Toward a framework for conceptual and formal outlines of programs

The author proposes the re-documentation of programs with outlines. The interesting feature of outlines is that they allow one to contract, as in a zoom, the amount of information necessary to understand programs, easing the localization of given computations or identification of the role of a piece of code. As a first stage toward a framework of program outlines, she has defined a model suited to the representation of computations performed within loops. The main feature of the outlines is that they are both formal and conceptual: they are represented within frames which are semantically equivalent to the outlined loop and help understanding what is computed by revealing how this is computed. In order to re-document loops, she implemented a system, PRISME, able to automatically construct outlines of a subset of Lisp looping functions. PRISME allowed one to validate the implementation of the model. Currently, she uses it intensively to experiment the role of outlines for debugging and reverse specification of programs