time_facet.hpp

来自「support vector clustering for vc++」· HPP 代码 · 共 1,264 行 · 第 1/4 页

                    catch(std::out_of_range bad_weekday) { // base class for bad_weekday exception
                      if(this->m_sv_parser.match(sitr, stream_end, mr)) {
                        t = time_type(static_cast<special_values>(mr.current_match));
                        return sitr;
                      }
                      else {
                        throw; // rethrow bad_weekday
                      }
                    }
                    // did m_parser already advance sitr to next char?
                    if(mr.has_remaining()) {
                      use_current_char = true;
                    }
                    break;
                  }
                case 'j':
                  {
                    // code that gets julian day (from format_date_parser)
                    match_results mr;
                    day_of_year = fixed_string_to_int<unsigned short, CharT>(sitr, stream_end, mr, 3);
                    if(day_of_year == -1) {
                      if(this->m_sv_parser.match(sitr, stream_end, mr)) {
                        t = time_type(static_cast<special_values>(mr.current_match));
                        return sitr;
                      }
                    }
                    // these next two lines are so we get an exception with bad input
                    typedef typename time_type::date_type::day_of_year_type day_of_year_type;
                    day_of_year_type t_day_of_year(day_of_year);
                    break;
                  }
                case 'd':
                  {
                    try {
                      t_day = this->m_parser.parse_day_of_month(sitr, stream_end);
                    }
                    catch(std::out_of_range bad_day_of_month) { // base class for exception
                      match_results mr;
                      if(this->m_sv_parser.match(sitr, stream_end, mr)) {
                        t = time_type(static_cast<special_values>(mr.current_match));
                        return sitr;
                      }
                      else {
                        throw; // rethrow bad_year
                      }
                    }
                    break;
                  }
                // time flags
                case 'H': 
                  {
                    match_results mr;
                    hour = fixed_string_to_int<short, CharT>(sitr, stream_end, mr, 2);
                    if(hour == -1){
                       return check_special_value(sitr, stream_end, t, c);
                    }
                    break;
                  }
                case 'M': 
                  {
                    match_results mr;
                    min = fixed_string_to_int<short, CharT>(sitr, stream_end, mr, 2);
                    if(min == -1){
                       return check_special_value(sitr, stream_end, t, c);
                    }
                    break;
                  }
                case 'S': 
                  {
                    match_results mr;
                    sec = fixed_string_to_int<short, CharT>(sitr, stream_end, mr, 2);
                    if(sec == -1){
                       return check_special_value(sitr, stream_end, t, c);
                    }
                    break;
                  }
                case 's':
                  {
                    match_results mr;
                    sec = fixed_string_to_int<short, CharT>(sitr, stream_end, mr, 2);
                    if(sec == -1){
                       return check_special_value(sitr, stream_end, t, c);
                    }
                    // %s is the same as %S%f so we drop through into %f
                    //break;
                  }
                case 'f':
                  {
                    // check for decimal, check SV if missing
                    if(*sitr == '.') {
                      ++sitr;
                      parse_frac_type(sitr, stream_end, frac);
                      // sitr will point to next expected char after this parsing 
                      // is complete so no need to advance it
                      use_current_char = true;
                    }
                    else {
                      return check_special_value(sitr, stream_end, t, c);
                    }
                    break;
                  }
                case 'F': 
                  {
                    // check for decimal, skip if missing
                    if(*sitr == '.') {
                      ++sitr;
                      parse_frac_type(sitr, stream_end, frac);
                      // sitr will point to next expected char after this parsing 
                      // is complete so no need to advance it
                      use_current_char = true;
                    }
                    else {
                      // nothing was parsed so we don't want to advance sitr
                      use_current_char = true;
                    }
                    break;
                  }
                  // time_zone flags
                //case 'q':
                //case 'Q':
                //case 'z':
                case 'Z':
                  {
                    if(time_is_local) { // skip if 't' is a ptime
                      ++itr;
                      if(*itr == 'P') {
                        // skip leading whitespace
                        while((sitr != stream_end) && std::isspace(*sitr)) { ++sitr; }
                        // parse zone
                        while((sitr != stream_end) && (!std::isspace(*sitr))) {
                          tz_str += *sitr;
                          ++sitr;
                        }
                      }
                      else {
                        use_current_format_char = true;
                      }
                    
                    }
                    else {
                      // nothing was parsed so we don't want to advance sitr
                      use_current_char = true;
                    }
                   
                    break;
                  }
                default:
                {} // ignore what we don't understand?
              }// switch
            } 
            else { // itr == '%', second consecutive
              sitr++;
            }
       
            if(use_current_format_char) {
              use_current_format_char = false;
            }
            else {
              itr++; //advance past format specifier
            }
             
          }
          else {  //skip past chars in format and in buffer
            itr++;
            // set use_current_char when sitr is already 
            // pointing at the next character to process
            if (use_current_char) {
              use_current_char = false;
            }
            else {
              sitr++;
            }
          }
        }
        
        date_type d(not_a_date_time);
        if (day_of_year > 0) {
          d = date_type(static_cast<unsigned short>(t_year-1),12,31) + date_duration_type(day_of_year);
        }
        else {
          d = date_type(t_year, t_month, t_day);
        }

        time_duration_type td(hour, min, sec, frac);
        t = time_type(d, td);
        return sitr;
      }

      //! Helper function to check for special_value
      /*! First character may have been consumed during original parse 
       * attempt. Parameter 'c' should be a copy of that character. 
       * Throws ios_base::failure if parse fails. */
      template<class temporal_type>
      inline
      InItrT check_special_value(InItrT& sitr,InItrT& stream_end, temporal_type& tt, char_type c='\0') const
      {
        match_results mr;
        if((c == '-' || c == '+') && (*sitr != c)) { // was the first character consumed?
          mr.cache += c;
        }
        this->m_sv_parser.match(sitr, stream_end, mr);
        if(mr.current_match == match_results::PARSE_ERROR) {
          std::string tmp = convert_string_type<char_type, char>(mr.cache);
          throw std::ios_base::failure("Parse failed. No match found for '" + tmp + "'");
        }
        tt = temporal_type(static_cast<special_values>(mr.current_match)); 
        return sitr;
      }

      //! Helper function for parsing a fractional second type from the stream
      void parse_frac_type(InItrT& sitr, 
                           InItrT& stream_end, 
                           fracional_seconds_type& frac) const
      {
        string_type cache;
        while((sitr != stream_end) && std::isdigit(*sitr)) {
          cache += *sitr;
          ++sitr;
        }
        if(cache.size() > 0) {
          unsigned short precision = time_duration_type::num_fractional_digits();
          // input may be only the first few decimal places
          if(cache.size() < precision) {
            frac = lexical_cast<fracional_seconds_type>(cache);
            frac = decimal_adjust(frac, static_cast<unsigned short>(precision - cache.size()));
          }
          else {
            // if input has too many decimal places, drop excess digits
            frac = lexical_cast<fracional_seconds_type>(cache.substr(0, precision));
          }
        }
      }
      
    private:
      string_type m_time_duration_format;

      //! Helper function to adjust trailing zeros when parsing fractional digits
      template<class int_type>
      inline
      int_type decimal_adjust(int_type val, const unsigned short places) const
      {
        unsigned long factor = 1;
        for(int i = 0; i < places; ++i){
          factor *= 10; // shift decimal to the right
        }
        return val * factor;
      }

  };

template <class time_type, class CharT, class InItrT>
  std::locale::id time_input_facet<time_type, CharT, InItrT>::id;

template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::fractional_seconds_format = time_formats<CharT>::fractional_seconds_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::fractional_seconds_or_none_format = time_formats<CharT>::fractional_seconds_or_none_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::seconds_with_fractional_seconds_format = time_formats<CharT>::seconds_with_fractional_seconds_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::seconds_format = time_formats<CharT>::seconds_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::standard_format = time_formats<CharT>::standard_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::zone_abbrev_format = time_formats<CharT>::zone_abbrev_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::zone_name_format = time_formats<CharT>::zone_name_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::zone_iso_format = time_formats<CharT>::zone_iso_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::zone_iso_extended_format = time_formats<CharT>::zone_iso_extended_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::duration_seperator = time_formats<CharT>::duration_seperator;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::iso_time_format_specifier = time_formats<CharT>::iso_time_format_specifier;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::iso_time_format_extended_specifier = time_formats<CharT>::iso_time_format_extended_specifier;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::default_time_input_format = time_formats<CharT>::default_time_input_format;

  template <class time_type, class CharT, class InItrT>  
  const typename time_input_facet<time_type, CharT, InItrT>::char_type* 
  time_input_facet<time_type, CharT, InItrT>::default_time_duration_format = time_formats<CharT>::default_time_duration_format;


} } // namespaces


#endif