* data/glr.c (yynewGLRStackItem, YY_RESERVE_GLRSTACK): New.

[bison.git] / TODO

diff --git a/TODO b/TODO
index 56038fc633fe45fe039748ce7fffda704db774a4..a44f64ece477177531dc7e42dd733d5b37d12751 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,62 +1,33 @@
 -*- outline -*-
 
 -*- 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.

 
 

-* Stupid error messages
-An example shows it easily:
+* Yacc.c: CPP Macros

 
 

-src/bison/tests % ./testsuite -k calc,location,error-verbose -l
-GNU Bison 1.49a test suite test groups:
+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...).

 
 

- NUM: FILENAME:LINE      TEST-GROUP-NAME
-      KEYWORDS
-
-  51: calc.at:440        Calculator --locations --yyerror-verbose
-  52: calc.at:442        Calculator --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
-  54: calc.at:445        Calculator --debug --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
-src/bison/tests % ./testsuite 51 -d
-## --------------------------- ##
-## GNU Bison 1.49a test suite. ##
-## --------------------------- ##
- 51: calc.at:440       ok
-## ---------------------------- ##
-## All 1 tests were successful. ##
-## ---------------------------- ##
-src/bison/tests % cd ./testsuite.dir/51
-tests/testsuite.dir/51 % echo "()" | ./calc
-1.2-1.3: parse error, unexpected ')', expecting error or "number" or '-' or '('
-
-
-* 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,
 
 * 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.
 
 part of $default.  Should we make the two reductions explicit, or just
 keep $default?  See the following point.
 


@@ -77,12 +48,49 @@ a sample text exhibiting the (LALR) ambiguity.  See the paper from
 DeRemer and Penello: they already provide the algorithm.
 
 
 DeRemer and Penello: they already provide the algorithm.
 
 

-* Extentions
+* Extensions
+
+** 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; }

 
 

-** yyerror, yysymprint interface
+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
 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
 
 ** Several %unions
 I think this is a pleasant (but useless currently) feature, but in the


@@ -105,6 +113,31 @@ When implementing multiple-%union support, bare the following in mind:
          char *sval;
        }
 
          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
 
 * Unit rules
 Maybe we could expand unit rules, i.e., transform
 


@@ -132,6 +165,25 @@ Are there any Texinfo standards for bibliography?
 
 
 
 
 
 

+* 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>
+
+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
 Paul notes:
 
 * Coding system independence
 Paul notes:


@@ -146,27 +198,19 @@ Paul notes:
        PDP-10 ports :-) but they should probably be documented
        somewhere.
 
        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 ?
 
 * --graph
 Show reductions.       []
 
 * Broken options ?

-** %no-lines           [ok]

 ** %no-parser          []
 ** %no-parser          []

-** %pure-parser                []

 ** %token-table                []
 ** %token-table                []

-** Options which could use parse_dquoted_param ().
-Maybe transfered in lex.c.
-*** %skeleton          [ok]
-*** %output            []
-*** %file-prefix       []
-*** %name-prefix       []
-

 ** Skeleton strategy.  []
 Must we keep %no-parser?
             %token-table?
 ** Skeleton strategy.  []
 Must we keep %no-parser?
             %token-table?

-*** New skeletons.     []

 
 * src/print_graph.c
 Find the best graph parameters.        []
 
 * src/print_graph.c
 Find the best graph parameters.        []


@@ -174,7 +218,7 @@ Find the best graph parameters.     []
 * doc/bison.texinfo
 ** Update
 informations about ERROR_VERBOSE.      []
 * doc/bison.texinfo
 ** Update
 informations about ERROR_VERBOSE.      []

-** Add explainations about
+** Add explanations about

 skeleton muscles.      []
 %skeleton.             []
 
 skeleton muscles.      []
 %skeleton.             []
 


@@ -182,20 +226,19 @@ skeleton muscles. []
 ** tests/pure-parser.at        []
 New tests.
 
 ** 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
 * 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
 to the executables).  Find where the conflicts are preserved.
 
 ** Compare with the GLR tables
 
 ** Keeping the conflicted actions
 First, analyze the differences between byacc and btyacc (I'm referring
 to the executables).  Find where the conflicts are preserved.
 
 ** Compare with the GLR tables

-See how isomorphic the way BTYacc and the way the GLR adjustements in
+See how isomorphic the way BTYacc and the way the GLR adjustments in

 Bison are compatible.  *As much as possible* one should try to use the
 same implementation in the Bison executables.  I insist: it should be
 very feasible to use the very same conflict tables.
 Bison are compatible.  *As much as possible* one should try to use the
 same implementation in the Bison executables.  I insist: it should be
 very feasible to use the very same conflict tables.


@@ -302,7 +345,7 @@ 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 Free Software Foundation, Inc.

 
 This file is part of GNU Bison.
 
 
 This file is part of GNU Bison.
 


@@ -318,5 +361,5 @@ 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
 
 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.