Version 2.3a.

[bison.git] / src / tables.h

diff --git a/src/tables.h b/src/tables.h
index 937c3ffdcf78e8b143f0543393720ecabbeccc2c..5f78df929cb0e9c15fdeacf7f54dea8813283eda 100644 (file)
--- a/src/tables.h
+++ b/src/tables.h
@@ -1,5 +1,5 @@
 /* Prepare the LALR and GLR parser tables.
-   Copyright (C) 2002  Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -15,38 +15,105 @@
 
    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.  */
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301, USA.  */
 
 #ifndef TABLES_H_
 # define TABLES_H_
 
 # include "state.h"
 
+/* The parser tables consist of these tables.
+
+   YYTRANSLATE = vector mapping yylex's token numbers into bison's
+   token numbers.
+
+   YYTNAME = vector of string-names indexed by bison token number.
+
+   YYTOKNUM = vector of yylex token numbers corresponding to entries
+   in YYTNAME.
+
+   YYRLINE = vector of line-numbers of all rules.  For yydebug
+   printouts.
+
+   YYRHS = vector of items of all rules.  This is exactly what RITEMS
+   contains.  For yydebug and for semantic parser.
+
+   YYPRHS[R] = index in YYRHS of first item for rule R.
+
+   YYR1[R] = symbol number of symbol that rule R derives.
+
+   YYR2[R] = number of symbols composing right hand side of rule R.
+
+   YYSTOS[S] = the symbol number of the symbol that leads to state S.
+
+   YYDEFACT[S] = default rule to reduce with in state s, when YYTABLE
+   doesn't specify something else to do.  Zero means the default is an
+   error.
+
+   YYDEFGOTO[I] = default state to go to after a reduction of a rule
+   that generates variable NTOKENS + I, except when YYTABLE specifies
+   something else to do.
+
+   YYPACT[S] = index in YYTABLE of the portion describing state S.
+   The lookahead token's type is used to index that portion to find
+   out what to do.
+
+   If the value in YYTABLE is positive, we shift the token and go to
+   that state.
+
+   If the value is negative, it is minus a rule number to reduce by.
+
+   If the value is zero, the default action from YYDEFACT[S] is used.
+
+   YYPGOTO[I] = the index in YYTABLE of the portion describing what to
+   do after reducing a rule that derives variable I + NTOKENS.  This
+   portion is indexed by the parser state number, S, as of before the
+   text for this nonterminal was read.  The value from YYTABLE is the
+   state to go to if the corresponding value in YYCHECK is S.
+
+   YYTABLE = a vector filled with portions for different uses, found
+   via YYPACT and YYPGOTO.
+
+   YYCHECK = a vector indexed in parallel with YYTABLE.  It indicates,
+   in a roundabout way, the bounds of the portion you are trying to
+   examine.
+
+   Suppose that the portion of YYTABLE starts at index P and the index
+   to be examined within the portion is I.  Then if YYCHECK[P+I] != I,
+   I is outside the bounds of what is actually allocated, and the
+   default (from YYDEFACT or YYDEFGOTO) should be used.  Otherwise,
+   YYTABLE[P+I] should be used.
+
+   YYFINAL = the state number of the termination state.
+
+   YYLAST ( = high) the number of the last element of YYTABLE, i.e.,
+   sizeof (YYTABLE) - 1.  */
+
 extern int nvectors;
 
-typedef int base_t;
-extern base_t *base;
+typedef int base_number;
+extern base_number *base;
 /* A distinguished value of BASE, negative infinite.  During the
-   computation equals to BASE_MIN, later mapped to BASE_NINF to
+   computation equals to BASE_MINIMUM, later mapped to BASE_NINF to
    keep parser tables small.  */
-extern base_t base_ninf;
+extern base_number base_ninf;
 
 extern unsigned int *conflict_table;
 extern unsigned int *conflict_list;
 extern int conflict_list_cnt;
 
-extern base_t *table;
-extern base_t *check;
-/* The value used in TABLE to denote explicit parse errors
+extern base_number *table;
+extern base_number *check;
+/* The value used in TABLE to denote explicit syntax errors
    (%nonassoc), a negative infinite.  */
-extern base_t table_ninf;
+extern base_number table_ninf;
 
-extern state_number_t *yydefgoto;
-extern rule_number_t *yydefact;
+extern state_number *yydefgoto;
+extern rule_number *yydefact;
 extern int high;
 
-void tables_generate PARAMS ((void));
-void tables_free PARAMS ((void));
+void tables_generate (void);
+void tables_free (void);
 
 #endif /* !TABLES_H_ */