The Brisk Project: Concurrent and Distributed Functional Systems

The Brisk project has been set up to investigate the possibility of extending the expressive power of purely functional languages. The aim is to be able to build concurrent and distributed working environments completely functionally, reversing the usual situation in which functional programs are regarded as guests within a procedural environment. This paper gives an overview of the project, and the current status of the work in progress. The Bristol Haskell System, or Brisk for short, is based on a compiler for the Haskell functional programming language which is used to provide practical support for this research, and to demonstrate its results. The compiler adds a purely deterministic form of concurrency to Haskell in order to improve support for interactive and distributed programming. This has been used, for example, to build an interface to the X window system. Features have also been added to support the dynamic loading and migration of code. This allows for a purely functional implementation of long-lived shell programs which manage files, processes and communications.