JoCaml is Objective Caml plus (&) the join calculus, that is, OCaml extended for concurrent and distributed programming. The new JoCaml is a re-implementation of the now unmaintained JoCaml by Fabrice Le Fessant. With respect to this previous implementation, main changes are: * Numerous syntax changes, we believe the new syntax to be cleaner. * Disparition of mobility features, sacrified for the sake of OCaml compatibility. * Much better compatibility with Objective Caml. o Source compatibility is about 99%, there are three new keywords (def, reply and spawn) ; or and & should definitely not be used as boolean operators. o Binary compatibility for matching versions.
concurrent paradigm, namely functional programming extended with threads and ports, which I call multi-agent dataflow programming. * The declarative concurrent subset (no ports) has no race conditions and can be programmed like a functional language. The basic concept is dataflow synchronization of single-assignment variables. A useful data structure is the stream, a list with dataflow tail used as a communication channel. * Nondeterminism can be added exactly where needed and minimally, by using ports - a named stream to which any thread can send. * All functional building blocks are concurrency patterns. Map, fold, filter, etc., are all useful for building concurrent programs. * Concurrent systems can be configured in any order and concurrently with actual use of the system. * Designing concurrent programs is any declarative part of the program can be put in own thread, loosening the coupling between system's parts * The paradigm is easily extended
This is an Erlang solution to "The Santa Claus problem", % as discussed by Simon Peyton Jones (with a Haskell solution using % Software Transactional Memory) in "Beautiful code". % He quotes J.A.Trono "A new exercise in concurrency", SIGCSE 26:8-10, 1994.
With the advent of multi-core processors concurrent programming is becoming indispensable. Scala's primary concurrency construct is actors. Actors are basically concurrent processes that communicate by exchanging messages. Actors can also be seen as a form of active objects where invoking a method corresponds to sending a message. The Scala Actors library provides both asynchronous and synchronous message sends (the latter are implemented by exchanging several asynchronous messages). Moreover, actors may communicate using futures where requests are handled asynchronously, but return a representation (the future) that allows to await the reply. This tutorial is mainly designed as a walk-through of several complete example programs Our first example consists of two actors that exchange a bunch of messages and then terminate. The first actor sends "ping" messages to the second actor, which in turn sends "pong" messages back (for each received "ping" message one "pong" message).