yacc and lex sources

[Len Reed]

In article <BRISTER.90Nov26133944 at westworld.decwrl.dec.com> brister at decwrl.dec.com (James Brister) writes:
>On 26 Nov 90 04:02:49 GMT, n138ct at tamuts.tamu.edu (Brent Burton) said:
>
>> I have flex and bison, but out of curiousity I was wondering if 
>> the soruces for yacc and lex are available....

>I'm sure someone will point it out if I'm wrong :-), but lex and yacc are
>AT&T code that you won't be able to get unless you pay big bucks.

Correct.  Be aware, though, that flex (fast lex) comes from Berkeley is
is owned by the Regents of the U. of Calif.  Berkeley yacc is also available;
it was posted to comp.sources.{unix or misc}.  Both of these programs
have very liberal copyrights: you can do pretty much what you want with
it other than sell it or claim you wrote it.  (Don't quote me on this--get
the copyright yourself and hire a team of laywers to decode it.  :-))

Bison comes from the FSF.  It's free in the sense that it doesn't cost any
money, but it comes with more strings attached.  In particular, I wouldn't
use it to generate anything I intended to sell.

I highly recommended flex as a drop in replacement for lex.  It runs much
faster than lex, generates faster lexers, and has additional useful features.
It even runs on DOS.  I consider it to have made lex obsolete.

I have no corresponding opinions on compiler-compilers.  Bison runs on
DOS; I don't know if Berkeley yacc runs on DOS.  I yacc'ed perl with it
on Xenix 386 after it [B. yacc] was posted, but I continue to use yacc.
-- 
Len Reed
Holos Software, Inc.
Voice: (404) 496-1358
UUCP: ...!gatech!holos0!lbr