net.sf.saxon.tree.iter

Interface GroundedIterator<T extends Item<?>>

All Superinterfaces:

AutoCloseable, Closeable, SequenceIterator<T>

All Known Implementing Classes:

ArrayIterator, ArrayIterator.OfNodes, EmptyIterator, EmptyIterator.OfAtomic, EmptyIterator.OfNodes, FocusTrackingIterator, ListIterator, ListIterator.Atomic, ListIterator.OfNodes, ManualIterator, MemoSequence.ProgressiveIterator, RangeIterator, SingleAtomicIterator, SingleNodeIterator, SingletonIterator, ValueTailIterator

public interface GroundedIterator<T extends Item<?>>
extends SequenceIterator<T>

This interface is an extension to the SequenceIterator interface; it represents a SequenceIterator that is based on an in-memory representation of a sequence, and that is therefore capable of returning a Sequence containing all the items in the sequence.

We stretch the concept to consider an iterator over a MemoClosure as a grounded iterator, on the basis that the in-memory sequence might exist already or might be created as a side-effect of navigating the iterator. This is why materializing the iterator can raise an exception.

Field Summary

Fields inherited from interface net.sf.saxon.om.SequenceIterator

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Method Summary

Modifier and Type	Method and Description
GroundedValue<T>	getResidue() Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position.
GroundedValue<T>	materialize() Return a GroundedValue containing all the items in the sequence returned by this SequenceIterator.

Methods inherited from interface net.sf.saxon.om.SequenceIterator

close, forEachOrFail, getProperties, next

Method Detail

materialize

GroundedValue<T> materialize()
                      throws XPathException

Return a GroundedValue containing all the items in the sequence returned by this SequenceIterator. 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:

materialize in interface SequenceIterator<T extends Item<?>>

Returns:

the corresponding Value

Throws:

XPathException - in the cases of subclasses (such as the iterator over a MemoClosure) which cause evaluation of expressions while materializing the value.

getResidue

GroundedValue<T> getResidue()
                     throws XPathException

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).

Returns:

the corresponding Value

Throws:

XPathException - in the cases of subclasses (such as the iterator over a MemoClosure) which cause evaluation of expressions while materializing the value.