GY-63_MS5611/libraries/Troolean/Troolean.cpp

//
//    FILE: Troolean.cpp
//  AUTHOR: Rob Tillaart
// VERSION: 0.1.1
// PURPOSE: class for troolean math (true false unknown)
//     URL:
//
// HISTORY:
// 0.1.0 initial version
// 0.1.1 adjust (in)equality so that unknown == unknown
//       although there could be arguments that unknown != unknown
//       added isTrue(), isFalse(), isUnknown()
//       first public release
//

#include "Troolean.h"


/////////////////////////////////////////////////////
//
// PUBLIC
//
Troolean::Troolean()
{
  _value = -1;
}

Troolean::Troolean(const int8_t val)
{
  if (val == 0) _value = 0;
  else if (val == -1) _value = -1;
  else _value = 1;
}

Troolean::Troolean(const Troolean &t)
{
  _value = t._value;
}


// PRINTING
size_t Troolean::printTo(Print& p) const
{
  size_t n = 0;
  if (_value == 0) n += p.print("false");
  else if (_value == -1) n += p.print("unknown");
  else n += p.print("true");
  return n;
};

// EQUALITIES
// t == t
// f == f
// u == u
bool Troolean::operator == (const Troolean &t)
{
  return (_value == t._value);
}

bool Troolean::operator == (const bool &b)
{
  if (_value == 0 && !b) return true;
  if (_value == 1 && b) return true;
  return false;
}

bool Troolean::operator == (const int &i)
{
  if (_value == 0 && i == 0) return true;
  if (_value == -1 && i == -1) return true;
  if (_value == 1 && i != 0 && i != -1) return true;
  return false;
}

bool Troolean::operator != (const Troolean &t)
{
  return (_value != t._value);
}

bool Troolean::operator != (const bool &b)
{
  if (_value == 0 && !b) return false;
  if (_value == 1 && b) return false;
  return true;
}

bool Troolean::operator != (const int &i)
{
  if (_value == 0 && i != 0) return true;
  if (_value == -1 && i != -1) return true;
  if (_value == 1 && (i == 0 || i == -1)) return true;
  return false;
}

Troolean::operator bool() const
{
  if (_value == 1) return true;
  if (_value == 0) return false;
  return false;
}


// NEGATE
// t -> f
// f -> t
// u -> u
Troolean Troolean::operator ! ()
{
  if (_value == -1) return Troolean(-1);  // random 0 1 :)
  if (_value == 1) return Troolean(0);
  return Troolean(1);
}

// LOGICAL OPERATORS
Troolean Troolean::operator && (const Troolean &t)
{
  if (_value == 0 || t._value == 0) return Troolean(0);
  if (_value == 1 && t._value == 1) return Troolean(1);
  return Troolean(-1);
}

Troolean Troolean::operator && (const bool &b)
{
  if (_value == 0 || !b) return Troolean(0);
  if (_value == 1 && b) return Troolean(1);
  return Troolean(-1);

}

Troolean Troolean::operator || (const Troolean &t)
{
  if (_value == 1 || t._value == 1) return Troolean(1);
  if (_value == 0 && t._value == 0) return Troolean(0);
  return Troolean(-1);
}

Troolean Troolean::operator || (const bool &b)
{
  if (_value == 1 || b) return Troolean(0);
  if (_value == 0 && !b) return Troolean(1);
  return Troolean(-1);
}




// END OF FILE