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_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 | |