| 1 | #ifndef DATE_TIME_DATE_GENERATORS_HPP__ |
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| 2 | #define DATE_TIME_DATE_GENERATORS_HPP__ |
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| 3 | |
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| 4 | /* Copyright (c) 2002,2003,2005 CrystalClear Software, Inc. |
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| 5 | * Use, modification and distribution is subject to the |
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| 6 | * Boost Software License, Version 1.0. (See accompanying |
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| 7 | * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt) |
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| 8 | * Author: Jeff Garland, Bart Garst |
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| 9 | * $Date$ |
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| 10 | */ |
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| 11 | |
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| 12 | /*! @file date_generators.hpp |
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| 13 | Definition and implementation of date algorithm templates |
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| 14 | */ |
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| 15 | |
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| 16 | #include <stdexcept> |
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| 17 | #include <sstream> |
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| 18 | #include <boost/throw_exception.hpp> |
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| 19 | #include <boost/date_time/date.hpp> |
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| 20 | #include <boost/date_time/compiler_config.hpp> |
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| 21 | |
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| 22 | namespace boost { |
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| 23 | namespace date_time { |
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| 24 | |
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| 25 | //! Base class for all generators that take a year and produce a date. |
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| 26 | /*! This class is a base class for polymorphic function objects that take |
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| 27 | a year and produce a concrete date. |
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| 28 | @param date_type The type representing a date. This type must |
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| 29 | export a calender_type which defines a year_type. |
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| 30 | */ |
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| 31 | template<class date_type> |
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| 32 | class year_based_generator |
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| 33 | { |
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| 34 | public: |
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| 35 | typedef typename date_type::calendar_type calendar_type; |
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| 36 | typedef typename calendar_type::year_type year_type; |
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| 37 | year_based_generator() {} |
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| 38 | virtual ~year_based_generator() {} |
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| 39 | virtual date_type get_date(year_type y) const = 0; |
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| 40 | //! Returns a string for use in a POSIX time_zone string |
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| 41 | virtual std::string to_string() const =0; |
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| 42 | }; |
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| 43 | |
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| 44 | //! Generates a date by applying the year to the given month and day. |
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| 45 | /*! |
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| 46 | Example usage: |
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| 47 | @code |
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| 48 | partial_date pd(1, Jan); |
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| 49 | partial_date pd2(70); |
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| 50 | date d = pd.get_date(2002); //2002-Jan-01 |
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| 51 | date d2 = pd2.get_date(2002); //2002-Mar-10 |
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| 52 | @endcode |
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| 53 | \ingroup date_alg |
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| 54 | */ |
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| 55 | template<class date_type> |
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| 56 | class partial_date : public year_based_generator<date_type> |
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| 57 | { |
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| 58 | public: |
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| 59 | typedef typename date_type::calendar_type calendar_type; |
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| 60 | typedef typename calendar_type::day_type day_type; |
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| 61 | typedef typename calendar_type::month_type month_type; |
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| 62 | typedef typename calendar_type::year_type year_type; |
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| 63 | typedef typename date_type::duration_type duration_type; |
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| 64 | typedef typename duration_type::duration_rep duration_rep; |
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| 65 | partial_date(day_type d, month_type m) : |
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| 66 | day_(d), |
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| 67 | month_(m) |
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| 68 | {} |
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| 69 | //! Partial date created from number of days into year. Range 1-366 |
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| 70 | /*! Allowable values range from 1 to 366. 1=Jan1, 366=Dec31. If argument |
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| 71 | * exceeds range, partial_date will be created with closest in-range value. |
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| 72 | * 60 will always be Feb29, if get_date() is called with a non-leap year |
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| 73 | * an exception will be thrown */ |
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| 74 | partial_date(duration_rep days) : |
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| 75 | day_(1), // default values |
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| 76 | month_(1) |
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| 77 | { |
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| 78 | date_type d1(2000,1,1); |
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| 79 | if(days > 1) { |
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| 80 | if(days > 366) // prevents wrapping |
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| 81 | { |
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| 82 | days = 366; |
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| 83 | } |
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| 84 | days = days - 1; |
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| 85 | duration_type dd(days); |
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| 86 | d1 = d1 + dd; |
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| 87 | } |
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| 88 | day_ = d1.day(); |
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| 89 | month_ = d1.month(); |
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| 90 | } |
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| 91 | //! Return a concrete date when provided with a year specific year. |
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| 92 | /*! Will throw an 'invalid_argument' exception if a partial_date object, |
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| 93 | * instantiated with Feb-29, has get_date called with a non-leap year. |
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| 94 | * Example: |
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| 95 | * @code |
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| 96 | * partial_date pd(29, Feb); |
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| 97 | * pd.get_date(2003); // throws invalid_argument exception |
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| 98 | * pg.get_date(2000); // returns 2000-2-29 |
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| 99 | * @endcode |
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| 100 | */ |
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| 101 | date_type get_date(year_type y) const |
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| 102 | { |
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| 103 | if((day_ == 29) && (month_ == 2) && !(calendar_type::is_leap_year(y))) { |
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| 104 | std::ostringstream ss; |
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| 105 | ss << "No Feb 29th in given year of " << y << "." ; |
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| 106 | boost::throw_exception(e: std::invalid_argument(ss.str())); |
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| 107 | } |
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| 108 | return date_type(y, month_, day_); |
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| 109 | } |
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| 110 | date_type operator()(year_type y) const |
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| 111 | { |
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| 112 | return get_date(y); |
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| 113 | //return date_type(y, month_, day_); |
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| 114 | } |
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| 115 | bool operator==(const partial_date& rhs) const |
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| 116 | { |
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| 117 | return (month_ == rhs.month_) && (day_ == rhs.day_); |
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| 118 | } |
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| 119 | bool operator<(const partial_date& rhs) const |
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| 120 | { |
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| 121 | if (month_ < rhs.month_) return true; |
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| 122 | if (month_ > rhs.month_) return false; |
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| 123 | //months are equal |
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| 124 | return (day_ < rhs.day_); |
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| 125 | } |
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| 126 | |
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| 127 | // added for streaming purposes |
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| 128 | month_type month() const |
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| 129 | { |
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| 130 | return month_; |
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| 131 | } |
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| 132 | day_type day() const |
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| 133 | { |
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| 134 | return day_; |
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| 135 | } |
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| 136 | |
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| 137 | //! Returns string suitable for use in POSIX time zone string |
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| 138 | /*! Returns string formatted with up to 3 digits: |
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| 139 | * Jan-01 == "0" |
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| 140 | * Feb-29 == "58" |
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| 141 | * Dec-31 == "365" */ |
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| 142 | virtual std::string to_string() const |
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| 143 | { |
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| 144 | std::ostringstream ss; |
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| 145 | date_type d(2004, month_, day_); |
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| 146 | unsigned short c = d.day_of_year(); |
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| 147 | c--; // numbered 0-365 while day_of_year is 1 based... |
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| 148 | ss << c; |
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| 149 | return ss.str(); |
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| 150 | } |
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| 151 | private: |
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| 152 | day_type day_; |
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| 153 | month_type month_; |
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| 154 | }; |
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| 155 | |
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| 156 | |
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| 157 | //! Returns nth arg as string. 1 -> "first", 2 -> "second", max is 5. |
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| 158 | BOOST_DATE_TIME_DECL const char* nth_as_str(int n); |
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| 159 | |
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| 160 | //! Useful generator functor for finding holidays |
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| 161 | /*! Based on the idea in Cal. Calc. for finding holidays that are |
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| 162 | * the 'first Monday of September'. When instantiated with |
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| 163 | * 'fifth' kday of month, the result will be the last kday of month |
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| 164 | * which can be the fourth or fifth depending on the structure of |
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| 165 | * the month. |
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| 166 | * |
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| 167 | * The algorithm here basically guesses for the first |
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| 168 | * day of the month. Then finds the first day of the correct |
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| 169 | * type. That is, if the first of the month is a Tuesday |
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| 170 | * and it needs Wenesday then we simply increment by a day |
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| 171 | * and then we can add the length of a week until we get |
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| 172 | * to the 'nth kday'. There are probably more efficient |
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| 173 | * algorithms based on using a mod 7, but this one works |
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| 174 | * reasonably well for basic applications. |
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| 175 | * \ingroup date_alg |
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| 176 | */ |
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| 177 | template<class date_type> |
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| 178 | class nth_kday_of_month : public year_based_generator<date_type> |
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| 179 | { |
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| 180 | public: |
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| 181 | typedef typename date_type::calendar_type calendar_type; |
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| 182 | typedef typename calendar_type::day_of_week_type day_of_week_type; |
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| 183 | typedef typename calendar_type::month_type month_type; |
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| 184 | typedef typename calendar_type::year_type year_type; |
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| 185 | typedef typename date_type::duration_type duration_type; |
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| 186 | enum week_num {first=1, second, third, fourth, fifth}; |
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| 187 | nth_kday_of_month(week_num week_no, |
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| 188 | day_of_week_type dow, |
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| 189 | month_type m) : |
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| 190 | month_(m), |
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| 191 | wn_(week_no), |
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| 192 | dow_(dow) |
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| 193 | {} |
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| 194 | //! Return a concrete date when provided with a year specific year. |
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| 195 | date_type get_date(year_type y) const |
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| 196 | { |
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| 197 | date_type d(y, month_, 1); //first day of month |
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| 198 | duration_type one_day(1); |
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| 199 | duration_type one_week(7); |
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| 200 | while (dow_ != d.day_of_week()) { |
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| 201 | d = d + one_day; |
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| 202 | } |
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| 203 | int week = 1; |
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| 204 | while (week < wn_) { |
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| 205 | d = d + one_week; |
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| 206 | week++; |
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| 207 | } |
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| 208 | // remove wrapping to next month behavior |
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| 209 | if(d.month() != month_) { |
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| 210 | d = d - one_week; |
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| 211 | } |
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| 212 | return d; |
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| 213 | } |
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| 214 | // added for streaming |
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| 215 | month_type month() const |
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| 216 | { |
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| 217 | return month_; |
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| 218 | } |
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| 219 | week_num nth_week() const |
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| 220 | { |
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| 221 | return wn_; |
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| 222 | } |
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| 223 | day_of_week_type day_of_week() const |
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| 224 | { |
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| 225 | return dow_; |
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| 226 | } |
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| 227 | const char* nth_week_as_str() const |
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| 228 | { |
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| 229 | return nth_as_str(wn_); |
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| 230 | } |
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| 231 | //! Returns string suitable for use in POSIX time zone string |
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| 232 | /*! Returns a string formatted as "M4.3.0" ==> 3rd Sunday in April. */ |
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| 233 | virtual std::string to_string() const |
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| 234 | { |
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| 235 | std::ostringstream ss; |
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| 236 | ss << 'M' |
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| 237 | << static_cast<int>(month_) << '.' |
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| 238 | << static_cast<int>(wn_) << '.' |
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| 239 | << static_cast<int>(dow_); |
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| 240 | return ss.str(); |
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| 241 | } |
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| 242 | private: |
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| 243 | month_type month_; |
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| 244 | week_num wn_; |
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| 245 | day_of_week_type dow_; |
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| 246 | }; |
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| 247 | |
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| 248 | //! Useful generator functor for finding holidays and daylight savings |
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| 249 | /*! Similar to nth_kday_of_month, but requires less paramters |
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| 250 | * \ingroup date_alg |
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| 251 | */ |
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| 252 | template<class date_type> |
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| 253 | class first_kday_of_month : public year_based_generator<date_type> |
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| 254 | { |
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| 255 | public: |
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| 256 | typedef typename date_type::calendar_type calendar_type; |
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| 257 | typedef typename calendar_type::day_of_week_type day_of_week_type; |
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| 258 | typedef typename calendar_type::month_type month_type; |
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| 259 | typedef typename calendar_type::year_type year_type; |
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| 260 | typedef typename date_type::duration_type duration_type; |
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| 261 | //!Specify the first 'Sunday' in 'April' spec |
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| 262 | /*!@param dow The day of week, eg: Sunday, Monday, etc |
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| 263 | * @param m The month of the year, eg: Jan, Feb, Mar, etc |
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| 264 | */ |
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| 265 | first_kday_of_month(day_of_week_type dow, month_type m) : |
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| 266 | month_(m), |
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| 267 | dow_(dow) |
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| 268 | {} |
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| 269 | //! Return a concrete date when provided with a year specific year. |
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| 270 | date_type get_date(year_type year) const |
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| 271 | { |
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| 272 | date_type d(year, month_,1); |
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| 273 | duration_type one_day(1); |
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| 274 | while (dow_ != d.day_of_week()) { |
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| 275 | d = d + one_day; |
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| 276 | } |
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| 277 | return d; |
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| 278 | } |
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| 279 | // added for streaming |
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| 280 | month_type month() const |
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| 281 | { |
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| 282 | return month_; |
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| 283 | } |
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| 284 | day_of_week_type day_of_week() const |
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| 285 | { |
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| 286 | return dow_; |
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| 287 | } |
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| 288 | //! Returns string suitable for use in POSIX time zone string |
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| 289 | /*! Returns a string formatted as "M4.1.0" ==> 1st Sunday in April. */ |
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| 290 | virtual std::string to_string() const |
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| 291 | { |
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| 292 | std::ostringstream ss; |
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| 293 | ss << 'M' |
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| 294 | << static_cast<int>(month_) << '.' |
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| 295 | << 1 << '.' |
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| 296 | << static_cast<int>(dow_); |
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| 297 | return ss.str(); |
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| 298 | } |
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| 299 | private: |
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| 300 | month_type month_; |
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| 301 | day_of_week_type dow_; |
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| 302 | }; |
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| 303 | |
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| 304 | |
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| 305 | |
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| 306 | //! Calculate something like Last Sunday of January |
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| 307 | /*! Useful generator functor for finding holidays and daylight savings |
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| 308 | * Get the last day of the month and then calculate the difference |
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| 309 | * to the last previous day. |
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| 310 | * @param date_type A date class that exports day_of_week, month_type, etc. |
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| 311 | * \ingroup date_alg |
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| 312 | */ |
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| 313 | template<class date_type> |
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| 314 | class last_kday_of_month : public year_based_generator<date_type> |
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| 315 | { |
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| 316 | public: |
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| 317 | typedef typename date_type::calendar_type calendar_type; |
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| 318 | typedef typename calendar_type::day_of_week_type day_of_week_type; |
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| 319 | typedef typename calendar_type::month_type month_type; |
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| 320 | typedef typename calendar_type::year_type year_type; |
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| 321 | typedef typename date_type::duration_type duration_type; |
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| 322 | //!Specify the date spec like last 'Sunday' in 'April' spec |
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| 323 | /*!@param dow The day of week, eg: Sunday, Monday, etc |
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| 324 | * @param m The month of the year, eg: Jan, Feb, Mar, etc |
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| 325 | */ |
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| 326 | last_kday_of_month(day_of_week_type dow, month_type m) : |
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| 327 | month_(m), |
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| 328 | dow_(dow) |
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| 329 | {} |
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| 330 | //! Return a concrete date when provided with a year specific year. |
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| 331 | date_type get_date(year_type year) const |
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| 332 | { |
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| 333 | date_type d(year, month_, calendar_type::end_of_month_day(year,month_)); |
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| 334 | duration_type one_day(1); |
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| 335 | while (dow_ != d.day_of_week()) { |
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| 336 | d = d - one_day; |
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| 337 | } |
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| 338 | return d; |
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| 339 | } |
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| 340 | // added for streaming |
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| 341 | month_type month() const |
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| 342 | { |
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| 343 | return month_; |
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| 344 | } |
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| 345 | day_of_week_type day_of_week() const |
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| 346 | { |
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| 347 | return dow_; |
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| 348 | } |
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| 349 | //! Returns string suitable for use in POSIX time zone string |
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| 350 | /*! Returns a string formatted as "M4.5.0" ==> last Sunday in April. */ |
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| 351 | virtual std::string to_string() const |
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| 352 | { |
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| 353 | std::ostringstream ss; |
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| 354 | ss << 'M' |
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| 355 | << static_cast<int>(month_) << '.' |
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| 356 | << 5 << '.' |
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| 357 | << static_cast<int>(dow_); |
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| 358 | return ss.str(); |
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| 359 | } |
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| 360 | private: |
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| 361 | month_type month_; |
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| 362 | day_of_week_type dow_; |
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| 363 | }; |
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| 364 | |
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| 365 | |
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| 366 | //! Calculate something like "First Sunday after Jan 1,2002 |
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| 367 | /*! Date generator that takes a date and finds kday after |
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| 368 | *@code |
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| 369 | typedef boost::date_time::first_kday_after<date> firstkdayafter; |
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| 370 | firstkdayafter fkaf(Monday); |
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| 371 | fkaf.get_date(date(2002,Feb,1)); |
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| 372 | @endcode |
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| 373 | * \ingroup date_alg |
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| 374 | */ |
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| 375 | template<class date_type> |
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| 376 | class first_kday_after |
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| 377 | { |
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| 378 | public: |
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| 379 | typedef typename date_type::calendar_type calendar_type; |
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| 380 | typedef typename calendar_type::day_of_week_type day_of_week_type; |
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| 381 | typedef typename date_type::duration_type duration_type; |
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| 382 | first_kday_after(day_of_week_type dow) : |
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| 383 | dow_(dow) |
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| 384 | {} |
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| 385 | //! Return next kday given. |
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| 386 | date_type get_date(date_type start_day) const |
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| 387 | { |
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| 388 | duration_type one_day(1); |
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| 389 | date_type d = start_day + one_day; |
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| 390 | while (dow_ != d.day_of_week()) { |
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| 391 | d = d + one_day; |
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| 392 | } |
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| 393 | return d; |
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| 394 | } |
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| 395 | // added for streaming |
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| 396 | day_of_week_type day_of_week() const |
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| 397 | { |
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| 398 | return dow_; |
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| 399 | } |
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| 400 | private: |
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| 401 | day_of_week_type dow_; |
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| 402 | }; |
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| 403 | |
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| 404 | //! Calculate something like "First Sunday before Jan 1,2002 |
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| 405 | /*! Date generator that takes a date and finds kday after |
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| 406 | *@code |
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| 407 | typedef boost::date_time::first_kday_before<date> firstkdaybefore; |
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| 408 | firstkdaybefore fkbf(Monday); |
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| 409 | fkbf.get_date(date(2002,Feb,1)); |
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| 410 | @endcode |
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| 411 | * \ingroup date_alg |
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| 412 | */ |
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| 413 | template<class date_type> |
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| 414 | class first_kday_before |
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| 415 | { |
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| 416 | public: |
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| 417 | typedef typename date_type::calendar_type calendar_type; |
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| 418 | typedef typename calendar_type::day_of_week_type day_of_week_type; |
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| 419 | typedef typename date_type::duration_type duration_type; |
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| 420 | first_kday_before(day_of_week_type dow) : |
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| 421 | dow_(dow) |
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| 422 | {} |
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| 423 | //! Return next kday given. |
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| 424 | date_type get_date(date_type start_day) const |
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| 425 | { |
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| 426 | duration_type one_day(1); |
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| 427 | date_type d = start_day - one_day; |
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| 428 | while (dow_ != d.day_of_week()) { |
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| 429 | d = d - one_day; |
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| 430 | } |
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| 431 | return d; |
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| 432 | } |
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| 433 | // added for streaming |
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| 434 | day_of_week_type day_of_week() const |
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| 435 | { |
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| 436 | return dow_; |
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| 437 | } |
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| 438 | private: |
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| 439 | day_of_week_type dow_; |
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| 440 | }; |
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| 441 | |
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| 442 | //! Calculates the number of days until the next weekday |
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| 443 | /*! Calculates the number of days until the next weekday. |
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| 444 | * If the date given falls on a Sunday and the given weekday |
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| 445 | * is Tuesday the result will be 2 days */ |
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| 446 | template<typename date_type, class weekday_type> |
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| 447 | inline |
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| 448 | typename date_type::duration_type days_until_weekday(const date_type& d, const weekday_type& wd) |
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| 449 | { |
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| 450 | typedef typename date_type::duration_type duration_type; |
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| 451 | duration_type wks(0); |
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| 452 | duration_type dd(wd.as_number() - d.day_of_week().as_number()); |
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| 453 | if(dd.is_negative()){ |
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| 454 | wks = duration_type(7); |
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| 455 | } |
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| 456 | return dd + wks; |
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| 457 | } |
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| 458 | |
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| 459 | //! Calculates the number of days since the previous weekday |
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| 460 | /*! Calculates the number of days since the previous weekday |
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| 461 | * If the date given falls on a Sunday and the given weekday |
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| 462 | * is Tuesday the result will be 5 days. The answer will be a positive |
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| 463 | * number because Tuesday is 5 days before Sunday, not -5 days before. */ |
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| 464 | template<typename date_type, class weekday_type> |
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| 465 | inline |
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| 466 | typename date_type::duration_type days_before_weekday(const date_type& d, const weekday_type& wd) |
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| 467 | { |
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| 468 | typedef typename date_type::duration_type duration_type; |
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| 469 | duration_type wks(0); |
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| 470 | duration_type dd(wd.as_number() - d.day_of_week().as_number()); |
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| 471 | if(dd.days() > 0){ |
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| 472 | wks = duration_type(7); |
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| 473 | } |
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| 474 | // we want a number of days, not an offset. The value returned must |
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| 475 | // be zero or larger. |
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| 476 | return (-dd + wks); |
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| 477 | } |
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| 478 | |
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| 479 | //! Generates a date object representing the date of the following weekday from the given date |
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| 480 | /*! Generates a date object representing the date of the following |
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| 481 | * weekday from the given date. If the date given is 2004-May-9 |
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| 482 | * (a Sunday) and the given weekday is Tuesday then the resulting date |
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| 483 | * will be 2004-May-11. */ |
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| 484 | template<class date_type, class weekday_type> |
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| 485 | inline |
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| 486 | date_type next_weekday(const date_type& d, const weekday_type& wd) |
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| 487 | { |
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| 488 | return d + days_until_weekday(d, wd); |
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| 489 | } |
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| 490 | |
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| 491 | //! Generates a date object representing the date of the previous weekday from the given date |
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| 492 | /*! Generates a date object representing the date of the previous |
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| 493 | * weekday from the given date. If the date given is 2004-May-9 |
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| 494 | * (a Sunday) and the given weekday is Tuesday then the resulting date |
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| 495 | * will be 2004-May-4. */ |
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| 496 | template<class date_type, class weekday_type> |
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| 497 | inline |
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| 498 | date_type previous_weekday(const date_type& d, const weekday_type& wd) |
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| 499 | { |
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| 500 | return d - days_before_weekday(d, wd); |
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| 501 | } |
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| 502 | |
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| 503 | } } //namespace date_time |
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| 504 | |
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| 505 | |
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| 506 | |
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| 507 | |
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| 508 | #endif |
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| 509 | |
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| 510 | |
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