source: NonGTP/Boost/boost/date_time/period_parser.hpp @ 857

Revision 857, 8.0 KB checked in by igarcia, 19 years ago (diff)
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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 or http://www.boost.org/LICENSE-1.0)
9 * Author: Jeff Garland, Bart Garst
10 * $Date: 2005/06/06 10:36:46 $
11 */
12
13#include "boost/date_time/string_parse_tree.hpp"
14#include "boost/date_time/string_convert.hpp"
15
16
17namespace boost { namespace date_time {
18
19
20  //! Not a facet, but a class used to specify and control period parsing
21  /*! Provides settings for the following:
22   *   - period_separator -- default '/'
23   *   - period_open_start_delimeter -- default '['
24   *   - period_open_range_end_delimeter -- default ')'
25   *   - period_closed_range_end_delimeter -- default ']'
26   *   - display_as_open_range, display_as_closed_range -- default closed_range
27   *
28   *  For a typical date_period, the contents of the input stream would be
29   *@code
30   *  [2004-Jan-04/2004-Feb-01]
31   *@endcode
32   * where the date format is controlled by the date facet
33   */
34  template<class date_type, typename CharT>
35  class period_parser {
36  public:
37    typedef std::basic_string<CharT> string_type;
38    typedef CharT                    char_type;
39    //typedef typename std::basic_string<char_type>::const_iterator const_itr_type;
40    typedef std::istreambuf_iterator<CharT> stream_itr_type;
41    typedef string_parse_tree<CharT> parse_tree_type;
42    typedef typename parse_tree_type::parse_match_result_type match_results;
43    typedef std::vector<std::basic_string<CharT> > collection_type;
44   
45    static const char_type default_period_separator[2];
46    static const char_type default_period_start_delimeter[2];
47    static const char_type default_period_open_range_end_delimeter[2];
48    static const char_type default_period_closed_range_end_delimeter[2];
49
50    enum period_range_option { AS_OPEN_RANGE, AS_CLOSED_RANGE };
51
52    //! Constructor that sets up period parser options
53    period_parser(period_range_option range_option = AS_CLOSED_RANGE,
54                  const char_type* const period_separator = default_period_separator,
55                  const char_type* const period_start_delimeter = default_period_start_delimeter,
56                  const char_type* const period_open_range_end_delimeter = default_period_open_range_end_delimeter,
57                  const char_type* const period_closed_range_end_delimeter = default_period_closed_range_end_delimeter)
58      : m_range_option(range_option)
59    {
60      delimiters.push_back(string_type(period_separator));
61      delimiters.push_back(string_type(period_start_delimeter));
62      delimiters.push_back(string_type(period_open_range_end_delimeter));
63      delimiters.push_back(string_type(period_closed_range_end_delimeter));
64    }
65
66    period_parser(const period_parser<date_type,CharT>& p_parser)
67    {
68      this->delimiters = p_parser.delimiters;
69      this->m_range_option = p_parser.m_range_option;
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        throw std::ios_base::failure("Parse failed. Expected '" + convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'");
174      }
175    }
176  };
177
178  template <class date_type, class char_type> 
179  const typename period_parser<date_type, char_type>::char_type
180  period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
181
182  template <class date_type, class char_type> 
183  const typename period_parser<date_type, char_type>::char_type
184  period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
185
186  template <class date_type, class char_type> 
187  const typename period_parser<date_type, char_type>::char_type
188  period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
189
190  template <class date_type, class char_type> 
191  const typename period_parser<date_type, char_type>::char_type
192  period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
193
194 } } //namespace boost::date_time
195
196#endif // DATETIME_PERIOD_PARSER_HPP___
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