gnulib: update

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 4f0b268880d01b16ffa14eca65dcb3b839616993..7b2aef2d85f82b6150f77dd490bd42047c4e9e36 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -17,94 +17,145 @@
 
 m4_include(b4_pkgdatadir/[c++.m4])
 
 
 m4_include(b4_pkgdatadir/[c++.m4])
 

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

 
 

-# The header is mandatory.
-b4_defines_if([],
-              [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
+# 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_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.
+m4_define([b4_integral_parser_table_define],
+[  const b4_int_type_for([$2])
+  b4_parser_class_name::yy$1_[[]] =
+  {
+  $2
+  };dnl
+])

 
 

-b4_percent_define_ifdef([[location_type]], [],
-  [# Backward compatibility.
-  m4_define([b4_location_constructors])
-  m4_include(b4_pkgdatadir/[location.cc])])
-m4_include(b4_pkgdatadir/[stack.hh])

 
 

-# We do want M4 expansion after # for CPP macros.
-m4_changecom()
-m4_divert_push(0)dnl
-b4_defines_if(
-[@output(b4_spec_defines_file@)@
-b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++],
-             [2002-2012])
-[
-/**
- ** \file ]b4_spec_defines_file[
- ** Define the ]b4_namespace_ref[::parser class.
- */
+# b4_symbol_value_template(VAL, [TYPE])
+# -------------------------------------
+# 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])

 
 

-/* C++ LALR(1) parser skeleton written by Akim Demaille.  */

 
 

-]b4_cpp_guard_open([b4_spec_defines_file])[
+# b4_lhs_value([TYPE])
+# --------------------
+# Expansion of $<TYPE>$.
+m4_define([b4_lhs_value],
+          [b4_symbol_value([yylhs.value], [$1])])

 
 

-]b4_percent_code_get([[requires]])[

 
 

-#include <string>
-#include <iostream>
-#include "stack.hh"
-]b4_percent_define_ifdef([[location_type]], [],
-                         [[#include "location.hh"]])[
+# b4_lhs_location()
+# -----------------
+# Expansion of @$.
+m4_define([b4_lhs_location],
+          [yylhs.location])

 
 

-]b4_null_define[

 
 

-/* Enabling traces.  */
-#ifndef YYDEBUG
-# define YYDEBUG ]b4_debug_flag[
-#endif
+# b4_rhs_data(RULE-LENGTH, NUM)
+# -----------------------------
+# Return the data corresponding to the symbol #NUM, where the current
+# rule has RULE-LENGTH symbols on RHS.
+m4_define([b4_rhs_data],
+          [yystack_@{b4_subtract($@)@}])

 
 

-/* Enabling verbose error messages.  */
-#ifdef YYERROR_VERBOSE
-# undef YYERROR_VERBOSE
-# define YYERROR_VERBOSE 1
-#else
-# define YYERROR_VERBOSE ]b4_error_verbose_flag[
-#endif

 
 

-/* Enabling the token table.  */
-#ifndef YYTOKEN_TABLE
-# define YYTOKEN_TABLE ]b4_token_table[
-#endif
+# 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],
+          [b4_rhs_data([$1], [$2]).state])
+
+
+# b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
+# --------------------------------------
+# Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
+# symbols on RHS.
+m4_define([b4_rhs_value],
+          [b4_symbol_value([b4_rhs_data([$1], [$2]).value], [$3])])
+
+
+# b4_rhs_location(RULE-LENGTH, NUM)
+# ---------------------------------
+# Expansion of @NUM, where the current rule has RULE-LENGTH symbols
+# on RHS.
+m4_define([b4_rhs_location],
+          [b4_rhs_data([$1], [$2]).location])
+
+
+# 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.
+m4_define([b4_symbol_action],
+[b4_symbol_if([$1], [has_$2],
+[m4_pushdef([b4_symbol_value], m4_defn([b4_symbol_value_template]))[]dnl
+b4_dollar_pushdef([yysym.value],
+                   b4_symbol_if([$1], [has_type],
+                                [m4_dquote(b4_symbol([$1], [type]))]),
+                   [yysym.location])dnl
+      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;
+
+m4_popdef([b4_symbol_value])[]dnl
+b4_dollar_popdef[]dnl
+])])
+
+
+m4_pushdef([b4_copyright_years],
+           [2002-2012])
+
+m4_define([b4_parser_class_name],
+          [b4_percent_define_get([[parser_class_name]])])
+
+b4_bison_locations_if([# Backward compatibility.
+   m4_define([b4_location_constructors])
+   m4_include(b4_pkgdatadir/[location.cc])])
+m4_include(b4_pkgdatadir/[stack.hh])
+b4_variant_if([m4_include(b4_pkgdatadir/[variant.hh])])
+
+# b4_shared_declarations
+# ----------------------
+# Declaration that might either go into the header (if --defines)
+# or open coded in the parser body.
+m4_define([b4_shared_declarations],
+[b4_percent_code_get([[requires]])[
+]b4_parse_assert_if([# include <cassert>])[
+# include <deque>
+# include <iostream>
+# include <stdexcept>
+# include <string>]b4_defines_if([[
+# include "stack.hh"
+]b4_bison_locations_if([[# include "location.hh"]])])[
+
+]b4_YYDEBUG_define[

 
 ]b4_namespace_open[
 
 
 ]b4_namespace_open[
 

+]b4_defines_if([],
+[b4_stack_define
+b4_bison_locations_if([b4_position_define
+b4_location_define])])[
+
+]b4_variant_if([b4_variant_define])[
+

   /// A Bison parser.
   class ]b4_parser_class_name[
   {
   public:
   /// A Bison parser.
   class ]b4_parser_class_name[
   {
   public:

-    /// Symbol semantic values.
-#ifndef YYSTYPE
-]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]])[ 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[ ();


@@ -113,7 +164,7 @@ b4_user_stype
     /// \returns  0 iff parsing succeeded.
     virtual int parse ();
 
     /// \returns  0 iff parsing succeeded.
     virtual int parse ();
 

-#if YYDEBUG
+#if ]b4_api_PREFIX[DEBUG

     /// The current debugging stream.
     std::ostream& debug_stream () const;
     /// Set the current debugging stream.
     /// The current debugging stream.
     std::ostream& debug_stream () const;
     /// Set the current debugging stream.


@@ -127,50 +178,27 @@ b4_user_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);
-
-#if YYDEBUG
-    /// \brief Report a symbol value on the debug stream.
-    /// \param yytype       The token type.
-    /// \param yyvaluep     Its semantic value.
-    /// \param yylocationp  Its location.
-    virtual void yy_symbol_value_print_ (int yytype,
-                                        const semantic_type* yyvaluep,
-                                        const location_type* yylocationp);
-    /// \brief Report a symbol on the debug stream.
-    /// \param yytype       The token type.
-    /// \param yyvaluep     Its semantic value.
-    /// \param yylocationp  Its location.
-    virtual void yy_symbol_print_ (int yytype,
-                                  const semantic_type* yyvaluep,
-                                  const location_type* yylocationp);
-#endif
+    virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);

 
 

+    /// Report a syntax error.
+    void error (const syntax_error& err);

 
 

+  private:

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

-    /// State stack type.
-    typedef stack<state_type>    state_stack_type;
-    /// Semantic value stack type.
-    typedef stack<semantic_type> semantic_stack_type;
-    /// location stack type.
-    typedef stack<location_type> location_stack_type;
-
-    /// The state stack.
-    state_stack_type yystate_stack_;
-    /// The semantic value stack.
-    semantic_stack_type yysemantic_stack_;
-    /// The location stack.
-    location_stack_type yylocation_stack_;
+
+    /// 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);
+
+    /// 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);

 
     /// Whether the given \c yypact_ value indicates a defaulted state.
     /// \param yyvalue   the value to check
 
     /// Whether the given \c yypact_ value indicates a defaulted state.
     /// \param yyvalue   the value to check


@@ -182,129 +210,167 @@ b4_user_stype
 
     /// Internal symbol numbers.
     typedef ]b4_int_type_for([b4_translate])[ token_number_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_;
     static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;

-
-    /// For a state, default reduction number.
-    /// Unless\a  yytable_ specifies something else to do.
-    /// Zero means the default is an error.
-    static const ]b4_int_type_for([b4_defact])[ yydefact_[];
-
-    static const ]b4_int_type_for([b4_pgoto])[ yypgoto_[];
-    static const ]b4_int_type_for([b4_defgoto])[ yydefgoto_[];
-
-    /// 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_;
 
     static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
 

-    static const ]b4_int_type_for([b4_check])[ yycheck_[];
-
-    /// For a state, its accessing symbol.
-    static const ]b4_int_type_for([b4_stos])[ yystos_[];
-
-    /// 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_[];
-
-#if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
-    /// For a symbol, its name in clear.
-    static const char* const yytname_[];
-#endif]b4_error_verbose_if([
+    // Tables.
+]b4_parser_tables_declare[]b4_error_verbose_if([

 
     /// Convert the symbol name \a n to a form suitable for a diagnostic.
     static std::string yytnamerr_ (const char *n);])[
 
 
     /// Convert the symbol name \a n to a form suitable for a diagnostic.
     static std::string yytnamerr_ (const char *n);])[
 

-#if YYDEBUG
-    /// A type to store symbol numbers and -1.
-    typedef ]b4_int_type_for([b4_rhs])[ rhs_number_type;
-    /// A `-1'-separated list of the rules' RHS.
-    static const rhs_number_type yyrhs_[];
-    /// For each rule, the index of the first RHS symbol in \a yyrhs_.
-    static const ]b4_int_type_for([b4_prhs])[ yyprhs_[];
-    /// 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_token_table_if([], [[#if ]b4_api_PREFIX[DEBUG]])[
+    /// For a symbol, its name in clear.
+    static const char* const yytname_[];
+]b4_token_table_if([[#if ]b4_api_PREFIX[DEBUG]])[
+]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.
     virtual void yystack_print_ ();
 
     /// 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.
     virtual void yystack_print_ ();
 

-    /* Debugging.  */
+    // Debugging.

     int yydebug_;
     std::ostream* yycdebug_;
     int yydebug_;
     std::ostream* yycdebug_;

-#endif
+#endif // ]b4_api_PREFIX[DEBUG

 
     /// Convert a scanner token number \a t to a symbol number.
 
     /// Convert a scanner token number \a t to a symbol number.

-    token_number_type yytranslate_ (int t);
+    static inline token_number_type yytranslate_ (]b4_token_ctor_if([token_type], [int])[ t);
+
+#if ]b4_api_PREFIX[DEBUG
+    /// \brief Display a symbol type, value and location.
+    /// \param yyo    The output stream.
+    /// \param yysym  The symbol.
+    template <typename Exact>
+    void yy_print_ (std::ostream& yyo,
+                    const symbol_base_type<Exact>& yysym) const;
+#endif

 
     /// \brief Reclaim the memory associated to a symbol.
 
     /// \brief Reclaim the memory associated to a symbol.

-    /// \param yymsg        Why this token is reclaimed.
-    /// \param yytype       The symbol type.
-    /// \param yyvaluep     Its semantic value.
-    /// \param yylocationp  Its location.
-    inline void yydestruct_ (const char* yymsg,
-                            int yytype,
-                            semantic_type* yyvaluep,
-                            location_type* yylocationp);
+    /// \param yymsg     Why this token is reclaimed.
+    ///                  If null, print nothing.
+    /// \param s         The symbol.
+    template <typename Exact>
+    inline void yy_destroy_ (const char* yymsg,
+                             symbol_base_type<Exact>& yysym) const;
+
+  private:
+    /// Element of the stack: a state and its attributes.
+    struct stack_symbol_type : symbol_base_type<stack_symbol_type>
+    {
+      /// The parent class.
+      typedef symbol_base_type<stack_symbol_type> super_type;
+
+      /// Default constructor.
+      inline stack_symbol_type ();
+
+      /// Constructor.
+      inline stack_symbol_type (]b4_join([state_type s],
+                                         [const semantic_type& v],
+                                         b4_locations_if([const location_type& l]))[);
+
+      /// The state.
+      state_type state;
+
+      /// The type (corresponding to \a state).
+      inline int type_get_ () const;
+    };
+
+    /// Stack type.
+    typedef stack<stack_symbol_type> stack_type;
+
+    /// The stack.
+    stack_type yystack_;
+
+    /// Push a new state on the stack.
+    /// \param m    a debug message to display
+    ///             if null, no trace is output.
+    /// \param s    the symbol
+    /// \warning the contents of \a s.value is stolen.
+    inline void yypush_ (const char* m, stack_symbol_type& s);
+
+    /// Push a new look ahead token on the state on the stack.
+    /// \param m    a debug message to display
+    ///             if null, no trace is output.
+    /// \param s    the state
+    /// \param sym  the symbol (for its value and location).
+    /// \warning the contents of \a s.value is stolen.
+    inline void yypush_ (const char* m, state_type s, symbol_type& sym);

 
     /// Pop \a n symbols the three stacks.
     inline void yypop_ (unsigned int n = 1);
 
     /* Constants.  */
 
     /// Pop \a n symbols the three stacks.
     inline void yypop_ (unsigned int n = 1);
 
     /* Constants.  */

-    static const int yyeof_;
-    /* LAST_ -- Last index in TABLE_.  */
-    static const int yylast_;
-    static const int yynnts_;
-    static const int yyempty_;
-    static const int yyfinal_;
-    static const int yyterror_;
-    static const int yyerrcode_;
-    static const int yyntokens_;
-    static const unsigned int yyuser_token_number_max_;
-    static const token_number_type yyundef_token_;
+    enum
+    {
+      yyeof_ = 0,
+      yylast_ = ]b4_last[,           //< Last index in yytable_.
+      yynnts_ = ]b4_nterms_number[,  //< Number of nonterminal symbols.
+      yyempty_ = -2,
+      yyfinal_ = ]b4_final_state_number[, //< Termination state number.
+      yyterror_ = 1,
+      yyerrcode_ = 256,
+      yyntokens_ = ]b4_tokens_number[    //< Number of tokens.
+    };
+

 ]b4_parse_param_vars[
   };
 ]b4_parse_param_vars[
   };

+
+]b4_token_ctor_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]],

-[b4_token_defines(b4_tokens)
+[b4_token_defines

 
 

-#ifndef YYSTYPE
+#ifndef ]b4_api_PREFIX[STYPE

  /* Redirection for backward compatibility.  */
  /* Redirection for backward compatibility.  */

-# define YYSTYPE b4_namespace_ref::b4_parser_class_name::semantic_type
+# define ]b4_api_PREFIX[STYPE b4_namespace_ref::b4_parser_class_name::semantic_type

 #endif
 ])[
 ]b4_percent_code_get([[provides]])[
 #endif
 ])[
 ]b4_percent_code_get([[provides]])[

+]])
+
+b4_defines_if(
+[b4_output_begin([b4_spec_defines_file])
+b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++])
+[
+/**
+ ** \file ]b4_spec_defines_file[
+ ** Define the ]b4_namespace_ref[::parser class.
+ */
+
+/* C++ LALR(1) parser skeleton written by Akim Demaille.  */
+
+]b4_cpp_guard_open([b4_spec_defines_file])[
+]b4_shared_declarations[

 ]b4_cpp_guard_close([b4_spec_defines_file])
 ]b4_cpp_guard_close([b4_spec_defines_file])

-])dnl
-@output(b4_parser_file_name@)@
-b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++],
-             [2002-2012])
+b4_output_end()
+])
+
+
+b4_output_begin([b4_parser_file_name])
+b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++])

 b4_percent_code_get([[top]])[]dnl
 m4_if(b4_prefix, [yy], [],
 [
 // Take the name prefix into account.
 #define yylex   b4_prefix[]lex])[
 
 b4_percent_code_get([[top]])[]dnl
 m4_if(b4_prefix, [yy], [],
 [
 // Take the name prefix into account.
 #define yylex   b4_prefix[]lex])[
 

-/* First part of user declarations.  */
-]b4_user_pre_prologue
+// First part of user declarations.
+]b4_user_pre_prologue[
+
+]b4_null_define[

 
 

-b4_defines_if([[
-#include "@basename(]b4_spec_defines_file[@)"]])[
+]b4_defines_if([[#include "@basename(]b4_spec_defines_file[@)"]],
+               [b4_shared_declarations])[

 
 /* User implementation prologue.  */
 
 /* User implementation prologue.  */

-]b4_user_post_prologue
-b4_percent_code_get[]dnl
+]b4_user_post_prologue[
+]b4_percent_code_get[

 
 

-[#ifndef YY_
+#ifndef YY_

 # if defined YYENABLE_NLS && YYENABLE_NLS
 #  if ENABLE_NLS
 #   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */
 # if defined YYENABLE_NLS && YYENABLE_NLS
 #  if ENABLE_NLS
 #   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */


@@ -316,72 +382,56 @@ b4_percent_code_get[]dnl
 # endif
 #endif
 
 # endif
 #endif
 

-/* 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).  */
-
-#define YYRHSLOC(Rhs, K) ((Rhs)[K])
-#ifndef YYLLOC_DEFAULT
-# define YYLLOC_DEFAULT(Current, Rhs, N)                               \
- do                                                                    \
-   if (N)                                                              \
-     {                                                                 \
-       (Current).begin = YYRHSLOC (Rhs, 1).begin;                      \
-       (Current).end   = YYRHSLOC (Rhs, N).end;                        \
-     }                                                                 \
-   else                                                                \
-     {                                                                 \
-       (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;        \
-     }                                                                 \
- while (false)
-#endif
+]b4_locations_if([dnl
+[#define YYRHSLOC(Rhs, K) ((Rhs)[K].location)
+]b4_yylloc_default_define])[

 
 /* Suppress unused-variable warnings by "using" E.  */
 #define YYUSE(e) ((void) (e))
 
 /* Enable debugging if requested.  */
 
 /* Suppress unused-variable warnings by "using" E.  */
 #define YYUSE(e) ((void) (e))
 
 /* Enable debugging if requested.  */

-#if YYDEBUG
+#if ]b4_api_PREFIX[DEBUG

 
 /* A pseudo ostream that takes yydebug_ into account.  */
 # define YYCDEBUG if (yydebug_) (*yycdebug_)
 
 
 /* A pseudo ostream that takes yydebug_ into account.  */
 # define YYCDEBUG if (yydebug_) (*yycdebug_)
 

-# define YY_SYMBOL_PRINT(Title, Type, Value, Location) \
-do {                                                   \
-  if (yydebug_)                                                \
-    {                                                  \
-      *yycdebug_ << Title << ' ';                      \
-      yy_symbol_print_ ((Type), (Value), (Location));  \
-      *yycdebug_ << std::endl;                         \
-    }                                                  \
-} while (false)
-
-# define YY_REDUCE_PRINT(Rule)         \
-do {                                   \
-  if (yydebug_)                                \
-    yy_reduce_print_ (Rule);           \
-} while (false)
-
-# define YY_STACK_PRINT()              \
-do {                                   \
-  if (yydebug_)                                \
-    yystack_print_ ();                 \
-} while (false)
-
-#else /* !YYDEBUG */
+# define YY_SYMBOL_PRINT(Title, Symbol)         \
+  do {                                          \
+    if (yydebug_)                               \
+    {                                           \
+      *yycdebug_ << Title << ' ';               \
+      yy_print_ (*yycdebug_, Symbol);           \
+      *yycdebug_ << std::endl;                  \
+    }                                           \
+  } while (false)
+
+# define YY_REDUCE_PRINT(Rule)          \
+  do {                                  \
+    if (yydebug_)                       \
+      yy_reduce_print_ (Rule);          \
+  } while (false)
+
+# define YY_STACK_PRINT()               \
+  do {                                  \
+    if (yydebug_)                       \
+      yystack_print_ ();                \
+  } while (false)
+
+#else /* !]b4_api_PREFIX[DEBUG */

 
 # define YYCDEBUG if (false) std::cerr
 
 # define YYCDEBUG if (false) std::cerr

-# define YY_SYMBOL_PRINT(Title, Type, Value, Location)
-# define YY_REDUCE_PRINT(Rule)
-# define YY_STACK_PRINT()
+# define YY_SYMBOL_PRINT(Title, Symbol)  YYUSE(Symbol)
+# define YY_REDUCE_PRINT(Rule)           static_cast<void>(0)
+# define YY_STACK_PRINT()                static_cast<void>(0)

 
 

-#endif /* !YYDEBUG */
+#endif /* !]b4_api_PREFIX[DEBUG */

 
 

-#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_)
 
 ]b4_namespace_open[]b4_error_verbose_if([[
 #define YYRECOVERING()  (!!yyerrstatus_)
 
 ]b4_namespace_open[]b4_error_verbose_if([[


@@ -427,7 +477,7 @@ do {                                        \
   /// 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], [
     :])[

-#if YYDEBUG
+#if ]b4_api_PREFIX[DEBUG

     ]m4_ifset([b4_parse_param], [  ], [ :])[yydebug_ (false),
       yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 #endif]b4_parse_param_cons[
     ]m4_ifset([b4_parse_param], [  ], [ :])[yydebug_ (false),
       yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 #endif]b4_parse_param_cons[


@@ -438,68 +488,120 @@ do {                                     \
   {
   }
 
   {
   }
 

-#if YYDEBUG
-  /*--------------------------------.
-  | Print this symbol on YYOUTPUT.  |
-  `--------------------------------*/

 
 

-  inline void
-  ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
-                          const semantic_type* yyvaluep, const location_type* yylocationp)
+  /*---------------.
+  | Symbol types.  |
+  `---------------*/
+
+]b4_token_ctor_if([], [b4_public_types_define])[
+
+  // stack_symbol_type.
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
+    : super_type ()
+    , state ()
+  {
+  }
+
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (]b4_join(
+                 [state_type s],
+                 [const semantic_type& v],
+                 b4_locations_if([const location_type& l]))[)
+    : super_type (v]b4_locations_if([, l])[)
+    , state (s)
+  {
+  }
+
+  int
+  ]b4_parser_class_name[::stack_symbol_type::type_get_ () const
+  {
+    return yystos_[state];
+  }
+
+
+  template <typename Exact>
+  void
+  ]b4_parser_class_name[::yy_destroy_ (const char* yymsg,
+                                       symbol_base_type<Exact>& yysym) const
+  {
+    if (yymsg)
+      YY_SYMBOL_PRINT (yymsg, yysym);
+
+    // User destructor.
+    int yytype = yysym.type_get ();
+    switch (yytype)
+      {
+]b4_symbol_foreach([b4_symbol_destructor])dnl
+[       default:
+          break;
+      }]b4_variant_if([
+
+    // Type destructor.
+  b4_symbol_variant([[yytype]], [[yysym.value]], [[template destroy]])])[
+  }
+
+#if ]b4_api_PREFIX[DEBUG
+  template <typename Exact>
+  void
+  ]b4_parser_class_name[::yy_print_ (std::ostream& yyo,
+                                     const symbol_base_type<Exact>& yysym) const

   {
   {

-    YYUSE (yylocationp);
-    YYUSE (yyvaluep);
-    std::ostream& yyo = debug_stream ();

     std::ostream& yyoutput = yyo;
     YYUSE (yyoutput);
     std::ostream& yyoutput = yyo;
     YYUSE (yyoutput);

+    int yytype = yysym.type_get ();
+    yyo << (yytype < yyntokens_ ? "token" : "nterm")
+        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
+        << yysym.location << ": "])[;

     switch (yytype)
       {
     switch (yytype)
       {

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

 [       default:
 [       default:

-         break;
+          break;

       }
       }

+    yyo << ')';

   }
   }

-
+#endif

 
   void
 
   void

-  ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
-                          const semantic_type* yyvaluep, const location_type* yylocationp)
+  ]b4_parser_class_name[::yypush_ (const char* m, state_type s,
+                                   symbol_type& sym)

   {
   {

-    *yycdebug_ << (yytype < yyntokens_ ? "token" : "nterm")
-              << ' ' << yytname_[yytype] << " ("
-              << *yylocationp << ": ";
-    yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
-    *yycdebug_ << ')';
+    if (m)
+      YY_SYMBOL_PRINT (m, sym);
+]b4_variant_if(
+[[    yystack_.push (stack_symbol_type (]b4_join(
+                    [s],
+                    [semantic_type()],
+                    b4_locations_if([sym.location]))[));
+    ]b4_symbol_variant([[yystos_[s]]], [[yystack_[0].value]],
+                       [build], [sym.value])],
+[[    yystack_.push (stack_symbol_type (]b4_join(
+                      [s],
+                      [sym.value],
+                      b4_locations_if([sym.location]))[));]])[

   }
   }

-#endif

 
   void
 
   void

-  ]b4_parser_class_name[::yydestruct_ (const char* yymsg,
-                          int yytype, semantic_type* yyvaluep, location_type* yylocationp)
+  ]b4_parser_class_name[::yypush_ (const char* m, stack_symbol_type& s)

   {
   {

-    YYUSE (yylocationp);
-    YYUSE (yymsg);
-    YYUSE (yyvaluep);
-
-    YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
-
-    switch (yytype)
-      {
-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
-       default:
-         break;
-      }
+    if (m)
+      YY_SYMBOL_PRINT (m, s);
+]b4_variant_if(
+[[    yystack_.push (stack_symbol_type (]b4_join(
+                       [s.state],
+                       [semantic_type()],
+                       b4_locations_if([s.location]))[));
+    ]b4_symbol_variant([[yystos_[s.state]]], [[yystack_[0].value]],
+                       [build], [s.value])],
+[    yystack_.push (s);])[

   }
 
   void
   ]b4_parser_class_name[::yypop_ (unsigned int n)
   {
   }
 
   void
   ]b4_parser_class_name[::yypop_ (unsigned int n)
   {

-    yystate_stack_.pop (n);
-    yysemantic_stack_.pop (n);
-    yylocation_stack_.pop (n);
+    yystack_.pop (n);

   }
 
   }
 

-#if YYDEBUG
+#if ]b4_api_PREFIX[DEBUG

   std::ostream&
   ]b4_parser_class_name[::debug_stream () const
   {
   std::ostream&
   ]b4_parser_class_name[::debug_stream () const
   {


@@ -524,7 +626,17 @@ do {                                       \
   {
     yydebug_ = l;
   }
   {
     yydebug_ = l;
   }

-#endif
+#endif // ]b4_api_PREFIX[DEBUG
+
+  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)
 
   inline bool
   ]b4_parser_class_name[::yy_pact_value_is_default_ (int yyvalue)


@@ -541,60 +653,54 @@ do {                                      \
   int
   ]b4_parser_class_name[::parse ()
   {
   int
   ]b4_parser_class_name[::parse ()
   {

-    /// Lookahead and lookahead in internal form.
-    int yychar = yyempty_;
-    int yytoken = 0;
+    /// Whether yyla contains a lookahead.
+    bool yyempty = true;

 
 

-    /* State.  */
+    // State.

     int yyn;
     int yylen = 0;
     int yyn;
     int yylen = 0;

-    int yystate = 0;

 
 

-    /* Error handling.  */
+    // Error handling.

     int yynerrs_ = 0;
     int yyerrstatus_ = 0;
 
     int yynerrs_ = 0;
     int yyerrstatus_ = 0;
 

-    /// Semantic value of the lookahead.
-    semantic_type yylval;
-    /// Location of the lookahead.
-    location_type yylloc;
+    /// The lookahead symbol.
+    symbol_type yyla;]b4_locations_if([[
+

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

-    location_type yyerror_range[3];
+    stack_symbol_type yyerror_range[3];]])[

 
 

-    /// $$.
-    semantic_type yyval;
-    /// @@$.
-    location_type yyloc;
+    /// $$ and @@$.
+    stack_symbol_type yylhs;

 
 

+    /// The return value of parse ().

     int yyresult;
 
     int yyresult;
 

+    // FIXME: This shoud be completely indented.  It is not yet to
+    // avoid gratuitous conflicts when merging into the master branch.
+    try
+      {

     YYCDEBUG << "Starting parse" << std::endl;
 
 ]m4_ifdef([b4_initial_action], [
     YYCDEBUG << "Starting parse" << std::endl;
 
 ]m4_ifdef([b4_initial_action], [

-m4_pushdef([b4_at_dollar],     [yylloc])dnl
-m4_pushdef([b4_dollar_dollar], [yylval])dnl
+b4_dollar_pushdef([yyla.value], [], [yyla.location])dnl

     /* User initialization code.  */
     b4_user_initial_action
     /* User initialization code.  */
     b4_user_initial_action

-m4_popdef([b4_dollar_dollar])dnl
-m4_popdef([b4_at_dollar])])dnl
+b4_dollar_popdef])[]dnl

 
 

-  [  /* Initialize the stacks.  The initial state will be pushed in
+  [  /* Initialize the stack.  The initial state will be set in

        yynewstate, since the latter expects the semantical and the
        location values to have been already stored, initialize these
        stacks with a primary value.  */
        yynewstate, since the latter expects the semantical and the
        location values to have been already stored, initialize these
        stacks with a primary value.  */

-    yystate_stack_ = state_stack_type (0);
-    yysemantic_stack_ = semantic_stack_type (0);
-    yylocation_stack_ = location_stack_type (0);
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yylloc);
+    yystack_ = stack_type (0);
+    yypush_ (YY_NULL, 0, yyla);

 
 

-    /* New state.  */
+    // A new symbol was pushed on the stack.

   yynewstate:
   yynewstate:

-    yystate_stack_.push (yystate);
-    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;


@@ -603,71 +709,66 @@ 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];
+    yyn = yypact_[yystack_[0].state];

     if (yy_pact_value_is_default_ (yyn))
       goto yydefault;
 
     /* Read a lookahead token.  */
     if (yy_pact_value_is_default_ (yyn))
       goto yydefault;
 
     /* Read a lookahead token.  */

-    if (yychar == yyempty_)
-      {
-       YYCDEBUG << "Reading a token: ";
-       yychar = ]b4_c_function_call([yylex], [int],
-                                    [[YYSTYPE*], [&yylval]][]dnl
-b4_locations_if([, [[location*], [&yylloc]]])dnl
-m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
-      }
-
-
-    /* Convert token to internal form.  */
-    if (yychar <= yyeof_)
-      {
-       yychar = yytoken = yyeof_;
-       YYCDEBUG << "Now at end of input." << std::endl;
-      }
-    else
+    if (yyempty)

       {
       {

-       yytoken = yytranslate_ (yychar);
-       YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+        YYCDEBUG << "Reading a token: ";
+        try
+          {
+]b4_token_ctor_if(
+[            yyla = b4_function_call([yylex], [symbol_type],
+                                     m4_ifdef([b4_lex_param], b4_lex_param));],
+[            yyla.type = yytranslate_ (b4_function_call([yylex], [int],
+                                     [b4_api_PREFIX[STYPE*], [&yyla.value]][]dnl
+b4_locations_if([, [[location*], [&yyla.location]]])dnl
+m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[
+          }
+        catch (const syntax_error& yyexc)
+          {
+            error (yyexc);
+            goto yyerrlab1;
+          }
+        yyempty = false;

       }
       }

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

 
 

-    /* If the proper action on seeing token YYTOKEN is to reduce or to
-       detect an error, take that action.  */
-    yyn += yytoken;
-    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yytoken)
+    /* If the proper action on seeing token YYLA.TYPE is to reduce or
+       to detect an error, take that action.  */
+    yyn += yyla.type;
+    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type)

       goto yydefault;
 
     /* Reduce or error.  */
     yyn = yytable_[yyn];
     if (yyn <= 0)
       {
       goto yydefault;
 
     /* Reduce or error.  */
     yyn = yytable_[yyn];
     if (yyn <= 0)
       {

-       if (yy_table_value_is_error_ (yyn))
-         goto yyerrlab;
-       yyn = -yyn;
-       goto yyreduce;
+        if (yy_table_value_is_error_ (yyn))
+          goto yyerrlab;
+        yyn = -yyn;
+        goto yyreduce;

       }
 
       }
 

-    /* Shift the lookahead token.  */
-    YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
-

     /* Discard the token being shifted.  */
     /* Discard the token being shifted.  */

-    yychar = yyempty_;
-
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yylloc);
+    yyempty = true;

 
     /* Count tokens shifted since error; after three, turn off error
        status.  */
     if (yyerrstatus_)
       --yyerrstatus_;
 
 
     /* Count tokens shifted since error; after three, turn off error
        status.  */
     if (yyerrstatus_)
       --yyerrstatus_;
 

-    yystate = yyn;
+    /* Shift the lookahead token.  */
+    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;


@@ -677,92 +778,97 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
   `-----------------------------*/
   yyreduce:
     yylen = yyr2_[yyn];
   `-----------------------------*/
   yyreduce:
     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
+       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.
 

-       Otherwise, the following line sets YYVAL to garbage.
+       Otherwise, the following line sets YYLHS.VALUE to garbage.

        This behavior is undocumented and Bison
        users should not rely upon it.  */
     if (yylen)
        This behavior is undocumented and Bison
        users should not rely upon it.  */
     if (yylen)

-      yyval = yysemantic_stack_[yylen - 1];
+      yylhs.value = yystack_@{yylen - 1@}.value;

     else
     else

-      yyval = yysemantic_stack_[0];
-
+      yylhs.value = yystack_@{0@}.value;])[
+]b4_locations_if([dnl
+[
+    // Compute the default @@$.

     {
     {

-      slice<location_type, location_stack_type> slice (yylocation_stack_, yylen);
-      YYLLOC_DEFAULT (yyloc, slice, yylen);
-    }
+      slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
+      YYLLOC_DEFAULT (yylhs.location, slice, yylen);
+    }]])[
+
+    // Perform the reduction.

     YY_REDUCE_PRINT (yyn);
     YY_REDUCE_PRINT (yyn);

-    switch (yyn)
+    try

       {
       {

-       ]b4_user_actions[
-       default:
-          break;
+        switch (yyn)
+          {
+]b4_user_actions[
+          default:
+            break;
+          }
+      }
+    catch (const syntax_error& yyexc)
+      {
+        error (yyexc);
+        YYERROR;

       }
       }

-    /* User semantic actions sometimes alter yychar, and that requires
-       that yytoken be updated with the new translation.  We take the
-       approach of translating immediately before every use of yytoken.
-       One alternative is translating here after every semantic action,
-       but that translation would be missed if the semantic action
-       invokes YYABORT, YYACCEPT, or YYERROR immediately after altering
-       yychar.  In the case of YYABORT or YYACCEPT, an incorrect
-       destructor might then be invoked immediately.  In the case of
-       YYERROR, subsequent parser actions might lead to an incorrect
-       destructor call or verbose syntax error message before the
-       lookahead is translated.  */
-    YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], &yyval, &yyloc);
+    YY_SYMBOL_PRINT ("-> $$ =", yylhs);
+]b4_variant_if([[
+    // Destroy the rhs symbols.
+    for (int i = 0; i < yylen; ++i)
+      // 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 construction 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_ (YY_NULL, yystack_[i]);]])[

 
     yypop_ (yylen);
     yylen = 0;
     YY_STACK_PRINT ();
 
 
     yypop_ (yylen);
     yylen = 0;
     YY_STACK_PRINT ();
 

-    yysemantic_stack_.push (yyval);
-    yylocation_stack_.push (yyloc);
-

     /* Shift the result of the reduction.  */
     /* Shift the result of the reduction.  */

-    yyn = yyr1_[yyn];
-    yystate = yypgoto_[yyn - yyntokens_] + yystate_stack_[0];
-    if (0 <= yystate && yystate <= yylast_
-       && yycheck_[yystate] == yystate_stack_[0])
-      yystate = yytable_[yystate];
-    else
-      yystate = yydefgoto_[yyn - yyntokens_];
+    yypush_ (YY_NULL, yylhs);

     goto yynewstate;
 
     goto yynewstate;
 

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

   yyerrlab:
   yyerrlab:

-    /* Make sure we have latest lookahead translation.  See comments at
-       user semantic actions for why this is necessary.  */
-    yytoken = yytranslate_ (yychar);
-

     /* If not already recovering from an error, report this error.  */
     if (!yyerrstatus_)
       {
     /* If not already recovering from an error, report this error.  */
     if (!yyerrstatus_)
       {

-       ++yynerrs_;
-       if (yychar == yyempty_)
-         yytoken = yyempty_;
-       error (yylloc, yysyntax_error_ (yystate, yytoken));
+        ++yynerrs_;
+        error (]b4_join(b4_locations_if([yyla.location]),
+                        [[yysyntax_error_ (yystack_[0].state,
+                                           yyempty ? yyempty_ : yyla.type)]])[);

       }
 
       }
 

-    yyerror_range[1] = yylloc;
+]b4_locations_if([[
+    yyerror_range[1].location = yyla.location;]])[

     if (yyerrstatus_ == 3)
       {
     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
-         {
-           yydestruct_ ("Error: discarding", yytoken, &yylval, &yylloc);
-           yychar = yyempty_;
-         }
+        /* If just tried and failed to reuse lookahead token after an
+           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;
+          }

       }
 
     /* Else will try to reuse lookahead token after shifting the error
       }
 
     /* Else will try to reuse lookahead token after shifting the error


@@ -779,61 +885,54 @@ 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[1] = yylocation_stack_[yylen - 1];
+      goto yyerrorlab;]b4_locations_if([[
+    yyerror_range[1].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 = yystate_stack_[0];

     goto yyerrlab1;
 
   /*-------------------------------------------------------------.
   | yyerrlab1 -- common code for both syntax error and YYERROR.  |
   `-------------------------------------------------------------*/
   yyerrlab1:
     goto yyerrlab1;
 
   /*-------------------------------------------------------------.
   | yyerrlab1 -- common code for both syntax error and YYERROR.  |
   `-------------------------------------------------------------*/
   yyerrlab1:

-    yyerrstatus_ = 3;  /* Each real token shifted decrements this.  */
-
-    for (;;)
-      {
-       yyn = yypact_[yystate];
-       if (!yy_pact_value_is_default_ (yyn))
-       {
-         yyn += yyterror_;
-         if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
-           {
-             yyn = yytable_[yyn];
-             if (0 < yyn)
-               break;
-           }
-       }
-
-       /* Pop the current state because it cannot handle the error token.  */
-       if (yystate_stack_.height () == 1)
-       YYABORT;
-
-       yyerror_range[1] = yylocation_stack_[0];
-       yydestruct_ ("Error: popping",
-                    yystos_[yystate],
-                    &yysemantic_stack_[0], &yylocation_stack_[0]);
-       yypop_ ();
-       yystate = yystate_stack_[0];
-       YY_STACK_PRINT ();
-      }
-
-    yyerror_range[2] = yylloc;
-    // Using YYLLOC is tempting, but would change the location of
-    // the lookahead.  YYLOC is available though.
-    YYLLOC_DEFAULT (yyloc, yyerror_range, 2);
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yyloc);
+    yyerrstatus_ = 3;   /* Each real token shifted decrements this.  */
+    {
+      stack_symbol_type error_token;
+      for (;;)
+        {
+          yyn = yypact_[yystack_[0].state];
+          if (!yy_pact_value_is_default_ (yyn))
+            {
+              yyn += yyterror_;
+              if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
+                {
+                  yyn = yytable_[yyn];
+                  if (0 < yyn)
+                    break;
+                }
+            }

 
 

-    /* Shift the error token.  */
-    YY_SYMBOL_PRINT ("Shifting", yystos_[yyn],
-                    &yysemantic_stack_[0], &yylocation_stack_[0]);
+          // Pop the current state because it cannot handle the error token.
+          if (yystack_.size () == 1)
+            YYABORT;
+]b4_locations_if([[
+          yyerror_range[1].location = yystack_[0].location;]])[
+          yy_destroy_ ("Error: popping", yystack_[0]);
+          yypop_ ();
+          YY_STACK_PRINT ();
+        }
+]b4_locations_if([[
+      yyerror_range[2].location = yyla.location;
+      YYLLOC_DEFAULT (error_token.location, yyerror_range, 2);]])[

 
 

-    yystate = yyn;
+      /* Shift the error token.  */
+      error_token.state = yyn;
+      yypush_ ("Shifting", error_token);
+    }

     goto yynewstate;
 
     /* Accept.  */
     goto yynewstate;
 
     /* Accept.  */


@@ -847,34 +946,49 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     goto yyreturn;
 
   yyreturn:
     goto yyreturn;
 
   yyreturn:

-    if (yychar != yyempty_)
-      {
-        /* Make sure we have latest lookahead translation.  See comments
-           at user semantic actions for why this is necessary.  */
-        yytoken = yytranslate_ (yychar);
-        yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval,
-                     &yylloc);
-      }
+    if (!yyempty)
+      yy_destroy_ ("Cleanup: discarding lookahead", yyla);

 
     /* Do not reclaim the symbols of the rule which action triggered
        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);
 
     /* Do not reclaim the symbols of the rule which action triggered
        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);

-    while (yystate_stack_.height () != 1)
+    while (1 < yystack_.size ())

       {
       {

-       yydestruct_ ("Cleanup: popping",
-                  yystos_[yystate_stack_[0]],
-                  &yysemantic_stack_[0],
-                  &yylocation_stack_[0]);
-       yypop_ ();
+        yy_destroy_ ("Cleanup: popping", yystack_[0]);
+        yypop_ ();

       }
 
     return yyresult;
   }
       }
 
     return yyresult;
   }

+    catch (...)
+      {
+        YYCDEBUG << "Exception caught: cleaning lookahead and stack"
+                 << std::endl;
+        // Do not try to display the values of the reclaimed symbols,
+        // as their printer might throw an exception.
+        if (!yyempty)
+          yy_destroy_ (YY_NULL, yyla);
+
+        while (1 < yystack_.size ())
+          {
+            yy_destroy_ (YY_NULL, yystack_[0]);
+            yypop_ ();
+          }
+        throw;
+      }
+  }
+
+  void
+  ]b4_parser_class_name[::error (const syntax_error& yyexc)
+  {
+    error (]b4_join(b4_locations_if([yyexc.location]),
+                    [[yyexc.what()]])[);
+  }

 
   // Generate an error message.
   std::string
   ]b4_parser_class_name[::yysyntax_error_ (]dnl
 
   // Generate an error message.
   std::string
   ]b4_parser_class_name[::yysyntax_error_ (]dnl

-b4_error_verbose_if([int yystate, int yytoken],
+b4_error_verbose_if([state_type yystate, int yytoken],

                     [int, int])[)
   {]b4_error_verbose_if([[
     std::string yyres;
                     [int, int])[)
   {]b4_error_verbose_if([[
     std::string yyres;


@@ -900,7 +1014,7 @@ b4_error_verbose_if([int yystate, int yytoken],
          a consistent state with a default action.  There might have
          been a previous inconsistent state, consistent state with a
          non-default action, or user semantic action that manipulated
          a consistent state with a default action.  There might have
          been a previous inconsistent state, consistent state with a
          non-default action, or user semantic action that manipulated

-         yychar.
+         yyla.  (However, yyla is currently not documented for users.)

        - Of course, the expected token list depends on states to have
          correct lookahead information, and it depends on the parser not
          to perform extra reductions after fetching a lookahead from the
        - Of course, the expected token list depends on states to have
          correct lookahead information, and it depends on the parser not
          to perform extra reductions after fetching a lookahead from the


@@ -970,128 +1084,34 @@ b4_error_verbose_if([int yystate, int yytoken],
   }
 
 
   }
 
 

-  /* 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[;

-  const ]b4_int_type_for([b4_pact])[
-  ]b4_parser_class_name[::yypact_[] =
-  {
-    ]b4_pact[
-  };

 
 

-  /* YYDEFACT[S] -- default reduction number in state S.  Performed when
-     YYTABLE doesn't specify something else to do.  Zero means the
-     default is an error.  */
-  const ]b4_int_type_for([b4_defact])[
-  ]b4_parser_class_name[::yydefact_[] =
-  {
-    ]b4_defact[
-  };
-
-  /* YYPGOTO[NTERM-NUM].  */
-  const ]b4_int_type_for([b4_pgoto])[
-  ]b4_parser_class_name[::yypgoto_[] =
-  {
-    ]b4_pgoto[
-  };
-
-  /* YYDEFGOTO[NTERM-NUM].  */
-  const ]b4_int_type_for([b4_defgoto])[
-  ]b4_parser_class_name[::yydefgoto_[] =
-  {
-    ]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 YYTABLE_NINF_, syntax error.  */

   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[;

-  const ]b4_int_type_for([b4_table])[
-  ]b4_parser_class_name[::yytable_[] =
-  {
-    ]b4_table[
-  };
-
-  /* YYCHECK.  */
-  const ]b4_int_type_for([b4_check])[
-  ]b4_parser_class_name[::yycheck_[] =
-  {
-    ]b4_check[
-  };

 
 

-  /* STOS_[STATE-NUM] -- The (internal number of the) accessing
-     symbol of state STATE-NUM.  */
-  const ]b4_int_type_for([b4_stos])[
-  ]b4_parser_class_name[::yystos_[] =
-  {
-    ]b4_stos[
-  };
-
-#if YYDEBUG
-  /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal symbol number corresponding
-     to YYLEX-NUM.  */
-  const ]b4_int_type_for([b4_toknum])[
-  ]b4_parser_class_name[::yytoken_number_[] =
-  {
-    ]b4_toknum[
-  };
-#endif
+]b4_parser_tables_define[

 
 

-  /* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
-  const ]b4_int_type_for([b4_r1])[
-  ]b4_parser_class_name[::yyr1_[] =
-  {
-    ]b4_r1[
-  };
-
-  /* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
-  const ]b4_int_type_for([b4_r2])[
-  ]b4_parser_class_name[::yyr2_[] =
-  {
-    ]b4_r2[
-  };
-
-#if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
+]b4_token_table_if([], [[#if ]b4_api_PREFIX[DEBUG]])[

   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
      First, the terminals, then, starting at \a yyntokens_, nonterminals.  */
   const char*
   const ]b4_parser_class_name[::yytname_[] =
   {
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
      First, the terminals, then, starting at \a yyntokens_, nonterminals.  */
   const char*
   const ]b4_parser_class_name[::yytname_[] =
   {

-    ]b4_tname[
+  ]b4_tname[

   };
   };

-#endif

 
 

-#if YYDEBUG
-  /* YYRHS -- A `-1'-separated list of the rules' RHS.  */
-  const ]b4_parser_class_name[::rhs_number_type
-  ]b4_parser_class_name[::yyrhs_[] =
-  {
-    ]b4_rhs[
-  };
-
-  /* YYPRHS[YYN] -- Index of the first RHS symbol of rule number YYN in
-     YYRHS.  */
-  const ]b4_int_type_for([b4_prhs])[
-  ]b4_parser_class_name[::yyprhs_[] =
-  {
-    ]b4_prhs[
-  };
-
-  /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
-  const ]b4_int_type_for([b4_rline])[
-  ]b4_parser_class_name[::yyrline_[] =
-  {
-    ]b4_rline[
-  };
+]b4_token_table_if([[#if ]b4_api_PREFIX[DEBUG]])[
+]b4_integral_parser_table_define([rline], [b4_rline])[

 
   // Print the state stack on the debug stream.
   void
   ]b4_parser_class_name[::yystack_print_ ()
   {
     *yycdebug_ << "Stack now";
 
   // Print the state stack on the debug stream.
   void
   ]b4_parser_class_name[::yystack_print_ ()
   {
     *yycdebug_ << "Stack now";

-    for (state_stack_type::const_iterator i = yystate_stack_.begin ();
-        i != yystate_stack_.end (); ++i)
-      *yycdebug_ << ' ' << *i;
+    for (stack_type::const_iterator
+           i = yystack_.begin (),
+           i_end = yystack_.end ();
+         i != i_end; ++i)
+      *yycdebug_ << ' ' << i->state;

     *yycdebug_ << std::endl;
   }
 
     *yycdebug_ << std::endl;
   }
 


@@ -1103,44 +1123,18 @@ b4_error_verbose_if([int yystate, int yytoken],
     int yynrhs = yyr2_[yyrule];
     /* Print the symbols being reduced, and their result.  */
     *yycdebug_ << "Reducing stack by rule " << yyrule - 1
     int yynrhs = yyr2_[yyrule];
     /* Print the symbols being reduced, and their result.  */
     *yycdebug_ << "Reducing stack by rule " << yyrule - 1

-              << " (line " << yylno << "):" << std::endl;
+               << " (line " << yylno << "):" << std::endl;

     /* The symbols being reduced.  */
     for (int yyi = 0; yyi < yynrhs; yyi++)
       YY_SYMBOL_PRINT ("   $" << yyi + 1 << " =",
     /* The symbols being reduced.  */
     for (int yyi = 0; yyi < yynrhs; yyi++)
       YY_SYMBOL_PRINT ("   $" << yyi + 1 << " =",

-                      yyrhs_[yyprhs_[yyrule] + yyi],
-                      &]b4_rhs_value(yynrhs, yyi + 1)[,
-                      &]b4_rhs_location(yynrhs, yyi + 1)[);
-  }
-#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[
-    };
-    if ((unsigned int) t <= yyuser_token_number_max_)
-      return translate_table[t];
-    else
-      return yyundef_token_;
+                       ]b4_rhs_data(yynrhs, yyi + 1)[);

   }
   }

+#endif // ]b4_api_PREFIX[DEBUG

 
 

-  const int ]b4_parser_class_name[::yyeof_ = 0;
-  const int ]b4_parser_class_name[::yylast_ = ]b4_last[;
-  const int ]b4_parser_class_name[::yynnts_ = ]b4_nterms_number[;
-  const int ]b4_parser_class_name[::yyempty_ = -2;
-  const int ]b4_parser_class_name[::yyfinal_ = ]b4_final_state_number[;
-  const int ]b4_parser_class_name[::yyterror_ = 1;
-  const int ]b4_parser_class_name[::yyerrcode_ = 256;
-  const int ]b4_parser_class_name[::yyntokens_ = ]b4_tokens_number[;
+]b4_token_ctor_if([], [b4_yytranslate_define])[
+]b4_namespace_close[
+]b4_epilogue[]dnl
+b4_output_end()

 
 

-  const unsigned int ]b4_parser_class_name[::yyuser_token_number_max_ = ]b4_user_token_number_max[;
-  const ]b4_parser_class_name[::token_number_type ]b4_parser_class_name[::yyundef_token_ = ]b4_undef_token_number[;

 
 

-]b4_namespace_close[
-]b4_epilogue
-m4_divert_pop(0)
+m4_popdef([b4_copyright_years])dnl