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- #ifndef DATETIME_PERIOD_PARSER_HPP___
- #define DATETIME_PERIOD_PARSER_HPP___
- /* Copyright (c) 2002-2004 CrystalClear Software, Inc.
- * Use, modification and distribution is subject to the
- * Boost Software License, Version 1.0. (See accompanying
- * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
- * Author: Jeff Garland, Bart Garst
- * $Date$
- */
- #include <ios>
- #include <string>
- #include <vector>
- #include <iterator>
- #include <boost/throw_exception.hpp>
- #include <boost/date_time/special_defs.hpp>
- #include <boost/date_time/string_parse_tree.hpp>
- #include <boost/date_time/string_convert.hpp>
- namespace boost { namespace date_time {
- //! Not a facet, but a class used to specify and control period parsing
- /*! Provides settings for the following:
- * - period_separator -- default '/'
- * - period_open_start_delimeter -- default '['
- * - period_open_range_end_delimeter -- default ')'
- * - period_closed_range_end_delimeter -- default ']'
- * - display_as_open_range, display_as_closed_range -- default closed_range
- *
- * For a typical date_period, the contents of the input stream would be
- *@code
- * [2004-Jan-04/2004-Feb-01]
- *@endcode
- * where the date format is controlled by the date facet
- */
- template<class date_type, typename CharT>
- class period_parser {
- public:
- typedef std::basic_string<CharT> string_type;
- typedef CharT char_type;
- //typedef typename std::basic_string<char_type>::const_iterator const_itr_type;
- typedef std::istreambuf_iterator<CharT> stream_itr_type;
- typedef string_parse_tree<CharT> parse_tree_type;
- typedef typename parse_tree_type::parse_match_result_type match_results;
- typedef std::vector<std::basic_string<CharT> > collection_type;
- static const char_type default_period_separator[2];
- static const char_type default_period_start_delimeter[2];
- static const char_type default_period_open_range_end_delimeter[2];
- static const char_type default_period_closed_range_end_delimeter[2];
- enum period_range_option { AS_OPEN_RANGE, AS_CLOSED_RANGE };
- //! Constructor that sets up period parser options
- period_parser(period_range_option range_opt = AS_CLOSED_RANGE,
- const char_type* const period_separator = default_period_separator,
- const char_type* const period_start_delimeter = default_period_start_delimeter,
- const char_type* const period_open_range_end_delimeter = default_period_open_range_end_delimeter,
- const char_type* const period_closed_range_end_delimeter = default_period_closed_range_end_delimeter)
- : m_range_option(range_opt)
- {
- delimiters.push_back(string_type(period_separator));
- delimiters.push_back(string_type(period_start_delimeter));
- delimiters.push_back(string_type(period_open_range_end_delimeter));
- delimiters.push_back(string_type(period_closed_range_end_delimeter));
- }
- period_range_option range_option() const
- {
- return m_range_option;
- }
- void range_option(period_range_option option)
- {
- m_range_option = option;
- }
- collection_type delimiter_strings() const
- {
- return delimiters;
- }
- void delimiter_strings(const string_type& separator,
- const string_type& start_delim,
- const string_type& open_end_delim,
- const string_type& closed_end_delim)
- {
- delimiters.clear();
- delimiters.push_back(separator);
- delimiters.push_back(start_delim);
- delimiters.push_back(open_end_delim);
- delimiters.push_back(closed_end_delim);
- }
- //! Generic code to parse a period -- no matter the period type.
- /*! This generic code will parse any period using a facet to
- * to get the 'elements'. For example, in the case of a date_period
- * the elements will be instances of a date which will be parsed
- * according the to setup in the passed facet parameter.
- *
- * The steps for parsing a period are always the same:
- * - consume the start delimiter
- * - get start element
- * - consume the separator
- * - get either last or end element depending on range settings
- * - consume the end delimeter depending on range settings
- *
- * Thus for a typical date period the contents of the input stream
- * might look like this:
- *@code
- *
- * [March 01, 2004/June 07, 2004] <-- closed range
- * [March 01, 2004/June 08, 2004) <-- open range
- *
- *@endcode
- */
- template<class period_type, class duration_type, class facet_type>
- period_type get_period(stream_itr_type& sitr,
- stream_itr_type& stream_end,
- std::ios_base& a_ios,
- const period_type& /* p */,
- const duration_type& dur_unit,
- const facet_type& facet) const
- {
- // skip leading whitespace
- while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
- typedef typename period_type::point_type point_type;
- point_type p1(not_a_date_time), p2(not_a_date_time);
- consume_delim(sitr, stream_end, delimiters[START]); // start delim
- facet.get(sitr, stream_end, a_ios, p1); // first point
- consume_delim(sitr, stream_end, delimiters[SEPARATOR]); // separator
- facet.get(sitr, stream_end, a_ios, p2); // second point
- // period construction parameters are always open range [begin, end)
- if (m_range_option == AS_CLOSED_RANGE) {
- consume_delim(sitr, stream_end, delimiters[CLOSED_END]);// end delim
- // add 1 duration unit to p2 to make range open
- p2 += dur_unit;
- }
- else {
- consume_delim(sitr, stream_end, delimiters[OPEN_END]); // end delim
- }
- return period_type(p1, p2);
- }
- private:
- collection_type delimiters;
- period_range_option m_range_option;
- enum delim_ids { SEPARATOR, START, OPEN_END, CLOSED_END };
- //! throws ios_base::failure if delimiter and parsed data do not match
- void consume_delim(stream_itr_type& sitr,
- stream_itr_type& stream_end,
- const string_type& delim) const
- {
- /* string_parse_tree will not parse a string of punctuation characters
- * without knowing exactly how many characters to process
- * Ex [2000. Will not parse out the '[' string without knowing
- * to process only one character. By using length of the delimiter
- * string we can safely iterate past it. */
- string_type s;
- for(unsigned int i = 0; i < delim.length() && sitr != stream_end; ++i) {
- s += *sitr;
- ++sitr;
- }
- if(s != delim) {
- boost::throw_exception(std::ios_base::failure("Parse failed. Expected '"
- + convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'"));
- }
- }
- };
- template <class date_type, class char_type>
- const typename period_parser<date_type, char_type>::char_type
- period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
- template <class date_type, class char_type>
- const typename period_parser<date_type, char_type>::char_type
- period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
- template <class date_type, class char_type>
- const typename period_parser<date_type, char_type>::char_type
- period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
- template <class date_type, class char_type>
- const typename period_parser<date_type, char_type>::char_type
- period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
- } } //namespace boost::date_time
- #endif // DATETIME_PERIOD_PARSER_HPP___
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