An experiment in abstract machine design

In this article we present Typed Feature Structures as an extension of Prolog, and show how to come up with a compilation scheme and an abstract machine using a design methodology based on partial evaluation. First we define the transformations used by our partial evaluator. Then we present the design methodology which we will use later. Next, we clarify the notion of Typed Feature Structures that underlies our work, and formally define the unification of such structures. Based on this definition, we develop a unification procedure with explicit heap representation. By partially evaluating this procedure with respect to some example programs, we show how to come up with the machine instructions and translation schemes. Finally, we briefly address coreferences, cyclic structures and the unification of types.