Efficient parallel and incremental parsing of practical context-free languages
Artikel i vetenskaplig tidskrift, 2015

We present a divide-and-conquer algorithm for parsing context-free languages efficiently. Our algorithm is an instance of Valiant's (1975; General context-free recognition in less than cubic time. J. Comput. Syst. Sci. 10(2), 308-314), who reduced the problem of parsing to matrix multiplications. We show that, while the conquer step of Valiant's is O(n(3)), it improves to O(log(2) n) under certain conditions satisfied by many useful inputs that occur in practice, and if one uses a sparse representation of matrices. The improvement happens because the multiplications involve an overwhelming majority of empty matrices. This result is relevant to modern computing: divide-and-conquer algorithms with a polylogarithmic conquer step can be parallelized relatively easily.

Författare

Jean-Philippe Bernardy

Chalmers, Data- och informationsteknik, Programvaruteknik

Koen Lindström Claessen

Chalmers, Data- och informationsteknik, Programvaruteknik

Journal of Functional Programming

0956-7968 (ISSN) 1469-7653 (eISSN)

Vol. 25 Article Number: UNSP e10-

Ämneskategorier

Data- och informationsvetenskap

DOI

10.1017/s0956796815000131

Mer information

Skapat

2017-10-08