O'CIAO an object oriented programming model using CIAO Prolog

There have been several previous proposals for the integration of Object Oriented Programming features into Logic Programming, resulting in much support theory and several language proposals. However, none of these proposals seem to have made it into the mainstream. Perhaps one of the reasons for these is that the resulting languages depart too much from the standard logic programming languages to entice the average Prolog programmer. Another reason may be that most of what can be done with object-oriented programming can already be done in Prolog through the meta- and higher-order programming facilities that the language includes, albeit sometimes in a more cumbersome way. In light of this, in this paper we propose an alternative solution which is driven by two main objectives. The first one is to include only those characteristics of object-oriented programming which are cumbersome to implement in standard Prolog systems. The second one is to do this in such a way that there is minimum impact on the syntax and complexity of the language, i.e., to introduce the minimum number of new constructs, declarations, and concepts to be learned. Finally, we would like the implementation to be as straightforward as possible, ideally based on simple source to source expansions

Monitoring-Oriented Programming: A Tool-Supported Methodology for Higher Quality Object-Oriented Software

This paper presents a tool-supported methodological paradigm for object-oriented software development, called monitoring-oriented programming and abbreviated MOP, in which runtime monitoring is a basic software design principle. The general idea underlying MOP is that software developers insert specifications in their code via annotations. Actual monitoring code is automatically synthesized from these annotations before compilation and integrated at appropriate places in the program, according to user-defined configuration attributes. This way, the specification is checked at runtime against the implementation. Moreover, violations and/or validations of specifications can trigger user-defined code at any points in the program, in particular recovery code, outputting or sending messages, or raising exceptions. The MOP paradigm does not promote or enforce any specific formalism to specify requirements: it allows the users to plug-in their favorite or domain-specific specification formalisms via logic plug-in modules. There are two major technical challenges that MOP supporting tools unavoidably face: monitor synthesis and monitor integration. The former is heavily dependent on the specification formalism and comes as part of the corresponding logic plug-in, while the latter is uniform for all specification formalisms and depends only on the target programming language. An experimental prototype tool, called Java-MOP, is also discussed, which currently supports most but not all of the desired MOP features. MOP aims at reducing the gap between formal specification and implementation, by integrating the two and allowing them together to form a system

Structural Constraint-Based Modeling and Reasoning with Basic Configuration Cells

Configuration tasks are an important application area in engineering design. The proposed solving techniques use either a constraintbased framework or a logic-based approach. We propose a methodology to obtains desired configuration using basic configuration cells(BCC). They are built by means of the predefined components and connections of the given configuration problem. In practical applications of configuration tasks the BCCs and configuration goals are represented according to object-oriented programming paradigm. They are mapped into a numeric constraint satisfaction problem. The transformation of a basic configuration cell into a new one generates a sequence of numeric constraint satisfaction problems. We propose an algorithm that solves this sequence of problems in order to obtain a configuration solution according to the desired requirements or that detects inconsistencies in the requirements. The integration of objectoriented and constraint programming paradigms allows us to achieve a synergy that produces results that could not be obtained if each one were working individually

Customisable Handling of Java References in Prolog Programs

Integration techniques for combining programs written in distinct language paradigms facilitate the implementation of specialised modules in the best language for their task. In the case of Java-Prolog integration, a known problem is the proper representation of references to Java objects on the Prolog side. To solve it adequately, multiple dimensions should be considered, including reference representation, opacity of the representation, identity preservation, reference life span, and scope of the inter-language conversion policies. This paper presents an approach that addresses all these dimensions, generalising and building on existing representation patterns of foreign references in Prolog, and taking inspiration from similar inter-language representation techniques found in other domains. Our approach maximises portability by making few assumptions about the Prolog engine interacting with Java (e.g., embedded or executed as an external process). We validate our work by extending JPC, an open-source integration library, with features supporting our approach. Our JPC library is currently compatible with three different open source Prolog engines (SWI, YAP} and XSB) by means of drivers. To appear in Theory and Practice of Logic Programming (TPLP).Comment: 10 pages, 2 figure

Declarative Representation of Programming Access to Ontologies

Abstract. Using ontologies in software applications is a challenging task due to the chasm between the logics-based world of ontologies and the object-oriented world of software applications. The logics-based repre-sentation emphasizes the meaning of concepts and properties, i.e., their semantics. The modeler in the object-oriented paradigm also takes into account the pragmatics, i.e., how the classes are used, by whom, and why. To enable a comprehensive use of logics-based representations in object-oriented software systems, a seamless integration of the two paradigms is needed. However, the pragmatic issues of using logic-based knowledge in object-oriented software applications has yet not been considered suffi-ciently. Rather, the pragmatic issues that arise in using an ontology, e.g., which classes to instantiate in which order, remains a task to be care-fully considered by the application developer. In this paper, we present a declarative representation for designing and applying programming ac-cess to ontologies. Based on this declarative representation, we have build OntoMDE, a model-driven engineering toolkit that we have applied to several example ontologies with different Characteristics.