X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/34136e65fc7bd6babcfedcbfcfdca3b9feb10f1d..16d94f45c9be6a569147fa160993ffe41f8b0b2f:/TODO

diff --git a/TODO b/TODO
index addd135d..588bf468 100644
--- a/TODO
+++ b/TODO
@@ -118,50 +118,6 @@ so both 256 and 257 are "mysterious".
 ** 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:
 
@@ -251,31 +207,6 @@ DeRemer and Penello: they already provide the algorithm.
 
 * 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