An Object Data Model with Roles

摘要

Fibonacci is a strongly typed, object-oriented database programming language with a new mechanism to model objects with roles. Traditional object-oriented programming languages do not have the possibility of changing dynamically the type of an object to model the behaviour of real world entities which change their status over lime. This is a severe limitation in the context of a database programming language. Moreover, traditional objcct-oriented languages do not model the fact that the behaviour of real world entities may depend on the role that they play. We propose a mechanism to face both problems in the contcxt of a statically strongly typed object-oriented database programming language. We show that the two problems arc strictly related and can be solved without giving up the most useful features of object-oriented programming, namely: inheritance, late binding and encapsulation. Examples will be given referring to the prototype implementation of the language.