net.sf.saxon.s9api

Class XdmValue

Implemented Interfaces:
Iterable
Known Direct Subclasses:
XdmEmptySequence, XdmItem

public class XdmValue
extends java.lang.Object
implements Iterable

An value in the XDM data model. A value is a sequence of zero or more items, each item being either an atomic value or a node.

An XdmValue is immutable.

A sequence consisting of a single item may be represented as an instance of XdmItem, which is a subtype of XdmValue. However, there is no guarantee that a sequence of length one will always be an instance of XdmItem.

Similarly, a zero-length sequence may be represented as an instance of XdmEmptySequence, but there is no guarantee that every sequence of length zero will always be an instance of XdmEmptySequence.

Constructor Summary

XdmValue()
XdmValue(Iterable items)
Create an XdmValue as a sequence of XdmItem objects
XdmValue(ValueRepresentation value)

Method Summary

ValueRepresentation
getUnderlyingValue()
Get the underlying implementation object representing the value.
XdmItem
itemAt(int n)
Get the n'th item in the value, counting from zero.
XdmSequenceIterator
iterator()
Returns an iterator over the items in this value.
protected void
setValue(ValueRepresentation value)
int
size()
Get the number of items in the sequence
protected static XdmValue
wrap(ValueRepresentation value)

Constructor Details

XdmValue

protected XdmValue()

XdmValue

public XdmValue(Iterable items)
Create an XdmValue as a sequence of XdmItem objects
Parameters:
items - a sequence of XdmItem objects. Note that if this is supplied as a list or similar collection, subsequent changes to the list/collection will have no effect on the XdmValue.
Since:
9.0.0.4

XdmValue

protected XdmValue(ValueRepresentation value)

Method Details

getUnderlyingValue

public ValueRepresentation getUnderlyingValue()
Get the underlying implementation object representing the value. This method allows access to lower-level Saxon functionality, including classes and methods that offer no guarantee of stability across releases.
Returns:
the underlying implementation object representing the value

itemAt

public XdmItem itemAt(int n)
            throws IndexOutOfBoundsException,
                   SaxonApiUncheckedException
Get the n'th item in the value, counting from zero.
Parameters:
n - the item that is required, counting the first item in the sequence as item zero
Returns:
the n'th item in the sequence making up the value, counting from zero
Throws:
SaxonApiUncheckedException - if the value is lazily evaluated and the delayed evaluation fails with a dynamic error.

iterator

public XdmSequenceIterator iterator()
            throws SaxonApiUncheckedException
Returns an iterator over the items in this value.
Returns:
an Iterator over the items in this value.
Throws:
SaxonApiUncheckedException - if the value is lazily evaluated and the delayed evaluation fails with a dynamic error.

setValue

protected void setValue(ValueRepresentation value)

size

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

wrap

protected static XdmValue wrap(ValueRepresentation value)