Path: utzoo!attcan!uunet!zephyr.ens.tek.com!tektronix!sequent!mntgfx!lisch From: lisch@mentor.com (Ray Lischner) Newsgroups: comp.lang.perl Subject: Re: patches 19-27 -- # shift/reduce,reduce/reduce conflicts with Bison Message-ID: <1990Aug14.004857.14138@mentor.com> Date: 14 Aug 90 00:48:57 GMT References: <31306@rphroy.UUCP> Distribution: comp Organization: Mentor Graphics Corp., Beaverton, OR Lines: 34 In-reply-to: tkacik@rphroy.uucp's message of 13 Aug 90 13:05:14 GMT > In article , composer@bucsf.bu.edu > (Jeff Kellem) writes: > |> Just so people know what to expect for conflicts in the perl.y grammar if > |> they are using bison 1.11, for perl.y: > > |> Expect 27 shift/reduce and 61 reduce/reduce conflicts... > (Larry reports that yacc produces 59 reduce/reduce conflicts.) > > |> I haven't checked out the grammars to see if these differences will cause > |> problems. But, this is just FYI... > > Regardless of the version of yacc used, (yacc, berkley yacc, bison), the number > of shift/reduce and reduce/reduce conflicts should be the same. Agreed. Here are my results on an Apollo, running Domain/OS 10.3, using Bison 1.11, Corbett's Berkeley Yacc, and Apollo's release of plain, old yacc: % bison -y perl.y conflicts: 27 shift/reduce, 61 reduce/reduce % byacc perl.y byacc: 29 shift/reduce conflicts, 59 reduce/reduce conflicts. % yacc perl.y conflicts: 29 shift/reduce, 59 reduce/reduce > Does anybody know which parser generator has the bug? I don't know, yet. The y.output files from each are sufficiently different to make it difficult to compare. It will take some time... -- Ray Lischner UUCP: {uunet,apollo,decwrl}!mntgfx!lisch