Gisbert Dittrich

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This paper presents a canonical extension of object-oriented development for roles and context-dependent behavior. We syntactically distinguish between classes as natural types and roles as role types. Thereby a class contains roles and their dependencies. The visibility and the access to an object depend on its current role. We develop powerful facilities(More)
This paper presents, explores and compares object-oriented approaches for roles in statically typed programming languages. We choose five solutions which support information hiding. On the one hand, we investigate the established object-oriented possibilities multiple and interface inheritance and the role object pattern, on the other hand, we examine the(More)
It is known that fisheye-views prove beneficial to users who get lost in hyperspace. Until now, the fisheye-view strategy, introduced by Fumas, is only applicable in structures where the necessary components of the fisheye-view function can be defined. Unfortunately, directed graphs are structures where the fisheye-view function of Furnas cannot be applied.(More)
Document structures are a crucial mechanism for the creation and the usability of complex hypermedia documents. They form a possibility to deal with the inherent complexity of such documents and with document structures it is also possible to support the reuse of parts of hypermedia documents. In several theoretical approaches different kinds of document(More)