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

Revision 857, 6.2 KB checked in by igarcia, 19 years ago (diff)
Line 
1
2#ifndef DATE_TIME_SPECIAL_VALUES_PARSER_HPP__
3#define DATE_TIME_SPECIAL_VALUES_PARSER_HPP__
4
5/* Copyright (c) 2005 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:
11 */
12
13
14#include "boost/date_time/string_parse_tree.hpp"
15#include "boost/date_time/special_defs.hpp"
16#include <string>
17#include <vector>
18
19namespace boost { namespace date_time {
20
21  //! Class for special_value parsing
22  /*!
23   * TODO: add doc-comments for which elements can be changed
24   * Parses input stream for strings representing special_values.
25   * Special values parsed are:
26   *  - not_a_date_time
27   *  - neg_infin
28   *  - pod_infin
29   *  - min_date_time
30   *  - max_date_time
31   */
32  template<class date_type, typename charT>
33  class special_values_parser
34  {
35   public:
36    typedef std::basic_string<charT>        string_type;
37    //typedef std::basic_stringstream<charT>  stringstream_type;
38    typedef std::istreambuf_iterator<charT> stream_itr_type;
39    //typedef typename string_type::const_iterator const_itr;
40    //typedef typename date_type::year_type  year_type;
41    //typedef typename date_type::month_type month_type;
42    typedef typename date_type::duration_type duration_type;
43    //typedef typename date_type::day_of_week_type day_of_week_type;
44    //typedef typename date_type::day_type day_type;
45    typedef string_parse_tree<charT> parse_tree_type;
46    typedef typename parse_tree_type::parse_match_result_type match_results;
47    typedef std::vector<std::basic_string<charT> > collection_type;
48
49    typedef charT char_type;
50    static const char_type nadt_string[16];
51    static const char_type neg_inf_string[10];
52    static const char_type pos_inf_string[10];
53    static const char_type min_date_time_string[18];
54    static const char_type max_date_time_string[18];
55   
56    //! Creates a special_values_parser with the default set of "sv_strings"
57    special_values_parser()
58    {
59      sv_strings(string_type(nadt_string),
60                 string_type(neg_inf_string),
61                 string_type(pos_inf_string),
62                 string_type(min_date_time_string),
63                 string_type(max_date_time_string));
64    }
65
66    //! Creates a special_values_parser using a user defined set of element strings
67    special_values_parser(const string_type& nadt_str,
68                          const string_type& neg_inf_str,
69                          const string_type& pos_inf_str,
70                          const string_type& min_dt_str,
71                          const string_type& max_dt_str)
72    {
73      sv_strings(nadt_str, neg_inf_str, pos_inf_str, min_dt_str, max_dt_str);
74    }
75
76    special_values_parser(typename collection_type::iterator beg, typename collection_type::iterator end)
77    {
78      collection_type phrases;
79      std::copy(beg, end, std::back_inserter(phrases));
80      m_sv_strings = parse_tree_type(phrases, static_cast<int>(not_a_date_time));
81    }
82
83    special_values_parser(const special_values_parser<date_type,charT>& svp)
84    {
85      this->m_sv_strings = svp.m_sv_strings;
86    }
87
88    //! Replace special value strings
89    void sv_strings(const string_type& nadt_str,
90                    const string_type& neg_inf_str,
91                    const string_type& pos_inf_str,
92                    const string_type& min_dt_str,
93                    const string_type& max_dt_str)
94    {
95      collection_type phrases;
96      phrases.push_back(nadt_str);
97      phrases.push_back(neg_inf_str);
98      phrases.push_back(pos_inf_str);
99      phrases.push_back(min_dt_str);
100      phrases.push_back(max_dt_str);
101      m_sv_strings = parse_tree_type(phrases, static_cast<int>(not_a_date_time));
102    }
103
104    /* Does not return a special_value because if the parsing fails,
105     * the return value will always be not_a_date_time
106     * (mr.current_match retains its default value of -1 on a failed
107     * parse and that casts to not_a_date_time). */
108    //! Sets match_results.current_match to the corresponding special_value or -1
109    bool match(stream_itr_type& sitr,
110                        stream_itr_type& str_end,
111                        match_results& mr) const
112    {
113      unsigned int level = 0;
114      m_sv_strings.match(sitr, str_end, mr, level);
115      return (mr.current_match != match_results::PARSE_ERROR);
116    }
117    /*special_values match(stream_itr_type& sitr,
118                        stream_itr_type& str_end,
119                        match_results& mr) const
120    {
121      unsigned int level = 0;
122      m_sv_strings.match(sitr, str_end, mr, level);
123      if(mr.current_match == match_results::PARSE_ERROR) {
124        throw std::ios_base::failure("Parse failed. No match found for '" + mr.cache + "'");
125      }
126      return static_cast<special_values>(mr.current_match);
127    }*/
128                     
129
130   private:
131    parse_tree_type m_sv_strings;
132   
133  };
134
135  template<class date_type, class CharT>
136  const typename special_values_parser<date_type, CharT>::char_type
137  special_values_parser<date_type, CharT>::nadt_string[16] =
138  {'n','o','t','-','a','-','d','a','t','e','-','t','i','m','e'};
139  template<class date_type, class CharT>
140  const typename special_values_parser<date_type, CharT>::char_type
141  special_values_parser<date_type, CharT>::neg_inf_string[10] =
142  {'-','i','n','f','i','n','i','t','y'};
143  template<class date_type, class CharT>
144  const typename special_values_parser<date_type, CharT>::char_type
145  special_values_parser<date_type, CharT>::pos_inf_string[10] =
146  {'+','i','n','f','i','n','i','t','y'};
147  template<class date_type, class CharT>
148  const typename special_values_parser<date_type, CharT>::char_type
149  special_values_parser<date_type, CharT>::min_date_time_string[18] =
150  {'m','i','n','i','m','u','m','-','d','a','t','e','-','t','i','m','e'};
151  template<class date_type, class CharT>
152  const typename special_values_parser<date_type, CharT>::char_type
153  special_values_parser<date_type, CharT>::max_date_time_string[18] =
154  {'m','a','x','i','m','u','m','-','d','a','t','e','-','t','i','m','e'};
155
156} } //namespace
157
158#endif // DATE_TIME_SPECIAL_VALUES_PARSER_HPP__
159
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