char_letter.hxx

// char_letter.hxx: this file is part of the Vaucanson project.
//
// Vaucanson, a generic library for finite state machines.
//
// Copyright (C) 2008 The Vaucanson Group.
//
// 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 2
// of the License, or (at your option) any later version.
//
// The complete GNU General Public Licence Notice can be found as the
// `COPYING' file in the root directory.
//
// The Vaucanson Group consists of people listed in the `AUTHORS' file.
//
#ifndef VCSN_ALGEBRA_IMPLEMENTATION_LETTER_CHAR_LETTER_HXX
# define VCSN_ALGEBRA_IMPLEMENTATION_LETTER_CHAR_LETTER_HXX

# include <string>

# include <vaucanson/algebra/implementation/letter/char_letter.hh>

namespace vcsn {

  namespace algebra {

    template <>
    struct letter_traits<char>
    {
      enum
      {
        // Here we use 255 and not 256 because random::generate<char>
        // does not generates 0 to avoid conflicts with 0 terminated
        // C strings. Therefore char alphabets will never hold more
        // than 255 different letters.
        cardinal = 255
      };

      static const char default_epsilon() { return '1'; }
      static const char default_joker()   { return '?'; }
      static const char default_other()   { return '#'; }

      static
      char
      literal_to_letter(const std::string& str)
      {
        precondition(str.size() == 1);
        return str[0];
      }

      static
      std::string
      letter_to_literal(const char& c)
      {
        std::string str;
        str = str + c;
        return str;
      }
    };

    template <typename S, typename CharContainer>
    bool op_parse(const algebra::FreeMonoidBase<S>& set,
                  std::basic_string<char>& v,
                  const std::string& s,
                  typename std::string::const_iterator& i,
                  const CharContainer&)
    {
      typename std::string::const_iterator j = i;
      typename std::string::const_iterator k;

      while ((i != s.end()) && (set.alphabet().contains(*i)))
      {
        v += *i;
        ++i;
      }
      return (i != j);
    }

  } // ! algebra

} // ! vcsn

#endif // ! VCSN_ALGEBRA_IMPLEMENTATION_LETTER_CHAR_LETTER_HXX

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