as defined by XPath. In a forward iterator, I believe this equals the number of nodes which this iterator will yield. In a reverse iterator, I believe it should return 1 (since the "last" is the first produced.) This may be an expensive operation when called the first time, since it may have to iterate through a large part of the document to produce its answer.- Specified by:
getLast
in interfaceDTMAxisIterator
- Overrides:
getLast
in classDTMAxisIteratorBase
- Returns:
- The number of nodes in this iterator (forward) or 1 (reverse).
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getPosition
public int getPosition()- Specified by:
getPosition
in interfaceDTMAxisIterator
- Overrides:
getPosition
in classDTMAxisIteratorBase
- Returns:
- The position of the current node within the set, as defined by XPath. Note that this is one-based, not zero-based.
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setMark
public void setMark()Description copied from interface:DTMAxisIterator
Remembers the current node for the next call to gotoMark(). -
gotoMark
public void gotoMark()Description copied from interface:DTMAxisIterator
Restores the current node remembered by setMark().
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