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. Encodings of the π-calculus in the join-calculus, and vice versa, have been demonstrated.
The join-calculus is a member of the
π-calculus 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
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 ...
extended with join-calculus primitives
*
Polyphonic C# and its successor
Cω 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
* 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
Chymystlibraries are in
Scala
JoinHsby Einar Karttunen an
syallop/Join-Languageby 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 Boost
Yigong 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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Process calculi