Elimination of Single Productions from LR Parsers in Conjunction with the Use of Default Reductions

Abstract

One of the most attractive techniques in optimizing LR parsers is to eliminate reductions by semantically insignificant productions of the form A → X (single productions), where X is a nonterminal or a terminal; such a modification can lead to substantial savings in both space and time. Therefore, much effort has been devoted to the development of methods for eliminating reductions by single productions from LR parsers (Aho and Ullman [1973a,1973b], Anderson, Eve and Horning[1973], Pager[1973a,1974], Demers[1974,1975], Backhouse [1976], Joliat[1976], Koskimies[1976], LaLonde [1976], Soisalon-Soininen[1976]).