* data/lalr1.cc: Move the body of the ctor and dtor into the

[bison.git] / TODO

diff --git a/TODO b/TODO
index 7b4b7fd420bb3a998afec3b544308ee03493b4f9..a44f64ece477177531dc7e42dd733d5b37d12751 100644 (file)
--- a/TODO
+++ b/TODO
@@ -12,24 +12,22 @@ They should not: it is not documented.  But if they need to, let's
 find something clean (not like YYLSP_NEEDED...).
 
 
-* URGENT: Documenting C++ output
-Write a first documentation for C++ output.
-
-
 * Documentation
-Before releasing, make sure the documentation refers to the current
-`output' format.
-
+Before releasing, make sure the documentation ("Understanding your
+parser") refers to the current `output' format.
 
-* 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 look-ahead token, but one is
 part of $default.  Should we make the two reductions explicit, or just
 keep $default?  See the following point.
 
@@ -52,10 +50,47 @@ DeRemer and Penello: they already provide the algorithm.
 
 * 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
@@ -88,6 +123,20 @@ 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
@@ -131,7 +180,7 @@ There are a couple of proposed outputs:
   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
+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.
 
@@ -149,7 +198,9 @@ 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.       []
@@ -294,7 +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.
 
@@ -310,5 +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
-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.