In this paper, we describe AmbientTalk: a domain-specific language for orchestrating service discovery and composition in mobile ad hoc networks. AmbientTalk is a distributed object-oriented programming language whose actor-based, event-driven concurrency model makes it highly suitable for composing service objects across a mobile network. The language is a so-called ambient-oriented programming language which treats network partitions as a normal mode of operation. We describe AmbientTalk's object model, concurrency model and distributed communication model in detail. We also highlight the major influences from other languages and middleware that have shaped AmbientTalk's design.

We describe a linguistic symbiosis between AmbientTalk, a flexible, domain-specific language for writing distributed programs and Java, a conventional object-oriented language. This symbiosis allows concerns related to distribution (service discovery, asynchronous communication, failure handling) to be handled in the domain-specific language, while still enabling the reuse of existing software components written in a conventional language. The symbiosis is novel in the sense that a mapping is defined between the concurrency models of both languages. AmbientTalk employs an inherently event-driven model based on actors, while conventional object-oriented languages employ a concurrency model based on threads. The contribution of this paper is a linguistic symbiosis which ensures that the invariants of the event-driven concurrency model are not violated by engaging in symbiosis with multithreaded programs.

Mirror-based systems are object-oriented reflective architectures built around a set of design principles that lead to reflective APIs which foster a high degree of reusability, loose coupling with base-level objects and whose structure and design corresponds to the system being mirrored. However, support for behavioral intercession has been limited in contemporary mirror-based architectures, in spite of its many interesting applications. This is due to the fact that mirror-based architectures only support explicit reflection, while behavioral intercession requires implicit reflection. This work reconciles mirrors with behavioral intercession. We discuss the design of a mirror-based architecture with implicit mirrors that can be absorbed in the interpreter, and mirages, base objects whose semantics are defined by implicit mirrors. We describe and illustrate the integration of this reflective architecture for the distributed object-oriented programming language AmbientTalk.