number_impl.hpp

Go to the documentation of this file.

#ifndef NUMBER_IMPL_HPP_
#define NUMBER_IMPL_HPP_

#include <iosfwd>
#include <memory>
#include <string>

#include "rational.hpp"

class number_impl : public std::enable_shared_from_this<number_impl>
{
public:
  virtual ~number_impl();

  void print(std::ostream& stream) const;
  std::string to_string() const;

  void save(std::ostream& stream) const;
  static std::shared_ptr<number_impl> read_library(std::istream& stream);

  bool equals(number_impl const& rhs) const;
  bool less(number_impl const& rhs) const;

  std::shared_ptr<number_impl> add(number_impl const& rhs);
  std::shared_ptr<number_impl> subtract(number_impl const& rhs);
  std::shared_ptr<number_impl> multiply(number_impl const& rhs);
  std::shared_ptr<number_impl> divide(number_impl const& rhs);

  void add_ref();
  void del_ref();

  std::shared_ptr<number_impl> promote(number_impl& rhs) const;

  virtual std::shared_ptr<number_impl> promote_to_void();
  virtual std::shared_ptr<number_impl> promote_to_long();
  virtual std::shared_ptr<number_impl> promote_to_rational();
  virtual std::shared_ptr<number_impl> promote_to_double();

protected:
  number_impl() {}

private:
  number_impl(number_impl const& n); 
  number_impl& operator=(number_impl const& n); 

  virtual std::string do_to_string() const = 0;
  virtual void do_save(std::ostream& stream) const = 0;

  virtual bool do_equals(number_impl const& rhs) const = 0;
  virtual bool do_less(number_impl const& rhs) const = 0;

  virtual std::shared_ptr<number_impl> do_add(number_impl const& rhs) = 0;
  virtual std::shared_ptr<number_impl> do_subtract(number_impl const& rhs) = 0;
  virtual std::shared_ptr<number_impl> do_multiply(number_impl const& rhs) = 0;
  virtual std::shared_ptr<number_impl> do_divide(number_impl const& rhs) = 0;

  virtual std::shared_ptr<number_impl> do_promote(number_impl& rhs) const = 0;

  std::size_t refcount_;
};

class number_void : public number_impl {
public:
  number_void() : number_impl() {}
private:
  virtual std::string do_to_string() const;
  virtual void do_save(std::ostream& stream) const;
  virtual bool do_equals(number_impl const& rhs) const;
  virtual bool do_less(number_impl const& rhs) const;
  virtual std::shared_ptr<number_impl> do_add(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_subtract(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_multiply(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_divide(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_promote(number_impl& rhs) const;
};

class number_long : public number_impl {
public:
  number_long(long long value) : number_impl(), value_(value) {}
  long long value() const { return value_; }
  virtual std::shared_ptr<number_impl> promote_to_void();
  virtual std::shared_ptr<number_impl> promote_to_rational();
  virtual std::shared_ptr<number_impl> promote_to_double();
private:
  virtual std::string do_to_string() const;
  virtual void do_save(std::ostream& stream) const;
  virtual bool do_equals(number_impl const& rhs) const;
  virtual bool do_less(number_impl const& rhs) const;
  virtual std::shared_ptr<number_impl> do_add(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_subtract(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_multiply(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_divide(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_promote(number_impl& rhs) const;

  long long value_;
};

class number_rational: public number_impl {
public:
  number_rational(rational<long long> value) : number_impl(), value_(value) {}
  number_rational(long long num) : number_impl(), value_(num) {}
  number_rational(long long num, long long den) : number_impl(), value_(num, den) {}
  rational<long long> value() const { return value_; }
  virtual std::shared_ptr<number_impl> promote_to_void();
  virtual std::shared_ptr<number_impl> promote_to_double();
private:
  virtual std::string do_to_string() const;
  virtual void do_save(std::ostream& stream) const;
  virtual bool do_equals(number_impl const& rhs) const;
  virtual bool do_less(number_impl const& rhs) const;
  virtual std::shared_ptr<number_impl> do_add(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_subtract(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_multiply(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_divide(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_promote(number_impl& rhs) const;

  rational<long long> value_;
};

class number_double : public number_impl {
public:
  number_double(double value) : number_impl(), value_(value) {}
  double value() const { return value_; }
  virtual std::shared_ptr<number_impl> promote_to_void();
private:
  virtual std::string do_to_string() const;
  virtual void do_save(std::ostream& stream) const;
  virtual bool do_equals(number_impl const& rhs) const;
  virtual bool do_less(number_impl const& rhs) const;
  virtual std::shared_ptr<number_impl> do_add(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_subtract(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_multiply(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_divide(number_impl const& rhs);
  virtual std::shared_ptr<number_impl> do_promote(number_impl& rhs) const;

  double  value_;
};

#endif