+** YYFAIL
+It is seems to be *really* obsolete now, shall we remove it?
+
+** YYBACKUP
+There is no test about it, no examples in the doc, and I'm not sure
+what it should look like. For instance what follows crashes.
+
+ %error-verbose
+ %debug
+ %pure-parser
+ %code {
+ # include <stdio.h>
+ # include <stdlib.h>
+ # include <assert.h>
+
+ static void yyerror (const char *msg);
+ static int yylex (YYSTYPE *yylval);
+ }
+ %%
+ exp:
+ 'a' { printf ("a: %d\n", $1); }
+ | 'b' { YYBACKUP('a', 123); }
+ ;
+ %%
+ static int
+ yylex (YYSTYPE *yylval)
+ {
+ static char const input[] = "b";
+ static size_t toknum;
+ assert (toknum < sizeof input);
+ *yylval = (toknum + 1) * 10;
+ return input[toknum++];
+ }
+
+ static void
+ yyerror (const char *msg)
+ {
+ fprintf (stderr, "%s\n", msg);
+ }
+
+ int
+ main (void)
+ {
+ yydebug = !!getenv("YYDEBUG");
+ return yyparse ();
+ }
+
+** yychar == yyempty_
+The code in yyerrlab reads:
+
+ if (yychar <= YYEOF)
+ {
+ /* Return failure if at end of input. */
+ if (yychar == YYEOF)
+ YYABORT;
+ }
+
+There are only two yychar that can be <= YYEOF: YYEMPTY and YYEOF.
+But I can't produce the situation where yychar is YYEMPTY here, is it
+really possible? The test suite does not exercise this case.
+
+This shows that it would be interesting to manage to install skeleton
+coverage analysis to the test suite.
+
+** Table definitions
+It should be very easy to factor the definition of the various tables,
+including the separation bw declaration and definition. See for
+instance b4_table_define in lalr1.cc. This way, we could even factor
+C vs. C++ definitions.
+
+* From lalr1.cc to yacc.c
+** Single stack
+Merging the three stacks in lalr1.cc simplified the code, prompted for
+other improvements and also made it faster (probably because memory
+management is performed once instead of three times). I suggest that
+we do the same in yacc.c.
+
+** yysyntax_error
+The code bw glr.c and yacc.c is really alike, we can certainly factor
+some parts.
+
+* Header guards
+
+From Franc,ois: should we keep the directory part in the CPP guard?
+
+
+* 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...).
+
+
+* Installation
+
+* Documentation
+Before releasing, make sure the documentation ("Understanding your
+parser") refers to the current `output' format.
+
+* Report
+
+** Figures
+Some statistics about the grammar and the parser would be useful,
+especially when asking the user to send some information about the
+grammars she is working on. We should probably also include some
+information about the variables (I'm not sure for instance we even
+specify what LR variant was used).
+
+** GLR
+How would Paul like to display the conflicted actions? In particular,
+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.