Equation.hpp

#pragma once
#include <list>
#include <memory>
#include <functional>
#include <utility>
#include <ostream>
#include <string>
#include <type_traits>
#include <vector>
#include "creativity/data/Variable.hpp"

namespace creativity { namespace data {

class Equation {
    public:
        Equation() = delete;

        Equation(Equation &&move) = default;

        Equation(const Equation &copy) = default;

        Equation(const std::shared_ptr<const Variable> &y);

        // Forward declaration
        class Proxy;

        Proxy operator % (const std::shared_ptr<const Variable> &var);

        Proxy operator % (double c);

        Equation operator + (const std::shared_ptr<const Variable> &var) const &;

        Equation operator + (const std::shared_ptr<const Variable> &var) &&;

        Equation operator + (double c) const &;

        Equation operator + (double c) &&;

        std::shared_ptr<const Variable> depVar() const;

        unsigned int numVars() const;

        bool hasConstant() const;

        std::vector<std::string> names() const;

        std::list<std::shared_ptr<const Variable>>::const_iterator begin() const;

        std::list<std::shared_ptr<const Variable>>::const_iterator end() const;

        friend std::ostream& operator<<(std::ostream &os, const Equation &eq);

    protected:
        std::shared_ptr<const Variable> dep_var_;

        std::list<std::shared_ptr<const Variable>> indep_vars_{{ConstantVariable::create()}};

        void addVar(const std::shared_ptr<const Variable> &var);
};

class Equation::Proxy final {
    public:
        Proxy& operator + (const std::shared_ptr<const Variable> &var);
    private:
        Equation &eq_;
        Proxy(Equation &eq);
        friend class Equation;
};

}}