Chris@16: #ifndef DATE_TIME_DATE_GENERATORS_HPP__
Chris@16: #define DATE_TIME_DATE_GENERATORS_HPP__
Chris@16: 
Chris@16: /* Copyright (c) 2002,2003,2005 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: /*! @file date_generators.hpp
Chris@16:   Definition and implementation of date algorithm templates
Chris@16: */
Chris@16: 
Chris@16: #include <stdexcept>
Chris@16: #include <sstream>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/date_time/date.hpp>
Chris@16: #include <boost/date_time/compiler_config.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace date_time {
Chris@16: 
Chris@16:   //! Base class for all generators that take a year and produce a date.
Chris@16:   /*! This class is a base class for polymorphic function objects that take
Chris@16:     a year and produce a concrete date.
Chris@16:     @param date_type The type representing a date.  This type must
Chris@16:     export a calender_type which defines a year_type.
Chris@16:   */
Chris@16:   template<class date_type>
Chris@16:   class year_based_generator
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     typedef typename calendar_type::year_type        year_type;
Chris@16:     year_based_generator() {}
Chris@16:     virtual ~year_based_generator() {}
Chris@16:     virtual date_type get_date(year_type y) const = 0;
Chris@16:     //! Returns a string for use in a POSIX time_zone string
Chris@16:     virtual std::string to_string() const =0;
Chris@16:   };
Chris@16: 
Chris@16:   //! Generates a date by applying the year to the given month and day.
Chris@16:   /*!
Chris@16:     Example usage:
Chris@16:     @code
Chris@16:     partial_date pd(1, Jan);
Chris@16:     partial_date pd2(70);
Chris@16:     date d = pd.get_date(2002); //2002-Jan-01
Chris@16:     date d2 = pd2.get_date(2002); //2002-Mar-10
Chris@16:     @endcode
Chris@16:     \ingroup date_alg
Chris@16:   */
Chris@16:   template<class date_type>
Chris@16:  class partial_date : public year_based_generator<date_type>
Chris@16:  {
Chris@16:  public:
Chris@16:    typedef typename date_type::calendar_type calendar_type;
Chris@16:    typedef typename calendar_type::day_type         day_type;
Chris@16:    typedef typename calendar_type::month_type       month_type;
Chris@16:    typedef typename calendar_type::year_type        year_type;
Chris@16:    typedef typename date_type::duration_type        duration_type;
Chris@16:    typedef typename duration_type::duration_rep     duration_rep;
Chris@16:    partial_date(day_type d, month_type m) :
Chris@16:      day_(d),
Chris@16:      month_(m)
Chris@16:    {}
Chris@16:    //! Partial date created from number of days into year. Range 1-366
Chris@16:    /*! Allowable values range from 1 to 366. 1=Jan1, 366=Dec31. If argument
Chris@16:     * exceeds range, partial_date will be created with closest in-range value.
Chris@16:     * 60 will always be Feb29, if get_date() is called with a non-leap year
Chris@16:     * an exception will be thrown */
Chris@16:    partial_date(duration_rep days) :
Chris@16:      day_(1), // default values
Chris@16:      month_(1)
Chris@16:    {
Chris@16:      date_type d1(2000,1,1);
Chris@16:      if(days > 1) {
Chris@16:        if(days > 366) // prevents wrapping
Chris@16:        {
Chris@16:          days = 366;
Chris@16:        }
Chris@16:        days = days - 1;
Chris@16:        duration_type dd(days);
Chris@16:        d1 = d1 + dd;
Chris@16:      }
Chris@16:      day_ = d1.day();
Chris@16:      month_ = d1.month();
Chris@16:    }
Chris@16:    //! Return a concrete date when provided with a year specific year.
Chris@16:    /*! Will throw an 'invalid_argument' exception if a partial_date object,
Chris@16:     * instantiated with Feb-29, has get_date called with a non-leap year.
Chris@16:     * Example:
Chris@16:     * @code
Chris@16:     * partial_date pd(29, Feb);
Chris@16:     * pd.get_date(2003); // throws invalid_argument exception
Chris@16:     * pg.get_date(2000); // returns 2000-2-29
Chris@16:     * @endcode
Chris@16:          */
Chris@16:    date_type get_date(year_type y) const
Chris@16:    {
Chris@16:      if((day_ == 29) && (month_ == 2) && !(calendar_type::is_leap_year(y))) {
Chris@16:        std::ostringstream ss;
Chris@16:        ss << "No Feb 29th in given year of " << y << ".";
Chris@16:        boost::throw_exception(std::invalid_argument(ss.str()));
Chris@16:      }
Chris@16:      return date_type(y, month_, day_);
Chris@16:    }
Chris@16:    date_type operator()(year_type y) const
Chris@16:    {
Chris@16:      return get_date(y);
Chris@16:      //return date_type(y, month_, day_);
Chris@16:    }
Chris@16:    bool operator==(const partial_date& rhs) const
Chris@16:    {
Chris@16:      return (month_ == rhs.month_) && (day_ == rhs.day_);
Chris@16:    }
Chris@16:    bool operator<(const partial_date& rhs) const
Chris@16:    {
Chris@16:      if (month_ < rhs.month_) return true;
Chris@16:      if (month_ > rhs.month_) return false;
Chris@16:      //months are equal
Chris@16:      return (day_ < rhs.day_);
Chris@16:    }
Chris@16: 
Chris@16:    // added for streaming purposes
Chris@16:    month_type month() const
Chris@16:    {
Chris@16:      return month_;
Chris@16:    }
Chris@16:    day_type day() const
Chris@16:    {
Chris@16:      return day_;
Chris@16:    }
Chris@16: 
Chris@16:    //! Returns string suitable for use in POSIX time zone string
Chris@16:    /*! Returns string formatted with up to 3 digits:
Chris@16:     * Jan-01 == "0"
Chris@16:     * Feb-29 == "58"
Chris@16:     * Dec-31 == "365" */
Chris@16:    virtual std::string to_string() const
Chris@16:    {
Chris@16:      std::ostringstream ss;
Chris@16:      date_type d(2004, month_, day_);
Chris@16:      unsigned short c = d.day_of_year();
Chris@16:      c--; // numbered 0-365 while day_of_year is 1 based...
Chris@16:      ss << c;
Chris@16:      return ss.str();
Chris@16:    }
Chris@16:  private:
Chris@16:    day_type day_;
Chris@16:    month_type month_;
Chris@16:  };
Chris@16: 
Chris@16: 
Chris@16:   //! Returns nth arg as string. 1 -> "first", 2 -> "second", max is 5.
Chris@16:   BOOST_DATE_TIME_DECL const char* nth_as_str(int n);
Chris@16: 
Chris@16:   //! Useful generator functor for finding holidays
Chris@16:   /*! Based on the idea in Cal. Calc. for finding holidays that are
Chris@16:    *  the 'first Monday of September'. When instantiated with
Chris@16:    *  'fifth' kday of month, the result will be the last kday of month
Chris@16:    *  which can be the fourth or fifth depending on the structure of
Chris@16:    *  the month.
Chris@16:    *
Chris@16:    *  The algorithm here basically guesses for the first
Chris@16:    *  day of the month.  Then finds the first day of the correct
Chris@16:    *  type.  That is, if the first of the month is a Tuesday
Chris@16:    *  and it needs Wenesday then we simply increment by a day
Chris@16:    *  and then we can add the length of a week until we get
Chris@16:    *  to the 'nth kday'.  There are probably more efficient
Chris@16:    *  algorithms based on using a mod 7, but this one works
Chris@16:    *  reasonably well for basic applications.
Chris@16:    *  \ingroup date_alg
Chris@16:    */
Chris@16:   template<class date_type>
Chris@16:   class nth_kday_of_month : public year_based_generator<date_type>
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     typedef typename calendar_type::day_of_week_type  day_of_week_type;
Chris@16:     typedef typename calendar_type::month_type        month_type;
Chris@16:     typedef typename calendar_type::year_type         year_type;
Chris@16:     typedef typename date_type::duration_type        duration_type;
Chris@16:     enum week_num {first=1, second, third, fourth, fifth};
Chris@16:     nth_kday_of_month(week_num week_no,
Chris@16:                       day_of_week_type dow,
Chris@16:                       month_type m) :
Chris@16:       month_(m),
Chris@16:       wn_(week_no),
Chris@16:       dow_(dow)
Chris@16:     {}
Chris@16:     //! Return a concrete date when provided with a year specific year.
Chris@16:     date_type get_date(year_type y) const
Chris@16:     {
Chris@16:       date_type d(y, month_, 1); //first day of month
Chris@16:       duration_type one_day(1);
Chris@16:       duration_type one_week(7);
Chris@16:       while (dow_ != d.day_of_week()) {
Chris@16:         d = d + one_day;
Chris@16:       }
Chris@16:       int week = 1;
Chris@16:       while (week < wn_) {
Chris@16:         d = d + one_week;
Chris@16:         week++;
Chris@16:       }
Chris@16:       // remove wrapping to next month behavior
Chris@16:       if(d.month() != month_) {
Chris@16:         d = d - one_week;
Chris@16:       }
Chris@16:       return d;
Chris@16:     }
Chris@16:     // added for streaming
Chris@16:     month_type month() const
Chris@16:     {
Chris@16:       return month_;
Chris@16:     }
Chris@16:     week_num nth_week() const
Chris@16:     {
Chris@16:       return wn_;
Chris@16:     }
Chris@16:     day_of_week_type day_of_week() const
Chris@16:     {
Chris@16:       return dow_;
Chris@16:     }
Chris@16:     const char* nth_week_as_str() const
Chris@16:     {
Chris@16:       return nth_as_str(wn_);
Chris@16:     }
Chris@16:     //! Returns string suitable for use in POSIX time zone string
Chris@16:     /*! Returns a string formatted as "M4.3.0" ==> 3rd Sunday in April. */
Chris@16:     virtual std::string to_string() const
Chris@16:     {
Chris@16:      std::ostringstream ss;
Chris@16:      ss << 'M'
Chris@16:        << static_cast<int>(month_) << '.'
Chris@16:        << static_cast<int>(wn_) << '.'
Chris@16:        << static_cast<int>(dow_);
Chris@16:      return ss.str();
Chris@16:     }
Chris@16:   private:
Chris@16:     month_type month_;
Chris@16:     week_num wn_;
Chris@16:     day_of_week_type dow_;
Chris@16:   };
Chris@16: 
Chris@16:   //! Useful generator functor for finding holidays and daylight savings
Chris@16:   /*! Similar to nth_kday_of_month, but requires less paramters
Chris@16:    *  \ingroup date_alg
Chris@16:    */
Chris@16:   template<class date_type>
Chris@16:   class first_kday_of_month : public year_based_generator<date_type>
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     typedef typename calendar_type::day_of_week_type  day_of_week_type;
Chris@16:     typedef typename calendar_type::month_type        month_type;
Chris@16:     typedef typename calendar_type::year_type         year_type;
Chris@16:     typedef typename date_type::duration_type        duration_type;
Chris@16:     //!Specify the first 'Sunday' in 'April' spec
Chris@16:     /*!@param dow The day of week, eg: Sunday, Monday, etc
Chris@16:      * @param m The month of the year, eg: Jan, Feb, Mar, etc
Chris@16:      */
Chris@16:     first_kday_of_month(day_of_week_type dow, month_type m) :
Chris@16:       month_(m),
Chris@16:       dow_(dow)
Chris@16:     {}
Chris@16:     //! Return a concrete date when provided with a year specific year.
Chris@16:     date_type get_date(year_type year) const
Chris@16:     {
Chris@16:       date_type d(year, month_,1);
Chris@16:       duration_type one_day(1);
Chris@16:       while (dow_ != d.day_of_week()) {
Chris@16:         d = d + one_day;
Chris@16:       }
Chris@16:       return d;
Chris@16:     }
Chris@16:     // added for streaming
Chris@16:     month_type month() const
Chris@16:     {
Chris@16:       return month_;
Chris@16:     }
Chris@16:     day_of_week_type day_of_week() const
Chris@16:     {
Chris@16:       return dow_;
Chris@16:     }
Chris@16:     //! Returns string suitable for use in POSIX time zone string
Chris@16:     /*! Returns a string formatted as "M4.1.0" ==> 1st Sunday in April. */
Chris@16:     virtual std::string to_string() const
Chris@16:     {
Chris@16:      std::ostringstream ss;
Chris@16:      ss << 'M'
Chris@16:        << static_cast<int>(month_) << '.'
Chris@16:        << 1 << '.'
Chris@16:        << static_cast<int>(dow_);
Chris@16:      return ss.str();
Chris@16:     }
Chris@16:   private:
Chris@16:     month_type month_;
Chris@16:     day_of_week_type dow_;
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16:   //! Calculate something like Last Sunday of January
Chris@16:   /*! Useful generator functor for finding holidays and daylight savings
Chris@16:    *  Get the last day of the month and then calculate the difference
Chris@16:    *  to the last previous day.
Chris@16:    *  @param date_type A date class that exports day_of_week, month_type, etc.
Chris@16:    *  \ingroup date_alg
Chris@16:    */
Chris@16:   template<class date_type>
Chris@16:   class last_kday_of_month : public year_based_generator<date_type>
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     typedef typename calendar_type::day_of_week_type  day_of_week_type;
Chris@16:     typedef typename calendar_type::month_type        month_type;
Chris@16:     typedef typename calendar_type::year_type         year_type;
Chris@16:     typedef typename date_type::duration_type        duration_type;
Chris@16:     //!Specify the date spec like last 'Sunday' in 'April' spec
Chris@16:     /*!@param dow The day of week, eg: Sunday, Monday, etc
Chris@16:      * @param m The month of the year, eg: Jan, Feb, Mar, etc
Chris@16:      */
Chris@16:     last_kday_of_month(day_of_week_type dow, month_type m) :
Chris@16:       month_(m),
Chris@16:       dow_(dow)
Chris@16:     {}
Chris@16:     //! Return a concrete date when provided with a year specific year.
Chris@16:     date_type get_date(year_type year) const
Chris@16:     {
Chris@16:       date_type d(year, month_, calendar_type::end_of_month_day(year,month_));
Chris@16:       duration_type one_day(1);
Chris@16:       while (dow_ != d.day_of_week()) {
Chris@16:         d = d - one_day;
Chris@16:       }
Chris@16:       return d;
Chris@16:     }
Chris@16:     // added for streaming
Chris@16:     month_type month() const
Chris@16:     {
Chris@16:       return month_;
Chris@16:     }
Chris@16:     day_of_week_type day_of_week() const
Chris@16:     {
Chris@16:       return dow_;
Chris@16:     }
Chris@16:     //! Returns string suitable for use in POSIX time zone string
Chris@16:     /*! Returns a string formatted as "M4.5.0" ==> last Sunday in April. */
Chris@16:     virtual std::string to_string() const
Chris@16:     {
Chris@16:       std::ostringstream ss;
Chris@16:       ss << 'M'
Chris@16:          << static_cast<int>(month_) << '.'
Chris@16:          << 5 << '.'
Chris@16:          << static_cast<int>(dow_);
Chris@16:       return ss.str();
Chris@16:     }
Chris@16:   private:
Chris@16:     month_type month_;
Chris@16:     day_of_week_type dow_;
Chris@16:    };
Chris@16: 
Chris@16: 
Chris@16:   //! Calculate something like "First Sunday after Jan 1,2002
Chris@16:   /*! Date generator that takes a date and finds kday after
Chris@16:    *@code
Chris@16:      typedef boost::date_time::first_kday_after<date> firstkdayafter;
Chris@16:      firstkdayafter fkaf(Monday);
Chris@16:      fkaf.get_date(date(2002,Feb,1));
Chris@16:    @endcode
Chris@16:    *  \ingroup date_alg
Chris@16:    */
Chris@16:   template<class date_type>
Chris@16:   class first_kday_after
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     typedef typename calendar_type::day_of_week_type day_of_week_type;
Chris@16:     typedef typename date_type::duration_type        duration_type;
Chris@16:     first_kday_after(day_of_week_type dow) :
Chris@16:       dow_(dow)
Chris@16:     {}
Chris@16:     //! Return next kday given.
Chris@16:     date_type get_date(date_type start_day) const
Chris@16:     {
Chris@16:       duration_type one_day(1);
Chris@16:       date_type d = start_day + one_day;
Chris@16:       while (dow_ != d.day_of_week()) {
Chris@16:         d = d + one_day;
Chris@16:       }
Chris@16:       return d;
Chris@16:     }
Chris@16:     // added for streaming
Chris@16:     day_of_week_type day_of_week() const
Chris@16:     {
Chris@16:       return dow_;
Chris@16:     }
Chris@16:   private:
Chris@16:     day_of_week_type dow_;
Chris@16:   };
Chris@16: 
Chris@16:   //! Calculate something like "First Sunday before Jan 1,2002
Chris@16:   /*! Date generator that takes a date and finds kday after
Chris@16:    *@code
Chris@16:      typedef boost::date_time::first_kday_before<date> firstkdaybefore;
Chris@16:      firstkdaybefore fkbf(Monday);
Chris@16:      fkbf.get_date(date(2002,Feb,1));
Chris@16:    @endcode
Chris@16:    *  \ingroup date_alg
Chris@16:    */
Chris@16:   template<class date_type>
Chris@16:   class first_kday_before
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     typedef typename calendar_type::day_of_week_type day_of_week_type;
Chris@16:     typedef typename date_type::duration_type        duration_type;
Chris@16:     first_kday_before(day_of_week_type dow) :
Chris@16:       dow_(dow)
Chris@16:     {}
Chris@16:     //! Return next kday given.
Chris@16:     date_type get_date(date_type start_day) const
Chris@16:     {
Chris@16:       duration_type one_day(1);
Chris@16:       date_type d = start_day - one_day;
Chris@16:       while (dow_ != d.day_of_week()) {
Chris@16:         d = d - one_day;
Chris@16:       }
Chris@16:       return d;
Chris@16:     }
Chris@16:     // added for streaming
Chris@16:     day_of_week_type day_of_week() const
Chris@16:     {
Chris@16:       return dow_;
Chris@16:     }
Chris@16:   private:
Chris@16:     day_of_week_type dow_;
Chris@16:   };
Chris@16: 
Chris@16:   //! Calculates the number of days until the next weekday
Chris@16:   /*! Calculates the number of days until the next weekday.
Chris@16:    * If the date given falls on a Sunday and the given weekday
Chris@16:    * is Tuesday the result will be 2 days */
Chris@16:   template<typename date_type, class weekday_type>
Chris@16:   inline
Chris@16:   typename date_type::duration_type days_until_weekday(const date_type& d, const weekday_type& wd)
Chris@16:   {
Chris@16:     typedef typename date_type::duration_type duration_type;
Chris@16:     duration_type wks(0);
Chris@16:     duration_type dd(wd.as_number() - d.day_of_week().as_number());
Chris@16:     if(dd.is_negative()){
Chris@16:       wks = duration_type(7);
Chris@16:     }
Chris@16:     return dd + wks;
Chris@16:   }
Chris@16: 
Chris@16:   //! Calculates the number of days since the previous weekday
Chris@16:   /*! Calculates the number of days since the previous weekday
Chris@16:    * If the date given falls on a Sunday and the given weekday
Chris@16:    * is Tuesday the result will be 5 days. The answer will be a positive
Chris@16:    * number because Tuesday is 5 days before Sunday, not -5 days before. */
Chris@16:   template<typename date_type, class weekday_type>
Chris@16:   inline
Chris@16:   typename date_type::duration_type days_before_weekday(const date_type& d, const weekday_type& wd)
Chris@16:   {
Chris@16:     typedef typename date_type::duration_type duration_type;
Chris@16:     duration_type wks(0);
Chris@16:     duration_type dd(wd.as_number() - d.day_of_week().as_number());
Chris@16:     if(dd.days() > 0){
Chris@16:       wks = duration_type(7);
Chris@16:     }
Chris@16:     // we want a number of days, not an offset. The value returned must
Chris@16:     // be zero or larger.
Chris@16:     return (-dd + wks);
Chris@16:   }
Chris@16: 
Chris@16:   //! Generates a date object representing the date of the following weekday from the given date
Chris@16:   /*! Generates a date object representing the date of the following
Chris@16:    * weekday from the given date. If the date given is 2004-May-9
Chris@16:    * (a Sunday) and the given weekday is Tuesday then the resulting date
Chris@16:    * will be 2004-May-11. */
Chris@16:   template<class date_type, class weekday_type>
Chris@16:   inline
Chris@16:   date_type next_weekday(const date_type& d, const weekday_type& wd)
Chris@16:   {
Chris@16:     return d + days_until_weekday(d, wd);
Chris@16:   }
Chris@16: 
Chris@16:   //! Generates a date object representing the date of the previous weekday from the given date
Chris@16:   /*! Generates a date object representing the date of the previous
Chris@16:    * weekday from the given date. If the date given is 2004-May-9
Chris@16:    * (a Sunday) and the given weekday is Tuesday then the resulting date
Chris@16:    * will be 2004-May-4. */
Chris@16:   template<class date_type, class weekday_type>
Chris@16:   inline
Chris@16:   date_type previous_weekday(const date_type& d, const weekday_type& wd)
Chris@16:   {
Chris@16:     return d - days_before_weekday(d, wd);
Chris@16:   }
Chris@16: 
Chris@16: } } //namespace date_time
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: #endif
Chris@16: