A parsing algorithm which seems to be the most efficient general context-free algorithm known is described. It is similar to both Knuth's LR(k) algorithm and the familiar top-down algorithm. It has a time bound proportional to n3 (where n is the length of the string being parsed) in general; it has an n2 bound for unambiguous grammars; and it runs in linear time on a large class of grammars, which seems to include most practical context-free programming language grammars. In an empirical comparison it appears to be superior to the top-down and bottom-up algorithms studied by Griffiths and Petrick.

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An efficient context-free parsing algorithm

A parsing algorithm which seems to be the most efficient general context-free algorithm known is described. It is similar to both Knuth's LR(k) algorithm and the familiar top-down algorithm. It has...

One of the most fundamental questions in visual language research is how to specify a visual language. By a visual language we mean a set of diagrams which are valid “sentences” in that language where a diagram is a collection of “symbols” in a two or three dimensional space. Which sentences are valid and what their meaning is depends on spatial relationships between the symbols. Thus, for example, mathematical expressions, plans, and musical notation are commonly used visual languages. In this chapter we survey the many formalisms which have been suggested over the last three decades for visual language specification, and also indicate their possible applications.

A survey of visual language specification and recognition

Conjunctive and Boolean grammars: The true general case of the context-free grammars

A syntax-analys is Mgorithm is presented for a language generated by an unambiguous context-free grammar in a number of e lementary operat ions proportional to n = log n, where n is the length of a given string, using a random access memory. The amount of memory required for the a lgor i thm is proport ional to n 2 log n. The proposed algori thm is a modified version of Cocke's a lgor i thm and utilizes a eertair, proper ty of unambiguous normal grammars .

T. Kasami

Papers

A Syntax-Analysis Procedure for Unambiguous Context-Free Grammars