Grammar Re-Engineering for Language Centered Software Engineering

This paper describes a systematic approach to grammar re-engineering by transforming conventional restricted YACC grammars from legacy code into the purely declarative syntax definition formalism SDF. The declarative nature of SDF and its ability to handle the full class of context-free grammars allows grammar definitions that are more readable and maintainable compared to the original YACC grammars. We describe how the resulting SDF grammar and a language centered software engineering approach aid the process of language tool construction. Our method is carried out in an industrial project on a dialect of the specification and description language SDL.