[mod.compilers] PD yacc

compilers@ima.UUCP (01/07/86)

[from ihnp4!decvax!cwruecmp!bammi (Jwahar R. Bammi)]

I saw people discussing Public Domain compiler tools (wart etc) on
this group. I don't know if it is widely known that a Public domain
Yacc, called Bison is available from the GNU project (free software
foundation). It has two types of parser skeletons, controlled
by the presence of the directive '%semantic_parser'. The default, when
the directive is absent, is a Yacc compatible parser. There is one bug
that I have found. You cannot use the declaration
	%token <type> TERMINAL
	where type is the name of a member of the union type that the
lex. analyser returns. However
	%type <type> non-terminal
	works fine.
Another problem is the lack of documentation, but I guess there will
be some shortly. The version I am using is a few months old. Anyone
know if there has been a newer release?
--------

compilers@ima.UUCP (01/09/86)

[from ]

Organization: Johns Hopkins Univ. Comp. Ctr.
	There have been some changes made to bison since then.  I made a
couple of cosmetic changes to allow some of the "obsolete" features
mentioned in the appendix to the Yacc documentation.  In addition, I
discovered a bug (fixed by Stallman) which caused the grammar to do read
of tokens when it wasn't necessary.  The GNU project should have a copy
of this version of bison.

					Bill Bogstad
					bogstad@hopkins-eecs-bravo.arpa