P. America, J. de Bakker, J.N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2):152--205, 1989.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....di erent combinations of locally contractive and locally nonexpansive functors, usually given by domain equations. We mention P = fp 0 g [ P cl ( A [ f g) P=2 from [10] P = fp 0 g [ P co ( A [ f g) P=2 from [7] P = fp 0 g [ P cl (Step) 2 where Step = P) Send [ Answer from [2]. The result underpinning these equations, stated in the theorem below, is proven in [1] Theorem 2.9 Let F be a locally contractive functor F : CUMS CUMS Then the domain equation P F(P) has a unique solution up to isomorphism. spt( 6= g since ....

P.H.M. America, J.W. de Bakker, J.N. Kok, and J.J.M.M. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152-205, 1989.

....but to give a general framework in which different concurrent features, like synchronization primitives between active objects or mutual exclusion, can easily be inserted. A formal semantics for a particular parallel O O language in a classical denotational style may be found for example in [ABKR]. In this paper we consider a schema of programming languages. This means that the description of a class includes an implementation part containing method bodies where method is the O O notion which corresponds to the function procedure notion in Pascal like languages. Its semantic counter part ....

America, P.; de Bakker, J.; Kok, J.; Rutten, J. "Denotational semantics of a parallel object-oriented language", Report CS-R8626, Centre for Mathematics and Computer Science, Amsterdam, the Netherlands, August 1986.

....to composite systems of concurrent interacting objects is discussed in [45] Approaches based on set theoretic semantic models, such as Z [94] and CSP [70] can lead to very dicult proofs involving properties of sets and hence axioms for set theory 8 . Denotational semantic models (e.g. [3]) are no better in this respect, and as Abramsky [1] remarks, have only been really successful for functional languages; this should not be surprising, because denotational semantics is so strongly based on the calculus. For the ambitious veri er, settheoretic and denotational semantic de ....

Pierre America, Jaco de Bakker, Joost Kok, and Jan Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2):152-205, 1990.

....in point to point communication is methodological: we want to combine the power of nondeterminism and mobility with the simplicity of point to point reasoning. Although we could have formulated our semantics in a cpo context, we decided to base it on the topological tradition of metric spaces [Niv82, dBZ82, AdBKR89]. Firstly, we wanted to understand the exact relationship between our approach and those based on metric spaces. Secondly, the use of metric spaces seems more natural since our approach is based on infinite streams, and since our pulse drivenness constraint, guaranteeing the existence of a unique ....

P. America, J. de Bakker, J. N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152--205, 1989.

....( MPW92,Wal91] Then the proof that the faithfulness of C is maintained would give us confidence that what we are developing is sensible. Semantics of object oriented languages Two interesting approaches to the denotational semantics of parallel object oriented languages are exhibited in [AdBKR89] and [Wal90] In both cases the source Chapter 7. Conclusions and Future Work 159 language is POOL [Ame89] Let us point out here their weaknesses (in our view) In the former, a heavy mathematical machinery based on category of metric spaces, generalisations of) Banach s theorem is ....

....supplied. Finally, because the calculus is low level , the protocols implementing interactions among different components sometimes are burdensome. We would like to see if it is possible to gain some benefit by using the HO as target language. Higher order sorts would play the role of types in [AdBKR89]. The theory developed for the HO could be employed to reason on the semantic objects. The representation should be more succinct and readable than the one in [Wal90] especially if data are added to the HO as suggested in the previous subsection. As for calculus, using C the two translations ....

P. America, J. de Bakker, J. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2), 1989.

....r is infinite, and the number of elements in r otherwise. Note that time ticks are counted. ha 1 ; a 2 ; a n i denotes the stream of length n whose first element is a 1 , whose second element is a 2 , and so on. hi denotes the empty stream. 1 As a consequence of Banach s fix point theorem [2], since pulse driven functions can be understood as contracting functions in a complete metric space. 5 A c flr denotes the result of filtering away all messages (ticks included) not in A. If A = fdg we write d c flr instead of fdg c flr. For example fa; bg c flha; b; p ; c; p ; a; p i ....

P. America, J. de Bakker, J. N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152--205, 1989.

....Work 30 1 1 Introduction The modelling and design of large object oriented (OO) systems is still a difficult task. Much effort has been put into developing techniques to facilitate the design of such large systems. The behaviour of objects is a continuing topic of research within this effort [ABKR89, Jon93, Dem97, BKS98, Sil99] It is however essential for the design of large, complex models that the behaviour of a collection of objects of the model can be seen as a black box. This black box captures the behaviour of the individual objects while hiding them. This is essential if the ....

P. America, J.W. Bakker, J.N. Kok, and J.J.M.M. Rutten. Denotational semantics of a parallel object-oriented language. In Information and Computation, number 83 in 2, pages 152--205, 1989.

....semantics of inheritance has been investigated by Cook and Palsberg[5] based on Cardelli s work[4] Others [17, 22] have also contributed to the research work on the semantics of OOPLs. The denotational semantics of the parallel object oriented programming language POOL has also been studied in [1]. Our approach to the semantics of OOPLs is quite different. The key idea behind this approach is to use a class to model each language construct of OOPLs. That is, each language construct of OOPLs, such as expressions, statements, methods and classes, and even run time program entities such as ....

P. America, J. de Bakker, J. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2):152-- 205, 1989.

....L with algebraic and coalgebraic structures we can define the linearize and branch operators as the unique morphisms from the initial algebra and to the final coalgebra. Property 5. 4 can also be proved by means of the ffl 1 2 Delta ffl (coinductive) proof principle (see, e.g. page 174 of [ABKR89]) We conclude with some topics for future research. Besides dropping one half of the Hausdorff metric in the definitions of the generalized metrics g L and g B , we can also drop one half of the disjoint union (see Definition A.3) g X ; g Y ) v; w) 8 : g X (v; w) if v, w 2 X ....

P. America, J.W. de Bakker, J.N. Kok, and J.J.M.M. Rutten. Denotational Semantics of a Parallel Object-Oriented Language. Information and Computation, 83(2):152--205, November 1989.

....is imposed semantically. Thus, contrary to for example [SRP91] we do not need additional syntactic constraints to avoid inconsistencies. Although we could have formulated our semantics in a cpo context, we decided to base it on the topological tradition of metric spaces [Niv82, dBZ82, AdBKR89] Firstly, we wanted to understand the exact relationship between our approach and those based on metric spaces. Secondly, the use of metric spaces seems more natural since our approach is based on infinite streams, and since our pulse drivenness constraints strong and weak pulsedrivenness ....

P. America, J. de Bakker, J. N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152--205, 1989.

....( Mil91, Wal91] Then the proof that the faithfulness of C is maintained would give us confidence that what we are developing is sensible. Semantics of object oriented languages Two interesting approaches to the denotational semantics of parallel object oriented languages are exhibited in [AdBKR89] and [Wal90] using metric spaces and by translation into calculus, respectively. In both cases the source language is POOL [Ame89] Let us point out here their weaknesses. In the former, a heavy mathematical machinery, needed to ensure the well definedness of the semantics. In the latter, the ....

....agents defined; and since calculus is low level , the protocols implementing interactions among different components sometimes are burdensome. We would like to see if it is possible to gain some benefit by using the HO as target language. Higher order sorts would play the role of types in [AdBKR89]. The theory developed for the HO could be employed to reason on the semantic objects. The representation should be more succinct and readable than the one in [Wal90] even more if data are added to HO as suggested above. As for calculus, using C the two translations could be compared to see ....

P. America, J. de Bakker, J. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2), 1989.

....autonomes de calcul travaillant en concurrence et communiquant par messages) Ce mod#le est plut#t adapt# # la programmation fonctionnelle. Parmi les langages # objets parall#les, ceux de la famille pool ont #t# d#crits formellement: s#mantique op#rationnelle [2] s#mantique d#notationnelle [3], et calcul [21] La s#mantique d une autre extension parall#le de Eioeel (Concurrent Eioeel) a #t# d# nie de mani#re op#rationnelle dans [12] Une dioe#rence notable entre les deux langages r#side dans le contr#le d ex#cution; il est centralis# pour Eioeel et d#centralis# pour Concurrent ....

America P., de Bakker J., Kok J. N. , and Rutten J. "Denotational Semantics of a Parallel ObjectOriented Language (POOL)", In Information And Computation 83, 152205 (1989).

....from functions to specifications in a straightforward way. 3 Specification Based on the semantic model introduced in the previous section, we may write specifications at several levels of abstraction. Below we give three different specification 1 As a consequence of Banach s fix point theorem [AdBKR89], since pulse driven functions can be understood as contracting functions in a complete metric space. formats. However, first we introduce some useful operators on streams. 3.1 Operators on Streams We also use streams without ticks. We refer to such streams as untimed. Given a set of messages ....

P. America, J. de Bakker, J. N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152--205, 1989.

....model [1, 12] Which helps to explain why many concurrent object oriented languages either are, or claim to be, actor languages. More recently, both operational and denotational semantics have been developed for POOL, based respectively on transition systems [3] and on complete metric spaces [4]. Rewriting logics have been used to provide an operational semantics for Maude [23] with a corresponding denotational semantics based on category theory) Another promising direction is to use process calculi as a semantic foundation for concurrent objectoriented languages. In this case, the ....

P. America, J. de Bakker, J. Kok and J. Rutten, "Denotational Semantics of a Parallel ObjectOriented Language," Information and Computation, vol. 83, no. 2, pp. 152-205, Nov 1989.

....agents [51] More recently, Satoh and Tokoro developed RtCCS [59] a formalism for real time ob ject oriented computing based on ccs. For these dioeerent approaches, sound type sys tems were developed [4, 49, 65, 35] and formal semantics have been described in dioeerent frame works (denotational [6], operational [5, 48, 3, 19] based on the calculus [67] or traces [64] Based on a formal model or not, several concur rent object oriented programming languages have been designed, such as ConcurrentSmalltalk [72] Distributed Smalltalk [11] Hybrid [45] Pool [4] ABCL [68] Eioeel [16] ....

P. America, J. D. Bakker, J. N. Kok, and J. Rut ten. Denotational Semantics of a Parallel Ob ject-Oriented Language (POOL). Information and Computation 83, 152-205, 1989.

....Simple Actor Language (1986) on the other hand, provide a high level specification environment that lacks sufficient formal rigor. The experience with different languages from the POOL family also shows the apparent dilemma the higher the degree of abstraction, the less tractable the semantics (America, de Bakker, Kok and Rutten, 1989; America and van der Linden, 1990) Nevertheless, the need for high level actor languages dealing with sophisticated applications such as natural language understanding, robot control, etc. is evident, e.g. in the work of Shoham (1993) who proposes language constructs that incorporate notions ....

AMERICA, P.; BAKKER, J.; KOK, J. & RUTTEN, J. (1989). Denotational semantics of a parallel objectoriented language. Information and Computation, 83 (2), 152-205.

....to composite systems of concurrent interacting objects is discussed in [45] Approaches based on set theoretic semantic models, such as Z [92] and CSP [69] can lead to very difficult proofs involving properties of sets and hence axioms for set theory 8 . Denotational semantic models (e.g. [3]) are no better in this respect, and as Abramsky [1] remarks, have only been really successful for functional languages; this should not be surprising, because denotational semantics is so strongly based on the calculus. For the ambitious verifier, settheoretic and denotational semantic ....

Pierre America, Jaco de Bakker, Joost Kok, and Jan Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2):152--205, 1990.

....[JK91] develop their DisCo framework as a specification language for object oriented systems. Back et al. BBS97] show how objects are added into Action Oberon, an Oberon like language for parallel programming. The OO action system formalism is related with the object oriented language POOL [ABKR86, ABKR89] because objects are created dynamically, and their name can be assigned to variables. Furthermore, objects are active and distributed, hence, several objects are executed in parallel. The first model incorporating active objects was the actor model [Hew77, Agh86] Moreover, CCS and the calculus, ....

....e.g. by Mikhajlova and Sekerinski [MS97] This is problem is left for future research. Finally, it would be interesting to study both an operational and a denotational semantics of OO action systems without translating them into action systems, using, for example, the work of America et al. [ABKR86, ABKR89]. Acknowledgments The authors are grateful to Robin Milner for his suggestion to use the theory of remote procedures of action systems for objectoriented systems. We would also like to thank Marina Wald en and Jockum von Wright for their comments and several discussions on the contents of this ....

P. America, J.W. de Bakker, J.N. Kok, and J.J.M.M. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2):152--205, 1989.

....in the sequence ha i ; s i i n i=1 for Lemma 5.7. Although the statement of Lemma 5.6 is intuitively clear, we have to prepare for a technically involved proof as we quantify over all statements s and semantical refinements ae 1 and ae 2 . However, the so called 1 2 principle due to [ABKR89], turns out to fit quite well with the definition of D together with weight induction. A simplified form of the principle was already used in the third example following Lemma 3.7. In general this metric technique has the following form: Suppose that the expression x(ff) denotes an element in a ....

P. America, J.W. de Bakker, J.N. Kok, and J.J.M.M. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152--205, 1989.

No context found.

P. America, J. de Bakker, J.N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83(2):152--205, 1989.

No context found.

America, P.H.M., De Bakker, J.W., Kok, J.N., Rutten, J.J.M.M., "Denotational Semantics of parallel object-oriented languages," in Informationand Computation, 83(2), pp. 152-205, 1989.

No context found.

P. America, J. de Bakker, J. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. In ,volume 83, pages 152--205. 1989.

No context found.

P. America, J. de Bakker, J. N. Kok, and J. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation,83, 1989.

No context found.

America, P., Bakker, J.W. de, Kok, J.N., Rutten, J.J.M.M. 1989. Denotational Semantics of a Parallel Object-Oriented Language. Information and Computation, vol. 83(2), pp.

No context found.

P. America, J. W. de Bakker, J. N. Kok, and J. J. M. M. Rutten. Denotational semantics of a parallel object-oriented language. Information and Computation, 83:152205, 1989.

First 50 documents

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC