Package net.sf.saxon.expr
Class ValueTailIterator
java.lang.Object
net.sf.saxon.expr.ValueTailIterator
- All Implemented Interfaces:
Closeable
,AutoCloseable
,SequenceIterator
,GroundedIterator
,LookaheadIterator
public class ValueTailIterator
extends Object
implements SequenceIterator, GroundedIterator, LookaheadIterator
ValueTailIterator
iterates over a base sequence starting at an element other than the first.
It is used in the case where the base sequence is "grounded", that is, it exists in memory and
supports efficient direct addressing.-
Constructor Summary
ConstructorsConstructorDescriptionValueTailIterator
(GroundedValue base, int start) Construct a ValueTailIterator -
Method Summary
Modifier and TypeMethodDescriptionReturn a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position.boolean
hasNext()
Determine whether there are more items to come.boolean
Ask if the iterator is actually grounded.Return a Value containing all the items in the sequence returned by this SequenceIterator.next()
Get the next item in the sequence.boolean
Ask whether the hasNext() method can be called.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
-
ValueTailIterator
Construct a ValueTailIterator- Parameters:
base
- The items to be filteredstart
- The position of the first item to be included (zero-based)
-
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Method Details
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next
Description copied from interface:SequenceIterator
Get the next item in the sequence. This method changes the state of the iterator.- Specified by:
next
in interfaceSequenceIterator
- Returns:
- the next item, or null if there are no more items. Once a call on next() has returned null, no further calls should be made. The preferred action for an iterator if subsequent calls on next() are made is to return null again, and all implementations within Saxon follow this rule.
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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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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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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 interface:GroundedIterator
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
- Returns:
- the corresponding Value
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