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_parser(const period_parser<date_type,CharT>& p_parser)
  73     {
  74       this->delimiters = p_parser.delimiters;
  75       this->m_range_option = p_parser.m_range_option;
  76     }
  77
  78     period_range_option range_option() const
  79     {
  80       return m_range_option;
  81     }
  82     void range_option(period_range_option option)
  83     {
  84       m_range_option = option;
  85     }
  86     collection_type delimiter_strings() const
  87     {
  88       return delimiters;
  89     }
  90     void delimiter_strings(const string_type& separator,
  91                            const string_type& start_delim,
  92                            const string_type& open_end_delim,
  93                            const string_type& closed_end_delim)
  94     {
  95       delimiters.clear();
  96       delimiters.push_back(separator);
  97       delimiters.push_back(start_delim);
  98       delimiters.push_back(open_end_delim);
  99       delimiters.push_back(closed_end_delim);
 100     }
 101
 102     //! Generic code to parse a period -- no matter the period type.
 103     /*! This generic code will parse any period using a facet to
 104      *  to get the 'elements'.  For example, in the case of a date_period
 105      *  the elements will be instances of a date which will be parsed
 106      *  according the to setup in the passed facet parameter.
 107      *
 108      *  The steps for parsing a period are always the same:
 109      *  - consume the start delimiter
 110      *  - get start element
 111      *  - consume the separator
 112      *  - get either last or end element depending on range settings
 113      *  - consume the end delimeter depending on range settings
 114      *
 115      *  Thus for a typical date period the contents of the input stream
 116      *  might look like this:
 117      *@code
 118      *
 119      *    [March 01, 2004/June 07, 2004]   <-- closed range
 120      *    [March 01, 2004/June 08, 2004)   <-- open range
 121      *
 122      *@endcode
 123      */
 124     template<class period_type, class duration_type, class facet_type>
 125     period_type get_period(stream_itr_type& sitr,
 126                            stream_itr_type& stream_end,
 127                            std::ios_base& a_ios,
 128                            const period_type& /* p */,
 129                            const duration_type& dur_unit,
 130                            const facet_type& facet) const
 131     {
 132       // skip leading whitespace
 133       while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
 134
 135       typedef typename period_type::point_type point_type;
 136       point_type p1(not_a_date_time), p2(not_a_date_time);
 137
 138
 139       consume_delim(sitr, stream_end, delimiters[START]);       // start delim
 140       facet.get(sitr, stream_end, a_ios, p1);                   // first point
 141       consume_delim(sitr, stream_end, delimiters[SEPARATOR]);   // separator
 142       facet.get(sitr, stream_end, a_ios, p2);                   // second point
 143
 144       // period construction parameters are always open range [begin, end)
 145       if (m_range_option == AS_CLOSED_RANGE) {
 146         consume_delim(sitr, stream_end, delimiters[CLOSED_END]);// end delim
 147         // add 1 duration unit to p2 to make range open
 148         p2 += dur_unit;
 149       }
 150       else {
 151         consume_delim(sitr, stream_end, delimiters[OPEN_END]);  // end delim
 152       }
 153
 154       return period_type(p1, p2);
 155     }
 156
 157   private:
 158     collection_type delimiters;
 159     period_range_option m_range_option;
 160
 161     enum delim_ids { SEPARATOR, START, OPEN_END, CLOSED_END };
 162
 163     //! throws ios_base::failure if delimiter and parsed data do not match
 164     void consume_delim(stream_itr_type& sitr,
 165                        stream_itr_type& stream_end,
 166                        const string_type& delim) const
 167     {
 168       /* string_parse_tree will not parse a string of punctuation characters
 169        * without knowing exactly how many characters to process
 170        * Ex [2000. Will not parse out the '[' string without knowing
 171        * to process only one character. By using length of the delimiter
 172        * string we can safely iterate past it. */
 173       string_type s;
 174       for(unsigned int i = 0; i < delim.length() && sitr != stream_end; ++i) {
 175         s += *sitr;
 176         ++sitr;
 177       }
 178       if(s != delim) {
 179         boost::throw_exception(std::ios_base::failure("Parse failed. Expected '"
 180           + convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'"));
 181       }
 182     }
 183   };
 184
 185   template <class date_type, class char_type>
 186   const typename period_parser<date_type, char_type>::char_type
 187   period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
 188
 189   template <class date_type, class char_type>
 190   const typename period_parser<date_type, char_type>::char_type
 191   period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
 192
 193   template <class date_type, class char_type>
 194   const typename period_parser<date_type, char_type>::char_type
 195   period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
 196
 197   template <class date_type, class char_type>
 198   const typename period_parser<date_type, char_type>::char_type
 199   period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
 200
 201  } } //namespace boost::date_time
 202
 203 #endif // DATETIME_PERIOD_PARSER_HPP___