Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!purdue!gatech!ncsuvx!mcnc!decvax!ima!esegue!compilers-sender
From: naucse!jdc@arizona.edu (John Campbell)
Newsgroups: comp.compilers
Subject: bison/yacc
Message-ID: <1989Aug15.192607.4488@esegue.uucp>
Date: 15 Aug 89 19:26:07 GMT
Sender: compilers-sender@esegue.uucp (John R. Levine)
Reply-To: naucse!jdc@arizona.edu (John Campbell)
Organization: Compilers Central
Lines: 38
Approved: compilers@esegue.segue.bos.ma.us

>Many people are mentioning useful changes to Yacc that they can't
>distribute because of AT&T copyrights. Why not just make the changes
>to Bison, the Free Software Foundation copylefted Yacc clone (which
>generates slightly better parsers besides) and allow your improvements
>to be generally distributed? I am sure that Stallman & Co. at FSF will
>be happy to distribute any usefull contributions that people have
>made.
>
>Perry
>[From perry@snark.bellcore.com (Perry E. Metzger)]

Ah, but have you read bison.simple--there is a nasty copyleft there that
precludes putting this code into anything that isn't freely distributed.
Last time I asked the Gnu people told me this wasn't an oversight, it was
intentional.  

I want to hear more about the DECUS yacc.  Is this a PD yacc that we
have source code to that is not so restrictive?  (Note that the latest
flex made a point in saying that you could do what you would with the
output of flex--even recoup development costs!)
-- 
	John Campbell               ...!arizona!naucse!jdc
                                    CAMPBELL@NAUVAX.bitnet

[Decus yacc was a pirate version of AT&T yacc that Decus (the DEC users'
group) distributed for a while until they realized what it was.  I know of
no PD version of yacc and would be surprised to hear of one considering how
much work is involved; every allegedly PD yacc I've ever seen has turned out
to be a pirate copy of AT&T yacc.  Bison isn't yacc and doesn't claim to be,
but as noted above its parser is subject to Gnu copyleft.  AT&T has given
permission to redistribute the yacc parser and the C libraries as part of
application programs, but yacc itself remains very much AT&T's own.
Followups somewhere else, please, this is getting too far afield of compiler
issues.  -John]
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