Syntactic source to source transforms and program manipulation
Syntactic transforms are the source to source program transformations which preserve the history of computation, and thus do not modify the execution time. Combined with a small number of primitive semantic transforms, they provide a powerful tool for program manipulation. A complete catalogue of syntactic transforms, and its use for solution of a system of program equations, is given. Examples of derivation of more complex source to source transformations are also presented. Two case studies illustrate the way in which syntactic and semantic source to source transformations may be used for development of clear, simple, and reasonably efficient programs.