lalr1.cc: don't discard non-existent lookahead on syntax error.

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 4915caa245f55e49d035c5aa4bc9d9a6361929aa..6174e824edeb507beb4d33f60ae74cbfbd6d7367 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
 # C++ skeleton for Bison
 

-# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009

 # Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify


@@ -18,59 +18,47 @@
 
 m4_include(b4_pkgdatadir/[c++.m4])
 
 
 m4_include(b4_pkgdatadir/[c++.m4])
 

-# b4_table_define(TABLE-NAME, CONTENT)
-# ------------------------------------
+
+# b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
+# --------------------------------------------------------------
+# Declare "parser::yy<TABLE-NAME>_" which contents is CONTENT.
+m4_define([b4_integral_parser_table_declare],
+[m4_ifval([$3], [b4_c_comment([$3], [  ])
+])dnl
+  static const b4_int_type_for([$2]) yy$1_[[]];dnl
+])
+
+# b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
+# -------------------------------------------------------------

 # Define "parser::yy<TABLE-NAME>_" which contents is CONTENT.
 # Define "parser::yy<TABLE-NAME>_" which contents is CONTENT.

-m4_define([b4_table_define],
-[const b4_int_type_for([$2])
+m4_define([b4_integral_parser_table_define],
+[  const b4_int_type_for([$2])

   b4_parser_class_name::yy$1_[[]] =
   {
   $2
   b4_parser_class_name::yy$1_[[]] =
   {
   $2

-  }dnl
+  };dnl

 ])
 
 ])
 

+

 # b4_symbol_value_template(VAL, [TYPE])
 # -------------------------------------
 # b4_symbol_value_template(VAL, [TYPE])
 # -------------------------------------

-# Same as b4_symbol_value, but used in a template method.
+# Same as b4_symbol_value, but used in a template method.  It makes
+# a difference when using variants.

 m4_copy([b4_symbol_value], [b4_symbol_value_template])
 
 m4_copy([b4_symbol_value], [b4_symbol_value_template])
 

-# How the semantic value is extracted when using variants.
-b4_variant_if([
-  # b4_symbol_value(VAL, [TYPE])
-  # ----------------------------
-  m4_define([b4_symbol_value],
-  [m4_ifval([$2],
-            [$1.as<$2>()],
-            [$1])])
-
-  # b4_symbol_value_template(VAL, [TYPE])
-  # -------------------------------------
-  # Same as b4_symbol_value, but used in a template method.
-  m4_define([b4_symbol_value_template],
-  [m4_ifval([$2],
-            [$1.template as<$2>()],
-            [$1])])
-]) # b4_variant_if
-
-
-# b4_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
-# ------------------------------------------------
-m4_define([b4_assert_if],
-[b4_percent_define_ifdef([[assert]], [$1], [$2])])
-

 
 # b4_lhs_value([TYPE])
 # --------------------
 # Expansion of $<TYPE>$.
 m4_define([b4_lhs_value],
 
 # b4_lhs_value([TYPE])
 # --------------------
 # Expansion of $<TYPE>$.
 m4_define([b4_lhs_value],

-[b4_symbol_value([yylhs.value], [$1])])
+          [b4_symbol_value([yylhs.value], [$1])])

 
 
 # b4_lhs_location()
 # -----------------
 # Expansion of @$.
 m4_define([b4_lhs_location],
 
 
 # b4_lhs_location()
 # -----------------
 # Expansion of @$.
 m4_define([b4_lhs_location],

-[yylhs.location])
+          [yylhs.location])

 
 
 # b4_rhs_data(RULE-LENGTH, NUM)
 
 
 # b4_rhs_data(RULE-LENGTH, NUM)


@@ -78,11 +66,11 @@ m4_define([b4_lhs_location],
 # Return the data corresponding to the symbol #NUM, where the current
 # rule has RULE-LENGTH symbols on RHS.
 m4_define([b4_rhs_data],
 # Return the data corresponding to the symbol #NUM, where the current
 # rule has RULE-LENGTH symbols on RHS.
 m4_define([b4_rhs_data],

-          [yystack_@{($1) - ($2)@}])
+          [yystack_@{b4_subtract($@)@}])

 
 
 # b4_rhs_state(RULE-LENGTH, NUM)
 
 
 # b4_rhs_state(RULE-LENGTH, NUM)

-# -----------------------------
+# ------------------------------

 # The state corresponding to the symbol #NUM, where the current
 # rule has RULE-LENGTH symbols on RHS.
 m4_define([b4_rhs_state],
 # The state corresponding to the symbol #NUM, where the current
 # rule has RULE-LENGTH symbols on RHS.
 m4_define([b4_rhs_state],


@@ -105,196 +93,30 @@ m4_define([b4_rhs_location],
           [b4_rhs_data([$1], [$2]).location])
 
 
           [b4_rhs_data([$1], [$2]).location])
 
 

-# b4_symbol(NUM, FIELD)
-# ---------------------
-# Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
-# undefined.
-m4_define([b4_symbol],
-[m4_indir([b4_symbol($1, $2)])])
-
-
-# b4_symbol_if(NUM, FIELD, IF-TRUE, IF-FALSE)
-# -------------------------------------------
-# If FIELD about symbol #NUM is 1 expand IF-TRUE, if is 0, expand IF-FALSE.
-# Otherwise an error.
-m4_define([b4_symbol_if],
-[m4_case(b4_symbol([$1], [$2]),
-         [1], [$3],
-         [0], [$4],
-         [m4_fatal([$0: field $2 of $1 is not a Boolean:] b4_symbol([$1], [$2]))])])
-
-
-# b4_symbol_actions(FILENAME, LINENO,
-#                   SYMBOL-TAG, SYMBOL-NUM,
-#                   SYMBOL-ACTION, SYMBOL-TYPENAME)
-# -------------------------------------------------
+# b4_symbol_action(SYMBOL-NUM, KIND)
+# ----------------------------------
+# Run the action KIND (destructor or printer) for SYMBOL-NUM.

 # Same as in C, but using references instead of pointers.
 # Same as in C, but using references instead of pointers.

-m4_define([b4_symbol_actions],
+m4_define([b4_symbol_action],
+[b4_symbol_if([$1], [has_$2],

 [m4_pushdef([b4_dollar_dollar],
 [m4_pushdef([b4_dollar_dollar],

-            [b4_symbol_value_template([yysym.value], [$6])])dnl
+    [b4_symbol_value_template([yysym.value],
+                              b4_symbol_if([$1], [has_type],
+                                           [b4_symbol([$1], [type])]))])dnl

 m4_pushdef([b4_at_dollar], [yysym.location])dnl
 m4_pushdef([b4_at_dollar], [yysym.location])dnl

-      case $4: // $3
-b4_syncline([$2], [$1])
-        $5;
+      b4_symbol_case_([$1])
+b4_syncline([b4_symbol([$1], [$2_line])], ["b4_symbol([$1], [$2_file])"])
+        b4_symbol([$1], [$2])

 b4_syncline([@oline@], [@ofile@])
         break;
 b4_syncline([@oline@], [@ofile@])
         break;

+

 m4_popdef([b4_at_dollar])dnl
 m4_popdef([b4_dollar_dollar])dnl
 m4_popdef([b4_at_dollar])dnl
 m4_popdef([b4_dollar_dollar])dnl

-])
-
-
-# b4_symbol_case_(SYMBOL-NUM)
-# ---------------------------
-# Issue a "case NUM" for SYMBOL-NUM.
-m4_define([b4_symbol_case_],
-[      case b4_symbol([$1], [number]): // b4_symbol([$1], [tag])
-])
-
-
-# b4_type_action_(NUMS)
-# ---------------------
-# Run actions for the symbol NUMS that all have the same type-name.
-# Skip NUMS that have no type-name.
-m4_define([b4_type_action_],
-[b4_symbol_if([$1], [has_type_name],
-[m4_map([b4_symbol_case_], [$@])[]dnl
-        b4_dollar_dollar([b4_symbol([$1], [number])],
-                         [b4_symbol([$1], [tag])],
-                         [b4_symbol([$1], [type_name])]);
-       break;
-

 ])])
 
 
 ])])
 
 

-# b4_symbol_constructor_declaration_(SYMBOL-NUMBERS)
-# ----------------------------------------------------
-# Declare the overloaded version of make_symbol for the (common) type of
-# these SYMBOL-NUMBERS.  Use at class-level.
-m4_define([b4_symbol_constructor_declaration_],
-[    template <token_type>
-    static inline symbol_type
-    make_symbol (b4_symbol_if([$1], [has_type_name],
-                              [const b4_symbol([$1], [type_name])& v, ])dnl
-const location_type& l);
-
-])
-
-# b4_symbol_constructor_declarations
-# ----------------------------------
-# Declare the overloaded versions of make_symbol for all the value types.
-# Use at class-level.
-m4_define([b4_symbol_constructor_declarations],
-[b4_variant_if([
-    // Declaration of make_symbol for each value type.
-m4_map([b4_symbol_constructor_declaration_], m4_defn([b4_type_names]))])])
-
-
-
-# b4_symbol_constructor_specialization_(SYMBOL-NUMBER)
-# ----------------------------------------------------
-# Declare the specialization of make_symbol for this each SYMBOL-NUMBER.
-# Specializations cannot be declared at class-level, this must be done
-# at namespace-level.
-m4_define([b4_symbol_constructor_specialization_],
-[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [tag_is_id],
-[  template <>
-  inline
-  b4_parser_class_name::symbol_type
-  b4_parser_class_name::make_symbol <b4_parser_class_name::token::b4_symbol([$1], [tag])> (dnl
-b4_symbol_if([$1], [has_type_name],
-             [const b4_symbol([$1], [type_name])& v, ])dnl
-const b4_parser_class_name::location_type& l);
-])])])
-
-# b4_symbol_constructor_specializations
-# -------------------------------------
-# Declare specializations of make_symbol.
-m4_define([b4_symbol_constructor_specializations],
-[b4_variant_if([
-  // Specializations of make_symbol for each symbol type.
-m4_map([b4_symbol_constructor_specialization_],
-       m4_defn([b4_symbol_numbers]))])dnl
-])
-
-
-
-# b4_symbol_constructor_definition_(SYMBOL-NUMBER)
-# ------------------------------------------------
-# Define make_symbol for this SYMBOL-NUMBER.
-m4_define([b4_symbol_constructor_definition_],
-[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [tag_is_id],
-[  template <>
-  b4_parser_class_name::symbol_type
-  b4_parser_class_name::make_symbol <b4_parser_class_name::token::b4_symbol([$1], [tag])> (dnl
-b4_symbol_if([$1], [has_type_name],
-             [const b4_symbol([$1], [type_name])& v, ])dnl
-const location_type& l)
-  {
-    return symbol_type (yytranslate_ (token::b4_symbol([$1], [tag])),dnl
- b4_symbol_if([$1], [has_type_name], [v, ])l);
-  }
-
-])])])
-
-
-# b4_symbol_constructor_declarations
-# ----------------------------------
-# Define the overloaded versions of make_symbol for all the value types.
-m4_define([b4_symbol_constructor_definitions],
-[b4_variant_if(
-[  // Implementation of make_symbol for each symbol type.
-m4_map([b4_symbol_constructor_definition_], m4_defn([b4_symbol_numbers]))])])
-
-
-# b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS])
-# ------------------------------------------------
-# Run some ACTION ("build", or "destroy") on YYVAL of symbol type
-# YYTYPE.
-m4_define([b4_symbol_variant],
-[m4_pushdef([b4_dollar_dollar],
-            [$2.$3<$][3>(m4_shift3($@))])dnl
-  switch ($1)
-    {
-m4_map([b4_type_action_], m4_defn([b4_type_names]))[]dnl
-      default:
-        break;
-    }
-m4_popdef([b4_dollar_dollar])dnl
-])
-
-
-# _b4_char_sizeof_counter
-# -----------------------
-# A counter used by _b4_char_sizeof_dummy to create fresh symbols.
-m4_define([_b4_char_sizeof_counter],
-[0])
-
-# _b4_char_sizeof_dummy
-# ---------------------
-# At each call return a new C++ identifier.
-m4_define([_b4_char_sizeof_dummy],
-[m4_define([_b4_char_sizeof_counter], m4_incr(_b4_char_sizeof_counter))dnl
-dummy[]_b4_char_sizeof_counter])
-
-
-# b4_char_sizeof(SYMBOL-NUM)
-# --------------------------
-# To be mapped on the list of type names to produce:
-#
-#    char dummy1[sizeof(type_name_1)];
-#    char dummy2[sizeof(type_name_2)];
-#
-# for defined type names.
-# $3 is doubly-quoted, do not quote it again.
-m4_define([b4_char_sizeof],
-[m4_ifval(b4_symbol([$1], [type_name]),
-[
-      char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type_name])])@}; // b4_symbol([$1], [tag])])dnl
-])
-
-

 m4_pushdef([b4_copyright_years],
 m4_pushdef([b4_copyright_years],

-           [2002, 2003, 2004, 2005, 2006, 2007, 2008])
+           [2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009])

 
 m4_define([b4_parser_class_name],
           [b4_percent_define_get([[parser_class_name]])])
 
 m4_define([b4_parser_class_name],
           [b4_percent_define_get([[parser_class_name]])])


@@ -303,15 +125,17 @@ m4_define([b4_parser_class_name],
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 

-# Backward compatibility.
+b4_locations_if(
+[# Backward compatibility.

 m4_define([b4_location_constructors])
 m4_define([b4_location_constructors])

-m4_include(b4_pkgdatadir/[location.cc])
+m4_include(b4_pkgdatadir/[location.cc])])
+m4_include(b4_pkgdatadir/[stack.hh])
+b4_variant_if([m4_include(b4_pkgdatadir/[variant.hh])])

 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert_push(0)dnl
 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert_push(0)dnl

-b4_defines_if(
-[@output(b4_spec_defines_file@)@
+@output(b4_spec_defines_file@)@

 b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++])
 dnl FIXME: This is wrong, we want computed header guards.
 [
 b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++])
 dnl FIXME: This is wrong, we want computed header guards.
 [


@@ -322,119 +146,23 @@ dnl FIXME: This is wrong, we want computed header guards.
 
 ]b4_percent_code_get([[requires]])[
 
 
 ]b4_percent_code_get([[requires]])[
 

-]b4_assert_if([#include <cassert>])[
+]b4_parse_assert_if([#include <cassert>])[
+#include <stdexcept>

 #include <string>
 #include <iostream>
 #include "stack.hh"
 
 ]b4_namespace_open[
 #include <string>
 #include <iostream>
 #include "stack.hh"
 
 ]b4_namespace_open[

-  class position;
-  class location;
-]b4_variant_if(
-[[
-  /// A char[S] buffer to store and retrieve objects.
-  ///
-  /// Sort of a variant, but does not keep track of the nature
-  /// of the stored data, since that knowledge is available
-  /// via the current state.
-  template <size_t S>
-  struct variant
-  {]b4_assert_if([
-    /// Whether something is contained.
-    bool built;
-])[
-    /// Empty construction.
-    inline
-    variant ()]b4_assert_if([
-      : built(false)])[
-    {}
-
-    /// Instantiate a \a T in here.
-    template <typename T>
-    inline T&
-    build()
-    {]b4_assert_if([
-      assert(!built);
-      built = true;])[
-      return *new (buffer) T;
-    }
-
-    /// Instantiate a \a T in here from \a t.
-    template <typename T>
-    inline T&
-    build(const T& t)
-    {]b4_assert_if([
-      assert(!built);
-      built = true;])[
-      return *new (buffer) T(t);
-    }
-
-    /// Construct and fill.
-    template <typename T>
-    inline
-    variant (const T& t)]b4_assert_if([
-      : built(true)])[
-    {
-      new (buffer) T(t);
-    }
-
-    /// Accessor to a built \a T.
-    template <typename T>
-    inline T&
-    as()
-    {]b4_assert_if([
-      assert(built);])[
-      return reinterpret_cast<T&>(buffer);
-    }
-
-    /// Const accessor to a built \a T (for %printer).
-    template <typename T>
-    inline const T&
-    as() const
-    {]b4_assert_if([
-      assert(built);])[
-      return reinterpret_cast<const T&>(buffer);
-    }
-
-    /// Swap the content with \a other.
-    template <typename T>
-    inline void
-    swap(variant<S>& other)
-    {
-      std::swap(as<T>(), other.as<T>());
-    }
-
-    /// Assign the content of \a other to this.
-    /// Destroys \a other.
-    template <typename T>
-    inline void
-    build(variant<S>& other)
-    {
-      build<T>();
-      swap<T>(other);
-      other.destroy<T>();
-    }
-
-    /// Destroy the stored \a T.
-    template <typename T>
-    inline void
-    destroy()
-    {
-      as<T>().~T();]b4_assert_if([
-      built = false;])[
-    }
-
-    /// A buffer large enough to store any of the semantic values.
-    char buffer[S];
-  };
-]])[
+]b4_locations_if([  class position;
+  class location;])[
+]b4_variant_if([b4_variant_define])[

 ]b4_namespace_close[
 
 ]b4_namespace_close[
 

-#include "location.hh"
+]b4_locations_if([#include "location.hh"])[

 
 /* Enabling traces.  */
 #ifndef YYDEBUG
 
 /* Enabling traces.  */
 #ifndef YYDEBUG

-# define YYDEBUG ]b4_debug_flag[
+# define YYDEBUG ]b4_parse_trace_if([1], [0])[

 #endif
 
 /* Enabling verbose error messages.  */
 #endif
 
 /* Enabling verbose error messages.  */


@@ -442,7 +170,7 @@ dnl FIXME: This is wrong, we want computed header guards.
 # undef YYERROR_VERBOSE
 # define YYERROR_VERBOSE 1
 #else
 # undef YYERROR_VERBOSE
 # define YYERROR_VERBOSE 1
 #else

-# define YYERROR_VERBOSE ]b4_error_verbose_flag[
+# define YYERROR_VERBOSE ]b4_error_verbose_if([1], [0])[

 #endif
 
 /* Enabling the token table.  */
 #endif
 
 /* Enabling the token table.  */


@@ -450,7 +178,8 @@ dnl FIXME: This is wrong, we want computed header guards.
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 

-/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
+]b4_locations_if([dnl
+[/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].

    If N is 0, then set CURRENT to the empty location which ends
    the previous symbol: RHS[0] (always defined).  */
 
    If N is 0, then set CURRENT to the empty location which ends
    the previous symbol: RHS[0] (always defined).  */
 


@@ -467,7 +196,7 @@ do {                                                            \
       (Current).begin = (Current).end = (Rhs)[0].location.end; \
     }                                                           \
 } while (false)
       (Current).begin = (Current).end = (Rhs)[0].location.end; \
     }                                                           \
 } while (false)

-#endif
+#endif]])[

 
 ]b4_namespace_open[
 
 
 ]b4_namespace_open[
 


@@ -475,36 +204,7 @@ do {                                                            \
   class ]b4_parser_class_name[
   {
   public:
   class ]b4_parser_class_name[
   {
   public:

-#ifndef YYSTYPE
-]b4_variant_if(
-[    /// An auxiliary type to compute the largest semantic type.
-    union union_type
-    {]m4_map([b4_char_sizeof], m4_defn([b4_symbol_numbers]))[
-    };
-
-    /// Symbol semantic values.
-    typedef variant<sizeof(union_type)> semantic_type;],
-[    /// Symbol semantic values.
-m4_ifdef([b4_stype],
-[    union semantic_type
-    {b4_user_stype
-    };],
-[m4_if(b4_tag_seen_flag, 0,
-[[    typedef int semantic_type;]],
-[[    typedef YYSTYPE semantic_type;]])])])[
-#else
-    typedef YYSTYPE semantic_type;
-#endif
-    /// Symbol locations.
-    typedef ]b4_percent_define_get([[location_type]])[ location_type;
-    /// Tokens.
-    struct token
-    {
-      ]b4_token_enums(b4_tokens)[
-    };
-    /// Token type.
-    typedef token::yytokentype token_type;
-
+]b4_public_types_declare[

     /// Build a parser object.
     ]b4_parser_class_name[ (]b4_parse_param_decl[);
     virtual ~]b4_parser_class_name[ ();
     /// Build a parser object.
     ]b4_parser_class_name[ (]b4_parse_param_decl[);
     virtual ~]b4_parser_class_name[ ();


@@ -527,68 +227,52 @@ m4_ifdef([b4_stype],
     void set_debug_level (debug_level_type l);
 #endif
 
     void set_debug_level (debug_level_type l);
 #endif
 

-  private:
-    /// Report a syntax error.
-    /// \param loc    where the syntax error is found.
+    /// Report a syntax error.]b4_locations_if([
+    /// \param loc    where the syntax error is found.])[

     /// \param msg    a description of the syntax error.
     /// \param msg    a description of the syntax error.

-    virtual void error (const location_type& loc, const std::string& msg);
-
-    /// Generate an error message.
-    /// \param state   the state where the error occurred.
-    /// \param tok     the lookahead token.
-    virtual std::string yysyntax_error_ (int yystate, int tok);
+    virtual void error (]b4_locations_if([const location_type& loc, ])[const std::string& msg);

 
 

+  private:

     /// State numbers.
     typedef int state_type;
 
     /// State numbers.
     typedef int state_type;
 

-    /// Internal symbol numbers.
-    typedef ]b4_int_type_for([b4_translate])[ token_number_type;
-    /* Tables.  */
-    /// For a state, the index in \a yytable_ of its portion.
-    static const ]b4_int_type_for([b4_pact])[ yypact_[];
-    static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;
+    /// Generate an error message.
+    /// \param yystate   the state where the error occurred.
+    /// \param yytoken   the lookahead token.
+    virtual std::string yysyntax_error_ (state_type yystate, int yytoken);

 
 

-    /// For a state, default rule to reduce.
-    /// Unless\a  yytable_ specifies something else to do.
-    /// Zero means the default is an error.
-    static const ]b4_int_type_for([b4_defact])[ yydefact_[];
+    /// Compute post-reduction state.
+    /// \param yystate   the current state
+    /// \param yylhs     the nonterminal to push on the stack
+    state_type yy_lr_goto_state_ (state_type yystate, int yylhs);

 
 

-    static const ]b4_int_type_for([b4_pgoto])[ yypgoto_[];
-    static const ]b4_int_type_for([b4_defgoto])[ yydefgoto_[];
+    /// Whether the given \c yypact_ value indicates a defaulted state.
+    /// \param yyvalue   the value to check
+    static bool yy_pact_value_is_default_ (int yyvalue);

 
 

-    /// What to do in a state.
-    /// \a yytable_[yypact_[s]]: what to do in state \a s.
-    /// - if positive, shift that token.
-    /// - if negative, reduce the rule which number is the opposite.
-    /// - if zero, do what YYDEFACT says.
-    static const ]b4_int_type_for([b4_table])[ yytable_[];
-    static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
+    /// Whether the given \c yytable_ value indicates a syntax error.
+    /// \param yyvalue   the value to check
+    static bool yy_table_value_is_error_ (int yyvalue);

 
 

-    static const ]b4_int_type_for([b4_check])[ yycheck_[];
-
-    /// For a state, its accessing symbol.
-    static const ]b4_int_type_for([b4_stos])[ yystos_[];
+    /// Internal symbol numbers.
+    typedef ]b4_int_type_for([b4_translate])[ token_number_type;
+    static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;
+    static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;

 
 

-    /// For a rule, its LHS.
-    static const ]b4_int_type_for([b4_r1])[ yyr1_[];
-    /// For a rule, its RHS length.
-    static const ]b4_int_type_for([b4_r2])[ yyr2_[];
+    /* Tables.  */
+]b4_parser_tables_declare[

 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
     /// For a symbol, its name in clear.
     static const char* const yytname_[];
 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
     /// For a symbol, its name in clear.
     static const char* const yytname_[];

-#endif
+#endif]b4_error_verbose_if([

 
 

-#if YYERROR_VERBOSE

     /// Convert the symbol name \a n to a form suitable for a diagnostic.
     /// Convert the symbol name \a n to a form suitable for a diagnostic.

-    virtual std::string yytnamerr_ (const char *n);
-#endif
+    static std::string yytnamerr_ (const char *n);])[

 
 #if YYDEBUG
 
 #if YYDEBUG

-    /// For each rule, its source line number.
-    static const ]b4_int_type_for([b4_rline])[ yyrline_[];
-    /// For each scanner token number, its symbol number.
-    static const ]b4_int_type_for([b4_toknum])[ yytoken_number_[];
+]b4_integral_parser_table_declare([rline], [b4_rline],
+     [YYRLINE[YYN] -- Source line where rule number YYN was defined.])[

     /// Report on the debug stream that the rule \a r is going to be reduced.
     virtual void yy_reduce_print_ (int r);
     /// Print the state stack on the debug stream.
     /// Report on the debug stream that the rule \a r is going to be reduced.
     virtual void yy_reduce_print_ (int r);
     /// Print the state stack on the debug stream.


@@ -600,32 +284,7 @@ m4_ifdef([b4_stype],
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.

-    static inline token_number_type yytranslate_ (int t);
-
-    /// A complete symbol, with its type.
-    template <typename Exact>
-    struct symbol_base_type
-    {
-      /// Default constructor.
-      inline symbol_base_type ();
-
-      /// Constructor.
-      inline symbol_base_type (const location_type& l);
-      inline symbol_base_type (const semantic_type& v, const location_type& l);
-
-      /// Return this with its exact type.
-      const Exact& self () const;
-      Exact& self ();
-
-      /// Return the type of this symbol.
-      int type_get () const;
-
-      /// The semantic value.
-      semantic_type value;
-
-      /// The location.
-      location_type location;
-    };
+    static inline token_number_type yytranslate_ (]b4_lex_symbol_if([token_type], [int])[ t);

 
 #if YYDEBUG
     /// \brief Display a symbol type, value and location.
 
 #if YYDEBUG
     /// \brief Display a symbol type, value and location.


@@ -644,32 +303,6 @@ m4_ifdef([b4_stype],
     inline void yy_destroy_ (const char* yymsg,
                              symbol_base_type<Exact>& yysym) const;
 
     inline void yy_destroy_ (const char* yymsg,
                              symbol_base_type<Exact>& yysym) const;
 

-  public:
-    /// Element of the stack: a state and its attributes.
-    struct symbol_type : symbol_base_type<symbol_type>
-    {
-      /// The parent class.
-      typedef symbol_base_type<symbol_type> super_type;
-
-      /// Default constructor.
-      inline symbol_type ();
-
-      /// Constructor.
-      inline symbol_type (int t,
-                          const semantic_type& v, const location_type& l);
-
-      inline symbol_type (int t,
-                          const location_type& l);
-
-      /// The symbol type.
-      int type;
-
-      /// Return the type corresponding to this state.
-      inline int type_get_ () const;
-    };
-
-]b4_symbol_constructor_declarations[
-

   private:
     /// Element of the stack: a state and its attributes.
     struct stack_symbol_type : symbol_base_type<stack_symbol_type>
   private:
     /// Element of the stack: a state and its attributes.
     struct stack_symbol_type : symbol_base_type<stack_symbol_type>


@@ -681,13 +314,14 @@ m4_ifdef([b4_stype],
       inline stack_symbol_type ();
 
       /// Constructor.
       inline stack_symbol_type ();
 
       /// Constructor.

-      inline stack_symbol_type (state_type s,
-                                const semantic_type& v, const location_type& l);
+      inline stack_symbol_type (]b4_args([state_type s],
+                                         [const semantic_type& v],
+                                         b4_locations_if([const location_type& l]))[);

 
       /// The state.
       state_type state;
 
 
       /// The state.
       state_type state;
 

-      /// Return the type corresponding to this state.
+      /// The type (corresponding to \a state).

       inline int type_get_ () const;
     };
 
       inline int type_get_ () const;
     };
 


@@ -730,7 +364,9 @@ m4_ifdef([b4_stype],
 
 ]b4_parse_param_vars[
   };
 
 ]b4_parse_param_vars[
   };

-]b4_symbol_constructor_specializations[
+
+]b4_lex_symbol_if([b4_yytranslate_define
+b4_public_types_define])[

 ]b4_namespace_close[
 
 ]b4_percent_define_flag_if([[global_tokens_and_yystype]],
 ]b4_namespace_close[
 
 ]b4_percent_define_flag_if([[global_tokens_and_yystype]],


@@ -744,7 +380,6 @@ m4_ifdef([b4_stype],
 b4_percent_code_get([[provides]])[]dnl
 
 [#endif /* ! defined PARSER_HEADER_H */]
 b4_percent_code_get([[provides]])[]dnl
 
 [#endif /* ! defined PARSER_HEADER_H */]

-])dnl

 @output(b4_parser_file_name@)@
 b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++])
 b4_percent_code_get([[top]])[]dnl
 @output(b4_parser_file_name@)@
 b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++])
 b4_percent_code_get([[top]])[]dnl


@@ -754,17 +389,16 @@ m4_if(b4_prefix, [yy], [],
 #define yylex   b4_prefix[]lex])[
 
 /* First part of user declarations.  */
 #define yylex   b4_prefix[]lex])[
 
 /* First part of user declarations.  */

-]b4_user_pre_prologue
+]b4_user_pre_prologue[

 
 

-b4_defines_if([[
-#include "@basename(]b4_spec_defines_file[@)"]])[
+#include "@basename(]b4_spec_defines_file[@)"

 
 /* User implementation prologue.  */
 ]b4_user_post_prologue
 b4_percent_code_get[]dnl
 
 [#ifndef YY_
 
 /* User implementation prologue.  */
 ]b4_user_post_prologue
 b4_percent_code_get[]dnl
 
 [#ifndef YY_

-# if YYENABLE_NLS
+# if defined YYENABLE_NLS && YYENABLE_NLS

 #  if ENABLE_NLS
 #   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */
 #   define YY_(msgid) dgettext ("bison-runtime", msgid)
 #  if ENABLE_NLS
 #   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */
 #   define YY_(msgid) dgettext ("bison-runtime", msgid)


@@ -815,16 +449,15 @@ b4_percent_code_get[]dnl
 
 #endif /* !YYDEBUG */
 
 
 #endif /* !YYDEBUG */
 

-#define yyerrok                (yyerrstatus_ = 0)
-#define yyclearin      (yychar = yyempty_)
+#define yyerrok         (yyerrstatus_ = 0)
+#define yyclearin       (yyempty = true)

 
 

-#define YYACCEPT       goto yyacceptlab
-#define YYABORT                goto yyabortlab
-#define YYERROR                goto yyerrorlab
+#define YYACCEPT        goto yyacceptlab
+#define YYABORT         goto yyabortlab
+#define YYERROR         goto yyerrorlab

 #define YYRECOVERING()  (!!yyerrstatus_)
 
 #define YYRECOVERING()  (!!yyerrstatus_)
 

-]b4_namespace_open[
-#if YYERROR_VERBOSE
+]b4_namespace_open[]b4_error_verbose_if([[

 
   /* Return YYSTR after stripping away unnecessary quotes and
      backslashes, so that it's suitable for yyerror.  The heuristic is
 
   /* Return YYSTR after stripping away unnecessary quotes and
      backslashes, so that it's suitable for yyerror.  The heuristic is


@@ -862,8 +495,7 @@ b4_percent_code_get[]dnl
 
     return yystr;
   }
 
     return yystr;
   }

-
-#endif
+]])[

 
   /// Build a parser object.
   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 
   /// Build a parser object.
   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [


@@ -884,77 +516,7 @@ b4_percent_code_get[]dnl
   | Symbol types.  |
   `---------------*/
 
   | Symbol types.  |
   `---------------*/
 

-  // symbol_base_type.
-  template <typename Exact>
-  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type ()
-    : value()
-    , location()
-  {
-  }
-
-  template <typename Exact>
-  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (const location_type& l)
-    : value()
-    , location(l)
-  {
-  }
-
-  template <typename Exact>
-  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (const semantic_type& v, const location_type& l)
-    : value(v)
-    , location(l)
-  {
-  }
-
-  template <typename Exact>
-  const Exact&
-  ]b4_parser_class_name[::symbol_base_type<Exact>::self () const
-  {
-    return static_cast<const Exact&>(*this);
-  }
-
-  template <typename Exact>
-  Exact&
-  ]b4_parser_class_name[::symbol_base_type<Exact>::self ()
-  {
-    return static_cast<Exact&>(*this);
-  }
-
-  template <typename Exact>
-  int
-  ]b4_parser_class_name[::symbol_base_type<Exact>::type_get () const
-  {
-    return self ().type_get_ ();
-  }
-
-  // symbol_type.
-  ]b4_parser_class_name[::symbol_type::symbol_type ()
-    : super_type ()
-    , type ()
-  {
-  }
-
-  ]b4_parser_class_name[::symbol_type::symbol_type (int t,
-                           const location_type& l)
-    : super_type (l)
-    , type (t)
-  {
-  }
-
-  ]b4_parser_class_name[::symbol_type::symbol_type (int t,
-                           const semantic_type& v, const location_type& l)
-    : super_type (v, l)
-    , type (t)
-  {
-  }
-
-  int
-  ]b4_parser_class_name[::symbol_type::type_get_ () const
-  {
-    return type;
-  }
-
-]b4_symbol_constructor_definitions[
+]b4_lex_symbol_if([], [b4_public_types_define])[

 
   // stack_symbol_type.
   ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
 
   // stack_symbol_type.
   ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()


@@ -963,9 +525,11 @@ b4_percent_code_get[]dnl
   {
   }
 
   {
   }
 

-  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (state_type s,
-                           const semantic_type& v, const location_type& l)
-    : super_type (v, l)
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (]b4_args(
+                 [state_type s],
+                 [const semantic_type& v],
+                 b4_locations_if([const location_type& l]))[)
+    : super_type (v]b4_locations_if([, l])[)

     , state (s)
   {
   }
     , state (s)
   {
   }


@@ -990,9 +554,9 @@ b4_percent_code_get[]dnl
     // User destructor.
     switch (yytype)
       {
     // User destructor.
     switch (yytype)
       {

-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
-       default:
-         break;
+]b4_symbol_foreach([b4_symbol_destructor])dnl
+[       default:
+          break;

       }]b4_variant_if([
 
     // Type destructor.
       }]b4_variant_if([
 
     // Type destructor.


@@ -1007,12 +571,12 @@ b4_percent_code_get[]dnl
   {
     int yytype = yysym.type_get ();
     yyo << (yytype < yyntokens_ ? "token" : "nterm")
   {
     int yytype = yysym.type_get ();
     yyo << (yytype < yyntokens_ ? "token" : "nterm")

-        << ' ' << yytname_[yytype] << " ("
-        << yysym.location << ": ";
+        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
+        << yysym.location << ": "])[;

     switch (yytype)
       {
     switch (yytype)
       {

-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))[
-       default:
+]b4_symbol_foreach([b4_symbol_printer])dnl
+[       default:

          break;
       }
     yyo << ')';
          break;
       }
     yyo << ')';


@@ -1026,10 +590,16 @@ b4_percent_code_get[]dnl
     if (m)
       YY_SYMBOL_PRINT (m, sym);
 ]b4_variant_if(
     if (m)
       YY_SYMBOL_PRINT (m, sym);
 ]b4_variant_if(

-[[    yystack_.push (stack_symbol_type (s, semantic_type(), sym.location));
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                    [s],
+                    [semantic_type()],
+                    b4_locations_if([sym.location]))[));

     ]b4_symbol_variant([[yystos_[s]]], [[yystack_[0].value]],
                        [build], [sym.value])],
     ]b4_symbol_variant([[yystos_[s]]], [[yystack_[0].value]],
                        [build], [sym.value])],

-[    yystack_.push (stack_symbol_type (s, sym.value, sym.location));])[
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                      [s],
+                      [sym.value],
+                      b4_locations_if([sym.location]))[));]])[

   }
 
   void
   }
 
   void


@@ -1038,7 +608,10 @@ b4_percent_code_get[]dnl
     if (m)
       YY_SYMBOL_PRINT (m, s);
 ]b4_variant_if(
     if (m)
       YY_SYMBOL_PRINT (m, s);
 ]b4_variant_if(

-[[    yystack_.push (stack_symbol_type (s.state, semantic_type(), s.location));
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                       [s.state],
+                       [semantic_type()],
+                       b4_locations_if([s.location]))[));

     ]b4_symbol_variant([[yystos_[s.state]]], [[yystack_[0].value]],
                        [build], [s.value])],
 [    yystack_.push (s);])[
     ]b4_symbol_variant([[yystos_[s.state]]], [[yystack_[0].value]],
                        [build], [s.value])],
 [    yystack_.push (s);])[


@@ -1077,26 +650,47 @@ b4_percent_code_get[]dnl
   }
 #endif
 
   }
 #endif
 

+  inline ]b4_parser_class_name[::state_type
+  ]b4_parser_class_name[::yy_lr_goto_state_ (state_type yystate, int yylhs)
+  {
+    int yyr = yypgoto_[yylhs - yyntokens_] + yystate;
+    if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
+      return yytable_[yyr];
+    else
+      return yydefgoto_[yylhs - yyntokens_];
+  }
+
+  inline bool
+  ]b4_parser_class_name[::yy_pact_value_is_default_ (int yyvalue)
+  {
+    return yyvalue == yypact_ninf_;
+  }
+
+  inline bool
+  ]b4_parser_class_name[::yy_table_value_is_error_ (int yyvalue)
+  {
+    return yyvalue == yytable_ninf_;
+  }
+

   int
   ]b4_parser_class_name[::parse ()
   {
   int
   ]b4_parser_class_name[::parse ()
   {

-    /// Coded type of the lookahead.
-    int yychar = yyempty_;
+    /// Whether yyla contains a lookahead.
+    bool yyempty = true;

 
     /* State.  */
     int yyn;
     int yylen = 0;
 
     /* State.  */
     int yyn;
     int yylen = 0;

-    int yystate = 0;

 
     /* Error handling.  */
     int yynerrs_ = 0;
     int yyerrstatus_ = 0;
 
     /// The lookahead symbol.
 
     /* Error handling.  */
     int yynerrs_ = 0;
     int yyerrstatus_ = 0;
 
     /// The lookahead symbol.

-    symbol_type yyla;
+    symbol_type yyla;]b4_locations_if([[

 
     /// The locations where the error started and ended.
 
     /// The locations where the error started and ended.

-    stack_symbol_type yyerror_range[2];
+    stack_symbol_type yyerror_range[2];]])[

 
     /// $$ and @@$.
     stack_symbol_type yylhs;
 
     /// $$ and @@$.
     stack_symbol_type yylhs;


@@ -1121,14 +715,12 @@ m4_popdef([b4_at_dollar])])dnl
     yystack_ = stack_type (0);
     yypush_ (0, 0, yyla);
 
     yystack_ = stack_type (0);
     yypush_ (0, 0, yyla);
 

-    // A new state was pushed on the stack.
-    // Invariant: yystate == yystack_[0].state, i.e.,
-    // yystate was just pushed onto the state stack.
+    // A new symbol was pushed on the stack.

   yynewstate:
   yynewstate:

-    YYCDEBUG << "Entering state " << yystate << std::endl;
+    YYCDEBUG << "Entering state " << yystack_[0].state << std::endl;

 
     /* Accept?  */
 
     /* Accept?  */

-    if (yystate == yyfinal_)
+    if (yystack_[0].state == yyfinal_)

       goto yyacceptlab;
 
     goto yybackup;
       goto yyacceptlab;
 
     goto yybackup;


@@ -1137,31 +729,24 @@ m4_popdef([b4_at_dollar])])dnl
   yybackup:
 
     /* Try to take a decision without lookahead.  */
   yybackup:
 
     /* Try to take a decision without lookahead.  */

-    yyn = yypact_[yystate];
-    if (yyn == yypact_ninf_)
+    yyn = yypact_[yystack_[0].state];
+    if (yy_pact_value_is_default_ (yyn))

       goto yydefault;
 
     /* Read a lookahead token.  */
       goto yydefault;
 
     /* Read a lookahead token.  */

-    if (yychar == yyempty_)
+    if (yyempty)

       {
       {

-       YYCDEBUG << "Reading a token: ";
-       yychar = ]b4_c_function_call([yylex], [int],
+        YYCDEBUG << "Reading a token: ";
+]b4_lex_symbol_if(
+[        yyla = b4_c_function_call([yylex], [symbol_type],
+                                   m4_ifdef([b4_lex_param], b4_lex_param));],
+[        yyla.type = yytranslate_ (b4_c_function_call([yylex], [int],

                                     [[YYSTYPE*], [&yyla.value]][]dnl
 b4_locations_if([, [[location*], [&yyla.location]]])dnl
                                     [[YYSTYPE*], [&yyla.value]][]dnl
 b4_locations_if([, [[location*], [&yyla.location]]])dnl

-m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
-      }
-
-    /* Convert token to internal form.  */
-    if (yychar <= yyeof_)
-      {
-       yychar = yyla.type = yyeof_;
-       YYCDEBUG << "Now at end of input." << std::endl;
-      }
-    else
-      {
-       yyla.type = yytranslate_ (yychar);
-       YY_SYMBOL_PRINT ("Next token is", yyla);
+m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[
+        yyempty = false;

       }
       }

+    YY_SYMBOL_PRINT ("Next token is", yyla);

 
     /* If the proper action on seeing token YYLA.TYPE is to reduce or
        to detect an error, take that action.  */
 
     /* If the proper action on seeing token YYLA.TYPE is to reduce or
        to detect an error, take that action.  */


@@ -1173,14 +758,14 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     yyn = yytable_[yyn];
     if (yyn <= 0)
       {
     yyn = yytable_[yyn];
     if (yyn <= 0)
       {

-       if (yyn == 0 || yyn == yytable_ninf_)
+       if (yy_table_value_is_error_ (yyn))

          goto yyerrlab;
        yyn = -yyn;
        goto yyreduce;
       }
 
     /* Discard the token being shifted.  */
          goto yyerrlab;
        yyn = -yyn;
        goto yyreduce;
       }
 
     /* Discard the token being shifted.  */

-    yychar = yyempty_;
+    yyempty = true;

 
     /* Count tokens shifted since error; after three, turn off error
        status.  */
 
     /* Count tokens shifted since error; after three, turn off error
        status.  */


@@ -1188,15 +773,14 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       --yyerrstatus_;
 
     /* Shift the lookahead token.  */
       --yyerrstatus_;
 
     /* Shift the lookahead token.  */

-    yystate = yyn;
-    yypush_ ("Shifting", yystate, yyla);
+    yypush_ ("Shifting", yyn, yyla);

     goto yynewstate;
 
   /*-----------------------------------------------------------.
   | yydefault -- do the default action for the current state.  |
   `-----------------------------------------------------------*/
   yydefault:
     goto yynewstate;
 
   /*-----------------------------------------------------------.
   | yydefault -- do the default action for the current state.  |
   `-----------------------------------------------------------*/
   yydefault:

-    yyn = yydefact_[yystate];
+    yyn = yydefact_[yystack_[0].state];

     if (yyn == 0)
       goto yyerrlab;
     goto yyreduce;
     if (yyn == 0)
       goto yyerrlab;
     goto yyreduce;


@@ -1205,11 +789,12 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
   | yyreduce -- Do a reduction.  |
   `-----------------------------*/
   yyreduce:
   | yyreduce -- Do a reduction.  |
   `-----------------------------*/
   yyreduce:

-    yylen = yyr2_[yyn];]b4_variant_if([
+    yylen = yyr2_[yyn];
+    yylhs.state = yy_lr_goto_state_(yystack_[yylen].state, yyr1_[yyn]);]b4_variant_if([

     /* Variants are always initialized to an empty instance of the
     /* Variants are always initialized to an empty instance of the

-       correct type. The default $$=$1 rule is NOT applied when using
-       variants */
-    ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])[],[
+       correct type. The default $$=$1 action is NOT applied when using
+       variants.  */
+    b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])],[

     /* If YYLEN is nonzero, implement the default value of the action:
        `$$ = $1'.  Otherwise, use the top of the stack.
 
     /* If YYLEN is nonzero, implement the default value of the action:
        `$$ = $1'.  Otherwise, use the top of the stack.
 


@@ -1220,42 +805,45 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       yylhs.value = yystack_@{yylen - 1@}.value;
     else
       yylhs.value = yystack_@{0@}.value;])[
       yylhs.value = yystack_@{yylen - 1@}.value;
     else
       yylhs.value = yystack_@{0@}.value;])[

-
+]b4_locations_if([dnl
+[

     // Compute the default @@$.
     {
       slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
       YYLLOC_DEFAULT (yylhs.location, slice, yylen);
     // Compute the default @@$.
     {
       slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
       YYLLOC_DEFAULT (yylhs.location, slice, yylen);

-    }
+    }]])[

 
     // Perform the reduction.
     YY_REDUCE_PRINT (yyn);
 
     // Perform the reduction.
     YY_REDUCE_PRINT (yyn);

-    switch (yyn)
+    try
+    {
+      switch (yyn)

       {
 ]b4_user_actions[
        default:
           break;
       }
       {
 ]b4_user_actions[
        default:
           break;
       }

-    // Compute post-reduction state.
-    yyn = yyr1_[yyn];
-    yystate = yypgoto_[yyn - yyntokens_] + yystack_[yylen].state;
-    if (0 <= yystate && yystate <= yylast_
-       && yycheck_[yystate] == yystack_[yylen].state)
-      yystate = yytable_[yystate];
-    else
-      yystate = yydefgoto_[yyn - yyntokens_];
-    yylhs.state = yystate;
+    }
+    catch (const syntax_error& yyexc)
+    {
+      error (]b4_args(b4_locations_if([yyexc.location]),
+                      [[yyexc.what()]])[);
+      YYERROR;
+    }

     YY_SYMBOL_PRINT ("-> $$ =", yylhs);
 ]b4_variant_if([[
     YY_SYMBOL_PRINT ("-> $$ =", yylhs);
 ]b4_variant_if([[

-    // Destroy the lhs symbols.
+    // Destroy the rhs symbols.

     for (int i = 0; i < yylen; ++i)
     for (int i = 0; i < yylen; ++i)

-      // Destroy a variant which value may have be swapped with
-      // yylhs.value.  The value of yylhs.value (hence maybe one of
-      // these lhs symbols) depends on what does the default
-      // contruction for this type.  In the case of pointers for
-      // instance, nothing is done, so the value is junk.  Therefore
-      // do not try to report the content in the debug trace, it's
-      // junk.  Hence yymsg = 0.  Besides, that keeps exactly the same
-      // traces as with the other Bison skeletons.
+      // Destroy a variant which value may have been swapped with
+      // yylhs.value (for instance if the action was "std::swap($$,
+      // $1)").  The value of yylhs.value (hence possibly one of these
+      // rhs symbols) depends on the default contruction for this
+      // type.  In the case of pointers for instance, no
+      // initialization is done, so the value is junk.  Therefore do
+      // not try to report the value of symbols about to be destroyed
+      // in the debug trace, it's possibly junk.  Hence yymsg = 0.
+      // Besides, that keeps exactly the same traces as with the other
+      // Bison skeletons.

       yy_destroy_ (0, yystack_[i]);]])[
 
     yypop_ (yylen);
       yy_destroy_ (0, yystack_[i]);]])[
 
     yypop_ (yylen);


@@ -1266,33 +854,32 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     yypush_ (0, yylhs);
     goto yynewstate;
 
     yypush_ (0, yylhs);
     goto yynewstate;
 

-  /*------------------------------------.
-  | yyerrlab -- here on detecting error |
-  `------------------------------------*/
+  /*--------------------------------------.
+  | yyerrlab -- here on detecting error.  |
+  `--------------------------------------*/

   yyerrlab:
     /* If not already recovering from an error, report this error.  */
     if (!yyerrstatus_)
       {
        ++yynerrs_;
   yyerrlab:
     /* If not already recovering from an error, report this error.  */
     if (!yyerrstatus_)
       {
        ++yynerrs_;

-       error (yyla.location, yysyntax_error_ (yystate, yyla.type));
+       error (]b4_args(b4_locations_if([yyla.location]),
+                        [[yysyntax_error_ (yystack_[0].state, yyla.type)]])[);

       }
 
       }
 

-    yyerror_range[0].location = yyla.location;
+]b4_locations_if([[
+    yyerror_range[0].location = yyla.location;]])[

     if (yyerrstatus_ == 3)
       {
        /* If just tried and failed to reuse lookahead token after an
     if (yyerrstatus_ == 3)
       {
        /* If just tried and failed to reuse lookahead token after an

-        error, discard it.  */
-
-       if (yychar <= yyeof_)
-         {
-            /* Return failure if at end of input.  */
-            if (yychar == yyeof_)
-              YYABORT;
-         }
-       else
-         {
-           yy_destroy_ ("Error: discarding", yyla);
-           yychar = yyempty_;
+           error, discard it.  */
+
+        /* Return failure if at end of input.  */
+        if (yyla.type == yyeof_)
+          YYABORT;
+        else if (!yyempty)
+          {
+            yy_destroy_ ("Error: discarding", yyla);
+            yyempty = true;

          }
       }
 
          }
       }
 


@@ -1310,14 +897,14 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
        YYERROR and the label yyerrorlab therefore never appears in user
        code.  */
     if (false)
        YYERROR and the label yyerrorlab therefore never appears in user
        code.  */
     if (false)

-      goto yyerrorlab;
-
-    yyerror_range[0].location = yystack_[yylen - 1].location;
+      goto yyerrorlab;]b4_locations_if([[
+    yyerror_range[0].location = yystack_[yylen - 1].location;]])b4_variant_if([[
+    /* $$ was initialized before running the user action.  */
+    yy_destroy_ ("Error: discarding", yylhs);]])[

     /* Do not reclaim the symbols of the rule which action triggered
        this YYERROR.  */
     yypop_ (yylen);
     yylen = 0;
     /* Do not reclaim the symbols of the rule which action triggered
        this YYERROR.  */
     yypop_ (yylen);
     yylen = 0;

-    yystate = yystack_[0].state;

     goto yyerrlab1;
 
   /*-------------------------------------------------------------.
     goto yyerrlab1;
 
   /*-------------------------------------------------------------.


@@ -1329,8 +916,8 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       stack_symbol_type error_token;
       for (;;)
         {
       stack_symbol_type error_token;
       for (;;)
         {

-          yyn = yypact_[yystate];
-          if (yyn != yypact_ninf_)
+          yyn = yypact_[yystack_[0].state];
+          if (!yy_pact_value_is_default_ (yyn))

             {
               yyn += yyterror_;
               if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
             {
               yyn += yyterror_;
               if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)


@@ -1344,19 +931,18 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
           // Pop the current state because it cannot handle the error token.
           if (yystack_.size () == 1)
             YYABORT;
           // Pop the current state because it cannot handle the error token.
           if (yystack_.size () == 1)
             YYABORT;

-
-          yyerror_range[0].location = yystack_[0].location;
+]b4_locations_if([[
+          yyerror_range[0].location = yystack_[0].location;]])[

           yy_destroy_ ("Error: popping", yystack_[0]);
           yypop_ ();
           yy_destroy_ ("Error: popping", yystack_[0]);
           yypop_ ();

-          yystate = yystack_[0].state;

           YY_STACK_PRINT ();
         }
           YY_STACK_PRINT ();
         }

-
+]b4_locations_if([[

       yyerror_range[1].location = yyla.location;
       yyerror_range[1].location = yyla.location;

-      YYLLOC_DEFAULT (error_token.location, (yyerror_range - 1), 2);
+      YYLLOC_DEFAULT (error_token.location, (yyerror_range - 1), 2);]])[

 
       /* Shift the error token.  */
 
       /* Shift the error token.  */

-      error_token.state = yystate = yyn;
+      error_token.state = yyn;

       yypush_ ("Shifting", error_token);
     }
     goto yynewstate;
       yypush_ ("Shifting", error_token);
     }
     goto yynewstate;


@@ -1372,7 +958,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     goto yyreturn;
 
   yyreturn:
     goto yyreturn;
 
   yyreturn:

-    if (yychar != yyempty_)
+    if (!yyempty)

       yy_destroy_ ("Cleanup: discarding lookahead", yyla);
 
     /* Do not reclaim the symbols of the rule which action triggered
       yy_destroy_ ("Cleanup: discarding lookahead", yyla);
 
     /* Do not reclaim the symbols of the rule which action triggered


@@ -1389,95 +975,81 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
 
   // Generate an error message.
   std::string
 
   // Generate an error message.
   std::string

-  ]b4_parser_class_name[::yysyntax_error_ (int yystate, int]dnl
-b4_error_verbose_if([ tok])[)
+  ]b4_parser_class_name[::yysyntax_error_ (]dnl
+b4_error_verbose_if([state_type yystate, int yytoken],
+                    [int, int])[)

   {
   {

-    std::string res;
-    YYUSE (yystate);
-#if YYERROR_VERBOSE
+    std::string yyres;]b4_error_verbose_if([[

     int yyn = yypact_[yystate];
     if (yypact_ninf_ < yyn && yyn <= yylast_)
       {
        /* Start YYX at -YYN if negative to avoid negative indexes in
     int yyn = yypact_[yystate];
     if (yypact_ninf_ < yyn && yyn <= yylast_)
       {
        /* Start YYX at -YYN if negative to avoid negative indexes in

-          YYCHECK.  */
+          YYCHECK.  In other words, skip the first -YYN actions for this
+          state because they are default actions.  */

        int yyxbegin = yyn < 0 ? -yyn : 0;
 
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
        int yyxbegin = yyn < 0 ? -yyn : 0;
 
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;

-       int count = 0;
-       for (int x = yyxbegin; x < yyxend; ++x)
-         if (yycheck_[x + yyn] == x && x != yyterror_)
-           ++count;
-
-       // FIXME: This method of building the message is not compatible
-       // with internationalization.  It should work like yacc.c does it.
-       // That is, first build a string that looks like this:
-       // "syntax error, unexpected %s or %s or %s"
-       // Then, invoke YY_ on this string.
-       // Finally, use the string as a format to output
-       // yytname_[tok], etc.
-       // Until this gets fixed, this message appears in English only.
-       res = "syntax error, unexpected ";
-       res += yytnamerr_ (yytname_[tok]);
-       if (count < 5)
-         {
-           count = 0;
-           for (int x = yyxbegin; x < yyxend; ++x)
-             if (yycheck_[x + yyn] == x && x != yyterror_)
-               {
-                 res += (!count++) ? ", expecting " : " or ";
-                 res += yytnamerr_ (yytname_[x]);
-               }
-         }
+
+        // Number of reported tokens (one for the "unexpected", one per
+        // "expected").
+       size_t yycount = 0;
+        // Its maximum.
+        enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
+        // Arguments of yyformat.
+        char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
+        yyarg[yycount++] = yytname_[yytoken];
+       for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
+         if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_
+             && !yy_table_value_is_error_ (yytable_[yyx + yyn]))
+          {
+            if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
+            {
+              yycount = 1;
+              break;
+            }
+            else
+              yyarg[yycount++] = yytname_[yyx];
+          }
+
+        char const* yyformat = 0;
+        switch (yycount)
+        {
+#define YYCASE_(N, S)                           \
+          case N:                               \
+            yyformat = S;                       \
+          break
+          YYCASE_(1, YY_("syntax error, unexpected %s"));
+          YYCASE_(2, YY_("syntax error, unexpected %s, expecting %s"));
+          YYCASE_(3, YY_("syntax error, unexpected %s, expecting %s or %s"));
+          YYCASE_(4, YY_("syntax error, unexpected %s, expecting %s or %s or %s"));
+          YYCASE_(5, YY_("syntax error, unexpected %s, expecting %s or %s or %s or %s"));
+#undef YYCASE_
+        }
+        // Argument number.
+        size_t yyi = 0;
+        for (char const* yyp = yyformat; *yyp; ++yyp)
+          if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount)
+          {
+            yyres += yytnamerr_ (yyarg[yyi++]);
+            ++yyp;
+          }
+          else
+            yyres += *yyp;

       }
     else
       }
     else

-#endif
-      res = YY_("syntax error");
-    return res;
+  ]])dnl
+[    yyres = YY_("syntax error");
+    return yyres;

   }
 
 
   }
 
 

-  /* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
-     STATE-NUM.  */

   const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) b4_parser_class_name::yypact_ninf_ = b4_pact_ninf[;
   const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) b4_parser_class_name::yypact_ninf_ = b4_pact_ninf[;

-  ]b4_table_define([pact], [b4_pact])[;
-
-  /* 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.  */
-  ]b4_table_define([defact], [b4_defact])[;
-
-  /* YYPGOTO[NTERM-NUM].  */
-  ]b4_table_define([pgoto], [b4_pgoto])[;
-
-  /* YYDEFGOTO[NTERM-NUM].  */
-  ]b4_table_define([defgoto], [b4_defgoto])[;

 
 

-  /* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
-     positive, shift that token.  If negative, reduce the rule which
-     number is the opposite.  If zero, do what YYDEFACT says.  */

   const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class_name::yytable_ninf_ = b4_table_ninf[;
   const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class_name::yytable_ninf_ = b4_table_ninf[;

-  ]b4_table_define([table], [b4_table])[;

 
 

-  /* YYCHECK.  */
-  ]b4_table_define([check], [b4_check])[;
-
-  /* STOS_[STATE-NUM] -- The (internal number of the) accessing
-     symbol of state STATE-NUM.  */
-  ]b4_table_define([stos], [b4_stos])[;
-
-#if YYDEBUG
-  /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal symbol number corresponding
-     to YYLEX-NUM.  */
-  ]b4_table_define([token_number], [b4_toknum])[;
-#endif
-
-  /* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
-  ]b4_table_define([r1], [b4_r1])[;
-
-  /* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
-  ]b4_table_define([r2], [b4_r2])[;
+]b4_parser_tables_define[

 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.


@@ -1490,8 +1062,7 @@ b4_error_verbose_if([ tok])[)
 #endif
 
 #if YYDEBUG
 #endif
 
 #if YYDEBUG

-  /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
-  ]b4_table_define([rline], [b4_rline])[;
+]b4_integral_parser_table_define([rline], [b4_rline])[

 
   // Print the state stack on the debug stream.
   void
 
   // Print the state stack on the debug stream.
   void


@@ -1522,125 +1093,8 @@ b4_error_verbose_if([ tok])[)
   }
 #endif // YYDEBUG
 
   }
 #endif // YYDEBUG
 

-  /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
-  ]b4_parser_class_name[::token_number_type
-  ]b4_parser_class_name[::yytranslate_ (int t)
-  {
-    static
-    const token_number_type
-    translate_table[] =
-    {
-]b4_translate[
-    };
-    const unsigned int user_token_number_max_ = ]b4_user_token_number_max[;
-    const token_number_type undef_token_ = ]b4_undef_token_number[;
-
-    if (static_cast<unsigned int> (t) <= user_token_number_max_)
-      return translate_table[t];
-    else
-      return undef_token_;
-  }
-
+]b4_lex_symbol_if([], [b4_yytranslate_define])[

 ]b4_namespace_close[
 ]b4_namespace_close[

-

 ]b4_epilogue[]dnl
 ]b4_epilogue[]dnl

-@output(b4_dir_prefix[]stack.hh@)@
-b4_copyright([Stack handling for Bison parsers in C++])[
-
-#ifndef BISON_STACK_HH
-# define BISON_STACK_HH
-
-#include <deque>
-
-]b4_namespace_open[
-  template <class T, class S = std::deque<T> >
-  class stack
-  {
-  public:
-
-    // Hide our reversed order.
-    typedef typename S::reverse_iterator iterator;
-    typedef typename S::const_reverse_iterator const_iterator;
-
-    stack () : seq_ ()
-    {
-    }
-
-    stack (unsigned int n) : seq_ (n)
-    {
-    }
-
-    inline
-    T&
-    operator [] (unsigned int i)
-    {
-      return seq_[i];
-    }
-
-    inline
-    const T&
-    operator [] (unsigned int i) const
-    {
-      return seq_[i];
-    }
-
-    inline
-    void
-    push (const T& t)
-    {
-      seq_.push_front (t);
-    }
-
-    inline
-    void
-    pop (unsigned int n = 1)
-    {
-      for (; n; --n)
-       seq_.pop_front ();
-    }
-
-    inline
-    typename S::size_type
-    size () const
-    {
-      return seq_.size ();
-    }
-
-    inline const_iterator begin () const { return seq_.rbegin (); }
-    inline const_iterator end ()   const { return seq_.rend ();   }
-
-  private:
-    /// The wrapped container.
-    S seq_;
-  };
-
-  /// Present a slice of the top of a stack.
-  template <class T, class S = stack<T> >
-  class slice
-  {
-  public:
-
-    slice (const S& stack,
-          unsigned int range) : stack_ (stack),
-                                range_ (range)
-    {
-    }
-
-    inline
-    const T&
-    operator [] (unsigned int i) const
-    {
-      return stack_[range_ - i];
-    }
-
-  private:
-
-    const S& stack_;
-    unsigned int range_;
-  };
-]b4_namespace_close[
-
-#endif // not BISON_STACK_HH[]dnl
-]

 m4_divert_pop(0)
 m4_popdef([b4_copyright_years])dnl
 m4_divert_pop(0)
 m4_popdef([b4_copyright_years])dnl