Translation of Attribute Grammars into Procedures

Abstract

An efficient method for evaluating attribute grammars by translating them into sets of procedures is presented.The basic idea behind the method is to consider nonterminal symbols of the grammar as functions that map their inherited attributes to their synthesized attributes.Associated with the nonterminal symbols are procedures that realize the functions.The attribute grammar is translated into a program consisting of these procedures.The essential point about this method is that attribute grammars are completely compiled into procedures, in contrast with evaluation algorithms that work interpretively in a table-driven manner.No information is stored in the nodes of derivation trees.Although this evaluation method is applicable principally to absolutely noncircular attribute grammars in which the dependency relation among attribute occurrences of every production rule does not contain cycles, it is shown how the method is extended to the general noncircular attribute grammars.Problems of evaluating a set of attributes simultaneously and of recursive descent evaluation are also discussed.