-*- outline -*-
-* URGENT: Documenting C++ output
-Write a first documentation for C++ output.
+* Header guards
+From Franc,ois: should we keep the directory part in the CPP guard?
-* Documentation
-Before releasing, make sure the documentation refers to the current
-`output' format.
-
-
-* Error messages
-Some are really funky. For instance
-
- type clash (`%s' `%s') on default action
-is really weird. Revisit them all.
+* Yacc.c: CPP Macros
+Do some people use YYPURE, YYLSP_NEEDED like we do in the test suite?
+They should not: it is not documented. But if they need to, let's
+find something clean (not like YYLSP_NEEDED...).
-* read_pipe.c
-This is not portable to DOS for instance. Implement a more portable
-scheme. Sources of inspiration include GNU diff, and Free Recode.
+* Documentation
+Before releasing, make sure the documentation ("Understanding your
+parser") refers to the current `output' format.
-* value_components_used
-Was defined but not used: where was it coming from? It can't be to
-check if %union is used, since the user is free to $<foo>n on her
-union, doesn't she?
+* lalr1.cc
+** vector
+Move to using vector, drop stack.hh.
+** I18n
+Catch up with yacc.c.
* Report
** GLR
How would Paul like to display the conflicted actions? In particular,
-what when two reductions are possible on a given lookahead, but one is
+what when two reductions are possible on a given look-ahead token, but one is
part of $default. Should we make the two reductions explicit, or just
keep $default? See the following point.
* Extensions
-** yyerror, yysymprint interface
+** Labeling the symbols
+Have a look at the Lemon parser generator: instead of $1, $2 etc. they
+can name the values. This is much more pleasant. For instance:
+
+ exp (res): exp (a) '+' exp (b) { $res = $a + $b; };
+
+I love this. I have been bitten too often by the removal of the
+symbol, and forgetting to shift all the $n to $n-1. If you are
+unlucky, it compiles...
+
+But instead of using $a etc., we can use regular variables. And
+instead of using (), I propose to use `:' (again). Paul suggests
+supporting `->' in addition to `:' to separate LHS and RHS. In other
+words:
+
+ r:exp -> a:exp '+' b:exp { r = a + b; };
+
+That requires an significant improvement of the grammar parser. Using
+GLR would be nice. It also requires that Bison know the type of the
+symbols (which will be useful for %include anyway). So we have some
+time before...
+
+Note that there remains the problem of locations: `@r'?
+
+
+** $-1
+We should find a means to provide an access to values deep in the
+stack. For instance, instead of
+
+ baz: qux { $$ = $<foo>-1 + $<bar>0 + $1; }
+
+we should be able to have:
+
+ foo($foo) bar($bar) baz($bar): qux($qux) { $baz = $foo + $bar + $qux; }
+
+Or something like this.
+
+** yysymprint interface
It should be improved, in particular when using Bison features such as
-locations, and YYPARSE_PARAMS. For the time being, it is recommended
-to #define yyerror and yyprint to steal internal variables...
+locations, and YYPARSE_PARAMS. For the time being, it is almost
+recommended to yyprint to steal internal variables...
** Several %unions
I think this is a pleasant (but useless currently) feature, but in the
char *sval;
}
+** %if and the like
+It should be possible to have %if/%else/%endif. The implementation is
+not clear: should it be lexical or syntactic. Vadim Maslow thinks it
+must be in the scanner: we must not parse what is in a switched off
+part of %if. Akim Demaille thinks it should be in the parser, so as
+to avoid falling into another CPP mistake.
+
+** -D, --define-muscle NAME=VALUE
+To define muscles via cli. Or maybe support directly NAME=VALUE?
+
+** XML Output
+There are couple of available extensions of Bison targeting some XML
+output. Some day we should consider including them. One issue is
+that they seem to be quite orthogonal to the parsing technique, and
+seem to depend mostly on the possibility to have some code triggered
+for each reduction. As a matter of fact, such hooks could also be
+used to generate the yydebug traces. Some generic scheme probably
+exists in there.
+
+XML output for GNU Bison and gcc
+ http://www.cs.may.ie/~jpower/Research/bisonXML/
+
+XML output for GNU Bison
+ http://yaxx.sourceforge.net/
+
* Unit rules
Maybe we could expand unit rules, i.e., transform
* Java, Fortran, etc.
- Add support for languages other than C and C++. Here is a proposed
- patch for Java:
+** Java
+
+There are a couple of proposed outputs:
+
+- BYACC/J
+ which is based on Byacc.
+ <http://troi.lincom-asg.com/~rjamison/byacc/>
+
+- Bison Java
+ which is based on Bison.
<http://www.goice.co.jp/member/mo/hack-progs/bison-java.html>
+Sebastien Serrurier (serrur_s@epita.fr) is working on this: he is
+expected to contact the authors, design the output, and implement it
+into Bison.
* Coding system independence
PDP-10 ports :-) but they should probably be documented
somewhere.
-
+ More importantly, Bison does not currently allow NUL bytes in
+ tokens, either via escapes (e.g., "x\0y") or via a NUL byte in
+ the source code. This should get fixed.
* --graph
Show reductions. []
* Broken options ?
-** %no-lines [ok]
** %no-parser []
-** %pure-parser []
** %token-table []
-** Options which could use parse_dquoted_param ().
-Maybe transferred in lex.c.
-*** %skeleton [ok]
-*** %output []
-*** %file-prefix []
-*** %name-prefix []
-
** Skeleton strategy. []
Must we keep %no-parser?
%token-table?
-*** New skeletons. []
* src/print_graph.c
Find the best graph parameters. []
** tests/pure-parser.at []
New tests.
-* input synclines
-Some users create their foo.y files, and equip them with #line. Bison
-should recognize these, and preserve them.
-
* BTYacc
-See if we can integrate backtracking in Bison. Contact the BTYacc
-maintainers.
+See if we can integrate backtracking in Bison. Charles-Henri de
+Boysson <de-boy_c@epita.fr> is working on this, and already has some
+results. Vadim Maslow, the maintainer of BTYacc was contacted, and we
+stay in touch with him. Adjusting the Bison grammar parser will be
+needed to support some extra BTYacc features. This is less urgent.
** Keeping the conflicted actions
First, analyze the differences between byacc and btyacc (I'm referring
-----
-Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of GNU Bison.
You should have received a copy of the GNU General Public License
along with Bison; see the file COPYING. If not, write to
-the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.
projects / bison.git / blobdiff