# -*- coding: utf-8 -*-
        
      
        

          
          
          =begin rdoc
        
      
        

          
          
          Please see README
        
      
        

          
          
          =end
        
      
        

          
          
          
        
      
        

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          require 'date'
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

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          class Week
        
      
        

          
          
          
        
      
        

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            attr :date
        
      
        

          
          
          
        
      
        

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            def initialize(date)
        
      
        

          
          
              @date = date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return date.to_s
        
      
        

          
          
          
        
      
        

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            def to_s
        
      
        

          
          
              @date.to_s
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            ### Instantiations
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return the week that starts today
        
      
        

          
          
          
        
      
        

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            def self.now
        
      
        

          
          
              Week.new(Date.today)
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Parse date text to a week. 
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #   week = Week.parse('2012-01-02') 
        
      
        

          
          
          
        
      
        

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            def self.parse(date_text)
        
      
        

          
          
              Week.new(Date.parse(date_text))
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            ### Comparable
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return the hash for object comparison.
        
      
        

          
          
            #
        
      
        

          
          
            # This is simply the has of the date, which means
        
      
        

          
          
            # that two week objects created with the same date
        
      
        

          
          
            # will compare equally.
        
      
        

          
          
          
        
      
        

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            def hash
        
      
        

          
          
              date.hash
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date == week2.date
        
      
        

          
          
          
        
      
        

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            def ==(other)
        
      
        

          
          
              self.date == other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date.eql? week2.date
        
      
        

          
          
          
        
      
        

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            def eql?(other)
        
      
        

          
          
              self.date == other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date <=> week2.date
        
      
        

          
          
          
        
      
        

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            def <=>(other)
        
      
        

          
          
             return self.date <=> other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date < week2.date
        
      
        

          
          
          
        
      
        

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            def <(other)
        
      
        

          
          
              self.date < other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date <= week2.date
        
      
        

          
          
          
        
      
        

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            def <=(other)
        
      
        

          
          
              self.date <= other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date > week2.date
        
      
        

          
          
          
        
      
        

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            def >(other)
        
      
        

          
          
              self.date > other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return week1.date >= week2.date
        
      
        

          
          
          
        
      
        

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            def >=(other)
        
      
        

          
          
              self.date >= other.date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            ### Math
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Addition: week + other => week
        
      
        

          
          
            #
        
      
        

          
          
            # Return a date object pointing other weeks after self.
        
      
        

          
          
            # The other should be a numeric value.
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #     week = Week.parse('2012-01-02')
        
      
        

          
          
            #     week + 3 => three weeks later
        
      
        

          
          
          
        
      
        

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            def +(other)
        
      
        

          
          
              if other.is_a? Numeric
        
      
        

          
          
                return Week.new(date + (other.to_i * 7))
        
      
        

          
          
              else
        
      
        

          
          
                raise TypeError
        
      
        

          
          
              end
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Subtraction: week - other => week or integer
        
      
        

          
          
            #
        
      
        

          
          
            # If the other is a numeric value, return a week object pointing other weeks before self. 
        
      
        

          
          
            #   
        
      
        

          
          
            # If the other is a week object, then return the difference between the two weeks.
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #     date = date.parse('2012-01-02')
        
      
        

          
          
            #     week = Week.new(date)
        
      
        

          
          
            #     week - 3 => three weeks earlier
        
      
        

          
          
            #
        
      
        

          
          
            # @example 
        
      
        

          
          
            #     date = date.parse('2012-01-02')
        
      
        

          
          
            #     start_week =  Week.new(date)
        
      
        

          
          
            #     end_week =  Week.new(date + 21)
        
      
        

          
          
            #     end_week - start_week => 3
        
      
        

          
          
          
        
      
        

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            def -(other)
        
      
        

          
          
              if other.is_a? Numeric
        
      
        

          
          
                return Week.new(date - (other * 7))
        
      
        

          
          
              elsif other.is_a? Week
        
      
        

          
          
                return ((self.date - other.date) / 7).round
        
      
        

          
          
              else
        
      
        

          
          
                raise TypeError
        
      
        

          
          
              end
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
            
        
      
        

          
          
            ### Enumerable
        
      
        

          
          
          
        
      
        

          
          
            # Return the previous week, i.e. seven day earlier.
        
      
        

          
          
          
        
      
        

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            def previous
        
      
        

          
          
              return self - 1
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return the next week, i.e. seven day later.
        
      
        

          
          
          
        
      
        

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            def next
        
      
        

          
          
              return self + 1
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            ### Ranges
        
      
        

          
          
          
        
      
        

          
          
           
        
      
        

          
          
            # Return the start date of this week.
        
      
        

          
          
            # This is the same as week.date.
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #   week = Week.parse('2012-01-02')
        
      
        

          
          
            #   week.start_date.to_s => '2012-01-02'
        
      
        

          
          
          
        
      
        

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            def start_date
        
      
        

          
          
              @date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return the end date of this week.
        
      
        

          
          
            # This is the same as week.date + 6 days
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #   week = Week.parse('2012-01-02')
        
      
        

          
          
            #   week.end_date.to_s => '2012-01-08'
        
      
        

          
          
          
        
      
        

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            def end_date
        
      
        

          
          
              @date + 6
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return the range start_date..end_date
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #   week = Week.parse('2012-01-02')
        
      
        

          
          
            #   week.date_range => Range(2012-01-02..2012-01-08)
        
      
        

          
          
            
        
      
        

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            def date_range
        
      
        

          
          
              start_date..end_date
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
            # Return true iif the week includes the date, i.e. if the date is in start_date..end_date
        
      
        

          
          
            #
        
      
        

          
          
            # @example
        
      
        

          
          
            #   week = Week.parse('2012-01-02')
        
      
        

          
          
            #   week.include?(Date.parse('2012-01-05')) => true
        
      
        

          
          
            #   week.include?(Date.parse('2012-01-10')) => false
        
      
        

          
          
          
        
      
        

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            def include?(date)
        
      
        

          
          
              (start_date..end_date).include?(date)
        
      
        

          
          
            end
        
      
        

          
          
          
        
      
        

          
          
          
        
      
        

          
          
          end