Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!news.iecc.com!nerds-end From: glen herrmannsfeldt Newsgroups: comp.compilers Subject: Re: bison c-parse.y:1115.19-20: $$ for the midrule at $4 of `structsp' has no declared type Date: Mon, 7 Nov 2011 05:08:00 +0000 (UTC) Organization: Aioe.org NNTP Server Lines: 25 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <11-11-027@comp.compilers> References: <11-10-020@comp.compilers> <11-11-013@comp.compilers> <11-11-022@comp.compilers> <11-11-026@comp.compilers> NNTP-Posting-Host: news.iecc.com X-Trace: leila.iecc.com 1320686960 89003 64.57.183.58 (7 Nov 2011 17:29:20 GMT) X-Complaints-To: abuse@iecc.com NNTP-Posting-Date: Mon, 7 Nov 2011 17:29:20 +0000 (UTC) Keywords: bison, parse Posted-Date: 07 Nov 2011 12:29:20 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: x330-a1.tempe.blueboxinc.net comp.compilers:329 Alessandro Basili wrote: (snip) > That's another key point it worries me a lot. My goal is not to fix the > compiler, but start using it to build my program for the aforementioned > architecture. I would assume the shift/reduce conflicts is resulting > from an incorrect description of the language, but if I can be able to > understand what kind of construct of the language will trigger the > conflict I can probably avoid to use it in my program. Shift/reduce conflicts are not unusual, and not necessarily bad. They often come from ambiguities in the language being parsed, nested if-then-else being a favorite example. In many languages with if-then-else, the else is defined to go with the nearest if, but the syntax description doesn't know that. Specifying that resolves the shift/reduce conflict. Still, it might be worth trying to understand where the conflicts come from to be sure that it is part of the language definition. As I understand it, though, reduce/reduce conflicts are not so usual, and should be considered errors. -- glen