- All Implemented Interfaces:
- Enclosing class:
public static class ZenoSequence.ZenoSequenceIterator extends java.lang.Object implements GroundedIterator, LastPositionFinder, LookaheadIteratorA SequenceIterator over a ZenoSequence
All Methods Instance Methods Concrete Methods Modifier and Type Method Description
getLength()Get the last position (that is, the number of items in the sequence).
getResidue()Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position.
hasNext()Determine whether there are more items to come.
isActuallyGrounded()Ask if the iterator is actually grounded.
materialize()Create a GroundedValue (a sequence materialized in memory) containing all the values delivered by this SequenceIterator.
next()Get the next item in the sequence.
supportsGetLength()Ask whether this iterator supports use of the
supportsHasNext()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
public ZenoSequenceIterator(ZenoSequence sequence)
public Item next()Description copied from interface:
SequenceIteratorGet the next item in the sequence. This method changes the state of the iterator.
- Specified by:
- 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.
public boolean supportsGetLength()Description copied from interface:
LastPositionFinderAsk whether this iterator supports use of the
LastPositionFinder.getLength()method. This method should always be called before calling
LastPositionFinder.getLength(), because an iterator that implements this interface may support use of
LastPositionFinder.getLength()in some situations and not in others
public int getLength()Description copied from interface:
LastPositionFinderGet 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
LastPositionFinder.supportsGetLength()has been called and has returned true.
public boolean isActuallyGrounded()Ask if the iterator is actually grounded. This method must be called before calling
GroundedIterator.getResidue(), because the iterator might be grounded under some conditions and not others (usually when it delegates to another iterator)
public GroundedValue getResidue()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).
public GroundedValue materialize()Create a GroundedValue (a sequence materialized in memory) containing all the values delivered by this SequenceIterator. The method must only be used when the SequenceIterator is positioned at the start. If it is not positioned at the start, then it is implementation-dependant whether the returned sequence contains all the nodes delivered by the SequenceIterator from the beginning, or only those delivered starting at the current position.
It is implementation-dependant whether this method consumes the SequenceIterator. (More specifically, in the current implementation: if the iterator is backed by a
GroundedValue, then that value is returned and the iterator is not consumed; otherwise, the iterator is consumed and the method returns the remaining items after the current position only).
public boolean supportsHasNext()Description copied from interface:
LookaheadIteratorAsk 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)
public boolean hasNext()Description copied from interface:
LookaheadIteratorDetermine 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