Support for extensibility and reusability in a concurrent object-oriented programming language

In many concurrent programming languages programs are difficult to extend and modify. This is because changes in a concurrent program (either through modification or extension) require re-implementation of some or all components. This paper presents the design of a concurrent object-oriented programming language based upon separate specifications of computations and interactions of programs. Separate specification of computations and interactions allows each to be separately modified and extended. We show that separation also facilitates extension of other language composition mechanisms such as class, inheritance, and template in order to define concurrent program abstractions. The resulting language supports extensibility and modifiability of concurrent programs as well as reusability of specifications of computations and interactions