Fix typo in grammar.

Add lexertl.

inc/lexertl/char_traits.hpp

@@ -0,0 +1,50 @@
+// char_traits.hpp
+// Copyright (c) 2005-2012 Ben Hanson (http://www.benhanson.net/)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file licence_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef LEXERTL_CHAR_TRAITS_H
+#define LEXERTL_CHAR_TRAITS_H
+
+#include <cstddef>
+
+namespace lexertl
+{
+template<typename ch_type>
+struct basic_char_traits
+{
+    typedef ch_type char_type;
+    typedef ch_type index_type;
+
+    static index_type index (const char_type ch)
+    {
+       return ch;
+    }
+
+    static index_type max_val ()
+    {
+        return sizeof(char_type) > 2 ? 0x10ffff :
+            static_cast<index_type>(~0);
+    }
+};
+
+template<>
+struct basic_char_traits<char>
+{
+    typedef char char_type;
+    typedef unsigned char index_type;
+
+    static index_type index (const char ch)
+    {
+        return static_cast<index_type>(ch);
+    }
+
+    static index_type max_val ()
+    {
+        return static_cast<index_type>(~0);
+    }
+};
+}
+
+#endif