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 communication constructs found in other process calculi, such as rendezvous communications, which are difficult to implement in a distributed setting.
[, pg. 1] Despite this limitation, the join-calculus is as expressive as the full
Pi-calculus. Encodings of the π-calculus in the join-calculus, and vice versa, have been demonstrated.
The join-calculus is a member of the Pi-calculus family of process calculi, and can be considered, at its core, an asynchronous π-calculus with several strong restrictions:
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Scope restriction, reception, and replicated reception are syntactically merged into a single construct, the definition;
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Communication occurs only on defined names;
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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, and supports statically typed distributed programming, transparent remote communication, agent-based mobility, and some failure-detection.
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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:
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JoCaml is a version of OCaml extended with join-calculus primitives
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Polyphonic C# and its successor Cω extend C#
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MC# and Parallel C# extend Polyphonic C#
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Join Java extends Java
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A Concurrent Basic proposal that uses Join-calculus
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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:
External links
