Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!psuvax1!ukma!xanth!mcnc!decvax!ima!esegue!compilers-sender From: markg@well.sf.ca.us (Mark Grand) Newsgroups: comp.compilers Subject: Re: Error reporting in LR parsers Message-ID: <1989Aug12.201931.4857@esegue.uucp> Date: 12 Aug 89 20:19:31 GMT Sender: compilers-sender@esegue.uucp Reply-To: markg@well.sf.ca.us (Mark Grand) Organization: Whole Earth 'Lectronic Link, Sausalito, CA Lines: 15 Approved: compilers@esegue.segue.bos.ma.us In-Reply-To: <1989Aug8.130702.957@esegue.uucp> Generating a list of acceptable tokens before allowing YACC to perform a default reduction is expensive. A cheaper way (assumimg a fast implementation of memcpy) is to take a snapshot of YACC's state stack every time it gets a new token. That way you can generate a list of the expected tokens from the snapshot and only have to do it when actually needed. -- Mark Grand markg@well.sf.ca.usa GeoMaker Software {apple,pacbell,hplabs,ucbvax}!well!markg P.O. Box 273124 415-680-1964 Concord CA 94527-3124 -- Send compilers articles to compilers@ima.isc.com or, perhaps, Levine@YALE.EDU { decvax | harvard | yale | bbn }!ima. Meta-mail to ima!compilers-request. Please send responses to the author of the message, not the poster.