A declarative approach to inter-schema mappings

The requirements for the specification of mappings between tools in an integrated and interactive design system are described in this paper. The declarative mapping language, VML, is introduced. VML allows a high level, bidirectional specification of mappings between two arbitrary schemas. To illustrate the utility of VML, a demonstration system consisting of plan definition and code conformance tools is integrated via a common data model using VML mappings. The VML mappings are capable of handling both relational and object-oriented style schemas as well as interactive and batch style design tools. We illustrate the use of VML to specify correspondences between classes, conditional application of correspondences, different styles of equivalence, initialisation conditions as well as method handling for interactive systems.