//--------------- FRAC.CPP ---------------
// The class definition for fractions.
//
// Bob Myers

#include <iostream>
#include "frac.h"

using namespace std;

Fraction Fraction::operator+(const Fraction& f) const
// operator overload for + written as member function
{
   Fraction r;      // result
   r.numerator = (numerator * f.denominator)
                  + (f.numerator * denominator);
   r.denominator = (denominator * f.denominator);
   return r;
}

Fraction::Fraction()
// Default constructor.  Initializes fraction to 0/1
{
   numerator = 0; 
   denominator = 1;
}

Fraction::Fraction(int n, int d)
// initializes fraction to n/d (defaults to 0/1 if invalid data)
{
   if (SetValue(n, d) == false)
	SetValue(0, 1);
}

void Fraction::Input()
// Get a fraction from standard input, in the form "numerator/denominator."
// what kind of error checking should be added?
{
   char divSign;	// used to consume the '/' character during input
   do
   {
      cin >> numerator >> divSign >> denominator;
      if (denominator <= 0)
	cout << "*** Denominator must be positive.  Try again: ";

   } while (denominator <= 0);
}

void Fraction::Show() const
// Display a fraction, in the form "numerator/denominator."
{
   cout << numerator << '/' << denominator;
}

int Fraction::GetNumerator() const
{
   return numerator;
}

int Fraction::GetDenominator() const
{
   return denominator;
}

bool Fraction::SetValue(int n, int d)
// sets fraction to n/d and returns true for success (good data)
// returns false and leaves fraction alone if bad data
{
   if (d <= 0)
	return false;

   numerator = n;
   denominator = d;
   return true;
}


double Fraction::Evaluate() const
// Calculates and returns the decimal value of a fraction
{
   return static_cast<double>(numerator) / denominator;
}