cpp-json/json/json_tuple_binder.hpp

//
//  json_tuple_binder.hpp
//  json
//
//  Created by Sam Jaffe on 4/23/16.
//

#pragma once

namespace json { namespace binder {
  template <typename T>
  class tuple_binder : public binder_impl<T> {
  public:
    virtual binder_impl<T>* clone() const override { return new tuple_binder(*this); }
    
    tuple_binder& operator()(binder<T> const&b) {
      members.push_back(b);
      return *this;
    }
    
    virtual void parse(T& object, char const*& data) const override {
      const char ch = json::helper::get_next_element(data);
      if (ch == '[') {
        parse_tuple(object, ++data);
      } else {
        throw json::malformed_json_exception(std::string("Expected an object type for binding to ") + typeid(T).name());
      }
    }
    
    virtual void write(T const& val, std::string & data) const override {
      data += "[";
      for (typename std::vector<binder<T>>::const_iterator it = members.begin(),
           end = members.end(); it != end; ++it) {
        it->write(val, data);
        data += ",";
      }
      data.back() = ']';
    }
    
    void parse_tuple(T& object, char const*& data) const {
      auto it = members.begin();
      while (*data && *data != ']' && it != members.end()) {
        it->parse(object, data);
        json::helper::advance_to_boundary(']', data);
        ++it;
      }
      if (it != members.end()) {
        throw json::malformed_json_exception("Failed to parse every member of tuple");
      }
      if (*data) ++data;
      else throw json::malformed_json_exception("Reached end of parse string without finding array end");
    }
    
    template <typename E>
    tuple_binder& operator()(E T::*p) {
      return operator()(binder<T>(new direct_binder<T, E>(p)));
    }
    
  private:
    std::vector<binder<T>> members;
  };

} }