net.sf.saxon.s9api
Class XdmEmptySequence

java.lang.Object
  extended by net.sf.saxon.s9api.XdmValue
      extended by net.sf.saxon.s9api.XdmEmptySequence
All Implemented Interfaces:
Iterable<XdmItem>

public class XdmEmptySequence
extends XdmValue

The class XdmEmptySequence represents an empty sequence in the XDM Data Model.

This is a singleton class: there is only one instance, which may be obtained using the getInstance() method.

An empty sequence may also be represented by an XdmValue whose length happens to be zero. Applications should therefore not test to see whether an object is an instance of this class in order to decide whether it is empty.

Note: in interfaces that expect an XdmItem, an empty sequence is represented by a Java null value.


Method Summary
static XdmEmptySequence getInstance()
          Return the singleton instance of this class
 int size()
          Get the number of items in the sequence
 
Methods inherited from class net.sf.saxon.s9api.XdmValue
append, getUnderlyingValue, itemAt, iterator, setValue, wrap
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

getInstance

public static XdmEmptySequence getInstance()
Return the singleton instance of this class

Returns:
an XdmValue representing an empty sequence

size

public int size()
Get the number of items in the sequence

Overrides:
size in class XdmValue
Returns:
the number of items in the value - always zero


Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.