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At 10:15 AM 9/11/2003, sridhar dongara wrote:
>Hello I a´m doing my master's thesis on Upadting XML.
>
>I have confusion between a TextNode and an AtomicValue as it is specified
>in
><http://www.w3.org/TR/xpath-datamodel/>http://www.w3.org/TR/xpath-datamodel/
A TextNode is a node in a document. An AtomicValue is a value, which is not
a node in a document.
Consider the following:
<foo>5</foo>
This contains a TextNode with the character "5". Now consider the following
expression:
5 * <foo>5</foo>
This evaluates to the AtomicValue 25, which has a value and a type. An
AtomicValue is not found in a document, but a Data Model instance can
contain both nodes and values.
This quote from the XQuery document may be helpful:
>The value of an expression is always a
><http://www.w3.org/TR/xquery/#dt-sequence>sequence.[Definition: A sequence
>is an ordered collection of zero or more
><http://www.w3.org/TR/xquery/#dt-item>items.] [Definition: An item is
>either an <http://www.w3.org/TR/xquery/#dt-atomic-value>atomic value or a
><http://www.w3.org/TR/xquery/#dt-node>node.] [Definition: An atomic value
>is a value in the value space of an XML Schema atomic type, as defined in
><http://www.w3.org/TR/xquery/#XMLSchema>[XML Schema] (that is, a simple
>type that is not a list type or a union type).] [Definition: A node is an
>instance of one of the seven node kinds described in
><http://www.w3.org/TR/xquery/#datamodel>[XQuery 1.0 and XPath 2.0 Data
>Model].] Each node has a unique node identity. Some kinds of nodes have
>typed values, string values, and names, which can be extracted from the
>node. The <http://www.w3.org/TR/xquery/#dt-typed-value>typed value of a
>node is a sequence of zero or more atomic values. The
><http://www.w3.org/TR/xquery/#dt-string-value>string value of a node is a
>value of type xs:string. The name of a node is a value of type xs:QName.
Hope this is helpful,
Jonathan
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