ceph/src/boost/boost/date_time/period_parser.hpp

   1
   2 #ifndef DATETIME_PERIOD_PARSER_HPP___
   3 #define DATETIME_PERIOD_PARSER_HPP___
   4
   5 /* Copyright (c) 2002-2004 CrystalClear Software, Inc.
   6  * Use, modification and distribution is subject to the
   7  * Boost Software License, Version 1.0. (See accompanying
   8  * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
   9  * Author: Jeff Garland, Bart Garst
  10  * $Date$
  11  */
  12
  13 #include <ios>
  14 #include <string>
  15 #include <vector>
  16 #include <iterator>
  17 #include <boost/throw_exception.hpp>
  18 #include <boost/date_time/special_defs.hpp>
  19 #include <boost/date_time/string_parse_tree.hpp>
  20 #include <boost/date_time/string_convert.hpp>
  21
  22
  23 namespace boost { namespace date_time {
  24
  25
  26   //! Not a facet, but a class used to specify and control period parsing
  27   /*! Provides settings for the following:
  28    *   - period_separator -- default '/'
  29    *   - period_open_start_delimeter -- default '['
  30    *   - period_open_range_end_delimeter -- default ')'
  31    *   - period_closed_range_end_delimeter -- default ']'
  32    *   - display_as_open_range, display_as_closed_range -- default closed_range
  33    *
  34    *  For a typical date_period, the contents of the input stream would be
  35    *@code
  36    *  [2004-Jan-04/2004-Feb-01]
  37    *@endcode
  38    * where the date format is controlled by the date facet
  39    */
  40   template<class date_type, typename CharT>
  41   class period_parser {
  42   public:
  43     typedef std::basic_string<CharT> string_type;
  44     typedef CharT                    char_type;
  45     //typedef typename std::basic_string<char_type>::const_iterator const_itr_type;
  46     typedef std::istreambuf_iterator<CharT> stream_itr_type;
  47     typedef string_parse_tree<CharT> parse_tree_type;
  48     typedef typename parse_tree_type::parse_match_result_type match_results;
  49     typedef std::vector<std::basic_string<CharT> > collection_type;
  50
  51     static const char_type default_period_separator[2];
  52     static const char_type default_period_start_delimeter[2];
  53     static const char_type default_period_open_range_end_delimeter[2];
  54     static const char_type default_period_closed_range_end_delimeter[2];
  55
  56     enum period_range_option { AS_OPEN_RANGE, AS_CLOSED_RANGE };
  57
  58     //! Constructor that sets up period parser options
  59     period_parser(period_range_option range_opt = AS_CLOSED_RANGE,
  60                   const char_type* const period_separator = default_period_separator,
  61                   const char_type* const period_start_delimeter = default_period_start_delimeter,
  62                   const char_type* const period_open_range_end_delimeter = default_period_open_range_end_delimeter,
  63                   const char_type* const period_closed_range_end_delimeter = default_period_closed_range_end_delimeter)
  64       : m_range_option(range_opt)
  65     {
  66       delimiters.push_back(string_type(period_separator));
  67       delimiters.push_back(string_type(period_start_delimeter));
  68       delimiters.push_back(string_type(period_open_range_end_delimeter));
  69       delimiters.push_back(string_type(period_closed_range_end_delimeter));
  70     }
  71
  72     period_range_option range_option() const
  73     {
  74       return m_range_option;
  75     }
  76     void range_option(period_range_option option)
  77     {
  78       m_range_option = option;
  79     }
  80     collection_type delimiter_strings() const
  81     {
  82       return delimiters;
  83     }
  84     void delimiter_strings(const string_type& separator,
  85                            const string_type& start_delim,
  86                            const string_type& open_end_delim,
  87                            const string_type& closed_end_delim)
  88     {
  89       delimiters.clear();
  90       delimiters.push_back(separator);
  91       delimiters.push_back(start_delim);
  92       delimiters.push_back(open_end_delim);
  93       delimiters.push_back(closed_end_delim);
  94     }
  95
  96     //! Generic code to parse a period -- no matter the period type.
  97     /*! This generic code will parse any period using a facet to
  98      *  to get the 'elements'.  For example, in the case of a date_period
  99      *  the elements will be instances of a date which will be parsed
 100      *  according the to setup in the passed facet parameter.
 101      *
 102      *  The steps for parsing a period are always the same:
 103      *  - consume the start delimiter
 104      *  - get start element
 105      *  - consume the separator
 106      *  - get either last or end element depending on range settings
 107      *  - consume the end delimeter depending on range settings
 108      *
 109      *  Thus for a typical date period the contents of the input stream
 110      *  might look like this:
 111      *@code
 112      *
 113      *    [March 01, 2004/June 07, 2004]   <-- closed range
 114      *    [March 01, 2004/June 08, 2004)   <-- open range
 115      *
 116      *@endcode
 117      */
 118     template<class period_type, class duration_type, class facet_type>
 119     period_type get_period(stream_itr_type& sitr,
 120                            stream_itr_type& stream_end,
 121                            std::ios_base& a_ios,
 122                            const period_type& /* p */,
 123                            const duration_type& dur_unit,
 124                            const facet_type& facet) const
 125     {
 126       // skip leading whitespace
 127       while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
 128
 129       typedef typename period_type::point_type point_type;
 130       point_type p1(not_a_date_time), p2(not_a_date_time);
 131
 132
 133       consume_delim(sitr, stream_end, delimiters[START]);       // start delim
 134       facet.get(sitr, stream_end, a_ios, p1);                   // first point
 135       consume_delim(sitr, stream_end, delimiters[SEPARATOR]);   // separator
 136       facet.get(sitr, stream_end, a_ios, p2);                   // second point
 137
 138       // period construction parameters are always open range [begin, end)
 139       if (m_range_option == AS_CLOSED_RANGE) {
 140         consume_delim(sitr, stream_end, delimiters[CLOSED_END]);// end delim
 141         // add 1 duration unit to p2 to make range open
 142         p2 += dur_unit;
 143       }
 144       else {
 145         consume_delim(sitr, stream_end, delimiters[OPEN_END]);  // end delim
 146       }
 147
 148       return period_type(p1, p2);
 149     }
 150
 151   private:
 152     collection_type delimiters;
 153     period_range_option m_range_option;
 154
 155     enum delim_ids { SEPARATOR, START, OPEN_END, CLOSED_END };
 156
 157     //! throws ios_base::failure if delimiter and parsed data do not match
 158     void consume_delim(stream_itr_type& sitr,
 159                        stream_itr_type& stream_end,
 160                        const string_type& delim) const
 161     {
 162       /* string_parse_tree will not parse a string of punctuation characters
 163        * without knowing exactly how many characters to process
 164        * Ex [2000. Will not parse out the '[' string without knowing
 165        * to process only one character. By using length of the delimiter
 166        * string we can safely iterate past it. */
 167       string_type s;
 168       for(unsigned int i = 0; i < delim.length() && sitr != stream_end; ++i) {
 169         s += *sitr;
 170         ++sitr;
 171       }
 172       if(s != delim) {
 173         boost::throw_exception(std::ios_base::failure("Parse failed. Expected '"
 174           + convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'"));
 175       }
 176     }
 177   };
 178
 179   template <class date_type, class char_type>
 180   const typename period_parser<date_type, char_type>::char_type
 181   period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
 182
 183   template <class date_type, class char_type>
 184   const typename period_parser<date_type, char_type>::char_type
 185   period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
 186
 187   template <class date_type, class char_type>
 188   const typename period_parser<date_type, char_type>::char_type
 189   period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
 190
 191   template <class date_type, class char_type>
 192   const typename period_parser<date_type, char_type>::char_type
 193   period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
 194
 195  } } //namespace boost::date_time
 196
 197 #endif // DATETIME_PERIOD_PARSER_HPP___