Machines for attribute grammars

Two automata models are introduced that play, with respect to attribute grammars and attribute-evaluation for them, the same role as pushdown automata have with respect to context-free grammars and their parsing. It is shown, in fact, that these automata define the same class of string-to-value translations as attribute grammars. Their class of tree-to-value translations seems instead to be larger than that of attribute grammars and the difference is overcome by means of (a special type of) context-free grammar interpretations. An extended model of attribute grammar is presented that is as powerful as the automata with respect to tree-to-value translations