find something clean (not like YYLSP_NEEDED...).
-* URGENT: Documenting C++ output
-Write a first documentation for C++ output.
-
+* Installation
* 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
+Before releasing, make sure the documentation ("Understanding your
+parser") refers to the current `output' format.
-is really weird. Revisit them all.
-
-
-* GLR & C++
-Currently, the GLR parser cannot compile with a C++ compiler.
+* 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 lookahead token, but one is
part of $default. Should we make the two reductions explicit, or just
keep $default? See the following point.
a sample text exhibiting the (LALR) ambiguity. See the paper from
DeRemer and Penello: they already provide the algorithm.
+** Statically check for potential ambiguities in GLR grammars. See
+<http://www.i3s.unice.fr/~schmitz/papers.html#expamb> for an approach.
+
* Extensions
-** yyerror, 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...
+** 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'?
+
-** Several %unions
-I think this is a pleasant (but useless currently) feature, but in the
-future, I want a means to %include other bits of grammars, and _then_
-it will be important for the various bits to define their needs in
-%union.
+** $-1
+We should find a means to provide an access to values deep in the
+stack. For instance, instead of
-When implementing multiple-%union support, bare the following in mind:
+ baz: qux { $$ = $<foo>-1 + $<bar>0 + $1; }
-- when --yacc, this must be flagged as an error. Don't make it fatal
- though.
+we should be able to have:
-- The #line must now appear *inside* the definition of yystype.
- Something like
+ foo($foo) bar($bar) baz($bar): qux($qux) { $baz = $foo + $bar + $qux; }
- {
- #line 12 "foo.y"
- int ival;
- #line 23 "foo.y"
- char *sval;
- }
+Or something like this.
** %if and the like
It should be possible to have %if/%else/%endif. The implementation is
** -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.
-** 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>
-
-Sébastien 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
Paul notes:
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. []
+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. []
+** %token-table
+** Skeleton strategy
+Must we keep %token-table?
* src/print_graph.c
-Find the best graph parameters. []
-
-* doc/bison.texinfo
-** Update
-informations about ERROR_VERBOSE. []
-** Add explanations about
-skeleton muscles. []
-%skeleton. []
-
-* testsuite
-** 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.
+Find the best graph parameters.
* BTYacc
See if we can integrate backtracking in Bison. Charles-Henri de
makes it impossible to have modular precedence information. We should
move to partial orders (sounds like series/parallel orders to me).
-This will be possible with a Bison parser for the grammar, as it will
-make it much easier to extend the grammar.
-
** Correlation b/w precedence and associativity
Also, I fail to understand why we have to assign the same
associativity to operators with the same precedence. For instance,
I was wondering what you think about adding YYACT_PROLOGUE/EPILOGUE
to bison. If you're interested, I'll work on a patch.
-* Move to Graphviz
-Well, VCG seems really dead. Move to Graphviz instead. Also, equip
-the parser with a means to create the (visual) parse tree.
+* Better graphics
+Equip the parser with a means to create the (visual) parse tree.
-----
-Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+Copyright (C) 2001, 2002, 2003, 2004, 2006 Free Software Foundation,
+Inc.
-This file is part of GNU Bison.
+This file is part of Bison, the GNU Compiler Compiler.
-GNU Bison is free software; you can redistribute it and/or modify
+This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
-GNU Bison is distributed in the hope that it will be useful,
+This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
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.
+along with this program. If not, see <http://www.gnu.org/licenses/>.
projects / bison.git / blobdiff