format_date_parser.hpp

来自「support vector clustering for vc++」· HPP 代码 · 共 732 行 · 第 1/2 页

                if(sv_parser.match(sitr, stream_end, mr)) {
                  return date_type(static_cast<special_values>(mr.current_match));
                }
              }
              // these next two lines are so we get an exception with bad input
              day_of_year_type t_day_of_year(1);
              t_day_of_year = day_of_year_type(day_of_year);
              break;
            }
          case 'm': 
            {
              match_results mr;
              month = fixed_string_to_int<short, charT>(sitr, stream_end, mr, 2);
              if(month == -1) {
                if(sv_parser.match(sitr, stream_end, mr)) {
                  return date_type(static_cast<special_values>(mr.current_match));
                }
              }
              t_month = month_type(month);
              break;
            }
          case 'Y': 
            {
              match_results mr;
              year = fixed_string_to_int<short, charT>(sitr, stream_end, mr, 4);
              if(year == -1) {
                if(sv_parser.match(sitr, stream_end, mr)) {
                  return date_type(static_cast<special_values>(mr.current_match));
                }
              }
              t_year = year_type(year);
              break;
            }
          case 'y': 
            {
              match_results mr;
              year = fixed_string_to_int<short, charT>(sitr, stream_end, mr, 2);
              if(year == -1) {
                if(sv_parser.match(sitr, stream_end, mr)) {
                  return date_type(static_cast<special_values>(mr.current_match));
                }
              }
              year += 2000; //make 2 digit years in this century
              t_year = year_type(year);
              break;
            }
          default:
            {} //ignore those we don't understand
            
          }//switch
          
        }
        else { // itr == '%', second consecutive
          sitr++;
        }
        
        itr++; //advance past format specifier
      }
      else {  //skip past chars in format and in buffer
        itr++;
        if (use_current_char) {
          use_current_char = false;
          current_char = *sitr;
        }
        else {
          sitr++;
        }
      }
    }
    
    if (day_of_year > 0) {
      date_type d(static_cast<unsigned short>(year-1),12,31); //end of prior year
      return d + duration_type(day_of_year);
    }
    
    return date_type(t_year, t_month, t_day); // exceptions were thrown earlier 
                                        // if input was no good 
  }
 
  //! Throws bad_month if unable to parse
  month_type
  parse_month(std::istreambuf_iterator<charT>& sitr, 
             std::istreambuf_iterator<charT>& stream_end,
             string_type format_str) const
  {
    match_results mr;
    return parse_month(sitr, stream_end, format_str, mr);
  }
 
  //! Throws bad_month if unable to parse
  month_type
  parse_month(std::istreambuf_iterator<charT>& sitr, 
             std::istreambuf_iterator<charT>& stream_end,
             string_type format_str,
             match_results& mr) const
  {
    bool use_current_char = false;
    
    // skip leading whitespace
    while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; } 
    charT current_char = *sitr;

    short month(0);
    
    const_itr itr(format_str.begin());
    while (itr != format_str.end() && (sitr != stream_end)) {
      if (*itr == '%') {
        itr++;
        if (*itr != '%') {
          switch(*itr) {
          case 'b': 
            {
              mr = m_month_short_names.match(sitr, stream_end);
              month = mr.current_match;
              if (mr.has_remaining()) {
                current_char = mr.last_char();
                use_current_char = true;
              }
              break;
            }
          case 'B': 
            {
              mr = m_month_long_names.match(sitr, stream_end);
              month = mr.current_match;
              if (mr.has_remaining()) {
                current_char = mr.last_char();
                use_current_char = true;
              }
              break;
            }
          case 'm': 
            {
              month = var_string_to_int<short, charT>(sitr, stream_end, 2);
              // var_string_to_int returns -1 if parse failed. That will 
              // cause a bad_month exception to be thrown so we do nothing here
              break;
            }
          default:
            {} //ignore those we don't understand
            
          }//switch
          
        }
        else { // itr == '%', second consecutive
          sitr++;
        }
        
        itr++; //advance past format specifier
      }
      else {  //skip past chars in format and in buffer
        itr++;
        if (use_current_char) {
          use_current_char = false;
          current_char = *sitr;
        }
        else {
          sitr++;
        }
      }
    }
    
    return month_type(month); // throws bad_month exception when values are zero
  }

  //! Expects 1 or 2 digits 1-31. Throws bad_day_of_month if unable to parse
  day_type
  parse_var_day_of_month(std::istreambuf_iterator<charT>& sitr, 
                         std::istreambuf_iterator<charT>& stream_end) const
  {
    // skip leading whitespace
    while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; } 

    return day_type(var_string_to_int<short, charT>(sitr, stream_end, 2));
  }
  //! Expects 2 digits 01-31. Throws bad_day_of_month if unable to parse
  day_type
  parse_day_of_month(std::istreambuf_iterator<charT>& sitr, 
                     std::istreambuf_iterator<charT>& stream_end) const
  {
    // skip leading whitespace
    while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; } 

    //return day_type(var_string_to_int<short, charT>(sitr, stream_end, 2));
    match_results mr;
    return day_type(fixed_string_to_int<short, charT>(sitr, stream_end, mr, 2));
  }

  day_of_week_type
  parse_weekday(std::istreambuf_iterator<charT>& sitr, 
             std::istreambuf_iterator<charT>& stream_end,
             string_type format_str) const
  {
    match_results mr;
    return parse_weekday(sitr, stream_end, format_str, mr);
  }
  day_of_week_type
  parse_weekday(std::istreambuf_iterator<charT>& sitr, 
             std::istreambuf_iterator<charT>& stream_end,
             string_type format_str,
             match_results& mr) const
  {
    bool use_current_char = false;
    
    // skip leading whitespace
    while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; } 
    charT current_char = *sitr;

    short wkday(0);
    
    const_itr itr(format_str.begin());
    while (itr != format_str.end() && (sitr != stream_end)) {
      if (*itr == '%') {
        itr++;
        if (*itr != '%') {
          switch(*itr) {
          case 'a': 
            {
              //this value is just throw away.  It could be used for
              //error checking potentially, but it isn't helpful in 
              //actually constructing the date - we just need to get it
              //out of the stream
              mr = m_weekday_short_names.match(sitr, stream_end);
              wkday = mr.current_match;
              if (mr.has_remaining()) {
                current_char = mr.last_char();
                use_current_char = true;
              }
              break;
            }
          case 'A': 
            {
              //this value is just throw away.  It could be used for
              //error checking potentially, but it isn't helpful in 
              //actually constructing the date - we just need to get it
              //out of the stream
              mr = m_weekday_long_names.match(sitr, stream_end);
              wkday = mr.current_match;
              if (mr.has_remaining()) {
                current_char = mr.last_char();
                use_current_char = true;
              }
              break;
            }
          case 'w':
            {
              // weekday as number 0-6, Sunday == 0
              wkday = var_string_to_int<short, charT>(sitr, stream_end, 2);
              break;
            }
          default:
            {} //ignore those we don't understand
            
          }//switch
          
        }
        else { // itr == '%', second consecutive
          sitr++;
        }
        
        itr++; //advance past format specifier
      }
      else {  //skip past chars in format and in buffer
        itr++;
        if (use_current_char) {
          use_current_char = false;
          current_char = *sitr;
        }
        else {
          sitr++;
        }
      }
    }
    
    return day_of_week_type(wkday); // throws bad_day_of_month exception 
                                    // when values are zero
  }
  
  //! throws bad_year if unable to parse
  year_type
  parse_year(std::istreambuf_iterator<charT>& sitr, 
             std::istreambuf_iterator<charT>& stream_end,
             string_type format_str) const
  {
    match_results mr;
    return parse_year(sitr, stream_end, format_str, mr);
  }

  //! throws bad_year if unable to parse
  year_type
  parse_year(std::istreambuf_iterator<charT>& sitr, 
             std::istreambuf_iterator<charT>& stream_end,
             string_type format_str,
             match_results& mr) const
  {
    bool use_current_char = false;
    
    // skip leading whitespace
    while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; } 
    charT current_char = *sitr;

    unsigned short year(0);
    
    const_itr itr(format_str.begin());
    while (itr != format_str.end() && (sitr != stream_end)) {
      if (*itr == '%') {
        itr++;
        if (*itr != '%') {
          //match_results mr;
          switch(*itr) {
          case 'Y':
            {
              // year from 4 digit string
              year = fixed_string_to_int<short, charT>(sitr, stream_end, mr, 4);
              break;
            }
          case 'y':
            {
              // year from 2 digit string (no century)
              year = fixed_string_to_int<short, charT>(sitr, stream_end, mr, 2);
              year += 2000; //make 2 digit years in this century
              break;
            }
          default:
            {} //ignore those we don't understand
            
          }//switch
          
        }
        else { // itr == '%', second consecutive
          sitr++;
        }
        
        itr++; //advance past format specifier
      }
      else {  //skip past chars in format and in buffer
        itr++;
        if (use_current_char) {
          use_current_char = false;
          current_char = *sitr;
        }
        else {
          sitr++;
        }
      }
    }
    
    return year_type(year); // throws bad_year exception when values are zero
  }
  
  
 private:
  string_type m_format;
  parse_tree_type m_month_short_names;
  parse_tree_type m_month_long_names;
  parse_tree_type m_weekday_short_names;
  parse_tree_type m_weekday_long_names;

};

} } //namespace

#endif