A semantics for object-oriented systems

Citeseer

CiteSeerX - Document Details (Isaac Councill, Lee Giles): this document. It is first of all clear that each description of an object that is communicated between agents must contain the class to which the object belongs: an agent simply has to know if an object is a room, a column etc ...

Proceedings of the CERN School of Computing, …, 1986

1996

Abstract The-calculus is given an operational semantics in terms of the SECD machine. This is then extended with built-in operators and new transition rules to produce the-calculus which characterises object-oriented programming languages. Although there are many languages which can be called object-oriented, they are di cult to compare because the operations which provide facilities such as inheritance and message passing are hidden behind linguistic abstractions which make the languages rigid and di cult to modify.

… Methods, 2000. ICFEM 2000. Third IEEE …, 2000

The increasing complexity of software systems makes their development complicated and error prone. A widely used and generally accepted technique in software engineering is the combination of different models (or views) for the description of software systems. The primary benefit ...

Lecture Notes in Computer Science, 1998

In this paper, we present a possible way h o w a precise semantics of objectoriented modeling techniques can be achieved, and what the possible bene ts are. We outline the main modeling techniques used in the SysLab project, sketch, how a precise semantics can be given, and how this semantics can be used during the development process.

Science of Computer Programming, 1989

1997

The Uni ed Modeling Language (UML) builds upon some of the best objectoriented (OO) modeling concepts available, and is intended to serve as a common OO modeling notation. Given its intended role, it is important that the UML notation have a well-de ned semantic base. In this paper we present some early results from our work on the systematic formalization of UML modeling constructs. The paper focuses on the formalization of UML Class Diagrams. The formal notation Z is used to express the semantics of Class Diagrams.

Proceedings 6th World Conference on Integrated …, 2002

This paper deals with formal foundations for a subset of the UML notation (subset of class diagrams and constraints in OCL). There are already various proposals for semantics of UML and a few for OCL. Nevertheless, it is argued that these approaches are not fully adequate for building a conceptual bridge between the programming artifacts produced from UML/OCL and the formal semantics. A different approach is suggested which builds on one hand on the existing work on UML/OCL semantics, and which on the other hand re-introduces ideas, which were discussed for abstract data types under the term "loose semantics". The advantages of this approach are presented and a relationship to the meta-modeling approach is outlined.

We present work on a formal model for the composition of objectoriented modules, or hyperslices, which represent different perspectives on the system being built. With the model, we should be able to study existing approaches such as subject-oriented programming, as well as extend other object-oriented languages, such as the UML, to accommodate the use of hyperslices. We show here a sample of the specification language that accompanies the formal model, and a small example of its use.

Object-Oriented Programming'' and ''Data Abstraction'' have become very common terms. Unfortunately, few people agree on what they mean. I will offer informal definitions that appear to make sense in the context of languages like Ada, C + +, Modula-2, Simula, and Smalltalk. The general idea is to equate ''support for data abstraction'' with the ability to define and use new types and equate ''support for object-oriented programming'' with the ability to express type hierarchies. Features necessary to support these programming styles in a general purpose programming language will be discussed. The presentation centers around C + + but is not limited to facilities provided by that language.

conference proceedings on Object-oriented programming systems, languages, and applications - OOPSLA '92, 1992

We describe our experience with the object-oriented design methodology OMT [19] applied to a project in an undergraduate software engineering course at Carnegie Mellon University. The project involved 30 students previously unfamiliar with objectoriented modeling. They designed and implemented a system of 125 classes (27,000 lines of C++ and C code) in the relatively short time of 15 weeks. We describe the overall structure of the project and the system model, the usefulness of OMT and its impact on communication, and discuss some of the problems encountered during the development of the system.

Software - Concepts and Tools / Structured Programming, 1991

The object oriented paradigm, which advocates bottom-up program development, appears at first sight to run counter to the classical, top-down approach of structured programming. The deep requirement of structured programming, however, is that programming should be based on well-defined abstractions with clear meaning rather than on incidental characteris- tics of computing machinery. This requirement can be met by object oriented

Electronic Notes in Theoretical Computer Science, 2008

Object orientation and component-based development have both proven useful for the elaboration of open distributed systems. These paradigms are offered by the Creol language. Creol objects are concurrent, each with its own virtual processor and internal process control, and communicate using asynchronous (non-blocking) method calls. This provides the efficiency of message passing systems, while keeping the structuring benefits of methods and object-oriented programming. Conditional processor release points provide a high-level synchronization mechanism based on passive waiting that allows us to combine active and reactive behavior. A Creol component can be a single (concurrent) object or a collection of objects, together with a number of interfaces, and cointerfaces, defining the provided and required interaction and semantic behavior. Creol's semantics is defined formally using operational semantics and Hoare logic. An operational semantics lets us simulate an entire system, where all components are known in advance; in contrast, Hoare logic, together with class invariants and communication histories, lets us reason locally about a method body, without needing access to the implementations of the other classes. To bridge the gap between these two semantics, we introduce a history-based operational semantics for open systems. This new semantics can be used as an intermediate step for proving that Creol's Hoare logic is sound and complete with respect to the language's operational semantics. The approach can easily be adapted to other component-based languages where communication is done by message passing or by method interaction.

Electronic Notes in Theoretical Computer Science, 2014

We give a formal definition to a significant subset of the Object Constraint Language (ocl) in the K framework. The chosen subset includes the usual arithmetical, Boolean (including quantifiers), and string expressions; collection expressions (including iterators and navigation); and pre/post conditions for methods. Being executable, our definition provides us, for free, with an interpreter for the chosen subset of ocl. It can be used for free in K definitions of languages having ocl as a component We illustrate some of the advantages of K by comparing our semantical definition of ocl with the official semantics from the language's standard. We also report on a tool implementing our definition that users can try online.