A language for specifying program transformations

Large computer programs have to be maintained and hence understood by many different people most of whom are not their original authors. Such programs need to be evaluated and transformed into semantically equivalent but maintainable code. The paper introduces a tool that is designed to work on abstract representations, and directly manipulate them. The proposed tool is capable of performing program transformations based on formal language theory and the abstract program representations (introduced as abstract syntax by McCarthy (1962)). The definition of an abstract program representation is extended to mean a simple view of the program with respect to some program attributes that help us to concentrate on, clarify and simplify our manipulations.