cpp-dice-roller/include/die.h

//
//  die.hpp
//  dice-roll
//
//  Created by Sam Jaffe on 12/1/18.
//  Copyright © 2018 Sam Jaffe. All rights reserved.
//

#pragma once

#include <iosfwd>
#include <memory>
#include <vector>

namespace dice {
  enum sign { PLUS = 1, MINUS = -1, ZERO = 0 };
  template <typename T> static sign sgn(T val) {
    return sign((T(0) < val) - (val < T(0)));
  }
  int sgn(sign);
  std::string str(sign);

  struct die {
    sign sgn;
    int num, sides;
  };

  struct mod {
    operator int() const;
    sign sign;
    int value;
  };

  // Default value: 1{+0}
  struct dice {
    int num{1};
    std::vector<die> of{};
    std::vector<mod> modifier{+0};
  };
  
  /**
   * @brief A generator function to turn a string representation of a dice roll into a C++ object
   * @param strdice A string representation of a dice roll, represented as one of the
   * following expression classes:
   * Die = [1-9]?\d*d[1-9]\d*
   * SingleRoll: ($Die|\d+)((+|-)($Die|\d+))*
   * RepeatRoll: [1-9]\d*\{$SingleRoll\}
   * @return a dice object representing the roll
   * @throws dice::unexpected_token if a parse failure occurs
   */
  dice from_string(std::string const & strdice);

  std::ostream & operator<<(std::ostream & out, dice const & d);
  std::istream & operator>>(std::istream & out, dice & d);
}