jdc@arizona.edu (John Campbell) (08/16/89)
>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] -- Send compilers articles to compilers@ima.isc.com or, perhaps, Levine@YALE.EDU { decvax | harvard | yale | bbn }!ima. Meta-mail to ima!compilers-request. Please send responses to the author of the message, not the poster.
chasm@attctc.Dallas.TX.US (Charles Marslett) (08/19/89)
> [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. ... -John] I don't know if this is approriate, but it does sort-of wrap up the issue. A definitely non-AT&T, non-FSF version of yacc was posted to the minix newsgroup earlier this summer. I have self-compiled the parser, and it seems to be about on a par (size, speed, etc.) with the AT&T and FSF parser generators. The author mentioned that it runs rather slowly, but with a reasonable disk cache, I don't see any significant difference in speed (no more than perhaps 2-1), and the code is reputed to have run on a Z80 system at one time! Charles Marslett chasm@attctc.dallas.tx.us -- Send compilers articles to compilers@ima.isc.com or, perhaps, Levine@YALE.EDU { decvax | harvard | yale | bbn }!ima. Meta-mail to ima!compilers-request. Please send responses to the author of the message, not the poster.