An extended LR parsing algorithm for grammars using feature-based syntactic categories

Abstract

This paper proposes an LR parsing algorithm modified for grammars with feature-based categories. The proposed algorithm does not instantiate categories during preprocessing of a grammar as proposed elsewhere.As a result, it constructs a minimal size of GOTO/ACTION table and eliminates the necessity of search for GOTO table entries during parsing.

Example-based optimisation of surface-generation tables

“…Although the sample grammar used throughout the article is essentially context-free, there is nothing in principle that restricts the method to such grammars. In fact, the method could be extended to grammars employing complex feature structures as easily as the LR-parsing scheme itself, see for example (Nakazawa 1991), and this is currently being done. Some hand editing is necessary when preparing the grammar for the inversion step, but it is limited to specifying the ow of arguments in the grammar rules.…”

“…The goto entries, like \g4", simply indicate what state to transit to once a nonterminal of that type has been constructed. In conjunction with grammar formalisms employing complex feature structures, this procedure is associated with a number of interesting problems, many of which are discussed in (Nakazawa 1991) and (Samuelsson 1994c). For example, the termination criterion must be modi ed: If a new set of items is constructed that is more speci c than an existing one, then this search branch is abandoned and the recursion terminates.…”

Computing first and follow functions for feature theoretic grammars

“…The extension to the LR algorithm presented by Nakazawa (1991) uses a similar approach to that described here; the functions involved however are those necessary for the construction of an LR parsing table (i.e. the GOTO and ACTION functions).…”

Notes on LR parser design

“…This problem call I)e solved by using so called "resl;rictors" to block out the feature l)rol)agatioll leading to non-termination, see Ill], hut still the number of items t[lat are slight variants of oneanother may I)e quite large. In her paper [5], Nakazawa proposes a simple and elegant solution to this problem:…”