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 <boost/throw_exception.hpp>
14#include <boost/date_time/string_parse_tree.hpp>
15#include <boost/date_time/string_convert.hpp>
16
17
18namespace boost { namespace date_time {
19
20
21 //! Not a facet, but a class used to specify and control period parsing
22 /*! Provides settings for the following:
23 * - period_separator -- default '/'
24 * - period_open_start_delimeter -- default '['
25 * - period_open_range_end_delimeter -- default ')'
26 * - period_closed_range_end_delimeter -- default ']'
27 * - display_as_open_range, display_as_closed_range -- default closed_range
28 *
29 * For a typical date_period, the contents of the input stream would be
30 *@code
31 * [2004-Jan-04/2004-Feb-01]
32 *@endcode
33 * where the date format is controlled by the date facet
34 */
35 template<class date_type, typename CharT>
36 class period_parser {
37 public:
38 typedef std::basic_string<CharT> string_type;
39 typedef CharT char_type;
40 //typedef typename std::basic_string<char_type>::const_iterator const_itr_type;
41 typedef std::istreambuf_iterator<CharT> stream_itr_type;
42 typedef string_parse_tree<CharT> parse_tree_type;
43 typedef typename parse_tree_type::parse_match_result_type match_results;
44 typedef std::vector<std::basic_string<CharT> > collection_type;
45
46 static const char_type default_period_separator[2];
47 static const char_type default_period_start_delimeter[2];
48 static const char_type default_period_open_range_end_delimeter[2];
49 static const char_type default_period_closed_range_end_delimeter[2];
50
51 enum period_range_option { AS_OPEN_RANGE, AS_CLOSED_RANGE };
52
53 //! Constructor that sets up period parser options
54 period_parser(period_range_option range_opt = AS_CLOSED_RANGE,
55 const char_type* const period_separator = default_period_separator,
56 const char_type* const period_start_delimeter = default_period_start_delimeter,
57 const char_type* const period_open_range_end_delimeter = default_period_open_range_end_delimeter,
58 const char_type* const period_closed_range_end_delimeter = default_period_closed_range_end_delimeter)
59 : m_range_option(range_opt)
60 {
61 delimiters.push_back(string_type(period_separator));
62 delimiters.push_back(string_type(period_start_delimeter));
63 delimiters.push_back(string_type(period_open_range_end_delimeter));
64 delimiters.push_back(string_type(period_closed_range_end_delimeter));
65 }
66
67 period_parser(const period_parser<date_type,CharT>& p_parser)
68 {
69 this->delimiters = p_parser.delimiters;
70 this->m_range_option = p_parser.m_range_option;
71 }
72
73 period_range_option range_option() const
74 {
75 return m_range_option;
76 }
77 void range_option(period_range_option option)
78 {
79 m_range_option = option;
80 }
81 collection_type delimiter_strings() const
82 {
83 return delimiters;
84 }
85 void delimiter_strings(const string_type& separator,
86 const string_type& start_delim,
87 const string_type& open_end_delim,
88 const string_type& closed_end_delim)
89 {
90 delimiters.clear();
91 delimiters.push_back(separator);
92 delimiters.push_back(start_delim);
93 delimiters.push_back(open_end_delim);
94 delimiters.push_back(closed_end_delim);
95 }
96
97 //! Generic code to parse a period -- no matter the period type.
98 /*! This generic code will parse any period using a facet to
99 * to get the 'elements'. For example, in the case of a date_period
100 * the elements will be instances of a date which will be parsed
101 * according the to setup in the passed facet parameter.
102 *
103 * The steps for parsing a period are always the same:
104 * - consume the start delimiter
105 * - get start element
106 * - consume the separator
107 * - get either last or end element depending on range settings
108 * - consume the end delimeter depending on range settings
109 *
110 * Thus for a typical date period the contents of the input stream
111 * might look like this:
112 *@code
113 *
114 * [March 01, 2004/June 07, 2004] <-- closed range
115 * [March 01, 2004/June 08, 2004) <-- open range
116 *
117 *@endcode
118 */
119 template<class period_type, class duration_type, class facet_type>
120 period_type get_period(stream_itr_type& sitr,
121 stream_itr_type& stream_end,
122 std::ios_base& a_ios,
123 const period_type& /* p */,
124 const duration_type& dur_unit,
125 const facet_type& facet) const
126 {
127 // skip leading whitespace
128 while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
129
130 typedef typename period_type::point_type point_type;
131 point_type p1(not_a_date_time), p2(not_a_date_time);
132
133
134 consume_delim(sitr, stream_end, delim: delimiters[START]); // start delim
135 facet.get(sitr, stream_end, a_ios, p1); // first point
136 consume_delim(sitr, stream_end, delim: delimiters[SEPARATOR]); // separator
137 facet.get(sitr, stream_end, a_ios, p2); // second point
138
139 // period construction parameters are always open range [begin, end)
140 if (m_range_option == AS_CLOSED_RANGE) {
141 consume_delim(sitr, stream_end, delim: delimiters[CLOSED_END]);// end delim
142 // add 1 duration unit to p2 to make range open
143 p2 += dur_unit;
144 }
145 else {
146 consume_delim(sitr, stream_end, delim: delimiters[OPEN_END]); // end delim
147 }
148
149 return period_type(p1, p2);
150 }
151
152 private:
153 collection_type delimiters;
154 period_range_option m_range_option;
155
156 enum delim_ids { SEPARATOR, START, OPEN_END, CLOSED_END };
157
158 //! throws ios_base::failure if delimiter and parsed data do not match
159 void consume_delim(stream_itr_type& sitr,
160 stream_itr_type& stream_end,
161 const string_type& delim) const
162 {
163 /* string_parse_tree will not parse a string of punctuation characters
164 * without knowing exactly how many characters to process
165 * Ex [2000. Will not parse out the '[' string without knowing
166 * to process only one character. By using length of the delimiter
167 * string we can safely iterate past it. */
168 string_type s;
169 for(unsigned int i = 0; i < delim.length() && sitr != stream_end; ++i) {
170 s += *sitr;
171 ++sitr;
172 }
173 if(s != delim) {
174 boost::throw_exception(e: std::ios_base::failure("Parse failed. Expected '"
175 + convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'"));
176 }
177 }
178 };
179
180 template <class date_type, class char_type>
181 const typename period_parser<date_type, char_type>::char_type
182 period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
183
184 template <class date_type, class char_type>
185 const typename period_parser<date_type, char_type>::char_type
186 period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
187
188 template <class date_type, class char_type>
189 const typename period_parser<date_type, char_type>::char_type
190 period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
191
192 template <class date_type, class char_type>
193 const typename period_parser<date_type, char_type>::char_type
194 period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
195
196 } } //namespace boost::date_time
197
198#endif // DATETIME_PERIOD_PARSER_HPP___
199

source code of boost/boost/date_time/period_parser.hpp