9804662 Mairson, Harry G. Brandeis University CISE PostDoc: Design and Analysis of Symmetric, Hybrid Procedure-Calling Protocols This research has the ultimate goal of increasing the effective functionality of programming languages without sacrificing practical efficiency concerns. To this effect, the PI and Postdoctoral Associate intend to design, analyze, and implement a novel prototype procedure-calling protocol for programming languages, integrating the components of correctness, optimality, and symmetry. A correct implementation never diverges on procedure inputs that are not used; an optimal implementation never ``duplicates work'' by copying unevaluated procedure calls. A symmetric implementation facilitates programming with values and continuations in an identical manner. The fundamental approach carries over to any language that has standard procedure-calling protocols. This hybrid protocol encompasses the best features of call-by-value and call-by-name, together with a facility by which values and control contexts can be manipulated in an entirely dual fashion. The technology that supports the implementation depends on basic ideas from graph reduction, as reinterpreted using very recent new ideas about optimal evaluation. We intend to implement a prototype version of this protocol on top of the Scheme language. Several technical and implementation questions remain to be resolved in order that we may bring this idea from concept to implementation.
