style: remove useless C++ provisio

[bison.git] / examples / variant.yy

diff --git a/examples/variant.yy b/examples/variant.yy
index fafb6556ad7da88fc08d188f04a8da2e657def66..39a57ba8082ed555a1506f07a767d3df6152c61d 100644 (file)
--- a/examples/variant.yy
+++ b/examples/variant.yy
@@ -1,106 +1,139 @@
-/* Test file for C++ parsers using variants.
-   Based on an example by Michiel De Wilde <mdewilde.agilent@gmail.com>. */
-%language "C++"
+/*
+  Copyright (C) 2008-2012 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
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
 %debug
+%skeleton "lalr1.cc"
 %defines
+%define parse.assert
 %define variant
+%define lex_symbol
+%locations
 
 %code requires // *.hh
 {
+#include <list>
 #include <string>
+typedef std::list<std::string> strings_type;
 }
 
 %code // *.cc
 {
 #include <algorithm>
 #include <iostream>
+#include <iterator>
 #include <sstream>
 
-static yy::parser::token_type yylex(yy::parser::semantic_type* yylval);
+  // Prototype of the yylex function providing subsequent tokens.
+  static yy::parser::symbol_type yylex ();
+
+  // Printing a list of strings.
+  // Koening look up will look into std, since that's an std::list.
+  namespace std
+  {
+    std::ostream&
+    operator<< (std::ostream& o, const strings_type& s)
+    {
+      std::copy (s.begin (), s.end (),
+                 std::ostream_iterator<strings_type::value_type> (o, "\n"));
+      return o;
+    }
+  }
+
+  // Conversion to string.
+  template <typename T>
+    inline
+    std::string
+    string_cast (const T& t)
+  {
+    std::ostringstream o;
+    o << t;
+    return o.str ();
+  }
 }
 
-%token <std::string> TEXT
-%token <int> NUMBER
-%printer { debug_stream() << $$; } <int> <std::string>
-%token END_OF_FILE 0
+%token <::std::string> TEXT;
+%token <int> NUMBER;
+%printer { debug_stream () << $$; }
+   <int> <::std::string> <::std::list<std::string>>;
+%token END_OF_FILE 0;
 
-%type <std::string> text result
+%type <::std::string> item;
+%type <::std::list<std::string>> list;
 
 %%
 
 result:
- text  { std::cout << $1 << std::endl; }
+  list  { std::cout << $1 << std::endl; }
 ;
 
-text:
-  /* nothing */         { /* This will generate an empty string */ }
-| text TEXT             { std::swap($$,$1); $$.append($2); }
-| text NUMBER           {
-                          std::swap($$,$1);
-                          std::ostringstream o;
-                          o << ' ' << $2;
-                          $$.append(o.str());
-                        }
+list:
+  /* nothing */ { /* Generates an empty string list */ }
+| list item     { std::swap ($$, $1); $$.push_back ($2); }
+;
+
+item:
+  TEXT          { std::swap ($$, $1); }
+| NUMBER        { $$ = string_cast ($1); }
 ;
 %%
 
 // The yylex function providing subsequent tokens:
-// TEXT                "I have three numbers for you:"
-// NUMBER      1
-// NUMBER      2
-// NUMBER      3
-// TEXT                " and that's all!"
+// TEXT         "I have three numbers for you:"
+// NUMBER       1
+// NUMBER       2
+// NUMBER       3
+// TEXT         " and that's all!"
 // END_OF_FILE
 
 static
-yy::parser::token_type
-yylex(yy::parser::semantic_type* yylval)
+yy::parser::symbol_type
+yylex ()
 {
-  static int stage = 0;
-  yy::parser::token_type result;
-
+  static int stage = -1;
+  ++stage;
+  yy::parser::location_type loc(0, stage + 1, stage + 1);
   switch (stage)
   {
     case 0:
-      yylval->build<std::string>();
-      yylval->as<std::string>() = std::string("I have three numbers for you:");
-      result = yy::parser::token::TEXT;
-      break;
+      return yy::parser::make_TEXT ("I have three numbers for you.", loc);
     case 1:
     case 2:
     case 3:
-      yylval->build<int>();
-      yylval->as<int>() = stage;
-      result = yy::parser::token::NUMBER;
-      break;
+      return yy::parser::make_NUMBER (stage, loc);
     case 4:
-      yylval->build<std::string>();
-      yylval->as<std::string>() = std::string(" and that's all!");
-      result = yy::parser::token::TEXT;
-      break;
+      return yy::parser::make_TEXT ("And that's all!", loc);
     default:
-      result = yy::parser::token::END_OF_FILE;
-      break;
+      return yy::parser::make_END_OF_FILE (loc);
   }
-
-  stage++;
-  return result;
 }
 
 // Mandatory error function
 void
-yy::parser::error(const yy::parser::location_type& yylloc,
-                  const std::string& message)
+yy::parser::error (const yy::parser::location_type& loc, const std::string& msg)
 {
-  std::cerr << yylloc << ": " << message << std::endl;
+  std::cerr << loc << ": " << msg << std::endl;
 }
 
 int
-main(int argc, char *argv[])
+main ()
 {
   yy::parser p;
-  p.set_debug_level(!!getenv("YYDEBUG"));
-  p.parse();
+  p.set_debug_level (!!getenv ("YYDEBUG"));
+  return p.parse ();
 }
 
 // Local Variables: