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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.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 28 : 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 14 : : m_range_option(range_opt)
65 14 : {
66 14 : delimiters.push_back(string_type(period_separator));
67 14 : delimiters.push_back(string_type(period_start_delimeter));
68 14 : delimiters.push_back(string_type(period_open_range_end_delimeter));
69 14 : delimiters.push_back(string_type(period_closed_range_end_delimeter));
70 28 : }
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 : boost::throw_exception(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___
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