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Information about Xpointer

XPointer is a system for addressing components of XML based internet media.

At the present time (late 2002), XPointer is divided among four specifications: a "framework" which forms the basis for identifying XML fragments, a positional element addressing scheme, a scheme for namespaces, and a scheme for XPath-based addressing.

The XPointer language is designed to address structural aspects of XML, including text content and other information objects created as a result of parsing the document. Thus, it could be used to point to a section of a document highlighted by a user through a mouse drag action.

XPointer is encumbered by a technology patent held by Sun Microsystems.

Positional Element Addressing

The element() scheme introduces positional addressing of child elements. This is similar to a simple XPath address, but subsequent steps can only be numbers representing the position of a descendant relative to its branch on the tree.

For instance, given the following fragment:



results as the following examples:

xpointer(id("foo")) => foobar xpointer(/foobar/1) => bar xpointer(//bom) => bom (a=1), bom (a=2) xpointer(/1/2/1) => bom (a=1) (/1 descend into first element (foobar), descend into second child element (baz), select first child element (bom))

See also

External links

Extensible Markup Language

File extension: .xml
MIME type: application/xml, text/xml (deprecated)
Uniform Type Identifier: public.xml
Developed by: World Wide Web Consortium
Type of format: Markup language
Extended from: SGML
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A framework is a basic conceptual structure used to solve a complex issue. This very broad definition has allowed the term to be used as a buzzword, especially in a software context.
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Put simply, a "Namespace" is a set of names in which all names are unique.

A namespace is a context in which a group of one or more identifiers might exist. An identifier defined in a namespace is associated with that namespace.
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XPath (XML Path Language) is an expression language for addressing portions of an XML document, or for computing values (strings, numbers, or boolean values) based on the content of an XML document. The current version of the language is XPath 2.0, but because version 1.
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parsing (more formally syntactic analysis) is the process of analyzing a sequence of tokens to determine its grammatical structure with respect to a given formal grammar. A parser is the component of a compiler that carries out this task.
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patent is a set of exclusive rights granted by a state to a patentee for a fixed period of time in exchange for a disclosure of an invention.

The procedure for granting patents, the requirements placed on the patentee and the extent of the exclusive rights vary widely
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Sun Microsystems

Public (NASDAQ:  JAVA )
Founded 1982
Headquarters Santa Clara, California, United States

Key people Scott McNealy, Chairman
Jonathan I.
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In computer hypertext, a fragment identifier is a short string of characters that refers to a resource that is subordinate to another, primary resource. The primary resource is identified by a Uniform Resource Identifier (URI), and the fragment identifier points to the subordinate
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Extensible Markup Language

File extension: .xml
MIME type: application/xml, text/xml (deprecated)
Uniform Type Identifier: public.xml
Developed by: World Wide Web Consortium
Type of format: Markup language
Extended from: SGML
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HTML (Hypertext Markup Language)

File extension: .html, .htm
MIME type: text/html
Type code: TEXT
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HyTime, the Hypermedia/Time-based Structuring Language, is a markup language that is an "application" of SGML. HyTime defines a set of hypertext-oriented element types that, in effect, supplement SGML and allow SGML document authors to build hypertext and multimedia presentations
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The Text Encoding Initiative (TEI) is a consortium of institutions and research projects which collectively maintains and develops a standard for the representation of texts in digital form.
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