L. Cardelli. Obliq: A language with distributed scope. Technical report, Digital Equipment Corporation, Systems Research Center, Palo Alto, California, June 1994.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....example of asynchronous groupware that can be speci ed in DiCons is a calendar for scheduling a project. Visual Obliq [4] is an environment for designing, programming and running distributed, multi user GUI applications. Its interface builder outputs code in an interpreted language called Obliq [5]. Unlike DiCons, an Obliq application can be distributed over several so called sites on a number of servers. Collaborative Objects Coordination Architecture (COCA) 14] is a generic framework for developing collaborative systems. In COCA, participants are divided into di erent roles, having ....

L. Cardelli. Obliq A language with distributed scope. SRC Research Report 122, Digital Equipment, June 1994.

....in Section 5. In Appendix A we recall briefly the Calculus of (Co)Inductive Constructions CC . Longer listings of Coq code are in Appendix B. 1 Abadi and Cardelli s imp# Calculus The imp# calculus [1, Ch.10,11] is an imperative calculus of objects forming the kernel of the language Obliq [8]. The syntax of imp# is the following (see [1] for an intuitive explanation) T erm : a, b : x variable object clone(a) cloning a.l method invocation a.l #(x)b method update let x = a in b local declaration Notice that let and # bind x in b. The usual conventions about # conversion ....

L. Cardelli. Obliq: A Language with Distributed Scope. Computing Systems, 8(1):27--59, 1995.

....of Coq code are in Appendix B; longer proofs in Appendixes C and D. 1 Abadi and Cardelli s imp# Calculus In this section, we introduce and survey the imp# calculus of Abadi and Cardelli [1, Chapter 10,11] in a nutshell it is an imperative, calculus of objects forming the kernel of the Obliq [8] programming language. Its type inference system is sound in the sense that every well typed object will not invoke methods not declared in its interface. The language of imp# is the following: a, b : x variable object clone(a) cloning a.l method invocation a.l #(x)b method update let ....

L. Cardelli. Obliq: A Language with Distributed Scope. Computing Systems, 8(1):27--59, 1995.

....allows more substantial type checking beyond simple safety properties. Some languages such as PLAN support dynamic scoping of identifiers, such that the unresolved bindings (for services and data) required by a mobile program must be satisfied at the executing site. Other languages such as Obliq [Cardelli94] use lexical scoping, whereby all free bindings must be resolvable at the point when a program fragment is transmitted over the network, and use of those bindings will e#ect remote invocations on objects at the originating site. Such lexical scoping enables a program fragment to see a more ....

Luca Cardelli. Obliq: A Language with Distributed Scope. Technical Report, Compaq (formerly DEC) Systems Research Centre, 1994. (p 31)

....and a standard environment within which FIPA complaint multiagent systems have to be developed. The major advantage derived from adoption of FIPA standards is the interoperability across applications. Other environments for developing and implementing multiagent systems are Telescript [58] Obiq [25], and M0 [121] 2.1.5 Applications of Multiagent Systems It is widely recognized [79] that multiagent systems are suitable to address the solutions of problems that involve open, complex, and ubiquitous systems. Moreover, multiagent systems can improve the solutions of problems, in particular of ....

L. Cardelli. Obliq: A language with distributed scope. Technical report, Digital Equipment Corporation, Systems Research Center, 1995.

....object calculi and they have been extended in various ways, including adding subtyping and polymorphism. The basic calculus has also been extended with encodings of function abstractions and applications, conditionals, numerals, arrays and so on. Cardelli has implemented a language called Obliq [3], which is an untyped objectoriented language with distributed scope. It is based on an imperative object calculus. Obliq objects have state and are local to a site. Obliq computations can roam over a network, while maintaining network connections. The objects are designed to be simple and ....

L Cardelli, Obliq - A Language with Distributed Scope, SRC Research Report 122, Digital, June 1994.

....: 217 msgLoop s ml Alternatively, TClone could have been defined as copying also the current execution state (e.g. the stacks) This, however, leaves the clone waiting for the same events as the original, raising interesting problems in message delivery. Therefore, this simpler, Obliq like [2] definition is used. Finally, frame creation first computes the slots of the new frame from the slot definitions (using the helper function evalslots) and then sends a CreateFrame message to the operating system. As for TClone, execution of the thread is suspended until the return message ....

Cardelli, L. Obliq -- A language with distributed scope. White Paper, Digital, Systems Research Center, March 1994.

.... execution (e.g. drop of bandwidth of a wireless communication link) the application components may dynamically be reallocated to other nodes (runtime adaptivity) The basic concept is described, for instance, in [14, 13] in [4] using the model of Relocatable Dynamic Objects) in [1] (within the definition of the language Obliq) and in [5] based on a combination of Object Fragmentation and Process Migration) However, the important problem of how to partition an application is unsolved [4, 5] In the current proposals, application partitioning schemes are individually ....

....which enables incremental data definition and data reuse data sharing. ffl The prototype based dynamic inheritance mechanism that allows a frame to inherit slots from an arbitrary other frame. This and the previous point also clearly separate frames from static object based models such as Obliq [1]. ffl The availability of type information at runtime enables the handlingof unknown (i.e. created by other users) frame structures. e.g. for creating visualizations, as in Oval [6] Frames therefore provide a dynamic environment that allows the user to flexibly create, augment, and modify ....

Cardelli, L. Obliq -- A languagewith distributed scope. White Paper, Digital, Systems Research Center, March 1994.

....e ective, the assembly of classes should rely on a small set of operators with a clear semantics and should support modular proof techniques. In a concurrency setting, such promises can be rather hard to achieve. The design and the implementation of concurrent object oriented languages, e.g. [2, 20, 1, 4], has recently prompted the investigation of the theoretical foundations of concurrent objects. Several works provide encodings of objects in process calculi [19, 18, 12, 5] or, alternatively, supplement objects with concurrent primitives [16, 3, 11] Those works promote a uni ed framework for ....

L. Cardelli. Obliq A language with distributed scope. SRC Research Report 122, Digital Equipment, June 1994.

....in MOA relies on the system using names that are neither location independent or transparent. If an object was required to change its mechanism of relocation, it would have no means of e#ciently updating all of the location objects that had been cached in the system. 2.2. 5 Obliq Obliq [29,30,94] is an object based language developed by Luca Cardelli. Obliq is a lexically scoped, dynamically typed and interpreted language which is not natively mobile, however objects can be relocated through explicit redirections. Objects can be transmitted across the network through parameter passing in ....

....that may be resident at a place, with no reference to the client object. This form of name sharing is common within mobile and distributed object systems [14, 34, 71, 109] Location independent naming systems are also name sharing systems. One positive side e#ect of shared names, as seen in Obliq [29, 30, 94], is that references can be transmitted and copies freely transmitted to anywhere within the network. Aleph is one of the few systems where names are private. Each name within Aleph consists of a channel map between the client object and the referenced mobile object. Each 6 The forwarding ....

[Article contains additional citation context not shown here]

Luca Cardelli. Obliq: A Language with Distributed Scope. Technical Report SRC Research Report 122, Digital Equipment Corporation Systems Research Center, June 1994.

....of an application from a Web server instead of multiple versions for each computer architecture and operating system combination. These benefits, combined with the pervasiveness of the WWW, have led to the development of several programming languages which can be used to produce mobile code [6, 7, 8, 9]. The most well known and widely supported is Java, developed by Sun Microsystems Inc. 10] Originally designed for embedded logic control in electronic devices, Java has found success on the WWW due to its capability as an ideal environment for the development of secure, distributed, ....

Cardelli, L. "Obliq: A Language with Distributed Scope," Research Report 122, Digital Equipment Corporation Systems Research Center, Palo Alto, CA (1994). On-line document. URL: http://gatekeeper.dec.com/pub/DEC/SRC/research-reports/abstracts/src-rr122. html.

....technologies. Mobile codeprograms which can be transmitted across a network and executed on the client s computermake it possible to deliver digital objects, in either executable or serialized form across the WWW. Several programming languages which can produce mobile code have been developed [4, 32, 33, 34]; the most well known and widely supported is Java [1] Compiled Java code, known as byte code, can be downloaded across the Web to the client where it is executed by a Java Virtual Machine. The Java run time system, incorporated within the Java Virtual Machine, provides an extensive class library ....

CARDELLI, L., "Obliq: A Language with Distributed Scope," Research Report 122, Digital Equipment Corporation Systems Research Center, 1994, On-line document, http://gatekeeper.dec.com/pub/DEC/SRC/research-reports/abstracts/src-rr-122. html.

....and group calendars for scheduling projects. More information on groupware can be found in [Ude99] Visual Obliq [BB94] is an environment for designing, programming and running distributed, multi user GUI applications. Its interface builder outputs code in an interpreted language called Obliq [Car94]. Unlike DiCons applications, Obliq applications do not have to run on one single server: an application can be distributed over several so called sites. After setting up a connection, sites can communicate directly. In this way, an application can be partitioned over different servers. Another ....

L. Cardelli. Obliq: A language with distributed scope. Research Report 122, Digital Equipment Corporation Systems Research Center, 1994.

....An example of asynchronous groupware that can be speci ed in DiCons is a calendar for scheduling a project. Visual Obliq [8] is an environment for designing, programming and running distributed, multiuser GUI applications. Its interface builder outputs code in an interpreted language called Obliq [10]. Unlike DiCons, an Obliq application can be distributed over several so called sites on a number of servers. In [24] Nestmann et al. introduce jeblik, a distribution free subset of Obliq together with three di erent con guration style semantics for this language. COCA [20] is a generic ....

L. Cardelli. Obliq A language with distributed scope. SRC Research Report 122, Digital Equipment, June 1994.

....d 2 inconv [i] par i 2 invitees conf con rmed DiCons select var d : Date Fig. 18. Selection phase Visual Obliq [4] is an environment for designing, programming and running distributed, multi user GUI applications. Its interface builder outputs code in an interpreted language called Obliq [5]. Unlike DiCons, an Obliq application can be distributed over several so called sites on a number of servers. Collaborative Objects Coordination Architecture (COCA) 14] is a generic framework for developing collaborative systems. In COCA, participants are divided into di#erent roles, having ....

L. Cardelli. Obliq A language with distributed scope. SRC Research Report 122, Digital Equipment, June 1994.

....since there is no uniform object store that spans the local and remote site, programmers have to be aware of the implicit copy operations performed on function arguments and results. 4. 2 Remote Execution Engines In higher order languages, remote evaluation [SG90] and remote execution engines [Car94] provide an interesting alternative to the traditional RPC approach described in the previous section. Instead of exporting a fixed set of remote procedures operating on encapsulated state variables, a remote execution engine exports a single, generic higher order execute function that can be ....

....using the meta level interface supplied by Octopus. This model is more general than our binding support for ubiquitous resources, however, it is unclear whether it is suitable for the efficient handling of large scale module libraries. Network objects as found in Modula 3 [BNOW93] Obliq [Car94] Emerald [JLHB88, Jul88] and SOS [SGM89, Sha93] are a particularly attractive programming paradigm for distributed applications. In this model ( transparent object invocation or distributed objects ) a (non persistent) object store may contain network references to objects in a remote store. ....

L. Cardelli. Obliq: A language with distributed scope. Technical report, Digital Equipment Corporation, Systems Research Center, Palo Alto, California, June 1994.

....:Site(Tuple persons :Persons . end) administration :Site(Tuple insertAll( Addresses) Ok . end) Abstracting from the (significant) differences in typing and naming, this programming style is very similar to the one used in Telescript [GM95a] Mole [Hoh95] Facile [Kna95] or Obliq [Card94]. Unfortunately, such a programming style does not scale well to cooperative information systems since it inherits many of the deficiencies described in the previous section: the agent accesses directly through methods (admin.insertAll) or even through unprotected database variables ....

Cardelli, L. Obliq: A Language with Distributed Scope. Technical report, Digital Equipment Corporation, Systems Research Center, Palo Alto, California, June 1994.

No context found.

L. Cardelli. Obliq: A language with distributed scope. Technical report, Digital Equipment Corporation, Systems Research Center, Palo Alto, California, June 1994.

No context found.

Luca Cardelli. Obliq --- A Language with Distributed Scope. Research Report 122, Digital Equipment Corp., Systems Research Center, Palo Alto, CA (June 1994).

No context found.

L. Cardelli. Obliq: a Language with Distributed Scope. Technical report 122, Systems Research Center, Digital Equipment Corporation, 1994.

No context found.

L. Cardelli. Obliq: A Language with Distributed Scope. In Computing Systems, 1995.

No context found.

L. Cardelli. Obliq: A language with distributed scope. Technical report, Digital Equipment Corporation Systems Research Center, 130 Lytton Avenue, Palo Alto, California 94301, USA, Nov. 1994.

No context found.

L. Cardelli. Obliq A language with distributed scope. SRC Research Report 122, Digital Equipment, June 1994.

No context found.

Luca Cardelli. Obliq A Language with Distributed Scope. Technical Report 122, Digital, Systems Research Center, 1994.

No context found.

L. Cardelli. Obliq: A Language with Distributed Scope. Computing Systems, 8(1):27--59, 1995.

First 50 documents  Next 50

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