Grammar-based program transformation

A grammar-based technique is introduced for making sweeping changes, involving substantial restructuring, to large-scale software programs. Pervasive structural changes are often required to make changes in data structures, computational forms, or programming style during software maintenance. The concept of a grammar-based editor is introduced. It is a well-defined system that applies the descriptive power of context-free grammars to the software editing problem. Grammars allow generalization away from the specific details of any one program fragment, introducing the possibility for maintainers to browse and edit related program fragments simultaneously and create transformations reusable on other modules or programs. Examples of grammar-based editing of Ada programs are provided