Instead of using make_symbol<TOK_FOO>, generate make_FOO for each token type.

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 11490951cdeb35923e2bb048f234250ac46cf46c..c3678887386728d64805d2ac7217748f958a86b2 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -18,6 +18,38 @@
 
 m4_include(b4_pkgdatadir/[c++.m4])
 
 
 m4_include(b4_pkgdatadir/[c++.m4])
 

+# b4_subtract(LHS, RHS)
+# ---------------------
+# Evaluate LHS - RHS if they are integer literals, otherwise expand
+# to (LHS) - (RHS).
+m4_define([b4_subtract],
+[m4_bmatch([$1$2], [^[0123456789]*$],
+           [m4_eval([$1 - $2])],
+           [($1) - ($2)])])
+
+
+# b4_args(ARG1, ...)
+# _b4_args(ARG1, ...)
+# -------------------
+# Join with comma, skipping empty arguments.
+# b4_args calls itself recursively until it sees the first non-empty
+# argument, then calls _b4_args which prepends each non-empty argument
+# with a comma.
+m4_define([b4_args],
+[m4_if([$#$1],
+       [1], [],
+       [m4_ifval([$1],
+                 [$1[]_$0(m4_shift($@))],
+                 [$0(m4_shift($@))])])])
+
+# _b4_args(ARGS1, ...)
+# --------------------
+m4_define([_b4_args],
+[m4_if([$#$1],
+       [1], [],
+       [m4_ifval([$1], [, $1])[]$0(m4_shift($@))])])
+
+

 # b4_table_define(TABLE-NAME, CONTENT)
 # ------------------------------------
 # Define "parser::yy<TABLE-NAME>_" which contents is CONTENT.
 # b4_table_define(TABLE-NAME, CONTENT)
 # ------------------------------------
 # Define "parser::yy<TABLE-NAME>_" which contents is CONTENT.


@@ -29,6 +61,11 @@ m4_define([b4_table_define],
   }dnl
 ])
 
   }dnl
 ])
 

+# b4_symbol_value_template(VAL, [TYPE])
+# -------------------------------------
+# Same as b4_symbol_value, but used in a template method.
+m4_copy([b4_symbol_value], [b4_symbol_value_template])
+

 # How the semantic value is extracted when using variants.
 b4_variant_if([
   # b4_symbol_value(VAL, [TYPE])
 # How the semantic value is extracted when using variants.
 b4_variant_if([
   # b4_symbol_value(VAL, [TYPE])


@@ -37,11 +74,25 @@ b4_variant_if([
   [m4_ifval([$2],
             [$1.as<$2>()],
             [$1])])
   [m4_ifval([$2],
             [$1.as<$2>()],
             [$1])])

+
+  # b4_symbol_value_template(VAL, [TYPE])
+  # -------------------------------------
+  # Same as b4_symbol_value, but used in a template method.
+  m4_define([b4_symbol_value_template],
+  [m4_ifval([$2],
+            [$1.template as<$2>()],
+            [$1])])

 ]) # b4_variant_if
 
 
 ]) # b4_variant_if
 
 

+# b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT])
+# ----------------------------------------------------------------
+m4_define([b4_lex_symbol_if],
+[b4_percent_define_ifdef([[lex_symbol]], [$1], [$2])])
+
+

 # b4_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
 # b4_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])

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

 m4_define([b4_assert_if],
 [b4_percent_define_ifdef([[assert]], [$1], [$2])])
 
 m4_define([b4_assert_if],
 [b4_percent_define_ifdef([[assert]], [$1], [$2])])
 


@@ -65,7 +116,7 @@ m4_define([b4_lhs_location],
 # Return the data corresponding to the symbol #NUM, where the current
 # rule has RULE-LENGTH symbols on RHS.
 m4_define([b4_rhs_data],
 # Return the data corresponding to the symbol #NUM, where the current
 # rule has RULE-LENGTH symbols on RHS.
 m4_define([b4_rhs_data],

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

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


@@ -92,6 +143,36 @@ m4_define([b4_rhs_location],
           [b4_rhs_data([$1], [$2]).location])
 
 
           [b4_rhs_data([$1], [$2]).location])
 
 

+# b4_symbol_(NUM, FIELD)
+# ----------------------
+# Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
+# undefined.
+m4_define([b4_symbol_],
+[m4_indir([b4_symbol($1, $2)])])
+
+
+# b4_symbol(NUM, FIELD)
+# ---------------------
+# Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
+# undefined.  If FIELD = id, prepend the prefix.
+m4_define([b4_symbol],
+[m4_case([$2],
+         [id],    [m4_do([b4_percent_define_get([token.prefix])],
+                         [b4_symbol_([$1], [id])])],
+         [b4_symbol_($@)])])
+
+
+# b4_symbol_if(NUM, FIELD, IF-TRUE, IF-FALSE)
+# -------------------------------------------
+# If FIELD about symbol #NUM is 1 expand IF-TRUE, if is 0, expand IF-FALSE.
+# Otherwise an error.
+m4_define([b4_symbol_if],
+[m4_case(b4_symbol([$1], [$2]),
+         [1], [$3],
+         [0], [$4],
+         [m4_fatal([$0: field $2 of $1 is not a Boolean:] b4_symbol([$1], [$2]))])])
+
+

 # b4_symbol_actions(FILENAME, LINENO,
 #                   SYMBOL-TAG, SYMBOL-NUM,
 #                   SYMBOL-ACTION, SYMBOL-TYPENAME)
 # b4_symbol_actions(FILENAME, LINENO,
 #                   SYMBOL-TAG, SYMBOL-NUM,
 #                   SYMBOL-ACTION, SYMBOL-TYPENAME)


@@ -99,8 +180,8 @@ m4_define([b4_rhs_location],
 # Same as in C, but using references instead of pointers.
 m4_define([b4_symbol_actions],
 [m4_pushdef([b4_dollar_dollar],
 # Same as in C, but using references instead of pointers.
 m4_define([b4_symbol_actions],
 [m4_pushdef([b4_dollar_dollar],

-            [b4_symbol_value([yydata.value], [$6])])dnl
-m4_pushdef([b4_at_dollar], [yydata.location])dnl
+            [b4_symbol_value_template([yysym.value], [$6])])dnl
+m4_pushdef([b4_at_dollar], [yysym.location])dnl

       case $4: // $3
 b4_syncline([$2], [$1])
         $5;
       case $4: // $3
 b4_syncline([$2], [$1])
         $5;


@@ -111,17 +192,174 @@ m4_popdef([b4_dollar_dollar])dnl
 ])
 
 
 ])
 
 

-# b4_symbol_action_(SYMBOL-TAG, SYMBOL-NUM, SYMBOL-TYPENAME)
-# ----------------------------------------------------------
-# Invoke b4_dollar_dollar(SYMBOL_TYPENAME) for each symbol.
-m4_define([b4_symbol_action_],
-[m4_ifval($3,
-[      case $2: // $1
-        b4_dollar_dollar($@);
+# b4_symbol_case_(SYMBOL-NUM)
+# ---------------------------
+# Issue a "case NUM" for SYMBOL-NUM.
+m4_define([b4_symbol_case_],
+[      case b4_symbol([$1], [number]): // b4_symbol([$1], [tag])
+])
+
+
+# b4_type_action_(NUMS)
+# ---------------------
+# Run actions for the symbol NUMS that all have the same type-name.
+# Skip NUMS that have no type-name.
+m4_define([b4_type_action_],
+[b4_symbol_if([$1], [has_type],
+[m4_map([b4_symbol_case_], [$@])[]dnl
+        b4_dollar_dollar([b4_symbol([$1], [number])],
+                         [b4_symbol([$1], [tag])],
+                         [b4_symbol([$1], [type])]);

        break;
        break;

+

 ])])
 
 
 ])])
 
 

+# b4_symbol_constructor_declaration_(SYMBOL-NUMBER)
+# -------------------------------------------------
+# Declare the overloaded version of make_symbol for the (common) type of
+# these SYMBOL-NUMBERS.  Use at class-level.
+m4_define([b4_symbol_constructor_declaration_],
+[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id],
+[    static inline
+    symbol_type
+    make_[]b4_symbol_([$1], [id]) (dnl
+b4_args(b4_symbol_if([$1], [has_type],
+                     [const b4_symbol([$1], [type])& v]),
+        b4_locations_if([const location_type& l])));
+
+])])])
+
+
+# b4_symbol_constructor_declarations
+# ----------------------------------
+# Declare symbol constructors for all the value types.
+# Use at class-level.
+m4_define([b4_symbol_constructor_declarations],
+[b4_variant_if([
+    // Symbol constructors declarations.
+m4_map([b4_symbol_constructor_declaration_], m4_defn([b4_symbol_numbers]))])])
+
+
+
+# b4_symbol_constructor_definition_(SYMBOL-NUMBER)
+# ------------------------------------------------
+# Define symbol constructor for this SYMBOL-NUMBER.
+m4_define([b4_symbol_constructor_definition_],
+[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id],
+[  b4_parser_class_name::symbol_type
+  b4_parser_class_name::make_[]b4_symbol_([$1], [id]) (dnl
+b4_args(b4_symbol_if([$1], [has_type],
+                     [const b4_symbol([$1], [type])& v]),
+        b4_locations_if([const location_type& l])))
+  {
+    return symbol_type (b4_args([yytranslate_ (token::b4_symbol([$1], [id]))],
+                                b4_symbol_if([$1], [has_type], [v]),
+                                b4_locations_if([l])));
+  }
+
+])])])
+
+
+# b4_symbol_constructor_definitions
+# ----------------------------------
+# Define the overloaded versions of make_symbol for all the value types.
+m4_define([b4_symbol_constructor_definitions],
+[[  // symbol_base_type.
+  template <typename Exact>
+  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type ()
+    : value()]b4_locations_if([
+    , location()])[
+  {
+  }]b4_locations_if([[
+
+  template <typename Exact>
+  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (const location_type& l)
+    : value()
+    , location(l)
+  {
+  }]])[
+
+  template <typename Exact>
+  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (]b4_args(
+          [const semantic_type& v],
+          b4_locations_if([const location_type& l]))[)
+    : value(v)]b4_locations_if([
+    , location(l)])[
+  {
+  }
+
+  template <typename Exact>
+  const Exact&
+  ]b4_parser_class_name[::symbol_base_type<Exact>::self () const
+  {
+    return static_cast<const Exact&>(*this);
+  }
+
+  template <typename Exact>
+  Exact&
+  ]b4_parser_class_name[::symbol_base_type<Exact>::self ()
+  {
+    return static_cast<Exact&>(*this);
+  }
+
+  template <typename Exact>
+  int
+  ]b4_parser_class_name[::symbol_base_type<Exact>::type_get () const
+  {
+    return self ().type_get_ ();
+  }
+
+  // symbol_type.
+  ]b4_parser_class_name[::symbol_type::symbol_type ()
+    : super_type ()
+    , type ()
+  {
+  }
+
+  ]b4_parser_class_name[::symbol_type::symbol_type (]b4_args(
+                [int t],
+                b4_locations_if([const location_type& l]))[)
+    : super_type (]b4_locations_if([l])[)
+    , type (t)
+  {
+  }
+
+  ]b4_parser_class_name[::symbol_type::symbol_type (]b4_args(
+                 [int t],
+                 [const semantic_type& v],
+                 b4_locations_if([const location_type& l]))[)
+    : super_type (v]b4_locations_if([, l])[)
+    , type (t)
+  {
+  }
+
+  int
+  ]b4_parser_class_name[::symbol_type::type_get_ () const
+  {
+    return type;
+  }
+]b4_lex_symbol_if([[
+  ]b4_parser_class_name[::token_type
+  ]b4_parser_class_name[::symbol_type::token () const
+  {
+    // YYTOKNUM[NUM] -- (External) token number corresponding to the
+    // (internal) symbol number NUM (which must be that of a token).  */
+    static
+    const ]b4_int_type_for([b4_toknum])[
+    yytoken_number_[] =
+    {
+  ]b4_toknum[
+    };
+    return static_cast<token_type> (yytoken_number_[type]);
+  }
+]])[
+
+]b4_variant_if(
+[  // Implementation of make_symbol for each symbol type.
+m4_map([b4_symbol_constructor_definition_], m4_defn([b4_symbol_numbers]))])])
+
+

 # b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS])
 # ------------------------------------------------
 # Run some ACTION ("build", or "destroy") on YYVAL of symbol type
 # b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS])
 # ------------------------------------------------
 # Run some ACTION ("build", or "destroy") on YYVAL of symbol type


@@ -131,9 +369,9 @@ m4_define([b4_symbol_variant],
             [$2.$3<$][3>(m4_shift3($@))])dnl
   switch ($1)
     {
             [$2.$3<$][3>(m4_shift3($@))])dnl
   switch ($1)
     {

-m4_map([b4_symbol_action_], m4_defn([b4_type_names]))
-     default:
-       break;
+m4_map([b4_type_action_], m4_defn([b4_type_names]))[]dnl
+      default:
+        break;

     }
 m4_popdef([b4_dollar_dollar])dnl
 ])
     }
 m4_popdef([b4_dollar_dollar])dnl
 ])


@@ -153,20 +391,56 @@ m4_define([_b4_char_sizeof_dummy],
 dummy[]_b4_char_sizeof_counter])
 
 
 dummy[]_b4_char_sizeof_counter])
 
 

-# b4_char_sizeof(SYMBOL-TAG, SYMBOL-NUM, SYMBOL-TYPENAME)
-# -------------------------------------------------------
+# b4_char_sizeof_(SYMBOL-NUM)
+# ---------------------------
+# A comment describing this symbol.
+m4_define([b4_char_sizeof_],
+[      // b4_symbol([$1], [tag])
+])
+
+# b4_char_sizeof(SYMBOL-NUMS)
+# --------------------------

 # To be mapped on the list of type names to produce:
 #
 #    char dummy1[sizeof(type_name_1)];
 #    char dummy2[sizeof(type_name_2)];
 #
 # for defined type names.
 # To be mapped on the list of type names to produce:
 #
 #    char dummy1[sizeof(type_name_1)];
 #    char dummy2[sizeof(type_name_2)];
 #
 # for defined type names.

-# $3 is doubly-quoted, do not quote it again.

 m4_define([b4_char_sizeof],
 m4_define([b4_char_sizeof],

-[m4_ifval($3,
+[b4_symbol_if([$1], [has_type],

 [
 [

-      char _b4_char_sizeof_dummy@{sizeof($3)@}; // $1])dnl
-])
+m4_map([b4_char_sizeof_], [$@])dnl
+      char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@};
+])])
+
+
+# b4_yytranslate_definition
+# -------------------------
+# Define yytranslate_.  Sometimes we want it in the header file,
+# sometimes the cc file suffices.
+m4_define([b4_yytranslate_definition],
+[[  // Symbol number corresponding to token number t.
+  ]b4_parser_class_name[::token_number_type
+  ]b4_parser_class_name[::yytranslate_ (]b4_lex_symbol_if([token_type],
+                                                          [int])[ t)
+  {
+    static
+    const token_number_type
+    translate_table[] =
+    {
+]b4_translate[
+    };
+    const unsigned int user_token_number_max_ = ]b4_user_token_number_max[;
+    const token_number_type undef_token_ = ]b4_undef_token_number[;
+
+    if (static_cast<int>(t) <= yyeof_)
+      return yyeof_;
+    else if (static_cast<unsigned int> (t) <= user_token_number_max_)
+      return translate_table[t];
+    else
+      return undef_token_;
+  }
+]])

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


@@ -179,15 +453,15 @@ m4_define([b4_parser_class_name],
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 

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

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

-m4_include(b4_pkgdatadir/[location.cc])
+m4_include(b4_pkgdatadir/[location.cc])])

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

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

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


@@ -204,8 +478,8 @@ dnl FIXME: This is wrong, we want computed header guards.
 #include "stack.hh"
 
 ]b4_namespace_open[
 #include "stack.hh"
 
 ]b4_namespace_open[

-  class position;
-  class location;
+]b4_locations_if([  class position;
+  class location;])[

 ]b4_variant_if(
 [[
   /// A char[S] buffer to store and retrieve objects.
 ]b4_variant_if(
 [[
   /// A char[S] buffer to store and retrieve objects.


@@ -218,11 +492,12 @@ dnl FIXME: This is wrong, we want computed header guards.
   {]b4_assert_if([
     /// Whether something is contained.
     bool built;
   {]b4_assert_if([
     /// Whether something is contained.
     bool built;

-
-    /// Initially uninitialized.
-    variant ()
-      : built(false)
-    {}])[
+])[
+    /// Empty construction.
+    inline
+    variant ()]b4_assert_if([
+      : built(false)])[
+    {}

 
     /// Instantiate a \a T in here.
     template <typename T>
 
     /// Instantiate a \a T in here.
     template <typename T>


@@ -234,6 +509,25 @@ dnl FIXME: This is wrong, we want computed header guards.
       return *new (buffer) T;
     }
 
       return *new (buffer) T;
     }
 

+    /// Instantiate a \a T in here from \a t.
+    template <typename T>
+    inline T&
+    build(const T& t)
+    {]b4_assert_if([
+      assert(!built);
+      built = true;])[
+      return *new (buffer) T(t);
+    }
+
+    /// Construct and fill.
+    template <typename T>
+    inline
+    variant (const T& t)]b4_assert_if([
+      : built(true)])[
+    {
+      new (buffer) T(t);
+    }
+

     /// Accessor to a built \a T.
     template <typename T>
     inline T&
     /// Accessor to a built \a T.
     template <typename T>
     inline T&


@@ -286,7 +580,7 @@ dnl FIXME: This is wrong, we want computed header guards.
 ]])[
 ]b4_namespace_close[
 
 ]])[
 ]b4_namespace_close[
 

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

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


@@ -306,7 +600,8 @@ dnl FIXME: This is wrong, we want computed header guards.
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 

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

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


@@ -323,7 +618,7 @@ do {                                                            \
       (Current).begin = (Current).end = (Rhs)[0].location.end; \
     }                                                           \
 } while (false)
       (Current).begin = (Current).end = (Rhs)[0].location.end; \
     }                                                           \
 } while (false)

-#endif
+#endif]])[

 
 ]b4_namespace_open[
 
 
 ]b4_namespace_open[
 


@@ -335,8 +630,7 @@ do {                                                            \
 ]b4_variant_if(
 [    /// An auxiliary type to compute the largest semantic type.
     union union_type
 ]b4_variant_if(
 [    /// An auxiliary type to compute the largest semantic type.
     union union_type

-    {]m4_map([b4_char_sizeof], m4_defn([b4_type_names]))[
-    };
+    {]m4_map([b4_char_sizeof], m4_defn([b4_type_names]))[};

 
     /// Symbol semantic values.
     typedef variant<sizeof(union_type)> semantic_type;],
 
     /// Symbol semantic values.
     typedef variant<sizeof(union_type)> semantic_type;],


@@ -350,9 +644,9 @@ m4_ifdef([b4_stype],
 [[    typedef YYSTYPE semantic_type;]])])])[
 #else
     typedef YYSTYPE semantic_type;
 [[    typedef YYSTYPE semantic_type;]])])])[
 #else
     typedef YYSTYPE semantic_type;

-#endif
+#endif]b4_locations_if([

     /// Symbol locations.
     /// Symbol locations.

-    typedef ]b4_percent_define_get([[location_type]])[ location_type;
+    typedef b4_percent_define_get([[location_type]]) location_type;])[

     /// Tokens.
     struct token
     {
     /// Tokens.
     struct token
     {


@@ -384,10 +678,10 @@ m4_ifdef([b4_stype],
 #endif
 
   private:
 #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);
+    virtual void error (]b4_locations_if([const location_type& loc, ])[const std::string& msg);

 
     /// Generate an error message.
     /// \param state   the state where the error occurred.
 
     /// Generate an error message.
     /// \param state   the state where the error occurred.


@@ -433,18 +727,14 @@ m4_ifdef([b4_stype],
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
     /// For a symbol, its name in clear.
     static const char* const yytname_[];
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
     /// For a symbol, its name in clear.
     static const char* const yytname_[];

-#endif
+#endif]b4_error_verbose_if([

 
 

-#if YYERROR_VERBOSE

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

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

 
 #if YYDEBUG
     /// For each rule, its source line number.
     static const ]b4_int_type_for([b4_rline])[ yyrline_[];
 
 #if YYDEBUG
     /// For each rule, its source line number.
     static const ]b4_int_type_for([b4_rline])[ yyrline_[];

-    /// For each scanner token number, its symbol number.
-    static const ]b4_int_type_for([b4_toknum])[ yytoken_number_[];

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


@@ -456,54 +746,103 @@ m4_ifdef([b4_stype],
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.

-    token_number_type yytranslate_ (int t);
+    static inline token_number_type yytranslate_ (]b4_lex_symbol_if([token_type], [int])[ t);

 
 

-    /// Element of the stack: a state and its attributes.
-    struct stack_symbol_type
+    /// A complete symbol, with its type.
+    template <typename Exact>
+    struct symbol_base_type

     {
       /// Default constructor.
     {
       /// Default constructor.

-      stack_symbol_type ();
+      inline symbol_base_type ();

 
 

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

 
 

-      /// The state.
-      state_type state;
+      /// Return this with its exact type.
+      const Exact& self () const;
+      Exact& self ();
+
+      /// Return the type of this symbol.
+      int type_get () const;

 
       /// The semantic value.
 
       /// The semantic value.

-      semantic_type value;
+      semantic_type value;]b4_locations_if([

 
       /// The location.
 
       /// The location.

-      location_type location;
+      location_type location;])[

     };
 
 #if YYDEBUG
     };
 
 #if YYDEBUG

-    /// \brief Report a symbol value on the debug stream as per %printer.
-    /// \param yytype       The token type.
-    /// \param yydata       Its semantic value and location.
-    virtual void yy_symbol_value_print_ (int yytype,
-                                        const stack_symbol_type& yydata);
-    /// \brief Report a symbol on the debug stream.
-    /// \param yytype       The token type.
-    /// \param yydata       Its semantic value and location.
-    virtual void yy_symbol_print_ (int yytype,
-                                  const stack_symbol_type& yydata);
+    /// \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
 
 #endif
 

-    /// \brief Reclaim the memory associated to a lookahead symbol.
-    /// \param yymsg        Why this token is reclaimed.
-    ///                     If null, print nothing.
-    /// \param yytype       The symbol type.
-    /// \param yydata       Its semantic value and location.
-    inline void yydestruct_ (const char* yymsg,
-                            int yytype, stack_symbol_type& yydata);
+    /// \brief Reclaim the memory associated to a symbol.
+    /// \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;
+
+  public:
+    /// Element of the stack: a state and its attributes.
+    struct symbol_type : symbol_base_type<symbol_type>
+    {
+      /// The parent class.
+      typedef symbol_base_type<symbol_type> super_type;
+
+      /// Default constructor.
+      inline symbol_type ();
+
+      /// Constructor.
+      inline symbol_type (]b4_args([int t],
+                                   [const semantic_type& v],
+                                   b4_locations_if([const location_type& l]))[);
+
+      inline symbol_type (]b4_args([int t],
+                                   b4_locations_if([const location_type& l]))[);
+
+      /// The symbol type.
+      int type;

 
 

-    /// \brief Reclaim the memory associated to a stack symbol.
-    /// \param yymsg        Why this token is reclaimed.
-    ///                     If null, print nothing.
-    /// \param yysym        Its kind, semantic value and location.
-    inline void yydestruct_ (const char* yymsg, stack_symbol_type& yysym);
+      /// Return the type corresponding to this state.
+      inline int type_get_ () const;
+
+      /// Its token.
+      inline token_type token () const;
+    };
+
+]b4_symbol_constructor_declarations[
+
+  private:
+    /// Element of the stack: a state and its attributes.
+    struct stack_symbol_type : symbol_base_type<stack_symbol_type>
+    {
+      /// The parent class.
+      typedef symbol_base_type<stack_symbol_type> super_type;
+
+      /// Default constructor.
+      inline stack_symbol_type ();
+
+      /// Constructor.
+      inline stack_symbol_type (]b4_args([state_type s],
+                                         [const semantic_type& v],
+                                         b4_locations_if([const location_type& l]))[);
+
+      /// The state.
+      state_type state;
+
+      /// Return the type corresponding to this state.
+      inline int type_get_ () const;
+    };

 
     /// Stack type.
     typedef stack<stack_symbol_type> stack_type;
 
     /// Stack type.
     typedef stack<stack_symbol_type> stack_type;


@@ -518,23 +857,35 @@ m4_ifdef([b4_stype],
     /// \warning the contents of \a s.value is stolen.
     inline void yypush_ (const char* m, stack_symbol_type& s);
 
     /// \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_lex_symbol_if([b4_yytranslate_definition])[
+]b4_lex_symbol_if([b4_symbol_constructor_definitions])[

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


@@ -548,7 +899,6 @@ m4_ifdef([b4_stype],
 b4_percent_code_get([[provides]])[]dnl
 
 [#endif /* ! defined PARSER_HEADER_H */]
 b4_percent_code_get([[provides]])[]dnl
 
 [#endif /* ! defined PARSER_HEADER_H */]

-])dnl

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


@@ -558,10 +908,9 @@ m4_if(b4_prefix, [yy], [],
 #define yylex   b4_prefix[]lex])[
 
 /* First part of user declarations.  */
 #define yylex   b4_prefix[]lex])[
 
 /* First part of user declarations.  */

-]b4_user_pre_prologue
+]b4_user_pre_prologue[

 
 

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

 
 /* User implementation prologue.  */
 ]b4_user_post_prologue
 
 /* User implementation prologue.  */
 ]b4_user_post_prologue


@@ -588,12 +937,12 @@ b4_percent_code_get[]dnl
 /* 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, Data)    \
+# define YY_SYMBOL_PRINT(Title, Symbol)         \

   do {                                          \
     if (yydebug_)                               \
     {                                           \
       *yycdebug_ << Title << ' ';               \
   do {                                          \
     if (yydebug_)                               \
     {                                           \
       *yycdebug_ << Title << ' ';               \

-      yy_symbol_print_ ((Type), (Data));       \
+      yy_print_ (*yycdebug_, Symbol);           \

       *yycdebug_ << std::endl;                  \
     }                                           \
   } while (false)
       *yycdebug_ << std::endl;                  \
     }                                           \
   } while (false)


@@ -613,22 +962,21 @@ b4_percent_code_get[]dnl
 #else /* !YYDEBUG */
 
 # define YYCDEBUG if (false) std::cerr
 #else /* !YYDEBUG */
 
 # define YYCDEBUG if (false) std::cerr

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

 
 #endif /* !YYDEBUG */
 
 
 #endif /* !YYDEBUG */
 

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

 
 

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

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

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

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


@@ -666,8 +1014,7 @@ b4_percent_code_get[]dnl
 
     return yystr;
   }
 
     return yystr;
   }

-
-#endif
+]])[

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


@@ -683,87 +1030,108 @@ b4_percent_code_get[]dnl
   {
   }
 
   {
   }
 

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

 
 

-  inline void
-  ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
-                          const stack_symbol_type& yydata)
+  /*---------------.
+  | Symbol types.  |
+  `---------------*/
+
+]b4_lex_symbol_if([], [b4_symbol_constructor_definitions])[
+
+  // stack_symbol_type.
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
+    : super_type ()
+    , state ()

   {
   {

-    switch (yytype)
-      {
-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
-[       default:
-         break;
-      }

   }
 
   }
 

-
-  void
-  ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
-                          const stack_symbol_type& yydata)
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (]b4_args(
+                 [state_type s],
+                 [const semantic_type& v],
+                 b4_locations_if([const location_type& l]))[)
+    : super_type (v]b4_locations_if([, l])[)
+    , state (s)

   {
   {

-    *yycdebug_ << (yytype < yyntokens_ ? "token" : "nterm")
-              << ' ' << yytname_[yytype] << " ("
-              << yydata.location << ": ";
-    yy_symbol_value_print_ (yytype, yydata);
-    *yycdebug_ << ')';

   }
   }

-#endif

 
 

-  void
-  ]b4_parser_class_name[::yydestruct_ (const char* yymsg,
-                                       stack_symbol_type& yysym)
+  int
+  ]b4_parser_class_name[::stack_symbol_type::type_get_ () const

   {
   {

-    yydestruct_ (yymsg, yystos_[yysym.state], yysym);
+    return yystos_[state];

   }
 
   }
 

+
+  template <typename Exact>

   void
   void

-  ]b4_parser_class_name[::yydestruct_ (const char* yymsg,
-                          int yytype, stack_symbol_type& yydata)
+  ]b4_parser_class_name[::yy_destroy_ (const char* yymsg,
+                                       symbol_base_type<Exact>& yysym) const

   {
   {

+    int yytype = yysym.type_get ();

     YYUSE (yymsg);
     YYUSE (yymsg);

-

     if (yymsg)
     if (yymsg)

-      YY_SYMBOL_PRINT (yymsg, yytype, yydata);
+      YY_SYMBOL_PRINT (yymsg, yysym);

 
     // User destructor.
     switch (yytype)
       {
 
     // User destructor.
     switch (yytype)
       {

-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
+]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[

        default:
          break;
       }]b4_variant_if([
 
     // Type destructor.
        default:
          break;
       }]b4_variant_if([
 
     // Type destructor.

-  b4_symbol_variant([[yytype]], [[yydata.value]], [[destroy]])])[
+  b4_symbol_variant([[yytype]], [[yysym.value]], [[template destroy]])])[

   }
 
   }
 

-  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
-    : state()
-    , value()
-    , location()
+#if YYDEBUG
+  template <typename Exact>
+  void
+  ]b4_parser_class_name[::yy_print_ (std::ostream& yyo,
+                                     const symbol_base_type<Exact>& yysym) const

   {
   {

+    int yytype = yysym.type_get ();
+    yyo << (yytype < yyntokens_ ? "token" : "nterm")
+        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
+        << yysym.location << ": "])[;
+    switch (yytype)
+      {
+]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))[
+       default:
+         break;
+      }
+    yyo << ')';

   }
   }

+#endif

 
 

-  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (state_type s,
-                           const semantic_type& v, const location_type& l)
-    : state(s)
-    , value(v)
-    , location(l)
+  void
+  ]b4_parser_class_name[::yypush_ (const char* m, state_type s,
+                                   symbol_type& sym)

   {
   {

+    if (m)
+      YY_SYMBOL_PRINT (m, sym);
+]b4_variant_if(
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                    [s],
+                    [semantic_type()],
+                    b4_locations_if([sym.location]))[));
+    ]b4_symbol_variant([[yystos_[s]]], [[yystack_[0].value]],
+                       [build], [sym.value])],
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                      [s],
+                      [sym.value],
+                      b4_locations_if([sym.location]))[));]])[

   }
 
   void
   ]b4_parser_class_name[::yypush_ (const char* m, stack_symbol_type& s)
   {
     if (m)
   }
 
   void
   ]b4_parser_class_name[::yypush_ (const char* m, stack_symbol_type& s)
   {
     if (m)

-      YY_SYMBOL_PRINT (m, yystos_[s.state], s);
+      YY_SYMBOL_PRINT (m, s);

 ]b4_variant_if(
 ]b4_variant_if(

-[[    yystack_.push (stack_symbol_type (s, semantic_type(), l));
-    ]b4_symbol_variant([[yystos_[s]]], [[yystack_[0].value]],
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                       [s.state],
+                       [semantic_type()],
+                       b4_locations_if([s.location]))[));
+    ]b4_symbol_variant([[yystos_[s.state]]], [[yystack_[0].value]],

                        [build], [s.value])],
 [    yystack_.push (s);])[
   }
                        [build], [s.value])],
 [    yystack_.push (s);])[
   }


@@ -804,9 +1172,8 @@ b4_percent_code_get[]dnl
   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.  */
     int yyn;
 
     /* State.  */
     int yyn;


@@ -818,10 +1185,10 @@ b4_percent_code_get[]dnl
     int yyerrstatus_ = 0;
 
     /// The lookahead symbol.
     int yyerrstatus_ = 0;
 
     /// The lookahead symbol.

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

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

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

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


@@ -844,7 +1211,7 @@ m4_popdef([b4_at_dollar])])dnl
        location values to have been already stored, initialize these
        stacks with a primary value.  */
     yystack_ = stack_type (0);
        location values to have been already stored, initialize these
        stacks with a primary value.  */
     yystack_ = stack_type (0);

-    yypush_ (0, yyla);
+    yypush_ (0, 0, yyla);

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


@@ -867,32 +1234,24 @@ m4_popdef([b4_at_dollar])])dnl
       goto yydefault;
 
     /* Read a lookahead token.  */
       goto yydefault;
 
     /* Read a lookahead token.  */

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

       {
       {

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

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

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

       }
       }

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

 
 

-    /* If the proper action on seeing token 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.  */
       goto yydefault;
 
     /* Reduce or error.  */


@@ -906,7 +1265,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       }
 
     /* Discard the token being shifted.  */
       }
 
     /* Discard the token being shifted.  */

-    yychar = yyempty_;
+    yyempty = true;

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


@@ -914,8 +1273,8 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       --yyerrstatus_;
 
     /* Shift the lookahead token.  */
       --yyerrstatus_;
 
     /* Shift the lookahead token.  */

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

     goto yynewstate;
 
   /*-----------------------------------------------------------.
     goto yynewstate;
 
   /*-----------------------------------------------------------.


@@ -946,18 +1305,19 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       yylhs.value = yystack_@{yylen - 1@}.value;
     else
       yylhs.value = yystack_@{0@}.value;])[
       yylhs.value = yystack_@{yylen - 1@}.value;
     else
       yylhs.value = yystack_@{0@}.value;])[

-
+]b4_locations_if([dnl
+[

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

-    }
+    }]])[

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

-       ]b4_user_actions[
+]b4_user_actions[

        default:
           break;
       }
        default:
           break;
       }


@@ -970,7 +1330,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     else
       yystate = yydefgoto_[yyn - yyntokens_];
     yylhs.state = yystate;
     else
       yystate = yydefgoto_[yyn - yyntokens_];
     yylhs.state = yystate;

-    YY_SYMBOL_PRINT ("-> $$ =", yyn, yylhs);
+    YY_SYMBOL_PRINT ("-> $$ =", yylhs);

 ]b4_variant_if([[
     // Destroy the lhs symbols.
     for (int i = 0; i < yylen; ++i)
 ]b4_variant_if([[
     // Destroy the lhs symbols.
     for (int i = 0; i < yylen; ++i)


@@ -982,7 +1342,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       // do not try to report the content in the debug trace, it's
       // junk.  Hence yymsg = 0.  Besides, that keeps exactly the same
       // traces as with the other Bison skeletons.
       // do not try to report the content in the debug trace, it's
       // junk.  Hence yymsg = 0.  Besides, that keeps exactly the same
       // traces as with the other Bison skeletons.

-      yydestruct_ (0, yystack_[i]);]])[
+      yy_destroy_ (0, yystack_[i]);]])[

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


@@ -1000,25 +1360,24 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     if (!yyerrstatus_)
       {
        ++yynerrs_;
     if (!yyerrstatus_)
       {
        ++yynerrs_;

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

       }
 
       }
 

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

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

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

          }
       }
 
          }
       }
 


@@ -1038,7 +1397,8 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     if (false)
       goto yyerrorlab;
 
     if (false)
       goto yyerrorlab;
 

-    yyerror_range[0].location = yystack_[yylen - 1].location;
+]b4_locations_if([[
+    yyerror_range[0].location = yystack_[yylen - 1].location;]])[

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


@@ -1070,16 +1430,16 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
           // Pop the current state because it cannot handle the error token.
           if (yystack_.size () == 1)
             YYABORT;
           // Pop the current state because it cannot handle the error token.
           if (yystack_.size () == 1)
             YYABORT;

-
-          yyerror_range[0].location = yystack_[0].location;
-          yydestruct_ ("Error: popping", yystack_[0]);
+]b4_locations_if([[
+          yyerror_range[0].location = yystack_[0].location;]])[
+          yy_destroy_ ("Error: popping", yystack_[0]);

           yypop_ ();
           yystate = yystack_[0].state;
           YY_STACK_PRINT ();
         }
           yypop_ ();
           yystate = yystack_[0].state;
           YY_STACK_PRINT ();
         }

-
+]b4_locations_if([[

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

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

 
       /* Shift the error token.  */
       error_token.state = yystate = yyn;
 
       /* Shift the error token.  */
       error_token.state = yystate = yyn;


@@ -1098,15 +1458,15 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     goto yyreturn;
 
   yyreturn:
     goto yyreturn;
 
   yyreturn:

-    if (yychar != yyempty_)
-      yydestruct_ ("Cleanup: discarding lookahead", yytoken, yyla);
+    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);
     while (yystack_.size () != 1)
       {
 
     /* Do not reclaim the symbols of the rule which action triggered
        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);
     while (yystack_.size () != 1)
       {

-       yydestruct_ ("Cleanup: popping", yystack_[0]);
+       yy_destroy_ ("Cleanup: popping", yystack_[0]);

        yypop_ ();
       }
 
        yypop_ ();
       }
 


@@ -1115,12 +1475,11 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
 
   // Generate an error message.
   std::string
 
   // Generate an error message.
   std::string

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

   {
   {

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

     int yyn = yypact_[yystate];
     if (yypact_ninf_ < yyn && yyn <= yylast_)
       {
     int yyn = yypact_[yystate];
     if (yypact_ninf_ < yyn && yyn <= yylast_)
       {


@@ -1131,36 +1490,55 @@ b4_error_verbose_if([ tok])[)
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;

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

       }
     else
       }
     else

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

   }
 
 
   }
 
 


@@ -1193,12 +1571,6 @@ b4_error_verbose_if([ tok])[)
      symbol of state STATE-NUM.  */
   ]b4_table_define([stos], [b4_stos])[;
 
      symbol of state STATE-NUM.  */
   ]b4_table_define([stos], [b4_stos])[;
 

-#if YYDEBUG
-  /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal symbol number corresponding
-     to YYLEX-NUM.  */
-  ]b4_table_define([token_number], [b4_toknum])[;
-#endif
-

   /* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
   ]b4_table_define([r1], [b4_r1])[;
 
   /* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
   ]b4_table_define([r1], [b4_r1])[;
 


@@ -1244,39 +1616,11 @@ b4_error_verbose_if([ tok])[)
     /* 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 << " =",

-                       ]yystos_@{b4_rhs_state(yynrhs, yyi + 1)@}[,
-                      ]b4_rhs_data(yynrhs, yyi + 1)[);
+                       ]b4_rhs_data(yynrhs, yyi + 1)[);

   }
 #endif // YYDEBUG
 
   }
 #endif // YYDEBUG
 

-  /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
-  ]b4_parser_class_name[::token_number_type
-  ]b4_parser_class_name[::yytranslate_ (int t)
-  {
-    static
-    const token_number_type
-    translate_table[] =
-    {
-  ]b4_translate[
-    };
-    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_lex_symbol_if([], [b4_yytranslate_definition])[

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