FractionTask/fraction.hpp

#pragma once

#include <QString>

namespace FractionNS {
  struct divide_by_zero_error : public std::logic_error { divide_by_zero_error() : std::logic_error("tried to divide by zero") {}; };
  struct not_real_error : public std::logic_error { not_real_error() : std::logic_error("value is not a real number") {}; };
  struct not_defined_error : public std::logic_error { not_defined_error() : std::logic_error("operation result is not defined") {}; };

  class Fraction
  {
  private:
    int m_numerator, m_denominator;
    void reduce();
  public:
    Fraction(int, int);
    Fraction(int);
    Fraction(double);
    Fraction(float);
    Fraction(const Fraction&);

    int getNumerator() const;
    int getDenominator() const;
    void setNumerator(const int);
    void setDenominator(const int);

    QString display() const;
    Fraction& inv() const;

    float toFloat() const;
    double toDouble() const;

    // Binary comparison operators
    bool operator==(const int) const;
    bool operator==(const float) const;
    bool operator==(const double) const;
    bool operator==(const Fraction&) const;

    bool operator!=(const int) const;
    bool operator!=(const float) const;
    bool operator!=(const double) const;
    bool operator!=(const Fraction&) const;

    bool operator<(const int) const;
    bool operator<(const float) const;
    bool operator<(const double) const;
    bool operator<(const Fraction&) const;

    bool operator<=(const int) const;
    bool operator<=(const float) const;
    bool operator<=(const double) const;
    bool operator<=(const Fraction&) const;

    bool operator>(const int) const;
    bool operator>(const float) const;
    bool operator>(const double) const;
    bool operator>(const Fraction&) const;

    bool operator>=(const int) const;
    bool operator>=(const float) const;
    bool operator>=(const double) const;
    bool operator>=(const Fraction&) const;

    // <=> would go here

    // Method versions of operators
    Fraction& add(const Fraction&) const;
    Fraction& add(const int) const;
    Fraction& sub(const Fraction&) const;
    Fraction& sub(const int) const;
    Fraction& mul(const Fraction&) const;
    Fraction& mul(const int) const;
    Fraction& div(const Fraction&) const;
    Fraction& div(const int) const;
    Fraction& inc();
    Fraction& dec();

    // Binary math operators
    Fraction& operator+(const int) const;
    Fraction& operator+(const Fraction&) const;

    Fraction& operator+=(const int);
    Fraction& operator+=(const Fraction&);

    Fraction& operator-(const int) const;
    Fraction& operator-(const Fraction&) const;

    Fraction& operator-=(const int);
    Fraction& operator-=(const Fraction&);

    Fraction& operator*(const int) const;
    Fraction& operator*(const Fraction&) const;

    Fraction& operator*=(const int);
    Fraction& operator*=(const Fraction&);

    Fraction& operator/(const int) const;
    Fraction& operator/(const Fraction&) const;

    Fraction& operator/=(const int);
    Fraction& operator/=(const Fraction&);

    // Maybe replace with ^ operator, as it's unused for this class.
    // Might be syntactically not-so-nice though?
    // Python uses / for combining paths, does cpp do something similar anywhere?
    // How does one raise a Fraction to a power while keeping it a Fraction (avoid double return type)
    double pow(const int) const;
    double pow(const Fraction&) const;

    // Unary operators
    Fraction& operator-() const;
    Fraction& operator+() const; // Should return a copy of the Fraction.

    Fraction& operator++(); // ++x
    Fraction& operator++(const int); // x++

    Fraction& operator--(); // --x
    Fraction& operator--(const int); // x--
  };
}