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xgboost/dmlc-core/include/dmlc/json.h  view on Meta::CPAN

   *  If this call is successful, user can proceed to call
   *  reader->Read to read in the value.
   * \return true if the read is successful, false if we are at end of the array.
   */
  inline bool NextArrayItem();
  /*!
   * \brief Read next ValueType.
   * \param out_value any STL or json readable type to be read
   * \throw dmlc::Error when the read of ValueType is not successful.
   * \tparam ValueType the data type to be read.
   */
  template<typename ValueType>
  inline void Read(ValueType *out_value);

  /*! \return current line count */
  inline std::string line_info() const {
    char temp[64];
    std::ostringstream os;
    os << " Line " << std::max(line_count_r_, line_count_n_);
    is_->getline(temp, 64);
    os << ", around ^`" << temp << "`";
    return os.str();
  }

 private:
  /*! \brief internal reader stream */
  std::istream *is_;
  /*! \brief "\\r" counter */
  size_t line_count_r_;
  /*! \brief "\\n" counter */
  size_t line_count_n_;
  /*!
   * \brief record how many element processed in
   *  current array/object scope.
   */
  std::vector<size_t> scope_counter_;
  /*!
   * \brief Read next nonspace character.
   * \return the next nonspace character.
   */
  inline int NextNonSpace();
  /*!
   * \brief Read just before next nonspace but not read that.
   * \return the next nonspace character.
   */
  inline int PeekNextNonSpace();
};

/*!
 * \brief Lightweight json to write any STL compositions.
 */
class JSONWriter {
 public:
  /*!
   * \brief Constructor.
   * \param os the output stream.
   */
  explicit JSONWriter(std::ostream *os)
      : os_(os) {}
  /*!
   * \brief Write a string that do not contain escape characters.
   * \param s the string to be written.
   */
  inline void WriteNoEscape(const std::string &s);
  /*!
   * \brief Write a string that can contain escape characters.
   * \param s the string to be written.
   */
  inline void WriteString(const std::string &s);
  /*!
   * \brief Write a string that can contain escape characters.
   * \param v the value to be written.
   * \tparam ValueType The value type to be written.
   */
  template<typename ValueType>
  inline void WriteNumber(const ValueType &v);
  /*!
   * \brief Start beginning of array.
   * \param multi_line whether to start an multi_line array.
   * \code
   *  writer->BeginArray();
   *  for (auto& v : vdata) {
   *    writer->WriteArrayItem(v);
   *  }
   *  writer->EndArray();
   * \endcode
   */
  inline void BeginArray(bool multi_line = true);
  /*! \brief Finish writing an array. */
  inline void EndArray();
  /*!
   * \brief Start beginning of array.
   * \param multi_line whether to start an multi_line array.
   * \code
   *  writer->BeginObject();
   *  for (auto& kv : vmap) {
   *    writer->WriteObjectKeyValue(kv.first, kv.second);
   *  }
   *  writer->EndObject();
   * \endcode
   */
  inline void BeginObject(bool multi_line = true);
  /*! \brief Finish writing object. */
  inline void EndObject();
  /*!
   * \brief Write key value pair in the object.
   * \param key the key of the object.
   * \param value the value of to be written.
   * \tparam ValueType The value type to be written.
   */
  template<typename ValueType>
  inline void WriteObjectKeyValue(const std::string &key,
                                  const ValueType &value);
  /*!
   * \brief Write seperator of array, before writing next element.
   * User can proceed to call writer->Write to write next item
   */
  inline void WriteArraySeperator();
  /*!
   * \brief Write value into array.
   * \param value The value of to be written.
   * \tparam ValueType The value type to be written.
   */
  template<typename ValueType>
  inline void WriteArrayItem(const ValueType &value);
  /*!
   * \brief Write value to json.
   * \param value any STL or json readable that can be written.
   * \tparam ValueType the data type to be write.
   */
  template<typename ValueType>

xgboost/dmlc-core/include/dmlc/json.h  view on Meta::CPAN

  inline static void Read(JSONReader *reader, any *data) {
    std::string type_name;
    reader->BeginArray();
    CHECK(reader->NextArrayItem()) << "invalid any json format";
    Handler<std::string>::Read(reader, &type_name);
    std::unordered_map<std::string, AnyJSONManager::Entry>&
        tmap = AnyJSONManager::Global()->type_map_;
    auto it = tmap.find(type_name);
    CHECK(it != tmap.end() && it->first == type_name)
        << "Typename " << type_name << " has not been registered via DMLC_JSON_ENABLE_ANY";
    AnyJSONManager::Entry e = it->second;
    CHECK(reader->NextArrayItem()) << "invalid any json format";
    e.read(reader, data);
    CHECK(!reader->NextArrayItem()) << "invalid any json format";
  }
};
#endif  // DMLC_ENABLE_RTTI
#endif  // DMLC_STRICT_CXX11

}  // namespace json

// implementations of JSONReader/Writer
inline int JSONReader::NextNonSpace() {
  int ch;
  do {
    ch = is_->get();
    if (ch == '\n') ++line_count_n_;
    if (ch == '\r') ++line_count_r_;
  } while (isspace(ch));
  return ch;
}

inline int JSONReader::PeekNextNonSpace() {
  int ch;
  while (true) {
    ch = is_->peek();
    if (ch == '\n') ++line_count_n_;
    if (ch == '\r') ++line_count_r_;
    if (!isspace(ch)) break;
    is_->get();
  }
  return ch;
}

inline void JSONReader::ReadString(std::string *out_str) {
  int ch = NextNonSpace();
  CHECK_EQ(ch, '\"')
      << "Error at" << line_info()
      << ", Expect \'\"\' but get \'" << static_cast<char>(ch) << '\'';
  std::ostringstream os;
  while (true) {
    ch = is_->get();
    if (ch == '\\') {
      char sch = static_cast<char>(is_->get());
      switch (sch) {
        case 'r': os << "\r"; break;
        case 'n': os << "\n"; break;
        case '\\': os << "\\"; break;
        case '\t': os << "\t"; break;
        case '\"': os << "\""; break;
        default: LOG(FATAL) << "unknown string escape \\" << sch;
      }
    } else {
      if (ch == '\"') break;
      os << static_cast<char>(ch);
    }
    if (ch == EOF || ch == '\r' || ch == '\n') {
      LOG(FATAL)
          << "Error at" << line_info()
          << ", Expect \'\"\' but reach end of line ";
    }
  }
  *out_str = os.str();
}

template<typename ValueType>
inline void JSONReader::ReadNumber(ValueType *out_value) {
  *is_ >> *out_value;
  CHECK(!is_->fail())
      << "Error at" << line_info()
      << ", Expect number";
}

inline void JSONReader::BeginObject() {
  int ch = NextNonSpace();
  CHECK_EQ(ch, '{')
      << "Error at" << line_info()
      << ", Expect \'{\' but get \'" << static_cast<char>(ch) << '\'';
  scope_counter_.push_back(0);
}

inline void JSONReader::BeginArray() {
  int ch = NextNonSpace();
  CHECK_EQ(ch, '[')
      << "Error at" << line_info()
      << ", Expect \'{\' but get \'" << static_cast<char>(ch) << '\'';
  scope_counter_.push_back(0);
}

inline bool JSONReader::NextObjectItem(std::string *out_key) {
  bool next = true;
  if (scope_counter_.back() != 0) {
    int ch = NextNonSpace();
    if (ch == EOF) {
      next = false;
    } else if (ch == '}') {
      next = false;
    } else {
      CHECK_EQ(ch, ',')
          << "Error at" << line_info()
          << ", JSON object expect \'}\' or \',\' \'" << static_cast<char>(ch) << '\'';
    }
  } else {
    int ch = PeekNextNonSpace();
    if (ch == '}') {
      is_->get();
      next = false;
    }
  }
  if (!next) {
    scope_counter_.pop_back();