Object - Oriented Attribute Grammars

This paper introduces object-oriented attribute grammars. These can be characterized as a notation for all classes of attribute grammars. Based on a subtype relation between grammar rules, inheritance of attributes and attribute computations are defined. With this approach, attributes local to grammar rules and the elimination of chain rules are possible without any special constructs. We present object-oriented attribute grammars by a formal definition and by a few typical examples. They are compared to the concepts of related areas. We conclude by sketching an implementation of object-oriented attribute grammars as specification language of an attribute evaluator generator called Ag which processes ordered attribute grammars (OAGs) and higher order attribute grammars (HAGs). A first realistic application showed that the generated attribute evaluators are very efficient and can be used in production quality systems.