/* Boost interval/interval.hpp header file

 *

 * Copyright 2002-2003 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion

 *

 * Distributed under the Boost Software License, Version 1.0.

 * (See accompanying file LICENSE_1_0.txt or

 * copy at http://www.boost.org/LICENSE_1_0.txt)

 */



#ifndef BOOST_NUMERIC_INTERVAL_INTERVAL_HPP

#define BOOST_NUMERIC_INTERVAL_INTERVAL_HPP



#include <stdexcept>

#include <string>

#include <boost/numeric/interval/detail/interval_prototype.hpp>



namespace boost {

namespace numeric {



namespace interval_lib {

    

class comparison_error

  : public std::runtime_error 

{

public:

  comparison_error()

    : std::runtime_error("boost::interval: uncertain comparison")

  { }

};



} // namespace interval_lib



/*

 * interval class

 */



template<class T, class Policies>

class interval

{

private:

  struct interval_holder;

  struct number_holder;

public:

  typedef T base_type;

  typedef Policies traits_type;



  T const &lower() const;

  T const &upper() const;



  interval();

  interval(T const &v);

  template<class T1> interval(T1 const &v);

  interval(T const &l, T const &u);

  template<class T1, class T2> interval(T1 const &l, T2 const &u);

  interval(interval<T, Policies> const &r);

  template<class Policies1> interval(interval<T, Policies1> const &r);

  template<class T1, class Policies1> interval(interval<T1, Policies1> const &r);



  interval &operator=(T const &v);

  template<class T1> interval &operator=(T1 const &v);

  interval &operator=(interval<T, Policies> const &r);

  template<class Policies1> interval &operator=(interval<T, Policies1> const &r);

  template<class T1, class Policies1> interval &operator=(interval<T1, Policies1> const &r);

 

  void assign(const T& l, const T& u);



  static interval empty();

  static interval whole();

  static interval hull(const T& x, const T& y);



  interval& operator+= (const T& r);

  interval& operator+= (const interval& r);

  interval& operator-= (const T& r);

  interval& operator-= (const interval& r);

  interval& operator*= (const T& r);

  interval& operator*= (const interval& r);

  interval& operator/= (const T& r);

  interval& operator/= (const interval& r);



  bool operator< (const interval_holder& r) const;

  bool operator> (const interval_holder& r) const;

  bool operator<= (const interval_holder& r) const;

  bool operator>= (const interval_holder& r) const;

  bool operator== (const interval_holder& r) const;

  bool operator!= (const interval_holder& r) const;



  bool operator< (const number_holder& r) const;

  bool operator> (const number_holder& r) const;

  bool operator<= (const number_holder& r) const;

  bool operator>= (const number_holder& r) const;

  bool operator== (const number_holder& r) const;

  bool operator!= (const number_holder& r) const;



  // the following is for internal use only, it is not a published interface

  // nevertheless, it's public because friends don't always work correctly.

  interval(const T& l, const T& u, bool): low(l), up(u) {}

  void set_empty();

  void set_whole();

  void set(const T& l, const T& u);



private:

  struct interval_holder {

    template<class Policies2>

    interval_holder(const interval<T, Policies2>& r)

      : low(r.lower()), up(r.upper())

    {

      typedef typename Policies2::checking checking2;

      if (checking2::is_empty(low, up))

        throw interval_lib::comparison_error();

    }



    const T& low;

    const T& up;

  };



  struct number_holder {

    number_holder(const T& r) : val(r)

    {

      typedef typename Policies::checking checking;

      if (checking::is_nan(r))

        throw interval_lib::comparison_error();

    }

    

    const T& val;

  };



  typedef typename Policies::checking checking;

  typedef typename Policies::rounding rounding;



  T low;

  T up;

};



template<class T, class Policies> inline

interval<T, Policies>::interval():

  low(static_cast<T>(0)), up(static_cast<T>(0))

{}



template<class T, class Policies> inline

interval<T, Policies>::interval(T const &v): low(v), up(v)

{

  if (checking::is_nan(v)) set_empty();

}



template<class T, class Policies> template<class T1> inline

interval<T, Policies>::interval(T1 const &v)

{

  if (checking::is_nan(v)) set_empty();

  else {

    rounding rnd;

    low = rnd.conv_down(v);

    up  = rnd.conv_up  (v);

  }

}



template<class T, class Policies> template<class T1, class T2> inline

interval<T, Policies>::interval(T1 const &l, T2 const &u)

{

  if (checking::is_nan(l) || checking::is_nan(u) || !(l <= u)) set_empty();

  else {

    rounding rnd;

    low = rnd.conv_down(l);

    up  = rnd.conv_up  (u);

  }

}



template<class T, class Policies> inline

interval<T, Policies>::interval(T const &l, T const &u): low(l), up(u)

{

  if (checking::is_nan(l) || checking::is_nan(u) || !(l <= u))

    set_empty();

}





template<class T, class Policies> inline

interval<T, Policies>::interval(interval<T, Policies> const &r): low(r.lower()), up(r.upper())

{}



template<class T, class Policies> template<class Policies1> inline

interval<T, Policies>::interval(interval<T, Policies1> const &r): low(r.lower()), up(r.upper())

{

  typedef typename Policies1::checking checking1;

  if (checking1::is_empty(r.lower(), r.upper())) set_empty();

}



template<class T, class Policies> template<class T1, class Policies1> inline

interval<T, Policies>::interval(interval<T1, Policies1> const &r)

{

  typedef typename Policies1::checking checking1;

  if (checking1::is_empty(r.lower(), r.upper())) set_empty();

  else {

    rounding rnd;

    low = rnd.conv_down(r.lower());

    up  = rnd.conv_up  (r.upper());

  }

}



template<class T, class Policies> inline

interval<T, Policies> &interval<T, Policies>::operator=(T const &v)

{

  if (checking::is_nan(v)) set_empty();

  else low = up = v;

  return *this;

}



template<class T, class Policies> template<class T1> inline

interval<T, Policies> &interval<T, Policies>::operator=(T1 const &v)

{

  if (checking::is_nan(v)) set_empty();

  else {

    rounding rnd;

    low = rnd.conv_down(v);

    up  = rnd.conv_up  (v);

  }

  return *this;

}



template<class T, class Policies> inline

interval<T, Policies> &interval<T, Policies>::operator=(interval<T, Policies> const &r)

{

  low = r.lower();

  up  = r.upper();

  return *this;

}



template<class T, class Policies> template<class Policies1> inline

interval<T, Policies> &interval<T, Policies>::operator=(interval<T, Policies1> const &r)

{

  typedef typename Policies1::checking checking1;

  if (checking1::is_empty(r.lower(), r.upper())) set_empty();

  else {

    low = r.lower();

    up  = r.upper();

  }

  return *this;

}



template<class T, class Policies> template<class T1, class Policies1> inline

interval<T, Policies> &interval<T, Policies>::operator=(interval<T1, Policies1> const &r)

{

  typedef typename Policies1::checking checking1;

  if (checking1::is_empty(r.lower(), r.upper())) set_empty();

  else {

    rounding rnd;

    low = rnd.conv_down(r.lower());

    up  = rnd.conv_up  (r.upper());

  }

  return *this;

}



template<class T, class Policies> inline

void interval<T, Policies>::assign(const T& l, const T& u)

{

  if (checking::is_nan(l) || checking::is_nan(u) || !(l <= u))

    set_empty();

  else set(l, u);

}



template<class T, class Policies> inline

void interval<T, Policies>::set(const T& l, const T& u)

{

  low = l;

  up  = u;

}



template<class T, class Policies> inline

void interval<T, Policies>::set_empty()

{

  low = checking::empty_lower();

  up  = checking::empty_upper();

}



template<class T, class Policies> inline

void interval<T, Policies>::set_whole()

{

  low = checking::neg_inf();

  up  = checking::pos_inf();

}



template<class T, class Policies> inline

interval<T, Policies> interval<T, Policies>::hull(const T& x, const T& y)

{

  bool bad_x = checking::is_nan(x);

  bool bad_y = checking::is_nan(y);

  if (bad_x)

    if (bad_y) return interval::empty();

    else       return interval(y, y, true);

  else

    if (bad_y) return interval(x, x, true);

  if (x <= y) return interval(x, y, true);

  else        return interval(y, x, true);

}



template<class T, class Policies> inline

interval<T, Policies> interval<T, Policies>::empty()

{

  return interval<T, Policies>(checking::empty_lower(),

                               checking::empty_upper(), true);

}



template<class T, class Policies> inline

interval<T, Policies> interval<T, Policies>::whole()

{

  return interval<T, Policies>(checking::neg_inf(), checking::pos_inf(), true);

}



template<class T, class Policies> inline

const T& interval<T, Policies>::lower() const

{

  return low;

}



template<class T, class Policies> inline

const T& interval<T, Policies>::upper() const

{

  return up;

}



/*

 * interval/interval comparisons

 */



template<class T, class Policies> inline

bool interval<T, Policies>::operator< (const interval_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up < r.low) return true;

    else if (low >= r.up) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator> (const interval_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (low > r.up) return true;

    else if (up <= r.low) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator<= (const interval_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up <= r.low) return true;

    else if (low > r.up) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator>= (const interval_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (low >= r.up) return true;

    else if (up < r.low) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator== (const interval_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up == r.low && low == r.up) return true;

    else if (up < r.low || low > r.up) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator!= (const interval_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up < r.low || low > r.up) return true;

    else if (up == r.low && low == r.up) return false;

  }

  throw interval_lib::comparison_error();

}



/*

 * interval/number comparisons

 */



template<class T, class Policies> inline

bool interval<T, Policies>::operator< (const number_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up < r.val) return true;

    else if (low >= r.val) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator> (const number_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (low > r.val) return true;

    else if (up <= r.val) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator<= (const number_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up <= r.val) return true;

    else if (low > r.val) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator>= (const number_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (low >= r.val) return true;

    else if (up < r.val) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator== (const number_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up == r.val && low == r.val) return true;

    else if (up < r.val || low > r.val) return false;

  }

  throw interval_lib::comparison_error();

}



template<class T, class Policies> inline

bool interval<T, Policies>::operator!= (const number_holder& r) const

{

  if (!checking::is_empty(low, up)) {

    if (up < r.val || low > r.val) return true;

    else if (up == r.val && low == r.val) return false;

  }

  throw interval_lib::comparison_error();

}



} // namespace numeric

} // namespace boost



#endif // BOOST_NUMERIC_INTERVAL_INTERVAL_HPP

