RISE-XMLCOMP subproject

Experts predict that every entity found on the web (XML data, software such as applets or 3-tier applications) will be coalesced to active documents (active components, docware). Active documents consist of XML tags with both static and dynamic semantics (see as an example the RXML language of the Swedish Web Service company Roxen). Active documents are structured documents in the spirit of OpenDoc and XML but have a life of their own. They will be able to migrate, they will be shipped everywhere on the web, they will be embedded into other active documents and combined with others visually via drag-and-drop techniques. Active documents will replace desktops, browser clients, 3-tier architectures, and complete applications: everything will be an active document. However, the worlds of web documents and programming languages are still separate: each world develops its own component technology, i.e. component composition does not work uniformly for data and software in active documents. Nevertheless, integration will be inevitable and a common composition technology is needed. The foundations of such a technology have been developed in the EASYCOMP European FET basic research project [UA12, UA13]. However, the project will mainly develop a basic model for XML based compositions. Applications of that model, such as the uniform specification of static and dynamic semantics for XML documents with specification languages should be tackled by the RISE-I project.

Subproject members

Peter Fritzson , subproject leader
Adrian Pop, PhD student

Subproject description

Ontology languages, developed in the Semantic Web, such as DAML, and the new W3C Recommendations Resource Description Framework(RDF) and Web Ontology Language (OWL) provide mechanisms to specify class hierarchies and constraints on the classes. On the other hand, in static semantics of programming languages, Natural Semantics [K87] is one of the most advanced, but still easy to use, specification technologies [PF96]. It has been successfully used for such complex semantic tasks as compiler frontends and additionally allows for the specification of dynamic semantics, i.e. interpreters.
For active documents, specification languages for both static and dynamic semantics will be indispensable. Hence, this work applies Natural Semantics. Since the technology will be integrated with existing languages, such as RDF and OWL, Natural Semantics will be one of the first languages for static and dynamic XML semantics, and an ideal candidate to be included in the family of specification languages of the RuleML initiative .
To summarize: the structure will be specified by XML Schemata, the static semantics by OWL/Natural Semantics and the dynamic semantics by Natural Semantics.
As a case study for the framework, we choosed the Modelica language. Modelica is an object-oriented modeling language designed to allow convenient, component-oriented modeling of complex physical systems, e.g., systems containing mechanical, electrical, electronic, hydraulic, thermal, control, electric power or process-oriented subcomponents. Because the Modelica language is at the border between modeling lanuguages and programming languages it makes an attractive case study.
XML will be used to describe the structure of the Modelica language and OWL/Natural Semantics for certain static semantics. Adapting our Natural Semantics framework to OWL will allow the specification of both static and dynamic semantics of XML documents.

Subproject plan

Subproject status

Publications

Acknowledgment

This subproject is part of the RISE project at PELAB, IDA, Linköpings universitet, and supported by SSF.


Peter Fritzson (petfr@ida.liu.se)