Classical and Incremental Attribute Evaluation by Means of Recursive Procedures

The class of absolutely noncircular (ANC) attribute grammars (AGs) has been heavily studied, mainly because simple and recursive evaluators can be automatically produced for such grammars. We give a characterization of ANC AGs that includes as special cases most of the already existing definitions of this class. Our goal is that of clarifying the relationships among these definitions and also among the evaluators corresponding to them. We show also that for a more restricted class of AGs (the doubly noncircular AGs) recursive incremental evaluators can be constructed in a way very similar to that used for the ANC AGs. © 1987.