Join-calculus
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.[1] 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.[2] 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:[3]
- 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.[4]
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, and supports statically typed distributed programming, transparent remote communication, agent-based mobility, and some failure-detection.[5]
- 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 is a version of OCaml extended with join-calculus primitives
- Polyphonic C# and its successor Cω extend C#
- MC# and Parallel C# extend Polyphonic C#
- Join Java extends Java
- A Concurrent Basic proposal that uses Join-calculus
- JErlang (the J is for Join, erjang is Erlang for the JVM)[6]
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 the Chymyst libraries are in Scala
- JoinHs by Einar Karttunen and 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 in Python 3[7]
- C++ via Boost[8] (for boost from 2009, ca. v. 40, current (Dec '19) is 72).
References
- ↑ Cedric Fournet, Georges Gonthier (1995). The reflexive CHAM and the join-calculus. http://citeseer.ist.psu.edu/fournet95reflexive.html., pg. 1
- ↑ Cedric Fournet, Georges Gonthier (1995). The reflexive CHAM and the join-calculus. http://citeseer.ist.psu.edu/fournet95reflexive.html., pg. 2
- ↑ Cedric Fournet, Georges Gonthier (1995). The reflexive CHAM and the join-calculus. http://citeseer.ist.psu.edu/fournet95reflexive.html., pg. 19
- ↑ Petricek, Tomas. "TryJoinads (IV.) - Concurrency using join calculus". http://tomasp.net/blog/joinads-join-calculus.aspx/.
- ↑ Cedric Fournet, Georges Gonthier (2000). The Join Calculus: A Language for Distributed Mobile Programming. pp. 268–332. https://www.microsoft.com/en-us/research/publication/join-calculus-language-distributed-mobile-programming/.
- ↑ "JErlang: Erlang with Joins". http://www.doc.ic.ac.uk/~susan/jerlang/.
- ↑ Join Python, Join-calculus for Python by Mattias Andree
- ↑ Yigong Liu - Join-Asynchronous Message Coordination and Concurrency Library
External links
- INRIA, Join Calculus homepage
- Microsoft Research, The Join Calculus: a Language for Distributed Mobile Programming
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