Chris@16: 
Chris@16: #ifndef DATETIME_PERIOD_PARSER_HPP___
Chris@16: #define DATETIME_PERIOD_PARSER_HPP___
Chris@16: 
Chris@16: /* Copyright (c) 2002-2004 CrystalClear Software, Inc.
Chris@16:  * Use, modification and distribution is subject to the 
Chris@16:  * Boost Software License, Version 1.0. (See accompanying
Chris@16:  * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  * Author: Jeff Garland, Bart Garst
Chris@101:  * $Date$
Chris@16:  */
Chris@16: 
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/date_time/string_parse_tree.hpp>
Chris@16: #include <boost/date_time/string_convert.hpp>
Chris@16: 
Chris@16: 
Chris@16: namespace boost { namespace date_time {
Chris@16: 
Chris@16: 
Chris@16:   //! Not a facet, but a class used to specify and control period parsing 
Chris@16:   /*! Provides settings for the following:
Chris@16:    *   - period_separator -- default '/'
Chris@16:    *   - period_open_start_delimeter -- default '['
Chris@16:    *   - period_open_range_end_delimeter -- default ')' 
Chris@16:    *   - period_closed_range_end_delimeter -- default ']' 
Chris@16:    *   - display_as_open_range, display_as_closed_range -- default closed_range
Chris@16:    *
Chris@16:    *  For a typical date_period, the contents of the input stream would be
Chris@16:    *@code
Chris@16:    *  [2004-Jan-04/2004-Feb-01]
Chris@16:    *@endcode
Chris@16:    * where the date format is controlled by the date facet
Chris@16:    */
Chris@16:   template<class date_type, typename CharT>
Chris@16:   class period_parser {
Chris@16:   public:
Chris@16:     typedef std::basic_string<CharT> string_type;
Chris@16:     typedef CharT                    char_type;
Chris@16:     //typedef typename std::basic_string<char_type>::const_iterator const_itr_type;
Chris@16:     typedef std::istreambuf_iterator<CharT> stream_itr_type;
Chris@16:     typedef string_parse_tree<CharT> parse_tree_type;
Chris@16:     typedef typename parse_tree_type::parse_match_result_type match_results;
Chris@16:     typedef std::vector<std::basic_string<CharT> > collection_type;
Chris@16: 
Chris@16:     static const char_type default_period_separator[2];
Chris@16:     static const char_type default_period_start_delimeter[2];
Chris@16:     static const char_type default_period_open_range_end_delimeter[2];
Chris@16:     static const char_type default_period_closed_range_end_delimeter[2];
Chris@16: 
Chris@16:     enum period_range_option { AS_OPEN_RANGE, AS_CLOSED_RANGE };
Chris@16: 
Chris@16:     //! Constructor that sets up period parser options
Chris@16:     period_parser(period_range_option range_opt = AS_CLOSED_RANGE,
Chris@16:                   const char_type* const period_separator = default_period_separator,
Chris@16:                   const char_type* const period_start_delimeter = default_period_start_delimeter,
Chris@16:                   const char_type* const period_open_range_end_delimeter = default_period_open_range_end_delimeter,
Chris@16:                   const char_type* const period_closed_range_end_delimeter = default_period_closed_range_end_delimeter)
Chris@16:       : m_range_option(range_opt)
Chris@16:     {
Chris@16:       delimiters.push_back(string_type(period_separator));
Chris@16:       delimiters.push_back(string_type(period_start_delimeter));
Chris@16:       delimiters.push_back(string_type(period_open_range_end_delimeter));
Chris@16:       delimiters.push_back(string_type(period_closed_range_end_delimeter));
Chris@16:     }
Chris@16: 
Chris@16:     period_parser(const period_parser<date_type,CharT>& p_parser)
Chris@16:     {
Chris@16:       this->delimiters = p_parser.delimiters;
Chris@16:       this->m_range_option = p_parser.m_range_option;
Chris@16:     }
Chris@16: 
Chris@16:     period_range_option range_option() const
Chris@16:     {
Chris@16:       return m_range_option;
Chris@16:     }
Chris@16:     void range_option(period_range_option option)
Chris@16:     {
Chris@16:       m_range_option = option;
Chris@16:     }
Chris@16:     collection_type delimiter_strings() const
Chris@16:     {
Chris@16:       return delimiters;
Chris@16:     }
Chris@16:     void delimiter_strings(const string_type& separator,
Chris@16:                            const string_type& start_delim,
Chris@16:                            const string_type& open_end_delim,
Chris@16:                            const string_type& closed_end_delim)
Chris@16:     {
Chris@16:       delimiters.clear();
Chris@16:       delimiters.push_back(separator);
Chris@16:       delimiters.push_back(start_delim);
Chris@16:       delimiters.push_back(open_end_delim);
Chris@16:       delimiters.push_back(closed_end_delim);
Chris@16:     }
Chris@16: 
Chris@16:     //! Generic code to parse a period -- no matter the period type.
Chris@16:     /*! This generic code will parse any period using a facet to
Chris@16:      *  to get the 'elements'.  For example, in the case of a date_period
Chris@16:      *  the elements will be instances of a date which will be parsed
Chris@16:      *  according the to setup in the passed facet parameter.
Chris@16:      * 
Chris@16:      *  The steps for parsing a period are always the same:
Chris@16:      *  - consume the start delimiter
Chris@16:      *  - get start element
Chris@16:      *  - consume the separator 
Chris@16:      *  - get either last or end element depending on range settings
Chris@16:      *  - consume the end delimeter depending on range settings
Chris@16:      *
Chris@16:      *  Thus for a typical date period the contents of the input stream
Chris@16:      *  might look like this:
Chris@16:      *@code
Chris@16:      *
Chris@16:      *    [March 01, 2004/June 07, 2004]   <-- closed range
Chris@16:      *    [March 01, 2004/June 08, 2004)   <-- open range
Chris@16:      *
Chris@16:      *@endcode
Chris@16:      */
Chris@16:     template<class period_type, class duration_type, class facet_type>
Chris@16:     period_type get_period(stream_itr_type& sitr, 
Chris@16:                            stream_itr_type& stream_end,
Chris@16:                            std::ios_base& a_ios, 
Chris@16:                            const period_type& /* p */,
Chris@16:                            const duration_type& dur_unit,
Chris@16:                            const facet_type& facet) const 
Chris@16:     {
Chris@16:       // skip leading whitespace
Chris@16:       while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; } 
Chris@16: 
Chris@16:       typedef typename period_type::point_type point_type;
Chris@16:       point_type p1(not_a_date_time), p2(not_a_date_time);
Chris@16: 
Chris@16: 
Chris@16:       consume_delim(sitr, stream_end, delimiters[START]);       // start delim
Chris@16:       facet.get(sitr, stream_end, a_ios, p1);                   // first point
Chris@16:       consume_delim(sitr, stream_end, delimiters[SEPARATOR]);   // separator
Chris@16:       facet.get(sitr, stream_end, a_ios, p2);                   // second point
Chris@16: 
Chris@16:       // period construction parameters are always open range [begin, end)
Chris@16:       if (m_range_option == AS_CLOSED_RANGE) {
Chris@16:         consume_delim(sitr, stream_end, delimiters[CLOSED_END]);// end delim
Chris@16:         // add 1 duration unit to p2 to make range open
Chris@16:         p2 += dur_unit;
Chris@16:       }
Chris@16:       else {
Chris@16:         consume_delim(sitr, stream_end, delimiters[OPEN_END]);  // end delim
Chris@16:       }
Chris@16: 
Chris@16:       return period_type(p1, p2);
Chris@16:     }
Chris@16: 
Chris@16:   private:
Chris@16:     collection_type delimiters; 
Chris@16:     period_range_option m_range_option;
Chris@16: 
Chris@16:     enum delim_ids { SEPARATOR, START, OPEN_END, CLOSED_END };
Chris@16: 
Chris@16:     //! throws ios_base::failure if delimiter and parsed data do not match
Chris@16:     void consume_delim(stream_itr_type& sitr,
Chris@16:                        stream_itr_type& stream_end,
Chris@16:                        const string_type& delim) const
Chris@16:     {
Chris@16:       /* string_parse_tree will not parse a string of punctuation characters 
Chris@16:        * without knowing exactly how many characters to process
Chris@16:        * Ex [2000. Will not parse out the '[' string without knowing 
Chris@16:        * to process only one character. By using length of the delimiter 
Chris@16:        * string we can safely iterate past it. */
Chris@16:       string_type s;
Chris@16:       for(unsigned int i = 0; i < delim.length() && sitr != stream_end; ++i) {
Chris@16:         s += *sitr;
Chris@16:         ++sitr;
Chris@16:       }
Chris@16:       if(s != delim) {
Chris@16:         boost::throw_exception(std::ios_base::failure("Parse failed. Expected '"
Chris@16:           + convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'"));
Chris@16:       }
Chris@16:     }
Chris@16:   };
Chris@16: 
Chris@16:   template <class date_type, class char_type>  
Chris@16:   const typename period_parser<date_type, char_type>::char_type 
Chris@16:   period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
Chris@16: 
Chris@16:   template <class date_type, class char_type>  
Chris@16:   const typename period_parser<date_type, char_type>::char_type 
Chris@16:   period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
Chris@16: 
Chris@16:   template <class date_type, class char_type>  
Chris@16:   const typename period_parser<date_type, char_type>::char_type 
Chris@16:   period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
Chris@16: 
Chris@16:   template <class date_type, class char_type>  
Chris@16:   const typename period_parser<date_type, char_type>::char_type 
Chris@16:   period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
Chris@16: 
Chris@16:  } } //namespace boost::date_time
Chris@16: 
Chris@16: #endif // DATETIME_PERIOD_PARSER_HPP___