Newsgroups: comp.lang.c++
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!clarkson!grape.ecs.clarkson.edu!cline
From: cline@cheetah.ece.clarkson.edu (Marshall Cline)
Subject: Re: Roskind
Reply-To: cline@sun.soe.clarkson.edu (Marshall Cline)
Organization: (I don't speak for the) ECE Dept, Clarkson Univ, Potsdam, NY
Distribution: comp
Date: 11 Apr 91 15:51:59
Message-ID: <CLINE.91Apr11155159@cheetah.ece.clarkson.edu>
In-Reply-To: cimshop!davidm@uunet.UU.NET's message of 4 Apr 91 18:49:01 GMT
References: <812@llnl.LLNL.GOV> <CIMSHOP!DAVIDM.91Apr4104901@uunet.UU.NET>
Sender: usenet@grape.ecs.clarkson.edu

In article <CIMSHOP!DAVIDM.91Apr4104901@uunet.UU.NET> cimshop!davidm@uunet.UU.NET (David S. Masterson) writes:

> > On 3 Apr 91 18:32:21 GMT, rjshaw@ramius.llnl.gov (Robert Shaw) said:
> > Hi. After building the version of Berkeley yacc from ics.uci.edu, I
> > ran Roskind's grammar through it, and get this out:
> > ./yacc: 25 shift/reduce conflicts, 7 reduce/reduce conflicts.

>Check the documentation with the grammar.  From what I remember of the
>documentation, I believe a certain number of shift/reduce and reduce/reduce
>conflicts are expected and not considered to be a problem.  I also think he
>explains the reasons for the conflicts and possible ways of improving it.

Actually byacc is the problem in this case.
There *used* to be an old version of byacc sitting on one of our sun3's,
and the grammar worked under that, but the new byacc version is a bust.
Apparently byacc has some fprintf's that send junk to stderr in the event
that something unexpected(?) appears in the grammar.
The output Robert Shaw saw is the result.

Unfortunately this (apparently unexercised) part of byacc generates bad
output, since the parser doesn't work unless you use the old byacc.

I guess ``new and improved'' don't always go together.

Marshall Cline
--
PS: If your company is interested in on-site C++/OOD training, drop me a line!
--
Marshall Cline / Asst.Prof / ECE Dept / Clarkson Univ / Potsdam, NY 13676
cline@sun.soe.clarkson.edu / Bitnet:BH0W@CLUTX / uunet!clutx.clarkson.edu!bh0w
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