Maintenance and abstraction of program data using formal transformations

The authors present the DREAM (Data Reverse Engineering and Abstraction Mechanism) method for restructuring program data to meet the changing demands upon it. It is important that data changes are made correctly to avoid undesirable effects on the operation of the program and to minimise effort in maintenance. To facilitate this program transformations are used to manipulate the code, allowing the maintainer to concentrate upon the restructuring strategy without having to worry about the correctness of changes. Restructuring of programs containing discrete types is examined within the paper. This allows work to be focussed upon a small subset of commonly available data types to make development of solutions feasible and to provide a starting point for the development of a generic method which covers other types.