Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!ima!johnl From: johnl@ima.UUCP Newsgroups: mod.compilers Subject: Re: advice needed re: parsing C decl syntax Message-ID: <287@ima.UUCP> Date: Tue, 9-Dec-86 12:12:14 EST Article-I.D.: ima.287 Posted: Tue Dec 9 12:12:14 1986 Date-Received: Sun, 14-Dec-86 01:00:48 EST Reply-To: Steve VegdahlLines: 31 Approved: Cc: (Paul Tarvydas) csri!toronto.edu!tarvydas Paul Tarvydas writes: >I'm still reluctant to use a straight LALR table parser for reasons of >(ahem) efficiency. Things like expressions & statements are wonderful >candidates for recursive-descent. > ... >Has anybody successfully married LR parsing with recursive-descent >techniques? Are there any other clean tricks/techniques I could use? At the most recent Compiler Construction Conference (SigPlan notices, July 1986), Thomas Pennello presented a technique for "compiling" the parse-tables directly into (assembly) code, which apparently speeds up the parsing process by a factor of 6-10. >[But I really don't see the point. Yacc certainly has its problems, but >excessively slow parsing has never seemed to be one of them. -John] In his conclusions, Pennello also echoes this opinion: "Trying to speed up an LR parser may seem like beating as dead horse, since LR parsers are already reasonably fast." Still, I think the paper is worth reading. Steve Vegdahl Computer Research Lab Tektronix Labs Beaverton, Oregon -- Send compilers mail to ima!compilers or, in a pinch to Levine@YALE.EDU Plausible paths are { ihnp4 | decvax | cbosgd | harvard | yale | bbncca}!ima Please send responses to the originator of the message -- I cannot forward mail accidentally sent back to compilers. Meta-mail to ima!compilers-request