Programmers constantly design, implement, and program in little languages. Two different approaches to the implementation of little languages have evolved. One emphasizes the design of little languages from scratch, using conventional technology to implement interpreters and compilers. The other advances the idea of extending a general-purpose host language; that is, the little language shares the host language’s features (variables, data, loops, functions) where possible; its interpreters and compilers; and even its type soundness theorem. The second approach is often called a language embedding. This paper directs the attention of little language designers to a badly neglected area: the programming environments of little languages. We argue that an embedded little language should inherit not only the host language’s syntactic and semantic structure, but also its programming environment. We illustrate the idea with our DrScheme programming environment and S-XML, a little transformation language for XML trees. DrScheme provides a host of tools for Scheme: a syntax analysis tool, a static debugger, an algebraic stepper, a portable plugin system, and an interactive evaluator. S-XML supports the definition of XML languages using a simple form of schemas, the convenient creation of XML data, and the definition of XML transformations.

This paper presents two standards for communicating mathematical objects between computer programs, for representing these objects on multimedia such as the web, and our experimentation with those standards to develop input and output compliant processors which can be used as basic components to build an effective World Wide Web computational server. 1 Introduction Recent trends in mathematical software include rapid development in computer algebra packages, numerical algorithm libraries and visualization packages. This proliferation has created a need for standard tools that allow the packages to communicate with each other. Since each package has its own strengths and weaknesses, it is desirable to be able to use a particular package for the specific tasks it is good at, and to switch between different packages when necessary. Moreover, the ability to share data between packages allows modular problem solving, where sub-tasks are delegated to specific packages. This eliminates the ...

this document used for what in other documents is named "general rating".

The SELECT protocol allows Internet users to supply their ratings of Internet documents, and to use ratings provided by other users to filter and select what to read In particular, SELECT supports so-called collaborative filtering. By this is meant that the filtering and selection for a particular user is made based on ratings provided by special groups of raters, such as peer groups, people with similar values, interests and expertise as the person for whom the selecting and filtering is done. The SELECT functionality is downwards compatible with PICS [PICS 1, PICS 2], but a major difference is that while PICS is mainly oriented towards keeping out unsuitable information from children (blackballing), SELECT is mainly oriented towards helping people find the best and most valuable information for them on the Internet (goldballing). A syntactical difference from PICS is that the encodings in SELECT are using the XML encoding format. More information More information and links to the mo...

This seminar paper concentrates on XML (Extensible Markup Language) parsers and XSL (Extensible Stylesheet Language) processors. XML parsers are used for reading XML formatted data, either just to ensure that it is properly formed or to store it in the system memory for further processing. XSL processors are used to transform and format XML data to different presentation formats.

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bei multiplen Data-Warehouse-Systemen