Package net.sf.saxon.expr
Class AscendingRangeIterator
java.lang.Object
net.sf.saxon.tree.iter.RangeIterator
net.sf.saxon.expr.AscendingRangeIterator
- All Implemented Interfaces:
Closeable
,AutoCloseable
,LastPositionFinder
,SequenceIterator
,AtomicIterator
,GroundedIterator
,LookaheadIterator
,ReversibleIterator
public class AscendingRangeIterator
extends RangeIterator
implements AtomicIterator, ReversibleIterator, LastPositionFinder, LookaheadIterator, GroundedIterator
An Iterator that produces numeric values in a monotonic sequence,
ascending or descending. Applying the reverse() function will produce
a DescendingRangeIterator.
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Constructor Summary
ConstructorsConstructorDescriptionAscendingRangeIterator
(long start, long step, long end) Create an iterator over a range of monotonically increasing integers -
Method Summary
Modifier and TypeMethodDescriptiongetFirst()
getLast()
int
Get the last position (that is, the number of items in the sequence).getMax()
getMin()
Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position.Get a new SequenceIterator that returns the same items in reverse order.getStep()
Get the increment between successive values.boolean
hasNext()
Determine whether there are more items to come.boolean
Ask if the iterator is actually grounded.static AtomicIterator
makeRangeIterator
(IntegerValue start, IntegerValue step, IntegerValue end) Return a Value containing all the items in the sequence returned by this SequenceIterator.next()
Get the next atomic value in the sequence.boolean
Ask whether this iterator supports use of theLastPositionFinder.getLength()
method.boolean
Ask whether the hasNext() method can be called.Methods inherited from class net.sf.saxon.tree.iter.RangeIterator
containsEq
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
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Constructor Details
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AscendingRangeIterator
public AscendingRangeIterator(long start, long step, long end) Create an iterator over a range of monotonically increasing integers- Parameters:
start
- the first integer in the sequencestep
- the increment; must be GT 0end
- the last integer in the sequence. Must be GE start.
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Method Details
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makeRangeIterator
public static AtomicIterator makeRangeIterator(IntegerValue start, IntegerValue step, IntegerValue end) throws XPathException - Throws:
XPathException
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getFirst
- Specified by:
getFirst
in classRangeIterator
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getLast
- Specified by:
getLast
in classRangeIterator
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getMin
- Specified by:
getMin
in classRangeIterator
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getMax
- Specified by:
getMax
in classRangeIterator
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getStep
Get the increment between successive values. For a descending iterator this will be negatiive value.- Specified by:
getStep
in classRangeIterator
- Returns:
- the increment between successive values
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supportsHasNext
public boolean supportsHasNext()Description copied from interface:LookaheadIterator
Ask whether the hasNext() method can be called. This method must be called before calling hasNext(), because some iterators implement this interface, but only support look-ahead under particular circumstances (this is usually because they delegate to another iterator)- Specified by:
supportsHasNext
in interfaceLookaheadIterator
- Returns:
- true if the
LookaheadIterator.hasNext()
method is available
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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
LookaheadIterator.supportsHasNext()
is true.- 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
- Specified by:
next
in interfaceSequenceIterator
- Returns:
- the next Item. If there are no more items, return null.
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isActuallyGrounded
public boolean isActuallyGrounded()Description copied from interface:GroundedIterator
Ask if the iterator is actually grounded. This method must be called before callingGroundedIterator.materialize()
orGroundedIterator.getResidue()
, because the iterator might be grounded under some conditions and not others (usually when it delegates to another iterator)- Specified by:
isActuallyGrounded
in interfaceGroundedIterator
- Returns:
- true if this iterator is grounded
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supportsGetLength
public boolean supportsGetLength()Description copied from interface:LastPositionFinder
Ask whether this iterator supports use of theLastPositionFinder.getLength()
method. This method should always be called before callingLastPositionFinder.getLength()
, because an iterator that implements this interface may support use ofLastPositionFinder.getLength()
in some situations and not in others- Specified by:
supportsGetLength
in interfaceLastPositionFinder
- Returns:
- true if the
LastPositionFinder.getLength()
method can be called to determine the length of the underlying sequence.
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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 theLastPositionFinder.supportsGetLength()
has been called and has returned true.- Specified by:
getLength
in interfaceLastPositionFinder
- Returns:
- the number of items in the sequence
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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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materialize
Return a Value containing all the items in the sequence returned by this SequenceIterator. This should be an "in-memory" value, not a Closure.- Specified by:
materialize
in interfaceGroundedIterator
- Returns:
- the corresponding Value
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getResidue
Description copied from class:RangeIterator
Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position. This should be an "in-memory" value, not a Closure. This method does not change the state of the iterator (in particular, it does not consume the iterator).- Specified by:
getResidue
in interfaceGroundedIterator
- Specified by:
getResidue
in classRangeIterator
- Returns:
- the corresponding Value
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