#include "direction.hh"
#include "posexcept.hh"

#include <boost/functional/hash.hpp>



/* *** Constructors *** */


Direction::Direction(const char source):
  direction(source)
{
  assert_valid() ;
}



/* *** Operations *** */


inline void Direction::assert_valid() const
{
  if (! (is_valid() || direction == 0))
    throw bad_direction(direction) ;
}


inline bool Direction::is_valid() const
{
  return direction > 0 && direction <= 4 ;
}



/* *** Operators *** */


Direction& Direction::operator=(const Direction &source)
{
  direction = source.direction ;
  return *this ;
}


Direction& Direction::operator=(const char source)
{
  direction = source ;
  assert_valid() ;
  return *this ;
}


Direction::operator std::string() const
{
  switch (direction)
    {
    case north:
      return "north" ;
    case east:
      return "east" ;
    case south:
      return "south" ;
    case west:
      return "west" ;
    }
  return "Bad direction!" ;
}



size_t hash_value(const Direction &source)
{
  return boost::hash_value(source.direction) ;
}