int_u.hh

// Copyright (C) 2007, 2008, 2009 EPITA Research and Development Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena 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, version 2 of the License.
//
// Olena 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 Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to produce
// an executable, this file does not by itself cause the resulting
// executable to be covered by the GNU General Public License.  This
// exception does not however invalidate any other reasons why the
// executable file might be covered by the GNU General Public License.

#ifndef MLN_VALUE_INT_U_HH
# define MLN_VALUE_INT_U_HH


# include <mln/trait/all.hh> // FIXME!

# include <mln/value/ops.hh>

# include <mln/metal/math/pow.hh>
# include <mln/value/internal/value_like.hh>
# include <mln/value/internal/encoding.hh>
# include <mln/value/concept/integer.hh>
# include <mln/trait/value_.hh>
# include <mln/debug/format.hh>



namespace mln
{

  namespace value
  {
    // Forward declaration.
    template <unsigned n> struct int_u;
  }

  namespace literal
  {
    // Forward declarations.
    struct zero_t;
    struct one_t;
  }


  namespace trait
  {

    template <unsigned n>
    struct set_precise_unary_< op::uminus, mln::value::int_u<n> >
    {
      typedef int ret;
    };


    template <unsigned n>
    struct value_< mln::value::int_u<n> >
    {
    private:
      typedef mln::value::int_u<n> self_;
      typedef typename mln::value::internal::encoding_unsigned_<n>::ret enc_;
    public:

      enum constants_ {
        dim = 1,
        nbits = n,
        card  = mln_value_card_from_(n)
      };

      typedef trait::value::nature::integer nature;
      typedef trait::value::kind::data      kind;
      typedef mln_value_quant_from_(card)   quant;

      static const self_ min() { return 0; }
      static const self_ max() { return mlc_pow_int(2, n) - 1; }
      static const self_ epsilon() { return 0; }

      typedef unsigned comp;

      typedef float sum;

      static const char* name()
      {
        static std::string s = std::string("int_u").append(1, n + '0');
        return s.c_str();
      }

    };

  } // end of namespace mln::trait



  namespace value
  {

    template <unsigned n>
    struct int_u
      :
      public Integer< int_u<n> >,

      public internal::value_like_< unsigned,    // Equivalent.
                                    typename internal::encoding_unsigned_<n>::ret, // Enc.
                                    int,         // Interoperation.
                                    int_u<n> >   // Exact.
    {
    protected:
      typedef typename internal::encoding_unsigned_<n>::ret enc_;

    public:

      int_u();

      int_u(int i);

      int_u(const mln::literal::zero_t&);
      int_u& operator=(const mln::literal::zero_t&);
      int_u(const mln::literal::one_t&);
      int_u& operator=(const mln::literal::one_t&);

      operator unsigned() const;

      int operator-() const;

      int_u<n>& operator=(int i);

      int_u<n> next() const;
    };


    // Safety.
    template <> struct int_u<0>;
    template <> struct int_u<1>;



    template <unsigned n>
    std::ostream& operator<<(std::ostream& ostr, const int_u<n>& i);


    // FIXME: Doc!
    template <unsigned n>
    std::istream& operator>>(std::istream& istr, int_u<n>& i);


# ifndef MLN_INCLUDE_ONLY

    template <unsigned n>
    inline
    int_u<n>::int_u()
    {
    }

    template <unsigned n>
    inline
    int_u<n>::int_u(int i)
    {
      mln_precondition(i >= 0);
      mln_precondition(unsigned(i) <= mln_max(enc_));
      this->v_ = static_cast<enc_>(i);
    }

    template <unsigned n>
    inline
    int_u<n>::int_u(const mln::literal::zero_t&)
    {
      this->v_ = 0;
    }

    template <unsigned n>
    inline
    int_u<n>&
    int_u<n>::operator=(const mln::literal::zero_t&)
    {
      this->v_ = 0;
      return *this;
    }

    template <unsigned n>
    inline
    int_u<n>::int_u(const mln::literal::one_t&)
    {
      this->v_ = 1;
    }

    template <unsigned n>
    inline
    int_u<n>&
    int_u<n>::operator=(const mln::literal::one_t&)
    {
      this->v_ = 1;
      return *this;
    }

    template <unsigned n>
    inline
    int_u<n>::operator unsigned() const
    {
      return this->v_;
    }

    template <unsigned n>
    inline
    int
    int_u<n>::operator-() const
    {
      return - int(this->v_);
    }

    template <unsigned n>
    inline
    int_u<n>&
    int_u<n>::operator=(int i)
    {
      mln_precondition(i >= 0);
      mln_precondition(unsigned(i) <= mln_max(enc_));
      this->v_ = static_cast<enc_>(i);
      return *this;
    }

    template <unsigned n>
    inline
    int_u<n>
    int_u<n>::next() const
    {
      return this->v_ + 1;
    }

    template <unsigned n>
    inline
    std::ostream& operator<<(std::ostream& ostr, const int_u<n>& i)
    {
      // FIXME: This code could be factored for almost every Value<*>...
      return ostr << debug::format(i.to_equiv()); // FIXME: is to_equiv OK?
    }

    template <unsigned n>
    inline
    std::istream& operator>>(std::istream& istr, int_u<n>& i)
    {
      return istr >> i.handle_();
    }

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::value

} // end of namespace mln


#endif // ! MLN_VALUE_INT_U_HH