lalr1, yacc: use the default location as initial error location

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 3b8c9215a3e93697003628d8153e2cbf0a3a2811..4c823409adea9827e67fb8d0dfd103ed803b4b7b 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
 # C++ skeleton for Bison
 

-# Copyright (C) 2002-2012 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 Free Software Foundation, Inc.

 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by


@@ -17,76 +17,164 @@
 
 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]])])
+# api.value.type=variant is valid.
+m4_define([b4_value_type_setup_variant])

 
 

-# 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>_" whose 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>_" whose 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_symbol_value_template(VAL, [TYPE])
+# -------------------------------------
+# Same as b4_symbol_value, but used in a template method.  It makes
+# a difference when using variants.  Note that b4_value_type_setup_union
+# overrides b4_symbol_value, so we must override it again.
+m4_copy([b4_symbol_value], [b4_symbol_value_template])
+m4_append([b4_value_type_setup_union],
+          [m4_copy_force([b4_symbol_value_union], [b4_symbol_value_template])])
+
+# b4_lhs_value([TYPE])
+# --------------------
+# Expansion of $<TYPE>$.
+m4_define([b4_lhs_value],
+          [b4_symbol_value([yylhs.value], [$1])])
+
+
+# b4_lhs_location()
+# -----------------
+# Expansion of @$.
+m4_define([b4_lhs_location],
+          [yylhs.location])
+
+
+# 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($@)@}])
+
+
+# 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;

 
 

-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])
+m4_popdef([b4_symbol_value])[]dnl
+b4_dollar_popdef[]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@)@
-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.
- */

 
 

-/* C++ LALR(1) parser skeleton written by Akim Demaille.  */
+# b4_lex
+# ------
+# Call yylex.
+m4_define([b4_lex],
+[b4_token_ctor_if(
+[b4_function_call([yylex],
+                  [symbol_type], m4_ifdef([b4_lex_param], b4_lex_param))],
+[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))])])

 
 

-]b4_cpp_guard_open([b4_spec_defines_file])[

 
 

-]b4_percent_code_get([[requires]])[
+m4_pushdef([b4_copyright_years],
+           [2002-2015])

 
 

-#include <string>
-#include <iostream>
-#include "stack.hh"
-]b4_percent_define_ifdef([[location_type]], [],
-                         [[#include "location.hh"]])[
+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 <cstdlib> // std::abort
+# include <iostream>
+# include <stdexcept>
+# include <string>
+# include <vector>]b4_defines_if([[
+# include "stack.hh"
+]b4_bison_locations_if([[# include "location.hh"]])])[
+]b4_variant_if([b4_variant_includes])[
+
+]b4_attribute_define[

 ]b4_YYDEBUG_define[
 
 ]b4_namespace_open[
 
 ]b4_YYDEBUG_define[
 
 ]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 ]b4_api_PREFIX[STYPE
-]m4_ifdef([b4_stype],
-[    union semantic_type
-    {
-b4_user_stype
-    };],
-[m4_if(b4_tag_seen_flag, 0,
-[[    typedef int semantic_type;]],
-[[    typedef ]b4_api_PREFIX[STYPE semantic_type;]])])[
-#else
-    typedef ]b4_api_PREFIX[STYPE 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[ ();


@@ -97,62 +185,44 @@ b4_user_stype
 
 #if ]b4_api_PREFIX[DEBUG
     /// The current debugging stream.
 
 #if ]b4_api_PREFIX[DEBUG
     /// The current debugging stream.

-    std::ostream& debug_stream () const;
+    std::ostream& debug_stream () const YY_ATTRIBUTE_PURE;

     /// Set the current debugging stream.
     void set_debug_stream (std::ostream &);
 
     /// Type for debugging levels.
     typedef int debug_level_type;
     /// The current debugging level.
     /// Set the current debugging stream.
     void set_debug_stream (std::ostream &);
 
     /// Type for debugging levels.
     typedef int debug_level_type;
     /// The current debugging level.

-    debug_level_type debug_level () const;
+    debug_level_type debug_level () const YY_ATTRIBUTE_PURE;

     /// Set the current debugging level.
     void set_debug_level (debug_level_type l);
 #endif
 
     /// Set the current debugging level.
     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);

 
 

-#if ]b4_api_PREFIX[DEBUG
-    /// \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
+    /// Report a syntax error.
+    void error (const syntax_error& err);

 
 

+  private:
+    /// This class is not copyable.
+    ]b4_parser_class_name[ (const ]b4_parser_class_name[&);
+    ]b4_parser_class_name[& operator= (const ]b4_parser_class_name[&);

 
     /// 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 yyla      the lookahead token.
+    virtual std::string yysyntax_error_ (state_type yystate,
+                                         const symbol_type& yyla) const;
+
+    /// Compute post-reduction state.
+    /// \param yystate   the current state
+    /// \param yysym     the nonterminal to push on the stack
+    state_type yy_lr_goto_state_ (state_type yystate, int yysym);

 
     /// 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


@@ -162,38 +232,14 @@ b4_user_stype
     /// \param yyvalue   the value to check
     static bool yy_table_value_is_error_ (int yyvalue);
 
     /// \param yyvalue   the value to check
     static bool yy_table_value_is_error_ (int yyvalue);
 

-    /// 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_[];
+    /// Convert a scanner token number \a t to a symbol number.
+    static token_number_type yytranslate_ (]b4_token_ctor_if([token_type], [int])[ t);

 
 

-    /// 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_[]; ]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);])[


@@ -202,95 +248,174 @@ b4_user_stype
     /// For a symbol, its name in clear.
     static const char* const yytname_[];
 ]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]])[

-    /// 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_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

 
 

-    /// Convert a scanner token number \a t to a symbol number.
-    token_number_type yytranslate_ (int t);
+    /// \brief Display a symbol type, value and location.
+    /// \param yyo    The output stream.
+    /// \param yysym  The symbol.
+    template <typename Base>
+    void yy_print_ (std::ostream& yyo, const basic_symbol<Base>& 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.
-    ///                     If null, do not display the symbol, just free it.
-    /// \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 yysym     The symbol.
+    template <typename Base>
+    void yy_destroy_ (const char* yymsg, basic_symbol<Base>& yysym) const;
+
+  private:
+    /// Type access provider for state based symbols.
+    struct by_state
+    {
+      /// Default constructor.
+      by_state ();
+
+      /// The symbol type as needed by the constructor.
+      typedef state_type kind_type;
+
+      /// Constructor.
+      by_state (kind_type s);
+
+      /// Copy constructor.
+      by_state (const by_state& other);
+
+      /// Record that this symbol is empty.
+      void clear ();
+
+      /// Steal the symbol type from \a that.
+      void move (by_state& that);
+
+      /// The (internal) type number (corresponding to \a state).
+      /// \a empty_symbol when empty.
+      symbol_number_type type_get () const;
+
+      /// The state number used to denote an empty symbol.
+      enum { empty_state = -1 };
+
+      /// The state.
+      /// \a empty when empty.
+      state_type state;
+    };
+
+    /// "Internal" symbol: element of the stack.
+    struct stack_symbol_type : basic_symbol<by_state>
+    {
+      /// Superclass.
+      typedef basic_symbol<by_state> super_type;
+      /// Construct an empty symbol.
+      stack_symbol_type ();
+      /// Steal the contents from \a sym to build this.
+      stack_symbol_type (state_type s, symbol_type& sym);
+      /// Assignment, needed by push_back.
+      stack_symbol_type& operator= (const stack_symbol_type& that);
+    };
+
+    /// 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.
+    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.
+    void yypush_ (const char* m, state_type s, symbol_type& sym);

 
     /// Pop \a n symbols the three stacks.
 
     /// 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_;
+    void yypop_ (unsigned n = 1);
+
+    /// Constants.
+    enum
+    {
+      yyeof_ = 0,
+      yylast_ = ]b4_last[,     ///< Last index in yytable_.
+      yynnts_ = ]b4_nterms_number[,  ///< Number of nonterminal symbols.
+      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 ]b4_api_PREFIX[STYPE
 
 #ifndef ]b4_api_PREFIX[STYPE

- /* Redirection for backward compatibility.  */
+ // Redirection for backward compatibility.

 # define ]b4_api_PREFIX[STYPE b4_namespace_ref::b4_parser_class_name::semantic_type
 #endif
 ])[
 ]b4_percent_code_get([[provides]])[
 # define ]b4_api_PREFIX[STYPE b4_namespace_ref::b4_parser_class_name::semantic_type
 #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.  */
+// First part of user declarations.

 ]b4_user_pre_prologue[
 
 ]b4_user_pre_prologue[
 

-]b4_defines_if([[
-#include "@basename(]b4_spec_defines_file[@)"]])[
+]b4_null_define[
+
+]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[
 
 ]b4_user_post_prologue[
 ]b4_percent_code_get[
 

-]b4_null_define[
-

 #ifndef YY_
 # if defined YYENABLE_NLS && YYENABLE_NLS
 #  if ENABLE_NLS
 #ifndef YY_
 # if defined YYENABLE_NLS && YYENABLE_NLS
 #  if ENABLE_NLS

-#   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */
+#   include <libintl.h> // FIXME: INFRINGES ON USER NAME SPACE.

 #   define YY_(msgid) dgettext ("bison-runtime", msgid)
 #  endif
 # endif
 #   define YY_(msgid) dgettext ("bison-runtime", msgid)
 #  endif
 # endif


@@ -299,55 +424,56 @@ m4_if(b4_prefix, [yy], [],
 # endif
 #endif
 
 # endif
 #endif
 

-#define YYRHSLOC(Rhs, K) ((Rhs)[K])
-]b4_yylloc_default_define[
+]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))
+// Suppress unused-variable warnings by "using" E.
+#define YYUSE(E) ((void) (E))

 
 

-/* Enable debugging if requested.  */
+// Enable debugging if requested.

 #if ]b4_api_PREFIX[DEBUG
 
 #if ]b4_api_PREFIX[DEBUG
 

-/* A pseudo ostream that takes yydebug_ into account.  */
+// A pseudo ostream that takes yydebug_ into account.

 # define YYCDEBUG if (yydebug_) (*yycdebug_)
 
 # 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 /* !]b4_api_PREFIX[DEBUG */
+# 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) YYUSE(Type)
-# define YY_REDUCE_PRINT(Rule)        static_cast<void>(0)
-# define YY_STACK_PRINT()             static_cast<void>(0)
+# 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 /* !]b4_api_PREFIX[DEBUG */
+#endif // !]b4_api_PREFIX[DEBUG

 
 

-#define yyerrok                (yyerrstatus_ = 0)
-#define yyclearin      (yychar = yyempty_)
+#define yyerrok         (yyerrstatus_ = 0)
+#define yyclearin       (yyla.clear ())

 
 

-#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([[


@@ -375,7 +501,7 @@ do {                                        \
             case '\\':
               if (*++yyp != '\\')
                 goto do_not_strip_quotes;
             case '\\':
               if (*++yyp != '\\')
                 goto do_not_strip_quotes;

-              /* Fall through.  */
+              // Fall through.

             default:
               yyr += *yyp;
               break;
             default:
               yyr += *yyp;
               break;


@@ -397,73 +523,143 @@ do {                                     \
     ]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[

+  {}
+
+  ]b4_parser_class_name::~b4_parser_class_name[ ()
+  {}
+
+
+  /*---------------.
+  | Symbol types.  |
+  `---------------*/
+
+]b4_token_ctor_if([], [b4_public_types_define])[
+
+  // by_state.
+  inline
+  ]b4_parser_class_name[::by_state::by_state ()
+    : state (empty_state)
+  {}
+
+  inline
+  ]b4_parser_class_name[::by_state::by_state (const by_state& other)
+    : state (other.state)
+  {}
+
+  inline
+  void
+  ]b4_parser_class_name[::by_state::clear ()

   {
   {

+    state = empty_state;

   }
 
   }
 

-  ]b4_parser_class_name::~b4_parser_class_name[ ()
+  inline
+  void
+  ]b4_parser_class_name[::by_state::move (by_state& that)

   {
   {

+    state = that.state;
+    that.clear ();

   }
 
   }
 

-#if ]b4_api_PREFIX[DEBUG
-  /*--------------------------------.
-  | Print this symbol on YYOUTPUT.  |
-  `--------------------------------*/
+  inline
+  ]b4_parser_class_name[::by_state::by_state (state_type s)
+    : state (s)
+  {}

 
 

-  inline void
-  ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
-                          const semantic_type* yyvaluep, const location_type* yylocationp)
+  inline
+  ]b4_parser_class_name[::symbol_number_type
+  ]b4_parser_class_name[::by_state::type_get () const

   {
   {

-    YYUSE (yylocationp);
-    YYUSE (yyvaluep);
-    std::ostream& yyo = debug_stream ();
-    std::ostream& yyoutput = yyo;
-    YYUSE (yyoutput);
-    switch (yytype)
-      {
-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
-[       default:
-         break;
-      }
+    if (state == empty_state)
+      return empty_symbol;
+    else
+      return yystos_[state];
+  }
+
+  inline
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
+  {}
+
+
+  inline
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (state_type s, symbol_type& that)
+    : super_type (s]b4_locations_if([, that.location])[)
+  {
+    ]b4_variant_if([b4_symbol_variant([that.type_get ()],
+                                      [value], [move], [that.value])],
+                   [[value = that.value;]])[
+    // that is emptied.
+    that.type = empty_symbol;
+  }
+
+  inline
+  ]b4_parser_class_name[::stack_symbol_type&
+  ]b4_parser_class_name[::stack_symbol_type::operator= (const stack_symbol_type& that)
+  {
+    state = that.state;
+    ]b4_variant_if([b4_symbol_variant([that.type_get ()],
+                                      [value], [copy], [that.value])],
+                   [[value = that.value;]])[]b4_locations_if([
+    location = that.location;])[
+    return *this;

   }
 
 
   }
 
 

+  template <typename Base>
+  inline

   void
   void

-  ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
-                          const semantic_type* yyvaluep, const location_type* yylocationp)
+  ]b4_parser_class_name[::yy_destroy_ (const char* yymsg, basic_symbol<Base>& yysym) const

   {
   {

-    *yycdebug_ << (yytype < yyntokens_ ? "token" : "nterm")
-              << ' ' << yytname_[yytype] << " ("
-              << *yylocationp << ": ";
-    yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
-    *yycdebug_ << ')';
+    if (yymsg)
+      YY_SYMBOL_PRINT (yymsg, yysym);]b4_variant_if([], [
+
+    // User destructor.
+    b4_symbol_actions([destructor], [yysym.type_get ()])])[

   }
   }

-#endif

 
 

+#if ]b4_api_PREFIX[DEBUG
+  template <typename Base>

   void
   void

-  ]b4_parser_class_name[::yydestruct_ (const char* yymsg,
-                          int yytype, semantic_type* yyvaluep, location_type* yylocationp)
+  ]b4_parser_class_name[::yy_print_ (std::ostream& yyo,
+                                     const basic_symbol<Base>& yysym) const

   {
   {

-    YYUSE (yylocationp);
-    YYUSE (yymsg);
-    YYUSE (yyvaluep);
+    std::ostream& yyoutput = yyo;
+    YYUSE (yyoutput);
+    symbol_number_type yytype = yysym.type_get ();
+    // Avoid a (spurious) G++ 4.8 warning about "array subscript is
+    // below array bounds".
+    if (yysym.empty ())
+      std::abort ();
+    yyo << (yytype < yyntokens_ ? "token" : "nterm")
+        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
+        << yysym.location << ": "])[;
+    ]b4_symbol_actions([printer])[
+    yyo << ')';
+  }
+#endif

 
 

-    if (yymsg)
-      YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
+  inline
+  void
+  ]b4_parser_class_name[::yypush_ (const char* m, state_type s, symbol_type& sym)
+  {
+    stack_symbol_type t (s, sym);
+    yypush_ (m, t);
+  }

 
 

-    switch (yytype)
-      {
-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
-       default:
-         break;
-      }
+  inline
+  void
+  ]b4_parser_class_name[::yypush_ (const char* m, stack_symbol_type& s)
+  {
+    if (m)
+      YY_SYMBOL_PRINT (m, s);
+    yystack_.push (s);

   }
 
   }
 

+  inline

   void
   void

-  ]b4_parser_class_name[::yypop_ (unsigned int n)
+  ]b4_parser_class_name[::yypop_ (unsigned n)

   {
   {

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

   }
 
 #if ]b4_api_PREFIX[DEBUG
   }
 
 #if ]b4_api_PREFIX[DEBUG


@@ -491,7 +687,17 @@ 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 yysym)
+  {
+    int yyr = yypgoto_[yysym - yyntokens_] + yystate;
+    if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
+      return yytable_[yyr];
+    else
+      return yydefgoto_[yysym - 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)


@@ -508,31 +714,22 @@ 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;
-
-    /* State.  */
+    // State.

     int yyn;
     int yyn;

+    /// Length of the RHS of the rule being reduced.

     int yylen = 0;
     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 locations where the error started and ended.
-    location_type yyerror_range[3];
+    /// The lookahead symbol.
+    symbol_type yyla;]b4_locations_if([[

 
 

-    /// $$.
-    semantic_type yyval;
-    /// @@$.
-    location_type yyloc;
+    /// The locations where the error started and ended.
+    stack_symbol_type yyerror_range[3];]])[

 
 

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

     int yyresult;
 
     // FIXME: This shoud be completely indented.  It is not yet to
     int yyresult;
 
     // FIXME: This shoud be completely indented.  It is not yet to


@@ -542,100 +739,83 @@ do {                                     \
     YYCDEBUG << "Starting parse" << std::endl;
 
 ]m4_ifdef([b4_initial_action], [
     YYCDEBUG << "Starting parse" << std::endl;
 
 ]m4_ifdef([b4_initial_action], [

-b4_dollar_pushdef([yylval], [], [yylloc])dnl
-/* User initialization code.  */
-b4_user_initial_action
+b4_dollar_pushdef([yyla.value], [], [yyla.location])dnl
+    // User initialization code.
+    b4_user_initial_action

 b4_dollar_popdef])[]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_.clear ();
+    yypush_ (YY_NULLPTR, 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?  */
-    if (yystate == yyfinal_)
+    // Accept?
+    if (yystack_[0].state == yyfinal_)

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

-    /* Backup.  */
+    // Backup.

   yybackup:
 
   yybackup:
 

-    /* Try to take a decision without lookahead.  */
-    yyn = yypact_[yystate];
+    // Try to take a decision without lookahead.
+    yyn = yypact_[yystack_[0].state];

     if (yy_pact_value_is_default_ (yyn))
       goto yydefault;
 
     if (yy_pact_value_is_default_ (yyn))
       goto yydefault;
 

-    /* Read a lookahead token.  */
-    if (yychar == yyempty_)
+    // Read a lookahead token.
+    if (yyla.empty ())

       {
         YYCDEBUG << "Reading a token: ";
       {
         YYCDEBUG << "Reading a token: ";

-        yychar = ]b4_c_function_call([yylex], [int],
-                                     [b4_api_PREFIX[STYPE*], [&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
-      {
-       yytoken = yytranslate_ (yychar);
-       YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+        try
+          {]b4_token_ctor_if([[
+            symbol_type yylookahead (]b4_lex[);
+            yyla.move (yylookahead);]], [[
+            yyla.type = yytranslate_ (]b4_lex[);]])[
+          }
+        catch (const syntax_error& yyexc)
+          {
+            error (yyexc);
+            goto yyerrlab1;
+          }

       }
       }

+    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_get ();
+    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type_get ())

       goto yydefault;
 
       goto yydefault;
 

-    /* Reduce or error.  */
+    // Reduce or error.

     yyn = yytable_[yyn];
     if (yyn <= 0)
       {
     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.  */
-    yychar = yyempty_;
-
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yylloc);
-
-    /* Count tokens shifted since error; after three, turn off error
-       status.  */
+    // Count tokens shifted since error; after three, turn off error status.

     if (yyerrstatus_)
       --yyerrstatus_;
 
     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;


@@ -645,99 +825,88 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
   `-----------------------------*/
   yyreduce:
     yylen = yyr2_[yyn];
   `-----------------------------*/
   yyreduce:
     yylen = yyr2_[yyn];

-    /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
-
-       Otherwise, the following line sets YYVAL to garbage.
-       This behavior is undocumented and Bison
-       users should not rely upon it.  */
-    if (yylen)
-      yyval = yysemantic_stack_[yylen - 1];
-    else
-      yyval = yysemantic_stack_[0];
-
-    // Compute the default @@$.

     {
     {

-      slice<location_type, location_stack_type> slice (yylocation_stack_, yylen);
-      YYLLOC_DEFAULT (yyloc, slice, yylen);
-    }
-
-    // Perform the reduction.
-    YY_REDUCE_PRINT (yyn);
-    switch (yyn)
+      stack_symbol_type yylhs;
+      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.
+
+         Otherwise, the following line sets YYLHS.VALUE to garbage.
+         This behavior is undocumented and Bison users should not rely
+         upon it.  */
+      if (yylen)
+        yylhs.value = yystack_@{yylen - 1@}.value;
+      else
+        yylhs.value = yystack_@{0@}.value;])[
+]b4_locations_if([dnl
+[
+      // Default location.

       {
       {

-        ]b4_user_actions[
-      default:
-        break;
-      }
-
-    /* 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 ("-> $$ =", yyr1_[yyn], &yyval, &yyloc);
-
-    yypop_ (yylen);
-    yylen = 0;
-    YY_STACK_PRINT ();
-
-    yysemantic_stack_.push (yyval);
-    yylocation_stack_.push (yyloc);
+        slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
+        YYLLOC_DEFAULT (yylhs.location, slice, yylen);
+        yyerror_range[1].location = yylhs.location;
+      }]])[
+
+      // Perform the reduction.
+      YY_REDUCE_PRINT (yyn);
+      try
+        {
+          switch (yyn)
+            {
+]b4_user_actions[
+            default:
+              break;
+            }
+        }
+      catch (const syntax_error& yyexc)
+        {
+          error (yyexc);
+          YYERROR;
+        }
+      YY_SYMBOL_PRINT ("-> $$ =", yylhs);
+      yypop_ (yylen);
+      yylen = 0;
+      YY_STACK_PRINT ();

 
 

-    /* 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_];
+      // Shift the result of the reduction.
+      yypush_ (YY_NULLPTR, 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 not already recovering from an error, report this error.

     if (!yyerrstatus_)
       {
     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, yyla)]])[);

       }
 
       }
 

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

     if (yyerrstatus_ == 3)
       {
         /* If just tried and failed to reuse lookahead token after an
            error, discard it.  */
     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
+
+        // Return failure if at end of input.
+        if (yyla.type_get () == yyeof_)
+          YYABORT;
+        else if (!yyla.empty ())

           {
           {

-            yydestruct_ ("Error: discarding", yytoken, &yylval, &yylloc);
-            yychar = yyempty_;
+            yy_destroy_ ("Error: discarding", yyla);
+            yyla.clear ();

           }
       }
 
           }
       }
 

-    /* Else will try to reuse lookahead token after shifting the error
-       token.  */
+    // Else will try to reuse lookahead token after shifting the error token.

     goto yyerrlab1;
 
 
     goto yyerrlab1;
 
 


@@ -751,130 +920,108 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
        code.  */
     if (false)
       goto yyerrorlab;
        code.  */
     if (false)
       goto yyerrorlab;

-
-    yyerror_range[1] = yylocation_stack_[yylen - 1];
-    /* Do not reclaim the symbols of the rule which action triggered
+    /* Do not reclaim the symbols of the rule whose action triggered

        this YYERROR.  */
     yypop_ (yylen);
     yylen = 0;
        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;
 
     goto yynewstate;
 

-    /* Accept.  */
+    // Accept.

   yyacceptlab:
     yyresult = 0;
     goto yyreturn;
 
   yyacceptlab:
     yyresult = 0;
     goto yyreturn;
 

-    /* Abort.  */
+    // Abort.

   yyabortlab:
     yyresult = 1;
     goto yyreturn;
 
   yyreturn:
   yyabortlab:
     yyresult = 1;
     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 (!yyla.empty ())
+      yy_destroy_ ("Cleanup: discarding lookahead", yyla);

 
 

-    /* Do not reclaim the symbols of the rule which action triggered
+    /* Do not reclaim the symbols of the rule whose action triggered

        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);
        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);

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

       {
       {

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

         yypop_ ();
       }
 
     return yyresult;
         yypop_ ();
       }
 
     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.
     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 (yychar != yyempty_)
-          {
-            /* Make sure we have latest lookahead translation.  See
-               comments at user semantic actions for why this is
-               necessary.  */
-            yytoken = yytranslate_ (yychar);
-            yydestruct_ (YY_NULL, yytoken, &yylval, &yylloc);
-          }
+        if (!yyla.empty ())
+          yy_destroy_ (YY_NULLPTR, yyla);

 
 

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

           {
           {

-            yydestruct_ (YY_NULL,
-                         yystos_[yystate_stack_[0]],
-                         &yysemantic_stack_[0],
-                         &yylocation_stack_[0]);
+            yy_destroy_ (YY_NULLPTR, yystack_[0]);

             yypop_ ();
           }
         throw;
       }
   }
 
             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],
-                    [int, int])[)
+b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
+                    [state_type, const symbol_type&])[) const

   {]b4_error_verbose_if([[
   {]b4_error_verbose_if([[

-    std::string yyres;

     // Number of reported tokens (one for the "unexpected", one per
     // "expected").
     size_t yycount = 0;
     // Number of reported tokens (one for the "unexpected", one per
     // "expected").
     size_t yycount = 0;


@@ -888,7 +1035,7 @@ b4_error_verbose_if([int yystate, int yytoken],
          the only way this function was invoked is if the default action
          is an error action.  In that case, don't check for expected
          tokens because there are none.
          the only way this function was invoked is if the default action
          is an error action.  In that case, don't check for expected
          tokens because there are none.

-       - The only way there can be no lookahead present (in yytoken) is
+       - The only way there can be no lookahead present (in yyla) is

          if this state is a consistent state with a default action.
          Thus, detecting the absence of a lookahead is sufficient to
          determine that there is no unexpected or expected token to
          if this state is a consistent state with a default action.
          Thus, detecting the absence of a lookahead is sufficient to
          determine that there is no unexpected or expected token to


@@ -897,7 +1044,7 @@ 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


@@ -908,8 +1055,9 @@ b4_error_verbose_if([int yystate, int yytoken],
          token that will not be accepted due to an error action in a
          later state.
     */
          token that will not be accepted due to an error action in a
          later state.
     */

-    if (yytoken != yyempty_)
+    if (!yyla.empty ())

       {
       {

+        int yytoken = yyla.type_get ();

         yyarg[yycount++] = yytname_[yytoken];
         int yyn = yypact_[yystate];
         if (!yy_pact_value_is_default_ (yyn))
         yyarg[yycount++] = yytname_[yytoken];
         int yyn = yypact_[yystate];
         if (!yy_pact_value_is_default_ (yyn))


@@ -918,7 +1066,7 @@ b4_error_verbose_if([int yystate, int yytoken],
                YYCHECK.  In other words, skip the first -YYN actions for
                this state because they are default actions.  */
             int yyxbegin = yyn < 0 ? -yyn : 0;
                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.  */
+            // Stay within bounds of both yycheck and yytname.

             int yychecklim = yylast_ - yyn + 1;
             int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
             for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
             int yychecklim = yylast_ - yyn + 1;
             int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
             for (int yyx = yyxbegin; yyx < yyxend; ++yyx)


@@ -936,22 +1084,23 @@ b4_error_verbose_if([int yystate, int yytoken],
           }
       }
 
           }
       }
 

-    char const* yyformat = YY_NULL;
+    char const* yyformat = YY_NULLPTR;

     switch (yycount)
       {
 #define YYCASE_(N, S)                         \
         case N:                               \
           yyformat = S;                       \
         break
     switch (yycount)
       {
 #define YYCASE_(N, S)                         \
         case N:                               \
           yyformat = S;                       \
         break

-        YYCASE_(0, YY_("syntax error"));
-        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"));
+        YYCASE_ (0, YY_("syntax error"));
+        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_
       }
 
 #undef YYCASE_
       }
 

+    std::string yyres;

     // Argument number.
     size_t yyi = 0;
     for (char const* yyp = yyformat; *yyp; ++yyp)
     // Argument number.
     size_t yyi = 0;
     for (char const* yyp = yyformat; *yyp; ++yyp)


@@ -967,127 +1116,34 @@ 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 ]b4_api_PREFIX[DEBUG
-  /* 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
-
-  /* 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[
-  };
+]b4_parser_tables_define[

 
 ]b4_token_table_if([], [[#if ]b4_api_PREFIX[DEBUG]])[
 
 ]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.  */
+  // 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_[] =
   {
   const char*
   const ]b4_parser_class_name[::yytname_[] =
   {

-    ]b4_tname[
+  ]b4_tname[

   };
 
 ]b4_token_table_if([[#if ]b4_api_PREFIX[DEBUG]])[
   };
 
 ]b4_token_table_if([[#if ]b4_api_PREFIX[DEBUG]])[

-  /* 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_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;
   }
 


@@ -1095,48 +1151,22 @@ b4_error_verbose_if([int yystate, int yytoken],
   void
   ]b4_parser_class_name[::yy_reduce_print_ (int yyrule)
   {
   void
   ]b4_parser_class_name[::yy_reduce_print_ (int yyrule)
   {

-    unsigned int yylno = yyrline_[yyrule];
+    unsigned yylno = yyrline_[yyrule];

     int yynrhs = yyr2_[yyrule];
     int yynrhs = yyr2_[yyrule];

-    /* Print the symbols being reduced, and their result.  */
+    // Print the symbols being reduced, and their result.

     *yycdebug_ << "Reducing stack by rule " << yyrule - 1
     *yycdebug_ << "Reducing stack by rule " << yyrule - 1

-              << " (line " << yylno << "):" << std::endl;
-    /* The symbols being reduced.  */
+               << " (line " << yylno << "):" << std::endl;
+    // The symbols being reduced.

     for (int yyi = 0; yyi < yynrhs; yyi++)
       YY_SYMBOL_PRINT ("   $" << yyi + 1 << " =",
     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)[);
+                       ]b4_rhs_data(yynrhs, yyi + 1)[);

   }
 #endif // ]b4_api_PREFIX[DEBUG
 
   }
 #endif // ]b4_api_PREFIX[DEBUG
 

-  /* 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_;
-  }
-
-  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[;
-
-  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_token_ctor_if([], [b4_yytranslate_define])[

 ]b4_namespace_close[
 ]b4_epilogue[]dnl
 ]b4_namespace_close[
 ]b4_epilogue[]dnl

-m4_divert_pop(0)
+b4_output_end()
+
+
+m4_popdef([b4_copyright_years])dnl