* data/lalr1.cc: Move towards a more standard C++ coding style

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 214adb27aca07381a4bd1f85c968ae325812b2e5..8405171098fbd9852998cc832f8e45907b5e62c3 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -1,6 +1,6 @@
 m4_divert(-1)
 # C++ skeleton for Bison
 m4_divert(-1)
 # C++ skeleton for Bison

-# Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003, 2004 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


@@ -81,13 +81,57 @@ m4_define([b4_constructor],
                    [])])
 
 
                    [])])
 
 

+# b4_parse_param_decl
+# -------------------
+# Extra formal arguments of the constructor.
+# Change the parameter names from "foo" into "foo_yyarg", so that
+# there is no collision bw the user chosen attribute name, and the
+# argument name in the constructor.
+m4_define([b4_parse_param_decl],
+[m4_ifset([b4_parse_param],
+          [, m4_map_sep([b4_parse_param_decl_1], [, ], [b4_parse_param])])])
+
+m4_define([b4_parse_param_decl_1],
+[$1_yyarg])
+
+
+
+# b4_parse_param_cons
+# -------------------
+# Extra initialisations of the constructor.
+m4_define([b4_parse_param_cons],
+          [m4_ifset([b4_parse_param],
+                   [,
+      b4_cc_constructor_calls(b4_parse_param)])])
+m4_define([b4_cc_constructor_calls],
+         [m4_map_sep([b4_cc_constructor_call], [,
+      ], [$@])])
+m4_define([b4_cc_constructor_call],
+         [$2 ($2_yyarg)])
+
+# b4_parse_param_vars
+# -------------------
+# Extra instance variables.
+m4_define([b4_parse_param_vars],
+          [m4_ifset([b4_parse_param],
+                   [
+    /* User arguments.  */
+b4_cc_var_decls(b4_parse_param)])])
+m4_define([b4_cc_var_decls],
+         [m4_map_sep([b4_cc_var_decl], [
+], [$@])])
+m4_define([b4_cc_var_decl],
+         [    $1;])
+
+
+

 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert(0)dnl
 m4_if(b4_defines_flag, 0, [],
 [@output @output_header_name@
 b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert(0)dnl
 m4_if(b4_defines_flag, 0, [],
 [@output @output_header_name@
 b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],

-             [2002, 2003])[
+             [2002, 2003, 2004])[

 /* FIXME: This is wrong, we want computed header guards.
    I don't know why the macros are missing now. :( */
 #ifndef PARSER_HEADER_H
 /* FIXME: This is wrong, we want computed header guards.
    I don't know why the macros are missing now. :( */
 #ifndef PARSER_HEADER_H


@@ -120,7 +164,9 @@ b4_syncline([@oline@], [@ofile@])[
 # define YYERROR_VERBOSE ]b4_error_verbose[
 #endif
 
 # define YYERROR_VERBOSE ]b4_error_verbose[
 #endif
 

-#ifndef YYSTYPE
+#ifdef YYSTYPE
+typedef YYSTYPE yystype;
+#else

 ]m4_ifdef([b4_stype],
 [b4_syncline([b4_stype_line], [b4_filename])
 typedef union b4_stype yystype;
 ]m4_ifdef([b4_stype],
 [b4_syncline([b4_stype_line], [b4_filename])
 typedef union b4_stype yystype;


@@ -135,27 +181,32 @@ b4_syncline([@oline@], [@ofile@])],
 
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[
 
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[

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

 #ifndef YYLLOC_DEFAULT
 #ifndef YYLLOC_DEFAULT

-# define YYLLOC_DEFAULT(Current, Rhs, N) \
-   Current.end = Rhs[N].end;
+# define YYLLOC_DEFAULT(Current, Rhs, N)       \
+do {                                           \
+   ((Current).begin = (Rhs)[1].begin);         \
+   ((Current).end   = (Rhs)[N].end);           \
+} while (0)

 #endif
 
 namespace yy
 {
   class ]b4_parser_class_name[;
 
 #endif
 
 namespace yy
 {
   class ]b4_parser_class_name[;
 

-  template < typename P >
+  template <typename P>

   struct Traits
   {
   };
 
   struct Traits
   {
   };
 

-  template < >
-  struct Traits< ]b4_parser_class_name[ >
+  template <>
+  struct Traits<]b4_parser_class_name[>

   {
     typedef ]b4_int_type_for([b4_translate])[ TokenNumberType;
     typedef ]b4_int_type_for([b4_rhs])[       RhsNumberType;
   {
     typedef ]b4_int_type_for([b4_translate])[ TokenNumberType;
     typedef ]b4_int_type_for([b4_rhs])[       RhsNumberType;

-    typedef int      StateType;
-    typedef yystype  SemanticType;
+    typedef int StateType;
+    typedef yystype SemanticType;

     typedef ]b4_location_type[ LocationType;
   };
 }
     typedef ]b4_location_type[ LocationType;
   };
 }


@@ -166,28 +217,31 @@ namespace yy
   {
   public:
 
   {
   public:
 

-    typedef Traits< ]b4_parser_class_name[ >::TokenNumberType TokenNumberType;
-    typedef Traits< ]b4_parser_class_name[ >::RhsNumberType   RhsNumberType;
-    typedef Traits< ]b4_parser_class_name[ >::StateType       StateType;
-    typedef Traits< ]b4_parser_class_name[ >::SemanticType    SemanticType;
-    typedef Traits< ]b4_parser_class_name[ >::LocationType    LocationType;
+    typedef Traits<]b4_parser_class_name[>::TokenNumberType TokenNumberType;
+    typedef Traits<]b4_parser_class_name[>::RhsNumberType   RhsNumberType;
+    typedef Traits<]b4_parser_class_name[>::StateType       StateType;
+    typedef Traits<]b4_parser_class_name[>::SemanticType    SemanticType;
+    typedef Traits<]b4_parser_class_name[>::LocationType    LocationType;

 
 

-    typedef Stack< StateType >    StateStack;
-    typedef Stack< SemanticType > SemanticStack;
-    typedef Stack< LocationType > LocationStack;
+    typedef Stack<StateType>    StateStack;
+    typedef Stack<SemanticType> SemanticStack;
+    typedef Stack<LocationType> LocationStack;

 
 

-#if YYLSP_NEEDED
-    ]b4_parser_class_name[ (bool debug,
-           LocationType initlocation][]b4_param[) :
+    ]b4_parser_class_name[ (bool debug][]b4_param[]b4_parse_param_decl[) :

       ]b4_constructor[][debug_ (debug),
       ]b4_constructor[][debug_ (debug),

-      cdebug_ (std::cerr),
-      initlocation_ (initlocation)
-#else
-    ]b4_parser_class_name[ (bool debug][]b4_param[) :
+      cdebug_ (std::cerr)]b4_parse_param_cons[
+    {
+    }
+
+    ]b4_parser_class_name[ (bool debug,
+           LocationType][]b4_param[]b4_parse_param_decl[) :

       ]b4_constructor[][debug_ (debug),
       ]b4_constructor[][debug_ (debug),

-      cdebug_ (std::cerr)
-#endif
+      cdebug_ (std::cerr)]b4_parse_param_cons[

     {
     {

+      cdebug_ << __FILE__ << ':' << __LINE__
+             << ": this constructor is provided by backward compatibility"
+             << ", but will be removed in the near future."
+             << std::endl;

     }
 
     virtual ~]b4_parser_class_name[ ()
     }
 
     virtual ~]b4_parser_class_name[ ()


@@ -201,6 +255,13 @@ namespace yy
     virtual void lex_ ();
     virtual void error_ ();
     virtual void print_ ();
     virtual void lex_ ();
     virtual void error_ ();
     virtual void print_ ();

+    virtual void report_syntax_error_ ();
+#if YYDEBUG
+    virtual void symprint_ (int yytype,
+                           const SemanticType* yyvaluep,
+                           const LocationType* yylocationp);
+#endif /* ! YYDEBUG */
+

 
     /* Stacks.  */
     StateStack    state_stack_;
 
     /* Stacks.  */
     StateStack    state_stack_;


@@ -209,13 +270,14 @@ namespace yy
 
     /* Tables.  */
     static const ]b4_int_type_for([b4_pact])[ pact_[];
 
     /* Tables.  */
     static const ]b4_int_type_for([b4_pact])[ pact_[];

-    static const ]b4_int_type_for([b4_pact])[ pact_ninf_;
+    static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ pact_ninf_;

     static const ]b4_int_type_for([b4_defact])[ defact_[];
     static const ]b4_int_type_for([b4_pgoto])[ pgoto_[];
     static const ]b4_int_type_for([b4_defgoto])[ defgoto_[];
     static const ]b4_int_type_for([b4_table])[ table_[];
     static const ]b4_int_type_for([b4_defact])[ defact_[];
     static const ]b4_int_type_for([b4_pgoto])[ pgoto_[];
     static const ]b4_int_type_for([b4_defgoto])[ defgoto_[];
     static const ]b4_int_type_for([b4_table])[ table_[];

-    static const ]b4_int_type_for([b4_table])[ table_ninf_;
+    static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ table_ninf_;

     static const ]b4_int_type_for([b4_check])[ check_[];
     static const ]b4_int_type_for([b4_check])[ check_[];

+    static const ]b4_int_type_for([b4_stos])[ stos_[];

     static const ]b4_int_type_for([b4_r1])[ r1_[];
     static const ]b4_int_type_for([b4_r2])[ r2_[];
 
     static const ]b4_int_type_for([b4_r1])[ r1_[];
     static const ]b4_int_type_for([b4_r2])[ r2_[];
 


@@ -228,12 +290,19 @@ namespace yy
     static const RhsNumberType rhs_[];
     static const ]b4_int_type_for([b4_prhs])[ prhs_[];
     static const ]b4_int_type_for([b4_rline])[ rline_[];
     static const RhsNumberType rhs_[];
     static const ]b4_int_type_for([b4_prhs])[ prhs_[];
     static const ]b4_int_type_for([b4_rline])[ rline_[];

-    static const ]b4_int_type_for([b4_stos])[ stos_[];

     static const ]b4_int_type_for([b4_toknum])[ token_number_[];
     static const ]b4_int_type_for([b4_toknum])[ token_number_[];

+    virtual void reduce_print_ (int yyrule);
+    virtual void stack_print_ ();

 #endif
 
     /* Even more tables.  */
 #endif
 
     /* Even more tables.  */

-    static inline TokenNumberType translate_ (int token);
+    inline TokenNumberType translate_ (int token);
+    inline void destruct_ (const char* yymsg,
+                           int yytype,
+                           SemanticType* yyvaluep, LocationType* yylocationp);
+
+    /// Pop \a n symbols the three stacks.
+    inline void pop (unsigned int n = 1);

 
     /* Constants.  */
     static const int eof_;
 
     /* Constants.  */
     static const int eof_;


@@ -245,7 +314,7 @@ namespace yy
     static const int terror_;
     static const int errcode_;
     static const int ntokens_;
     static const int terror_;
     static const int errcode_;
     static const int ntokens_;

-    static const unsigned user_token_number_max_;
+    static const unsigned int user_token_number_max_;

     static const TokenNumberType undef_token_;
 
     /* State.  */
     static const TokenNumberType undef_token_;
 
     /* State.  */


@@ -253,27 +322,33 @@ namespace yy
     int len_;
     int state_;
 
     int len_;
     int state_;
 

+    /* Error handling. */
+    int nerrs_;
+    int errstatus_;
+

     /* Debugging.  */
     int debug_;
     /* Debugging.  */
     int debug_;

-    std::ostream &cdebug_;
+    std::ostream& cdebug_;

 
 

-    /* Lookahead and lookahead in internal form.  */
+    /* Look-ahead and look-ahead in internal form.  */

     int looka_;
     int ilooka_;
 
     /* Message.  */
     std::string message;
 
     int looka_;
     int ilooka_;
 
     /* Message.  */
     std::string message;
 

-    /* Semantic value and location of lookahead token.  */
+    /// Semantic value of the look-ahead.

     SemanticType value;
     SemanticType value;

+    /// Location of the look-ahead.

     LocationType location;
     LocationType location;

+    /// The locations where the error started and ended.
+    Location error_range_[2];

 
 

-    /* @@$ and $$.  */
+    /// $$.

     SemanticType yyval;
     SemanticType yyval;

+    /// @@$.

     LocationType yyloc;
     LocationType yyloc;

-
-    /* Initial location.  */
-    LocationType initlocation_;
+]b4_parse_param_vars[

   };
 }
 
   };
 }
 


@@ -281,59 +356,151 @@ namespace yy
 ])dnl
 @output @output_parser_name@
 b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
 ])dnl
 @output @output_parser_name@
 b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],

-             [2002, 2003])
+             [2002, 2003, 2004])

 
 m4_if(b4_defines_flag, 0, [], [#include @output_header_name@])[
 
 /* Enable debugging if requested.  */
 #if YYDEBUG
 
 m4_if(b4_defines_flag, 0, [], [#include @output_header_name@])[
 
 /* Enable debugging if requested.  */
 #if YYDEBUG

-# define YYCDEBUG    if (debug_) cdebug_
+
+# define YYCDEBUG                              \
+  if (debug_)                                  \
+    cdebug_
+
+# define YY_SYMBOL_PRINT(Title, Type, Value, Location) \
+do {                                                   \
+  if (debug_)                                          \
+    {                                                  \
+      cdebug_ << (Title) << ' ';                       \
+      symprint_ ((Type), (Value), (Location));         \
+      cdebug_ << std::endl;                            \
+    }                                                  \
+} while (0)
+
+# define YY_REDUCE_PRINT(Rule)         \
+do {                                   \
+  if (debug_)                          \
+    reduce_print_ (Rule);              \
+} while (0)
+
+# define YY_STACK_PRINT()              \
+do {                                   \
+  if (debug_)                          \
+    stack_print_ ();                   \
+} while (0)
+

 #else /* !YYDEBUG */
 #else /* !YYDEBUG */

+

 # define YYCDEBUG    if (0) cdebug_
 # define YYCDEBUG    if (0) cdebug_

+# define YY_SYMBOL_PRINT(Title, Type, Value, Location)
+# define YY_REDUCE_PRINT(Rule)
+# define YY_STACK_PRINT()
+

 #endif /* !YYDEBUG */
 
 #define YYACCEPT       goto yyacceptlab
 #define YYABORT                goto yyabortlab
 #endif /* !YYDEBUG */
 
 #define YYACCEPT       goto yyacceptlab
 #define YYABORT                goto yyabortlab

-#define YYERROR                goto yyerrlab1
+#define YYERROR                goto yyerrorlab
+
+#if YYDEBUG
+/*--------------------------------.
+| Print this symbol on YYOUTPUT.  |
+`--------------------------------*/
+
+void
+yy::]b4_parser_class_name[::symprint_ (int yytype,
+                         const SemanticType* yyvaluep, const LocationType* yylocationp)
+{
+  /* Pacify ``unused variable'' warnings.  */
+  (void) yyvaluep;
+  (void) yylocationp;
+
+  cdebug_ << (yytype < ntokens_ ? "token" : "nterm")
+         << ' ' << name_[yytype] << " ("
+          << *yylocationp << ": ";
+  switch (yytype)
+    {
+]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
+[      default:
+        break;
+    }
+  cdebug_ << ')';
+}
+#endif /* ! YYDEBUG */

 
 

+void
+yy::]b4_parser_class_name[::destruct_ (const char* yymsg,
+                         int yytype, SemanticType* yyvaluep, LocationType* yylocationp)
+{
+  /* Pacify ``unused variable'' warnings.  */
+  (void) yyvaluep;
+  (void) yylocationp;
+
+  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
+
+  switch (yytype)
+    {
+]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
+      default:
+        break;
+    }
+}
+
+void
+yy::]b4_parser_class_name[::pop (unsigned int n)
+{
+  state_stack_.pop (n);
+  semantic_stack_.pop (n);
+  location_stack_.pop (n);
+}

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

-  int nerrs = 0;
-  int errstatus = 0;
+  YYCDEBUG << "Starting parse" << std::endl;

 
 

-  /* Initialize the stacks.  The initial state will be pushed in
-     yynewstate, since the latter expects the semantical and the
-     location values to have been already stored, initialize these
-     stacks with a primary value.  */
-  state_stack_ = StateStack (0);
-  semantic_stack_ = SemanticStack (1);
-  location_stack_ = LocationStack (1);
+  nerrs_ = 0;
+  errstatus_ = 0;

 
   /* Start.  */
   state_ = 0;
   looka_ = empty_;
 
   /* Start.  */
   state_ = 0;
   looka_ = empty_;

-#if YYLSP_NEEDED
-  location = initlocation_;
-#endif
-  YYCDEBUG << "Starting parse" << std::endl;
+
+]m4_ifdef([b4_initial_action], [
+m4_pushdef([b4_at_dollar],     [location])dnl
+m4_pushdef([b4_dollar_dollar], [value])dnl
+  /* User initialization code. */
+  b4_initial_action
+m4_popdef([b4_dollar_dollar])dnl
+m4_popdef([b4_at_dollar])dnl
+/* Line __line__ of yacc.c.  */
+b4_syncline([@oline@], [@ofile@])])dnl
+
+[  /* Initialize the stacks.  The initial state will be pushed in
+     yynewstate, since the latter expects the semantical and the
+     location values to have been already stored, initialize these
+     stacks with a primary value.  */
+  state_stack_ = StateStack (0);
+  semantic_stack_ = SemanticStack (0);
+  location_stack_ = LocationStack (0);
+  semantic_stack_.push (value);
+  location_stack_.push (location);

 
   /* New state.  */
 
   /* New state.  */

- yynewstate:
+yynewstate:

   state_stack_.push (state_);
   YYCDEBUG << "Entering state " << state_ << std::endl;
   goto yybackup;
 
   /* Backup.  */
   state_stack_.push (state_);
   YYCDEBUG << "Entering state " << state_ << std::endl;
   goto yybackup;
 
   /* Backup.  */

- yybackup:
+yybackup:

 
 

-  /* Try to take a decision without lookahead.  */
+  /* Try to take a decision without look-ahead.  */

   n_ = pact_[state_];
   if (n_ == pact_ninf_)
     goto yydefault;
 
   n_ = pact_[state_];
   if (n_ == pact_ninf_)
     goto yydefault;
 

-  /* Read a lookahead token.  */
+  /* Read a look-ahead token.  */

   if (looka_ == empty_)
     {
       YYCDEBUG << "Reading a token: ";
   if (looka_ == empty_)
     {
       YYCDEBUG << "Reading a token: ";


@@ -341,26 +508,19 @@ yy::]b4_parser_class_name[::parse ()
     }
 
   /* Convert token to internal form.  */
     }
 
   /* Convert token to internal form.  */

-  if (looka_ <= 0)
+  if (looka_ <= eof_)

     {
     {

-      looka_ = eof_;
-      ilooka_ = 0;
+      looka_ = ilooka_ = eof_;

       YYCDEBUG << "Now at end of input." << std::endl;
     }
   else
     {
       ilooka_ = translate_ (looka_);
       YYCDEBUG << "Now at end of input." << std::endl;
     }
   else
     {
       ilooka_ = translate_ (looka_);

-#if YYDEBUG
-      if (debug_)
-       {
-         YYCDEBUG << "Next token is " << looka_
-                << " (" << name_[ilooka_];
-         print_ ();
-         YYCDEBUG << ')' << std::endl;
-       }
-#endif
+      YY_SYMBOL_PRINT ("Next token is", ilooka_, &value, &location);

     }
 
     }
 

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

   n_ += ilooka_;
   if (n_ < 0 || last_ < n_ || check_[n_] != ilooka_)
     goto yydefault;
   n_ += ilooka_;
   if (n_ < 0 || last_ < n_ || check_[n_] != ilooka_)
     goto yydefault;


@@ -384,11 +544,8 @@ yy::]b4_parser_class_name[::parse ()
   if (n_ == final_)
     goto yyacceptlab;
 
   if (n_ == final_)
     goto yyacceptlab;
 

-  /* Shift the lookahead token.  */
-#if YYDEBUG
-  YYCDEBUG << "Shifting token " << looka_
-           << " (" << name_[ilooka_] << "), ";
-#endif
+  /* Shift the look-ahead token.  */
+  YY_SYMBOL_PRINT ("Shifting", ilooka_, &value, &location);

 
   /* Discard the token being shifted unless it is eof.  */
   if (looka_ != eof_)
 
   /* Discard the token being shifted unless it is eof.  */
   if (looka_ != eof_)


@@ -399,22 +556,32 @@ yy::]b4_parser_class_name[::parse ()
 
   /* Count tokens shifted since error; after three, turn off error
      status.  */
 
   /* Count tokens shifted since error; after three, turn off error
      status.  */

-  if (errstatus)
-    --errstatus;
+  if (errstatus_)
+    --errstatus_;

 
   state_ = n_;
   goto yynewstate;
 
 
   state_ = n_;
   goto yynewstate;
 

-  /* Default action.  */
- yydefault:
+/*-----------------------------------------------------------.
+| yydefault -- do the default action for the current state.  |
+`-----------------------------------------------------------*/
+yydefault:

   n_ = defact_[state_];
   if (n_ == 0)
     goto yyerrlab;
   goto yyreduce;
 
   n_ = defact_[state_];
   if (n_ == 0)
     goto yyerrlab;
   goto yyreduce;
 

-  /* Reduce.  */
- yyreduce:
+/*-----------------------------.
+| yyreduce -- Do a reduction.  |
+`-----------------------------*/
+yyreduce:

   len_ = r2_[n_];
   len_ = r2_[n_];

+  /* If LEN_ 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 (len_)
     {
       yyval = semantic_stack_[len_ - 1];
   if (len_)
     {
       yyval = semantic_stack_[len_ - 1];


@@ -426,24 +593,12 @@ yy::]b4_parser_class_name[::parse ()
       yyloc = location_stack_[0];
     }
 
       yyloc = location_stack_[0];
     }
 

-#if YYDEBUG
-  if (debug_)
-    {
-      YYCDEBUG << "Reducing via rule " << n_ - 1
-            << " (line " << rline_[n_] << "), ";
-      for (]b4_int_type_for([b4_prhs])[ i = prhs_[n_];
-          0 <= rhs_[i]; ++i)
-       YYCDEBUG << name_[rhs_[i]] << ' ';
-      YYCDEBUG << "-> " << name_[r1_[n_]] << std::endl;
-    }
-#endif
-

   if (len_)
     {
   if (len_)
     {

-      Slice< LocationType, LocationStack > slice (location_stack_, len_);
+      Slice<LocationType, LocationStack> slice (location_stack_, len_);

       YYLLOC_DEFAULT (yyloc, slice, len_);
     }
       YYLLOC_DEFAULT (yyloc, slice, len_);
     }

-
+  YY_REDUCE_PRINT (n_);

   switch (n_)
     {
       ]b4_actions[
   switch (n_)
     {
       ]b4_actions[


@@ -452,20 +607,9 @@ yy::]b4_parser_class_name[::parse ()
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[
 
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[
 

-  state_stack_.pop (len_);
-  semantic_stack_.pop (len_);
-  location_stack_.pop (len_);
+  pop (len_);

 
 

-#if YYDEBUG
-  if (debug_)
-    {
-      YYCDEBUG << "state stack now";
-      for (StateStack::ConstIterator i = state_stack_.begin ();
-          i != state_stack_.end (); ++i)
-       YYCDEBUG << ' ' << *i;
-      YYCDEBUG << std::endl;
-    }
-#endif
+  YY_STACK_PRINT ();

 
   semantic_stack_.push (yyval);
   location_stack_.push (yyloc);
 
   semantic_stack_.push (yyval);
   location_stack_.push (yyloc);


@@ -479,67 +623,71 @@ b4_syncline([@oline@], [@ofile@])[
     state_ = defgoto_[n_ - ntokens_];
   goto yynewstate;
 
     state_ = defgoto_[n_ - ntokens_];
   goto yynewstate;
 

-  /* Report and recover from errors.  This is very incomplete.  */
- yyerrlab:
+/*------------------------------------.
+| yyerrlab -- here on detecting error |
+`------------------------------------*/
+yyerrlab:

   /* If not already recovering from an error, report this error.  */
   /* If not already recovering from an error, report this error.  */

-  if (!errstatus)
+  report_syntax_error_ ();
+
+  error_range_[0] = location;
+  if (errstatus_ == 3)

     {
     {

-      ++nerrs;
+      /* If just tried and failed to reuse look-ahead token after an
+        error, discard it.  */

 
 

-#if YYERROR_VERBOSE
-      n_ = pact_[state_];
-      if (pact_ninf_ < n_ && n_ < last_)
-       {
-         message = "syntax error, unexpected ";
-         message += name_[ilooka_];
-         {
-           int count = 0;
-           for (int x = (n_ < 0 ? -n_ : 0); x < ntokens_ + nnts_; ++x)
-             if (check_[x + n_] == x && x != terror_)
-               ++count;
-           if (count < 5)
-             {
-               count = 0;
-               for (int x = (n_ < 0 ? -n_ : 0); x < ntokens_ + nnts_; ++x)
-                 if (check_[x + n_] == x && x != terror_)
-                   {
-                     message += (!count++) ? ", expecting " : " or ";
-                     message += name_[x];
-                   }
-             }
-         }
-       }
+      /* Return failure if at end of input.  */
+      if (looka_ <= eof_)
+        {
+          /* If at end of input, pop the error token,
+            then the rest of the stack, then return failure.  */
+         if (looka_ == eof_)
+            for (;;)
+              {
+                 error_range_[0] = location_stack_[0];
+                 pop ();
+                if (state_stack_.height () == 1)
+                  YYABORT;
+                 destruct_ ("Error: popping",
+                            stos_[state_stack_[0]],
+                            &semantic_stack_[0],
+                            &location_stack_[0]);
+              }
+        }

       else
       else

-#endif
-       message = "syntax error";
-      error_ ();
+        {
+          destruct_ ("Error: discarding", ilooka_, &value, &location);
+          looka_ = empty_;
+        }

     }
     }

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

   goto yyerrlab1;
 
 
   goto yyerrlab1;
 
 

-  /*----------------------------------------------------.
-  | yyerrlab1 -- error raised explicitly by an action.  |
-  `----------------------------------------------------*/
- yyerrlab1:
-  if (errstatus == 3)
-    {
-      /* If just tried and failed to reuse lookahead token after an
-        error, discard it.  */
+/*---------------------------------------------------.
+| yyerrorlab -- error raised explicitly by YYERROR.  |
+`---------------------------------------------------*/
+yyerrorlab:

 
 

-      /* Return failure if at end of input.  */
-      if (looka_ == eof_)
-       goto yyabortlab;
-#if YYDEBUG
-      YYCDEBUG << "Discarding token " << looka_
-              << " (" << name_[ilooka_] << ")." << std::endl;
+#ifdef __GNUC__
+  /* Pacify GCC when the user code never invokes YYERROR and the label
+     yyerrorlab therefore never appears in user code.  */
+  if (0)
+     goto yyerrorlab;

 #endif
 #endif

-      looka_ = empty_;
-    }

 
 

-  /* Else will try to reuse lookahead token after shifting the error
-     token.  */
+  error_range_[0] = location_stack_[len_ - 1];
+  pop (len_);
+  state_ = state_stack_[0];
+  goto yyerrlab1;

 
 

-  errstatus = 3;
+/*-------------------------------------------------------------.
+| yyerrlab1 -- common code for both syntax error and YYERROR.  |
+`-------------------------------------------------------------*/
+yyerrlab1:
+  errstatus_ = 3;      /* Each real token shifted decrements this.  */

 
   for (;;)
     {
 
   for (;;)
     {


@@ -557,63 +705,42 @@ b4_syncline([@oline@], [@ofile@])[
 
       /* Pop the current state because it cannot handle the error token.  */
       if (state_stack_.height () == 1)
 
       /* Pop the current state because it cannot handle the error token.  */
       if (state_stack_.height () == 1)

-       goto yyabortlab;
-
-#if YYDEBUG
-      if (debug_)
-       {
-         if (stos_[state_] < ntokens_)
-           {
-             YYCDEBUG << "Error: popping token "
-                    << token_number_[stos_[state_]]
-                    << " (" << name_[stos_[state_]];
-# ifdef YYPRINT
-             YYPRINT (stderr, token_number_[stos_[state_]],
-                      semantic_stack_.top ());
-# endif
-             YYCDEBUG << ')' << std::endl;
-           }
-         else
-           {
-             YYCDEBUG << "Error: popping nonterminal ("
-                    << name_[stos_[state_]] << ')' << std::endl;
-           }
-       }
-#endif
-
-      state_ = (state_stack_.pop (), state_stack_[0]);
-      semantic_stack_.pop ();
-      location_stack_.pop ();;
-
-#if YYDEBUG
-      if (debug_)
-       {
-         YYCDEBUG << "Error: state stack now";
-         for (StateStack::ConstIterator i = state_stack_.begin ();
-              i != state_stack_.end (); ++i)
-           YYCDEBUG << ' ' << *i;
-         YYCDEBUG << std::endl;
-       }
-#endif
+       YYABORT;
+
+      error_range_[0] = location_stack_[0];
+      destruct_ ("Error: popping",
+                 stos_[state_], &semantic_stack_[0], &location_stack_[0]);
+      pop ();
+      state_ = state_stack_[0];
+      YY_STACK_PRINT ();

     }
 
   if (n_ == final_)
     goto yyacceptlab;
 
     }
 
   if (n_ == final_)
     goto yyacceptlab;
 

-  YYCDEBUG << "Shifting error token, ";
-
+  error_range_[1] = location;
+  // Using LOCATION is tempting, but would change the location of
+  // the look-ahead.  YYLOC is available though.
+  YYLLOC_DEFAULT (yyloc, error_range_ - 1, 2);

   semantic_stack_.push (value);
   semantic_stack_.push (value);

-  location_stack_.push (location);
+  location_stack_.push (yyloc);
+
+  /* Shift the error token. */
+  YY_SYMBOL_PRINT ("Shifting", stos_[n_],
+                  &semantic_stack_[0], &location_stack_[0]);

 
   state_ = n_;
   goto yynewstate;
 
   /* Accept.  */
 
   state_ = n_;
   goto yynewstate;
 
   /* Accept.  */

- yyacceptlab:
+yyacceptlab:

   return 0;
 
   /* Abort.  */
   return 0;
 
   /* Abort.  */

- yyabortlab:
+yyabortlab:
+  /* Free the lookahead. */
+  destruct_ ("Error: discarding lookahead", ilooka_, &value, &location);
+  looka_ = empty_;

   return 1;
 }
 
   return 1;
 }
 


@@ -627,9 +754,49 @@ yy::]b4_parser_class_name[::lex_ ()
 #endif
 }
 
 #endif
 }
 

+/** Generate an error message, and invoke yyerror. */
+void
+yy::]b4_parser_class_name[::report_syntax_error_ ()
+{
+  /* If not already recovering from an error, report this error.  */
+  if (!errstatus_)
+    {
+      ++nerrs_;
+
+#if YYERROR_VERBOSE
+      n_ = pact_[state_];
+      if (pact_ninf_ < n_ && n_ < last_)
+       {
+         message = "syntax error, unexpected ";
+         message += name_[ilooka_];
+         {
+           int count = 0;
+           for (int x = (n_ < 0 ? -n_ : 0); x < ntokens_ + nnts_; ++x)
+             if (check_[x + n_] == x && x != terror_)
+               ++count;
+           if (count < 5)
+             {
+               count = 0;
+               for (int x = (n_ < 0 ? -n_ : 0); x < ntokens_ + nnts_; ++x)
+                 if (check_[x + n_] == x && x != terror_)
+                   {
+                     message += (!count++) ? ", expecting " : " or ";
+                     message += name_[x];
+                   }
+             }
+         }
+       }
+      else
+#endif
+       message = "syntax error";
+      error_ ();
+    }
+}
+
+

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

-const ]b4_int_type_for([b4_pact]) yy::b4_parser_class_name::pact_ninf_ = b4_pact_ninf[;
+const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) yy::b4_parser_class_name::pact_ninf_ = b4_pact_ninf[;

 const ]b4_int_type_for([b4_pact])[
 yy::]b4_parser_class_name[::pact_[] =
 {
 const ]b4_int_type_for([b4_pact])[
 yy::]b4_parser_class_name[::pact_[] =
 {


@@ -662,7 +829,7 @@ yy::]b4_parser_class_name[::defgoto_[] =
 /* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
    positive, shift that token.  If negative, reduce the rule which
    number is the opposite.  If zero, do what YYDEFACT says.  */
 /* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
    positive, shift that token.  If negative, reduce the rule which
    number is the opposite.  If zero, do what YYDEFACT says.  */

-const ]b4_int_type_for([b4_table]) yy::b4_parser_class_name::table_ninf_ = b4_table_ninf[;
+const ]b4_int_type(b4_table_ninf, b4_table_ninf) yy::b4_parser_class_name::table_ninf_ = b4_table_ninf[;

 const ]b4_int_type_for([b4_table])[
 yy::]b4_parser_class_name[::table_[] =
 {
 const ]b4_int_type_for([b4_table])[
 yy::]b4_parser_class_name[::table_[] =
 {


@@ -676,7 +843,6 @@ yy::]b4_parser_class_name[::check_[] =
   ]b4_check[
 };
 
   ]b4_check[
 };
 

-#if YYDEBUG

 /* STOS_[STATE-NUM] -- The (internal number of the) accessing
    symbol of state STATE-NUM.  */
 const ]b4_int_type_for([b4_stos])[
 /* STOS_[STATE-NUM] -- The (internal number of the) accessing
    symbol of state STATE-NUM.  */
 const ]b4_int_type_for([b4_stos])[


@@ -685,6 +851,7 @@ yy::]b4_parser_class_name[::stos_[] =
   ]b4_stos[
 };
 
   ]b4_stos[
 };
 

+#if YYDEBUG

 /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal token number corresponding
    to YYLEX-NUM.  */
 const ]b4_int_type_for([b4_toknum])[
 /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal token number corresponding
    to YYLEX-NUM.  */
 const ]b4_int_type_for([b4_toknum])[


@@ -710,7 +877,7 @@ yy::]b4_parser_class_name[::r2_[] =
 
 #if YYDEBUG || YYERROR_VERBOSE
 /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
 
 #if YYDEBUG || YYERROR_VERBOSE
 /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.

-   First, the terminals, then, starting at YYNTOKENS, nonterminals. */
+   First, the terminals, then, starting at NTOKENS_, nonterminals. */

 const char*
 const yy::]b4_parser_class_name[::name_[] =
 {
 const char*
 const yy::]b4_parser_class_name[::name_[] =
 {


@@ -740,7 +907,34 @@ yy::]b4_parser_class_name[::rline_[] =
 {
   ]b4_rline[
 };
 {
   ]b4_rline[
 };

-#endif
+
+/** Print the state stack from its BOTTOM up to its TOP (included).  */
+
+void
+yy::]b4_parser_class_name[::stack_print_ ()
+{
+  cdebug_ << "Stack now";
+  for (StateStack::const_iterator i = state_stack_.begin ();
+       i != state_stack_.end (); ++i)
+    cdebug_ << ' ' << *i;
+  cdebug_ << std::endl;
+}
+
+/** Report that the YYRULE is going to be reduced.  */
+
+void
+yy::]b4_parser_class_name[::reduce_print_ (int yyrule)
+{
+  unsigned int yylno = rline_[yyrule];
+  /* Print the symbols being reduced, and their result.  */
+  cdebug_ << "Reducing stack by rule " << n_ - 1
+          << " (line " << yylno << "), ";
+  for (]b4_int_type_for([b4_prhs])[ i = prhs_[n_];
+       0 <= rhs_[i]; ++i)
+    cdebug_ << name_[rhs_[i]] << ' ';
+  cdebug_ << "-> " << name_[r1_[n_]] << std::endl;
+}
+#endif // YYDEBUG

 
 /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
 yy::]b4_parser_class_name[::TokenNumberType
 
 /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
 yy::]b4_parser_class_name[::TokenNumberType


@@ -748,12 +942,12 @@ yy::]b4_parser_class_name[::translate_ (int token)
 {
   static
   const TokenNumberType
 {
   static
   const TokenNumberType

-  translate_[] =
+  translate_table[] =

   {
     ]b4_translate[
   };
   {
     ]b4_translate[
   };

-  if ((unsigned) token <= user_token_number_max_)
-    return translate_[token];
+  if ((unsigned int) token <= user_token_number_max_)
+    return translate_table[token];

   else
     return undef_token_;
 }
   else
     return undef_token_;
 }


@@ -767,13 +961,13 @@ const int yy::]b4_parser_class_name[::terror_ = 1;
 const int yy::]b4_parser_class_name[::errcode_ = 256;
 const int yy::]b4_parser_class_name[::ntokens_ = ]b4_tokens_number[;
 
 const int yy::]b4_parser_class_name[::errcode_ = 256;
 const int yy::]b4_parser_class_name[::ntokens_ = ]b4_tokens_number[;
 

-const unsigned yy::]b4_parser_class_name[::user_token_number_max_ = ]b4_user_token_number_max[;
+const unsigned int yy::]b4_parser_class_name[::user_token_number_max_ = ]b4_user_token_number_max[;

 const yy::]b4_parser_class_name[::TokenNumberType yy::]b4_parser_class_name[::undef_token_ = ]b4_undef_token_number[;
 
 ]b4_epilogue
 dnl
 @output stack.hh
 const yy::]b4_parser_class_name[::TokenNumberType yy::]b4_parser_class_name[::undef_token_ = ]b4_undef_token_number[;
 
 ]b4_epilogue
 dnl
 @output stack.hh

-b4_copyright([Stack handling for Bison C++ parsers], [2002, 2003])[
+b4_copyright([Stack handling for Bison C++ parsers], [2002, 2003, 2004])[

 
 #ifndef BISON_STACK_HH
 # define BISON_STACK_HH
 
 #ifndef BISON_STACK_HH
 # define BISON_STACK_HH


@@ -782,34 +976,35 @@ b4_copyright([Stack handling for Bison C++ parsers], [2002, 2003])[
 
 namespace yy
 {
 
 namespace yy
 {

-  template < class T, class S = std::deque< T > >
+  template <class T, class S = std::deque<T> >

   class Stack
   {
   public:
 
   class Stack
   {
   public:
 

-    typedef typename S::iterator Iterator;
-    typedef typename S::const_iterator ConstIterator;
+    // Hide our reversed order.
+    typedef typename S::reverse_iterator iterator;
+    typedef typename S::const_reverse_iterator const_iterator;

 
     Stack () : seq_ ()
     {
     }
 
 
     Stack () : seq_ ()
     {
     }
 

-    Stack (unsigned n) : seq_ (n)
+    Stack (unsigned int n) : seq_ (n)

     {
     }
 
     inline
     T&
     {
     }
 
     inline
     T&

-    operator [] (unsigned index)
+    operator [] (unsigned int i)

     {
     {

-      return seq_[index];
+      return seq_[i];

     }
 
     inline
     const T&
     }
 
     inline
     const T&

-    operator [] (unsigned index) const
+    operator [] (unsigned int i) const

     {
     {

-      return seq_[index];
+      return seq_[i];

     }
 
     inline
     }
 
     inline


@@ -821,115 +1016,269 @@ namespace yy
 
     inline
     void
 
     inline
     void

-    pop (unsigned n = 1)
+    pop (unsigned int n = 1)

     {
       for (; n; --n)
        seq_.pop_front ();
     }
 
     inline
     {
       for (; n; --n)
        seq_.pop_front ();
     }
 
     inline

-    unsigned
+    unsigned int

     height () const
     {
       return seq_.size ();
     }
 
     height () const
     {
       return seq_.size ();
     }
 

-    inline ConstIterator begin () const { return seq_.begin (); }
-    inline ConstIterator end () const { return seq_.end (); }
+    inline const_iterator begin () const { return seq_.rbegin (); }
+    inline const_iterator end () const { return seq_.rend (); }

 
   private:
 
     S seq_;
   };
 
 
   private:
 
     S seq_;
   };
 

-  template < class T, class S = Stack< T > >
+  template <class T, class S = Stack<T> >

   class Slice
   {
   public:
 
     Slice (const S& stack,
   class Slice
   {
   public:
 
     Slice (const S& stack,

-          unsigned range) : stack_ (stack),
-                            range_ (range)
+          unsigned int range) : stack_ (stack),
+                                range_ (range)

     {
     }
 
     inline
     const T&
     {
     }
 
     inline
     const T&

-    operator [] (unsigned index) const
+    operator [] (unsigned int i) const

     {
     {

-      return stack_[range_ - index];
+      return stack_[range_ - i];

     }
 
   private:
 
     const S& stack_;
     }
 
   private:
 
     const S& stack_;

-    unsigned range_;
+    unsigned int range_;

   };
 }
 
 #endif // not BISON_STACK_HH]
 dnl
   };
 }
 
 #endif // not BISON_STACK_HH]
 dnl

-@output location.hh
-b4_copyright([Location class for Bison C++ parsers], [2002, 2003])[
+@output position.hh
+b4_copyright([Position class for Bison C++ parsers], [2002, 2003, 2004])[

 
 

-#ifndef BISON_LOCATION_HH
-# define BISON_LOCATION_HH
+/**
+ ** \file position.hh
+ ** Define the Location class.
+ */
+
+#ifndef BISON_POSITION_HH
+# define BISON_POSITION_HH

 
 # include <iostream>
 # include <string>
 
 namespace yy
 {
 
 # include <iostream>
 # include <string>
 
 namespace yy
 {

+  /** \brief Abstract a Position. */

   class Position
   {
   public:
   class Position
   {
   public:

-    Position ()
-      : filename (), line (1), column (0)
-    {}
+    /** \brief Initial column number. */
+    static const unsigned int initial_column = 0;
+    /** \brief Initial line number. */
+    static const unsigned int initial_line = 1;
+
+    /** \name Ctor & dtor.
+     ** \{ */
+  public:
+    /** \brief Construct a Position. */
+    Position () :
+      filename (),
+      line (initial_line),
+      column (initial_column)
+    {
+    }
+    /** \} */
+
+
+    /** \name Line and Column related manipulators
+     ** \{ */
+  public:
+    /** \brief (line related) Advance to the COUNT next lines. */
+    inline void lines (int count = 1)
+    {
+      column = initial_column;
+      line += count;
+    }
+
+    /** \brief (column related) Advance to the COUNT next columns. */
+    inline void columns (int count = 1)
+    {
+      int leftmost = initial_column;
+      int current  = column;
+      if (leftmost <= current + count)
+       column += count;
+      else
+       column = initial_column;
+    }
+    /** \} */

 
 

+  public:
+    /** \brief File name to which this position refers. */

     std::string filename;
     std::string filename;

-    int line;
-    int column;
+    /** \brief Current line number. */
+    unsigned int line;
+    /** \brief Current column number. */
+    unsigned int column;

   };
 
   };
 

+  /** \brief Add and assign a Position. */
+  inline const Position&
+  operator+= (Position& res, const int width)
+  {
+    res.columns (width);
+    return res;
+  }
+
+  /** \brief Add two Position objects. */
+  inline const Position
+  operator+ (const Position& begin, const int width)
+  {
+    Position res = begin;
+    return res += width;
+  }
+
+  /** \brief Add and assign a Position. */
+  inline const Position&
+  operator-= (Position& res, const int width)
+  {
+    return res += -width;
+  }
+
+  /** \brief Add two Position objects. */
+  inline const Position
+  operator- (const Position& begin, const int width)
+  {
+    return begin + -width;
+  }
+
+  /** \brief Intercept output stream redirection.
+   ** \param ostr the destination output stream
+   ** \param pos a reference to the Position to redirect
+   */

   inline std::ostream&
   operator<< (std::ostream& ostr, const Position& pos)
   {
   inline std::ostream&
   operator<< (std::ostream& ostr, const Position& pos)
   {

-    if (pos.filename != "")
+    if (!pos.filename.empty ())

       ostr << pos.filename << ':';
       ostr << pos.filename << ':';

-    ostr << pos.line << '.' << pos.column;
-    return ostr;
+    return ostr << pos.line << '.' << pos.column;

   }
 
   }
 

-  inline Position
-  operator- (const Position& pos, int col)
-  {
-    Position res (pos);
-    res.column -= col;
-    return res;
-  }
+}
+#endif // not BISON_POSITION_HH]
+@output location.hh
+b4_copyright([Location class for Bison C++ parsers], [2002, 2003, 2004])[
+
+/**
+ ** \file location.hh
+ ** Define the Location class.
+ */
+
+#ifndef BISON_LOCATION_HH
+# define BISON_LOCATION_HH
+
+# include <iostream>
+# include <string>
+# include "position.hh"

 
 

+namespace yy
+{

 
 

+  /** \brief Abstract a Location. */

   class Location
   {
   class Location
   {

+    /** \name Ctor & dtor.
+     ** \{ */
+  public:
+    /** \brief Construct a Location. */
+    Location (void) :
+      begin (),
+      end ()
+    {
+    }
+    /** \} */
+
+
+    /** \name Line and Column related manipulators
+     ** \{ */
+  public:
+    /** \brief Reset initial location to final location. */
+    inline void step (void)
+    {
+      begin = end;
+    }
+
+    /** \brief Extend the current location to the COUNT next columns. */
+    inline void columns (unsigned int count = 1)
+    {
+      end += count;
+    }
+
+    /** \brief Extend the current location to the COUNT next lines. */
+    inline void lines (unsigned int count = 1)
+    {
+      end.lines (count);
+    }
+    /** \} */
+
+

   public:
   public:

+    /** \brief Beginning of the located region. */

     Position begin;
     Position begin;

+    /** \brief End of the located region. */

     Position end;
   };
 
     Position end;
   };
 

-  /* Don't issue twice the line number when the location is on a single
-     line.  */
+  /** \brief Join two Location objects to create a Location. */
+  inline const Location operator+ (const Location& begin, const Location& end)
+  {
+    Location res = begin;
+    res.end = end.end;
+    return res;
+  }

 
 

-  inline std::ostream&
-  operator<< (std::ostream& ostr, const Location& pos)
+  /** \brief Add two Location objects */
+  inline const Location operator+ (const Location& begin, unsigned int width)
+  {
+    Location res = begin;
+    res.columns (width);
+    return res;
+  }
+
+  /** \brief Add and assign a Location */
+  inline Location& operator+= (Location& res, unsigned int width)
+  {
+    res.columns (width);
+    return res;
+  }
+
+  /** \brief Intercept output stream redirection.
+   ** \param ostr the destination output stream
+   ** \param loc a reference to the Location to redirect
+   **
+   ** Avoid duplicate information.
+   */
+  inline std::ostream& operator<< (std::ostream& ostr, const Location& loc)

   {
   {

-    ostr << pos.begin;
-    if (pos.begin.filename != pos.end.filename)
-      ostr << '-' << pos.end - 1;
-    else if (pos.begin.line != pos.end.line)
-      ostr << '-' << pos.end.line  << '.' << pos.end.column - 1;
-    else if (pos.begin.column != pos.end.column - 1)
-      ostr << '-' << pos.end.column - 1;
+    Position last = loc.end - 1;
+    ostr << loc.begin;
+    if (loc.begin.filename != last.filename)
+      ostr << '-' << last;
+    else if (loc.begin.line != last.line)
+      ostr << '-' << last.line  << '.' << last.column;
+    else if (loc.begin.column != last.column)
+      ostr << '-' << last.column;

     return ostr;
   }
 
     return ostr;
   }