Synchrony vs Asynchrony in Communication Primitives

We study, from the expressiveness point of view, the impact of synchrony in the communication primitives that arise when combining together some common and useful programming features like arity of data, communication medium and possibility of pattern matching. For some primitives, we show how their synchronous version can be encoded in their asynchronous counterpart via a fully abstract encoding, thus proving that the two versions have the same expressive power. For the remaining primitives, we prove that no 'reasonable' encoding can exist, thus proving that synchrony adds expressiveness to the language. © 2007 Elsevier B.V. All rights reserved.