org.exist.xquery.value
Class ValueSequence

java.lang.Object
  org.exist.xquery.value.AbstractSequence
      org.exist.xquery.value.ValueSequence

All Implemented Interfaces:

Sequence

public class ValueSequence
extends AbstractSequence

A sequence that may contain a mixture of atomic values and nodes.

Author:

wolf

Field Summary

Fields inherited from interface org.exist.xquery.value.Sequence

EMPTY_SEQUENCE

Constructor Summary

ValueSequence()

ValueSequence(int initialSize)

ValueSequence(Sequence otherSequence)

Method Summary

void	add(Item item) Add an item to the current sequence.
void	addAll(Sequence otherSequence) Add all items of the other sequence to this item.
void	clear()
void	clearContext(int contextId) For every item in the sequence, clear any context-dependant information that is stored during query processing.
Iterator	getCollectionIterator() Return an iterator on all collections referenced by documents contained in this sequence..
DocumentSet	getDocumentSet() Returns the set of documents from which the node items in this sequence have been selected.
String	getHashKey() Returns a hashKey based on sequence item string values.
int	getItemCount() Returns the number of items contained in the sequence.
int	getItemType() Return the primary type to which all items in this sequence belong.
boolean	hasOne() Returns whether the sequence has just one item or not.
boolean	isEmpty() Returns whether the sequence is empty or not.
boolean	isPersistentSet()
Item	itemAt(int pos) Returns the item located at the specified position within this sequence.
SequenceIterator	iterate() Returns an iterator over all items in the sequence.
void	nodeMoved(NodeId oldNodeId, StoredNode newNode) Node sets may implement this method to be informed of storage address and node id changes after updates.
void	removeDuplicates() Explicitely remove all duplicate nodes from this sequence.
void	setHolderVariable(Variable var)
void	sortInDocumentOrder()
NodeSet	toNodeSet() Makes all in-memory nodes in this sequence persistent, so they can be handled like other node sets.
String	toString()
SequenceIterator	unorderedIterator() Returns an iterator over all items in the sequence.

Methods inherited from class org.exist.xquery.value.AbstractSequence

conversionPreference, convertTo, effectiveBooleanValue, getCardinality, getStringValue, hasMany, isCached, setIsCached, setSelfAsContext, toJavaObject

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ValueSequence

public ValueSequence()

ValueSequence

public ValueSequence(int initialSize)

ValueSequence

public ValueSequence(Sequence otherSequence)
              throws XPathException

Throws:

XPathException

Method Detail

clear

public void clear()

isEmpty

public boolean isEmpty()

Description copied from interface: Sequence

Returns whether the sequence is empty or not.

Specified by:

isEmpty in interface Sequence

Specified by:

isEmpty in class AbstractSequence

Returns:

true is the sequence is empty

hasOne

public boolean hasOne()

Description copied from interface: Sequence

Returns whether the sequence has just one item or not.

Specified by:

hasOne in interface Sequence

Specified by:

hasOne in class AbstractSequence

Returns:

true is the sequence has just one item

add

public void add(Item item)

Description copied from interface: Sequence

Add an item to the current sequence. An XPathException may be thrown if the item's type is incompatible with this type of sequence (e.g. if the sequence is a node set). The sequence may or may not allow duplicate values.

Specified by:

add in interface Sequence

Specified by:

add in class AbstractSequence

addAll

public void addAll(Sequence otherSequence)
            throws XPathException

Description copied from interface: Sequence

Add all items of the other sequence to this item. An XPathException may be thrown if the type of the items in the other sequence is incompatible with the primary type of this sequence.

Specified by:

addAll in interface Sequence

Overrides:

addAll in class AbstractSequence

Throws:

XPathException

getItemType

public int getItemType()

Description copied from interface: Sequence

Return the primary type to which all items in this sequence belong. This is Type.NODE for node sets, Type.ITEM for other sequences with mixed items.

Specified by:

getItemType in interface Sequence

Specified by:

getItemType in class AbstractSequence

Returns:

the primary type of the items in this sequence.

iterate

public SequenceIterator iterate()
                         throws XPathException

Description copied from interface: Sequence

Returns an iterator over all items in the sequence. The items are returned in document order where applicable.

Specified by:

iterate in interface Sequence

Specified by:

iterate in class AbstractSequence

Throws:

XPathException - TODO

unorderedIterator

public SequenceIterator unorderedIterator()

Description copied from interface: Sequence

Returns an iterator over all items in the sequence. The returned items may - but need not - to be in document order.

Specified by:

unorderedIterator in interface Sequence

Specified by:

unorderedIterator in class AbstractSequence

getItemCount

public int getItemCount()

Description copied from interface: Sequence

Returns the number of items contained in the sequence. Call this method only when necessary, since it can be resource consuming.

Specified by:

getItemCount in interface Sequence

Specified by:

getItemCount in class AbstractSequence

Returns:

The number of items in the sequence

itemAt

public Item itemAt(int pos)

Description copied from interface: Sequence

Returns the item located at the specified position within this sequence. Items are counted beginning at 0.

Specified by:

itemAt in interface Sequence

Specified by:

itemAt in class AbstractSequence

setHolderVariable

public void setHolderVariable(Variable var)

toNodeSet

public NodeSet toNodeSet()
                  throws XPathException

Makes all in-memory nodes in this sequence persistent, so they can be handled like other node sets.

Throws:

XPathException - if the sequence contains items which are not nodes.

See Also:

Sequence.toNodeSet()

isPersistentSet

public boolean isPersistentSet()

Specified by:

isPersistentSet in interface Sequence

Overrides:

isPersistentSet in class AbstractSequence

sortInDocumentOrder

public void sortInDocumentOrder()

removeDuplicates

public void removeDuplicates()

Description copied from interface: Sequence

Explicitely remove all duplicate nodes from this sequence.

clearContext

public void clearContext(int contextId)

Description copied from interface: Sequence

For every item in the sequence, clear any context-dependant information that is stored during query processing. This feature is used for node sets, which may store information about their context node.

Specified by:

clearContext in interface Sequence

Overrides:

clearContext in class AbstractSequence

nodeMoved

public void nodeMoved(NodeId oldNodeId,
                      StoredNode newNode)

Description copied from interface: Sequence

Node sets may implement this method to be informed of storage address and node id changes after updates.

Specified by:

nodeMoved in interface Sequence

Overrides:

nodeMoved in class AbstractSequence

See Also:

UpdateListener

getDocumentSet

public DocumentSet getDocumentSet()

Description copied from interface: Sequence

Returns the set of documents from which the node items in this sequence have been selected. This is for internal use only.

Specified by:

getDocumentSet in interface Sequence

Overrides:

getDocumentSet in class AbstractSequence

getCollectionIterator

public Iterator getCollectionIterator()

Description copied from interface: Sequence

Return an iterator on all collections referenced by documents contained in this sequence..

Specified by:

getCollectionIterator in interface Sequence

Overrides:

getCollectionIterator in class AbstractSequence

toString

public String toString()

Overrides:

toString in class AbstractSequence

getHashKey

public String getHashKey()

Returns a hashKey based on sequence item string values. This function is faster than toString() but need to be enhanced. Warning : don't use except for experimental GroupBy clause. author Boris Verhaegen

See Also:

GroupedValueSequenceTable