BIDDLE: A BIdirectional Data Driven Lisp Engine

Abstract

The authors propose BIDDLE, a direct execution architecture for Lisp based on both data- and demand-driven principles. A priority queuing mechanism is used to control the parallelism and the workload of the processing elements. Also introduced is a novel mechanism whereby the sequential semantics of Lisp can be enforced in such a way as not to reduce the parallelism too drastically. BIDDLE is, therefore, aimed at achieving a balance between eager and lazy evaluation, sequential semantics, and parallelism. At present, BIDDLE exists only on paper and is a long way from hardware implementation.