Heuristic control of design-directed program transformations

This paper describes a class of semantic source-to-source program transformations called design-directed program transformations (DDPT) for use in a transformational implementation (TI) approach to programming. A methodology is developed for applying such transformations based on symbolic evaluation and experimental computation of programs. A DDPT is a cognitive model of source-to-source transformations; it knows what it is trying to accomplish and contains a strategy of how to accomplish it. A DDPT is more than a syntactic pattern replacement rule; it is a semantic program transformation which is intuitively closer to one that a good programmer would invoke in transforming his program.