The join-calculus is a process calculus developed at INRIA. The join-calculus was developed to provide a formal basis for the design of distributed programming languages, and therefore intentionally avoids communications constructs found in other process calculi, such as rendezvous communications, which are difficult to implement in a distributed setting. Despite this limitation, the join-calculus is as expressive as the full

π-calculus In theoretical computer science, the -calculus (or pi-calculus) is a process calculus. The -calculus allows channel names to be communicated along the channels themselves, and in this way it is able to describe concurrent computations whose networ ...

. Encodings of the π-calculus in the join-calculus, and vice versa, have been demonstrated. The join-calculus is a member of the

family of process calculi, and can be considered, at its core, an asynchronous π-calculus with several strong restrictions: *Scope restriction, reception, and replicated reception are syntactically merged into a single construct, the ''definition''; *Communication occurs only on defined names; *For every defined name there is exactly one replicated reception. However, as a language for programming, the join-calculus offers at least one convenience over the π-calculus — namely the use of ''multi-way join patterns'', the ability to match against messages from multiple channels simultaneously.

Implementations

Languages based on the join-calculus

The join-calculus programming language is a new language based on the join-calculus process calculus. It is implemented as an interpreter written in

OCaml OCaml ( , formerly Objective Caml) is a general-purpose programming language, general-purpose, multi-paradigm programming language which extends the Caml dialect of ML (programming language), ML with object-oriented programming, object-oriented ...

, and supports statically typed distributed programming, transparent remote communication, agent-based mobility, and some failure-detection. * Though not explicitly based on join-calculus, the rule system of CLIPS implements it if every rule deletes its inputs when triggered (retracts the relevant facts when fired). Many implementations of the join-calculus were made as extensions of existing programming languages: *

JoCaml JoCaml is an experimental functional programming language derived from OCaml. It integrates the primitives of the join-calculus to enable flexible, type-checked concurrent and distributed programming. The current version of JoCaml is a re-imple ...

is a version of

extended with join-calculus primitives * Polyphonic C# and its successor

Cω Cω (pronounced "see omega"; usually written "Cw" or "Comega" whenever the "ω" symbol is not available) is a free extension to the C# programming language, developed by the WebData team in Microsoft SQL Server in collaboration with Microsoft ...

extend C# * MC# and Parallel C# extend Polyphonic C# *

Join Java Join Java is a programming language based on the join-pattern that extends the standard Java programming language with the join semantics of the join-calculus. It was written at the University of South Australia The University of South Aus ...

extends

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

* A Concurrent Basic proposal that uses Join-calculus * JErlang (the J is for Join, erjang is Erlang for the JVM)

Embeddings in other programming languages

These implementations do not change the underlying programming language but introduce join calculus operations through a custom library or DSL: * The ScalaJoins and th
Chymyst
libraries are in Scala
JoinHs
by Einar Karttunen an
syallop/Join-Language
by Samuel Yallop are DSLs for Join calculus in Haskell * Joinads - various implementations of join calculus in F# * CocoaJoin is an experimental implementation in Objective-C for iOS and Mac OS X * The Join Python library is in Python 3 * C++ via BoostYigong Liu - Join-Asynchronous Message Coordination and Concurrency Library
/ref> (for boost from 2009, ca. v. 40, current (Dec '19) is 72).

References

External links

* INRIA
Join Calculus homepage
* Microsoft Research
The Join Calculus: a Language for Distributed Mobile Programming
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