Parallel programming in the intensional language uLucid

Some parallel programming techniques in the intensional functional language uLucid are presented. Programs in uLucid have a kind of implicit parallelism, context parallelism, when the processes that evaluate independent expressions at different contexts are executed in parallel. Communications among the processes that evaluate expressions with dependency relations at different contexts are expressed explicitly by using context switching operators. The function of context switching operators is twofold. From the problem-solving point of view, they are part of the solution described by the program-that is, they have pure mathematical meanings. From the operational point of view, they are communication operators for parallel processes-that is, they have parallel operational meanings. It is shown that one can explicitly express control information about parallelism, communications, among processes, and process-to-processor mappings in uLucid programs by defining context spaces and the associated context switching operators that specify abstract parallel architecture