Cyclic inheritance detection for object-oriented database

[[abstract]]Inheritance is the main theme of schema design for the object-oriented software and object-oriented database. Misuse of inheritance will lead to cyclic inheritance which suffers from redundant classes and endless self-inheritance. For a class hierarchy with cyclic inheritance, to detect all the cyclic inheritances is a NP-complete problem. A graph-theoretical reduction methodology to reduce them in polynomial time is described. An algorithm to support this reduction is presented.[[conferencetype]]國際[[conferencedate]]19921111~19921113[[iscallforpapers]]Y[[conferencelocation]]Melbourne, Vic., Australi

Vers un profil UML pour la conception de composants multivues

International audienceThis paper aims to present an UML profile based on multiviews components. A multiviews component allows to encapsulate and deliver information according to the user's point of view and offers mechanisms to manage the dynamic evolution of viewpoints and consistency among views. In this paper, we first present the notion of multiviews component and its integration into a UML profile, and thus detail an object-oriented multiviews modelling applied to a concrete example. The transition to the coding stage is described through a generic implementation pattern.L' objectif de cet article est de présenter un profil UML permettant la construction de composants logiciels multivues. Un composant multivues est une extension de la notion de composant UML permettant de stocker et restituer de l' information en fonction du profil de l' utilisateur (point de vue), et offrant la possibilité de changement dynamique de point de vue. Dans cet article, nous présentons tout d' abord la notion de classe multivues, puis le composant multivues et son intégration dans un profil UML. Nous illustrons à l' aide d' un exemple concret la mise en oeuvre d' une modélisation objet multivues. La transition vers la phase de codage est présentée à travers un patron d'implémentation générique

Handles: Behavior-Propagating First Class References For Dynamically-Typed Languages

Preprint, Accepted with minor revisionsInternational audienceControlling object graphs and giving specific semantics to references (such as read-only, own- ership, scoped sharing) has been the focus of a large body of research in the context of static type systems. Controlling references to single objects and to graphs of objects is essential to be able to build more secure systems, but is notoriously hard to achieve in absence of static type systems. In this article we embrace this challenge by proposing a solution to the following question: What is the underlying mechanism that can support the definition of properties (such as revocable, read-only, lent) at the reference level in the absence of a static type system? We present handles: first class references that propagate behavioral change dynamically to the object subgraph during program execution. In this article we describe handles and show how handles support the implementation of read-only references and revocable references. Handles have been fully implemented by modifying an existing virtual machine and we report their costs

Handles: Behavior-Propagating First Class References For Dynamically-Typed Languages

International audienceControlling object graphs and giving specific semantics to references (such as read-only, ownership, scoped sharing) have been the focus of a large body of research in the context of static type systems. Controlling references to single objects and to graphs of objects is essential to build more secure systems, but is notoriously hard to achieve in the absence of static type systems. In this article we embrace this challenge by proposing a solution to the following question: What is an underlying mechanism that can support the definition of properties (such as revocable, read-only, lent) at the reference level in the absence of a static type system? We present handles: first-class references that propagate behavioral change dynamically to the object subgraph during program execution. In this article we describe handles and show how handles support the implementation of read-only references and revocable references. Handles have been fully implemented by modifying an existing virtual machine and we report their costs

A UML PROFILES FOR VIEWPOINT-ORIENTED MODELING

The viewpoint-oriented modeling consists in providing an unique model accessible by users with various access rights according to their needs. The system is represented as sub-systems (called sub-models). This cutting makes the design of system easier by an autonomous design of its sub-systems. UML is a standard modeling language and supports extension mechanism to allow tailoring UML to fit the needs of a specific domain. UML Profile is a predefined set of extension mechanisms. UML profile allows the stakeholders of a certain domain to express the semantics of their systems using a well-defined set of xtensions. In this paper we propose an initial discussion on UML profile for viewpoint oriented modeling, which extends the standard UML by incorporating new concepts like views, viewpoints, flexible, visibility relationships, etc

Supporting Explicit Disambiguation of Multi-Methods

Projet RODINMultiple inheritance and multiple dispatching are two sources of ambiguities in object-oriented languages. Solving ambiguities can be performed automatical- ly, using techniques such as totally ordering the supertypes of each type or taking the order of the methods' arguments into account. Such implicit disambiguation has the drawback of being difficult to understand by the programmer and hiding programming errors. Conversely, solving ambiguiti- es can be left up to the explicit intervention of the programmer. The most common explicit disambiguation technique consists in defining new methods for ambiguous invocations. However, finding ambiguities and adding as few methods as possible is a difficult task, especially in multi-method systems. In this paper, we show that there always exists a unique minimal set of method redefinitions to explicitly disambiguate a set of multi-methods. We propose an algorithm to compute the minimal disambiguation set, together with {\em ! explanations}: for each method that is to be added, the programmer is given the set of methods that caused the ambiguity

Handles: Behavior-Propagating First Class References For Dynamically-Typed Languages

Preprint, Accepted with minor revisionsInternational audienceControlling object graphs and giving specific semantics to references (such as read-only, own- ership, scoped sharing) has been the focus of a large body of research in the context of static type systems. Controlling references to single objects and to graphs of objects is essential to be able to build more secure systems, but is notoriously hard to achieve in absence of static type systems. In this article we embrace this challenge by proposing a solution to the following question: What is the underlying mechanism that can support the definition of properties (such as revocable, read-only, lent) at the reference level in the absence of a static type system? We present handles: first class references that propagate behavioral change dynamically to the object subgraph during program execution. In this article we describe handles and show how handles support the implementation of read-only references and revocable references. Handles have been fully implemented by modifying an existing virtual machine and we report their costs

La représentation de points de vue dans le système d'aide à la décision en cancérologie KASIMIR

National audienceDans cet article, nous décrivons la représentation de points de vue dans le système Kasimir d'aide à la décision en cancérologie. Cette mise en oeuvre théorique et pratique des points de vue se place dans la lignée des travaux sur le sujet en représentation des connaissances. Côté théorique, les points de vue sont considérés dans le cadre de la logique de descriptions distribuée C-OWL, qui autorise la représentation et la manipulation explicites de points de vue. Côté pratique, une implantation des points de vue (en C-OWL) dans une application pratique en cancérologie permet de détailler le raisonnement distribué entre les points de vue localement et globalement et montre qu'un nouveau pas est franchi dans la conception de représentation à points de vue multiples