XPointer

Abstract: Publisher Summary This chapter presents the first XPath query evaluation algorithm that runs in polynomial time with respect to the size of both the data and of the query. XPath has been proposed by the W3C as a practical language for selecting nodes from XML document trees. XPath is important because of its potential application as an XML query language per se, it being at the core of several other XML-related technologies, such as XSLT, XPointer, and XQuery, and the great and well-deserved interest such technologies receive. Since XPath and related technologies will be tested in ever-growing deployment scenarios, its implementations need to scale well both with respect to the size of the XML data and the growing size and intricacy of the queries (usually referred to as combined complexity).

Abstract: Methods and apparatus for disseminating over the Internet product information produced and maintained by product manufacturers using existing universal product codes (bar codes) as access keys A cross-referencing resource preferably implemented by the existing Internet Domain Name System (DNS) receives Internet request messages containing all or part of a universal product code value and returns the Internet address at which data or services relating to the identified product, or to the manufacturer of that product, may be obtained By using preferred Web data storage formats and protocol which conform to XML, XLS, XLink, Xpointer, RDF and Web service standards specifications, product and company information may be seamlessly identified, retrieved and integrated with information from other sources A “web register” module can be employed to provide an Internet interface between a shared sales Internet server and an otherwise conventional inventory control system, and operates in conjunction with the cross-referencing server to provide detailed product information to Internet shoppers who may purchase goods from existing stores via the Internet

Abstract: On 7 August 2001, the World Wide Web Consortium (W3C) released version 2.0 of Synchronized Multimedia Integration Language, or SMIL. Three years ago, SMIL 1.0 introduced a basic foundation for Web multimedia and it quickly gained widespread use. With a specification document about 15 times as large as version 1.0, SMIL 2.0 builds on this foundation and marks an enormous step forward in multimedia functionality. Although Web multimedia has long been obtainable with proprietary formats or Java programs, it's been largely inaccessible to most Web authors and isolated from the Web's technical framework. SMIL's HTML-like syntax aims to do for multimedia what HTML did for hypertext: bring it into every living room, with an easy-to-author descriptive format that works with readily available cross-platform players. SMIL lets authors create simple multimedia simply and add, more complex behavior incrementally. But SMIL isn't just HTML-like, it's XML, which makes it part of the W3C's family of XML-related standards including scalable vector graphics (SVG), cascading style sheets (CSS), XPointer, XSLT, namespaces, and XHTML. SMIL's features fall into five categories: media content, layout, timing, linking, and adaptivity. The latter brings altogether new features to the Web, letting authors adapt content to different market groups, user abilities, system configurations, and runtime system delays. The article covers each feature category and its basic constructs using a simple SMIL presentation built with the SMIL 2.0 Language Profile, which is the flagship SMIL-defined language for multimedia browsers.

Abstract: Programming language theorists have developed a number of techniques to formally capture the meaning of programming languages As our epigram insists, these theories are best applied not when a language is too old for help, but when it is aborning and subject to guidance XSLT is a language for transforming XML documents into other XML documents [XSLT] A key element of XSLT is the sub-language of patterns, which is used for matching and selection The pattern language of XSLT has recently evolved into XPath [XPath], a language of selection paths and expressions that performs core functions of both XSLT and XPointer [XPointer] This note presents a formal semantics of the pattern language from the 16 December 1998 draft of XSLT [XSL-Dec98] The semantics is clear and concise, summarizing in one page of formulas what required about ten pages of prose to describe With the aid of the semantics one can rigorously state and prove properties of the language; these properties helped to guide future development of the XSLT design; thus fullfilling Reynolds’s prescription The semantics was developed using standard techniques from the programming language community, and this article provides a tutorial introduction to these techniques While little here will be new to the language theorist, some of what is here may be of use to the markup technologist A formal semantics brings to light issues that can be hard to spot in an english language description For instance, matching is a central concept in XSLT Here is how it was described in [XSL-Dec98]