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
23namespace 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, delim: delimiters[START]); // start delim
134 facet.get(sitr, stream_end, a_ios, p1); // first point
135 consume_delim(sitr, stream_end, delim: 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, delim: 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, delim: 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(e: 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___
198

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