rational_classify.hpp

#ifndef PASTELSYS_RATIONAL_CLASSIFY_HPP
#define PASTELSYS_RATIONAL_CLASSIFY_HPP

#include "pastel/sys/rational/rational.h"
#include "pastel/sys/integer/gcd.h"

namespace Pastel
{

    template <typename Integer>
    bool Rational<Integer>::isInteger() const
    {
        // The rational number is stored such that
        // gcd(m, n) = 1, and n >= 0.
        return n() == 1;
    }

    template <typename Integer>
    bool Rational<Integer>::isInfinity() const
    {
        return classify() == NumberType::Infinity;
    }

    template <typename Integer>
    bool Rational<Integer>::isNan() const
    {
        return classify() == NumberType::Nan;
    }

    template <typename Integer>
    typename Rational<Integer>::NumberType
        Rational<Integer>::classify() const
    {
        NumberType result = NumberType::Normal;
        if (!zero(n()))
        {
            if (zero(m()))
            {
                result = NumberType::Zero;
            }
        }
        else
        {
            if (zero(m()))
            {
                result = NumberType::Nan;
            }
            else
            {
                if (positive(m()))
                {
                    result = NumberType::Infinity;
                }
                else
                {
                    result = NumberType::MinusInfinity;
                }
            }
        }

        return result;
    }

}

#endif