org.exist.xquery.value
Class AbstractSequence

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

All Implemented Interfaces:

Sequence

Direct Known Subclasses:

AbstractNodeSet, EmptySequence, OrderedValueSequence, PreorderedValueSequence, ValueSequence

public abstract class AbstractSequence

extends java.lang.Object

implements Sequence

An abstract implementation of Sequence with default implementations for some methods.

Field Summary

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

EMPTY_SEQUENCE

Constructor Summary

protected

AbstractSequence()

Method Summary

abstract void	add(Item item) Add an item to the current sequence.
void	addAll(Sequence other) Add all items of the other sequence to this item.
void	clearContext(int contextId) For every item in the sequence, clear any context-dependant information that is stored during query processing.
int	conversionPreference(java.lang.Class javaClass) Returns a preference indicator, indicating the preference of a value to be converted into the given Java class.
AtomicValue	convertTo(int requiredType) Try to convert the sequence into an atomic value.
boolean	effectiveBooleanValue() See 2.4.3 Effective Boolean Value
int	getCardinality() Returns the cardinality of this sequence.
DocumentSet	getDocumentSet() Returns the set of documents from which the node items in this sequence have been selected.
abstract int	getItemType() Return the primary type to which all items in this sequence belong.
abstract int	getLength() Returns the number of items contained in the sequence.
java.lang.String	getStringValue() Convert the sequence to a string.
boolean	isCached() Returns true if the sequence is the result of a previous operation and has been cached.
boolean	isPersistentSet()
abstract Item	itemAt(int pos) Returns the item located at the specified position within this sequence.
abstract SequenceIterator	iterate() Returns an iterator over all items in the sequence.
void	setIsCached(boolean cached) Indicates that the sequence is the result of a previous operation and has not been recomputed.
void	setSelfAsContext(int contextId)
java.lang.Object	toJavaObject(java.lang.Class target) Convert the value into an instance of the specified Java class.
java.lang.String	toString()
abstract SequenceIterator	unorderedIterator() Returns an iterator over all items in the sequence.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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

removeDuplicates, toNodeSet

Constructor Detail

AbstractSequence

protected AbstractSequence()

Method Detail

getItemType

public abstract 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

Returns:

the primary type of the items in this sequence.

iterate

public abstract SequenceIterator iterate()

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

Returns:

unorderedIterator

public abstract 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

Returns:

getLength

public abstract int getLength()

Description copied from interface: Sequence

Returns the number of items contained in the sequence.

Specified by:

getLength in interface Sequence

Returns:

getCardinality

public int getCardinality()

Description copied from interface: Sequence

Returns the cardinality of this sequence. The returned value is a combination of flags as defined in Cardinality.

Specified by:

getCardinality in interface Sequence

Returns:

See Also:

Cardinality

convertTo

public AtomicValue convertTo(int requiredType)
                      throws XPathException

Description copied from interface: Sequence

Try to convert the sequence into an atomic value. The target type should be specified by using one of the constants defined in class Type. An XPathException is thrown if the conversion is impossible.

Specified by:

convertTo in interface Sequence

Parameters:

requiredType - one of the type constants defined in class Type

Returns:

Throws:

XPathException

getStringValue

public java.lang.String getStringValue()
                                throws XPathException

Description copied from interface: Sequence

Convert the sequence to a string.

Specified by:

getStringValue in interface Sequence

Returns:

Throws:

XPathException

toString

public java.lang.String toString()

add

public abstract void add(Item item)
                  throws XPathException

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

Parameters:

item -

Throws:

XPathException

addAll

public void addAll(Sequence other)
            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

Parameters:

other -

Throws:

XPathException

itemAt

public abstract 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

Parameters:

pos -

Returns:

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

Returns:

effectiveBooleanValue

public boolean effectiveBooleanValue()
                              throws XPathException

See 2.4.3 Effective Boolean Value

Specified by:

effectiveBooleanValue in interface Sequence

Returns:

Throws:

XPathException

See Also:

Sequence.effectiveBooleanValue()

conversionPreference

public int conversionPreference(java.lang.Class javaClass)

Description copied from interface: Sequence

Returns a preference indicator, indicating the preference of a value to be converted into the given Java class. Low numbers mean that the value can be easily converted into the given class.

Specified by:

conversionPreference in interface Sequence

Parameters:

javaClass -

Returns:

toJavaObject

public java.lang.Object toJavaObject(java.lang.Class target)
                              throws XPathException

Description copied from interface: Sequence

Convert the value into an instance of the specified Java class.

Specified by:

toJavaObject in interface Sequence

Parameters:

target -

Returns:

Throws:

XPathException

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

setSelfAsContext

public void setSelfAsContext(int contextId)

Specified by:

setSelfAsContext in interface Sequence

isCached

public boolean isCached()

Description copied from interface: Sequence

Returns true if the sequence is the result of a previous operation and has been cached.

Specified by:

isCached in interface Sequence

Returns:

setIsCached

public void setIsCached(boolean cached)

Description copied from interface: Sequence

Indicates that the sequence is the result of a previous operation and has not been recomputed.

Specified by:

setIsCached in interface Sequence

Parameters:

cached -

isPersistentSet

public boolean isPersistentSet()

Specified by:

isPersistentSet in interface Sequence