Package net.sf.saxon.expr
Class ReverseRangeIterator
java.lang.Object
net.sf.saxon.expr.ReverseRangeIterator
- All Implemented Interfaces:
Closeable
,AutoCloseable
,LastPositionFinder
,SequenceIterator
,AtomicIterator<IntegerValue>
,LookaheadIterator
,ReversibleIterator
,UnfailingIterator
public class ReverseRangeIterator
extends Object
implements AtomicIterator<IntegerValue>, ReversibleIterator, LastPositionFinder, LookaheadIterator
Iterator that produces numeric values in a monotonic sequence,
ascending or descending. Although a range expression (N to M) is always
in ascending order, applying the reverse() function will produce
a RangeIterator that works in descending order.
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Nested Class Summary
Nested classes/interfaces inherited from interface net.sf.saxon.om.SequenceIterator
SequenceIterator.Property
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Field Summary
FieldsModifier and TypeFieldDescription(package private) long
(package private) long
(package private) long
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Constructor Summary
ConstructorsConstructorDescriptionReverseRangeIterator
(long start, long end) Create an iterator over a range of integers in monotonic descending order -
Method Summary
Modifier and TypeMethodDescriptionint
Get the last position (that is, the number of items in the sequence).Get properties of this iterator, as a bit-significant integer.Get a new SequenceIterator that returns the same items in reverse order.boolean
hasNext()
Determine whether there are more items to come.next()
Get the next atomic value in the sequence.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
close, forEachOrFail, materialize
Methods inherited from interface net.sf.saxon.tree.iter.UnfailingIterator
forEach, toList
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Field Details
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start
long start -
currentValue
long currentValue -
limit
long limit
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Constructor Details
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ReverseRangeIterator
Create an iterator over a range of integers in monotonic descending order- Parameters:
start
- the first integer to be delivered (the highest in the range)end
- the last integer to be delivered (the lowest in the range). Must be <= start- Throws:
XPathException
- if the values are inconsistent or if the length is greater than 2^31
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Method Details
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hasNext
public boolean hasNext()Description copied from interface:LookaheadIterator
Determine whether there are more items to come. Note that this operation is stateless and it is not necessary (or usual) to call it before calling next(). It is used only when there is an explicit need to tell if we are at the last element.This method must not be called unless the result of getProperties() on the iterator includes the property
SequenceIterator.Property.LOOKAHEAD
- Specified by:
hasNext
in interfaceLookaheadIterator
- Returns:
- true if there are more items in the sequence
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next
Description copied from interface:AtomicIterator
Get the next atomic value in the sequence.- Specified by:
next
in interfaceAtomicIterator<IntegerValue>
- Specified by:
next
in interfaceSequenceIterator
- Specified by:
next
in interfaceUnfailingIterator
- Returns:
- the next Item. If there are no more items, return null.
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getLength
public int getLength()Description copied from interface:LastPositionFinder
Get the last position (that is, the number of items in the sequence). This method is non-destructive: it does not change the state of the iterator. The result is undefined if the next() method of the iterator has already returned null. This method must not be called unless the result of getProperties() on the iterator includes the bit settingSequenceIterator.Property.LAST_POSITION_FINDER
- Specified by:
getLength
in interfaceLastPositionFinder
- Returns:
- the number of items in the sequence
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getProperties
Get properties of this iterator, as a bit-significant integer.- Specified by:
getProperties
in interfaceSequenceIterator
- Returns:
- the properties of this iterator. This will be some combination of
properties such as
SequenceIterator.Property.GROUNDED
,SequenceIterator.Property.LAST_POSITION_FINDER
, andSequenceIterator.Property.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.
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getReverseIterator
Description copied from interface:ReversibleIterator
Get a new SequenceIterator that returns the same items in reverse order. If this SequenceIterator is an AxisIterator, then the returned SequenceIterator must also be an AxisIterator.- Specified by:
getReverseIterator
in interfaceReversibleIterator
- Returns:
- an iterator over the items in reverse order
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