Actors with Multi-headed Message Receive Patterns

Abstract. The actor model provides high-level concurrency abstractions to coordinate simultaneous computations by message passing. Languages implementing the actor model such as Erlang commonly only support single-headed pattern matching over received messages. We propose and design an extension of Erlang style actors with receive clauses containing multi-headed message patterns. Patterns may be non-linear and constrained by guards. We provide a number of examples to show the usefulness of the extension. We also explore the design space for multi-headed message matching semantics, for example first-match and rule priority-match semantics. The various semantics are inspired by the multi-set constraint matching semantics found in Constraint Handling Rules. This provides us with a formal model to study actors with multiheaded message receive patterns. The system can be implemented efficiently and we have built a prototype as a library-extension to Haskell.

• Type: Conference
• Year: 2008
• Where: COORDINATION
• Authors: Martin Sulzmann, Edmund S. L. Lam, Peter Van Weert
• Keywords: Actor Model, Constraint Matching Semantics, COORDINATION 2008, Distributed And Parallel Computing, Message Matching Semantics