Implement Quarter parsing

Formats:
 * Arrow: 3 quarters ago, before 2 quarters
 * Anchor: last/this/next quarter
 * Narrow: Q1, 2nd quarter, fourth quarter

lib/chronic/arrow.rb

@@ -22,6 +22,7 @@ class Arrow
       :wdays,
       :weekends,
       :fortnights,
+      :quarters,
       :seasons
     ]
 
@@ -43,6 +44,7 @@ class Arrow
       :weeks,
       :fortnights,
       :months,
+      :quarters,
       :seasons,
       :years
     ]
@@ -116,6 +118,12 @@ def to_span(span, timezone = nil)
         when :seasons
           # TODO
           raise "Not Implemented Arrow #{unit}"
+        when :quarters
+          ds[0], quarter = Date::add_quarter(ds[0], Date::get_quarter_index(ds[1]), sign * count)
+          ds[1] = Date::QUARTERS[quarter]
+          ds[2] = 1
+          ds[3], ds[4], ds[5] = 0, 0, 0
+          precision = PRECISION.index(unit)
         when :fortnights
           ds[0], ds[1], ds[2] = Date::add_day(ds[0], ds[1], ds[2], sign * count * Date::FORTNIGHT_DAYS)
           precision = update_precision(precision, unit)
@@ -189,6 +197,11 @@ def to_span(span, timezone = nil)
         de[0], de[1] = Date::add_month(ds[0], ds[1])
         de[2] = 1
         de[3] = de[4] = de[5] = 0
+      when :quarters
+        de[0], quarter = Date::add_quarter(ds[0], Date::get_quarter_index(ds[1]))
+        de[1] = Date::QUARTERS[quarter]
+        de[2] = 1
+        de[3] = de[4] = de[5] = 0
       when :seasons
         # TODO
         raise "Not Implemented Arrow #{PRECISION[precision]}"

lib/chronic/date.rb

@@ -3,13 +3,15 @@ class Date
     YEAR_QUARTERS     = 4
     YEAR_MONTHS       = 12
     SEASON_MONTHS     = 3
+    QUARTER_MONTHS    = 3
     MONTH_DAYS        = [nil, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
     MONTH_DAYS_LEAP   = [nil, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
     FORTNIGHT_DAYS    = 14
     WEEK_DAYS         =  7
     DAY_HOURS         = 24
     YEAR_SECONDS      = 31_536_000 # 365 * 24 * 60 * 60
     SEASON_SECONDS    =  7_862_400 #  91 * 24 * 60 * 60
+    QUARTER_SECONDS   =  7_776_000 #  90 * 24 * 60 * 60
     MONTH_SECONDS     =  2_592_000 #  30 * 24 * 60 * 60
     FORTNIGHT_SECONDS =  1_209_600 #  14 * 24 * 60 * 60
     WEEK_SECONDS      =    604_800 #   7 * 24 * 60 * 60
@@ -27,6 +29,7 @@ class Date
       :autumn => [9, 23],
       :winter => [12, 22]
     }
+    QUARTERS = [nil, 1, 4, 7, 10]
     MONTHS = {
       :january => 1,
       :february => 2,
@@ -102,6 +105,15 @@ def self.add_season(year, season, modifier = 1)
       [year, season]
     end
 
+    def self.add_quarter(year, quarter, amount = 1)
+      quarter += amount
+      if quarter > YEAR_QUARTERS or quarter < 1
+        year += (quarter - 1) / YEAR_QUARTERS
+        quarter = (quarter - 1) % YEAR_QUARTERS + 1
+      end
+      [year, quarter]
+    end
+
     def self.add_month(year, month, amount = 1)
       month += amount
       if month > YEAR_MONTHS or month < 1
@@ -128,6 +140,18 @@ def self.add_day(year, month, day, amount = 1)
       [year, month, day]
     end
 
+    def self.get_quarter_index(month)
+      (month - 1) / QUARTER_MONTHS + 1
+    end
+
+    def self.get_quarter_month(month)
+      (get_quarter_index(month) - 1) * QUARTER_MONTHS + 1
+    end
+
+    def self.get_quarter_end(quarter)
+      QUARTERS[(quarter - 1) % YEAR_QUARTERS + 1]
+    end
+
     def self.normalize(year, month, day)
       year, month = add_month(year, month, 0)
       year, month, day = add_day(year, month, day, 0)
@@ -185,6 +209,11 @@ def self.month_diff(date_month, month, modifier = 1, context = 0)
       self.calculate_difference(month - date_month, YEAR_MONTHS, modifier, context)
     end
 
+    # Calculate difference in quarters between given quarter and date quarter
+    def self.quarter_diff(date_quarter, quarter, modifier = 1, context = 0)
+      self.calculate_difference(quarter - date_quarter, YEAR_QUARTERS, modifier, context)
+    end
+
   end
 
   module DateStructure

lib/chronic/definition.rb

@@ -121,9 +121,11 @@ def definitions
         [[Grabber, SeparatorSpace, MonthName],   :handle_gr_mn],
         [[Grabber, SeparatorSpace, SeasonName],  :handle_gr_sn],
         [[Grabber, SeparatorSpace, TimeSpecial], :handle_gr_ts],
+        [[Grabber, SeparatorSpace, KeywordQ, Scalar], :handle_gr_q_s],
         [[Grabber, SeparatorSpace, Unit],        :handle_gr_u],
         [[KeywordIn, SeparatorSpace, Scalar, SeparatorSpace, Unit], :handle_in_s_u],
         [[DaySpecial], :handle_ds],
+        [[KeywordQ, Scalar], :handle_q_s],
         [[Unit],       :handle_u]
       ]
     end
@@ -148,6 +150,7 @@ def definitions
         [[Grabber,  SeparatorSpace, Ordinal, SeparatorSpace, Unit], :handle_gr_o_u],
         [[Ordinal,  SeparatorSpace, Unit], :handle_o_u],
         [[Ordinal,  SeparatorSpace, DayName], :handle_o_dn],
+        [[KeywordQ, Scalar], :handle_q_s]
       ]
     end
   end

lib/chronic/handlers/anchor.rb

@@ -53,5 +53,13 @@ def handle_in_s_u
       handle_u
     end
 
+    # Handle grabber/keyword-q/scalar
+    # formats: gr Qs
+    def handle_gr_q_s
+      handle_gr
+      next_tag
+      handle_q_s
+    end
+
   end
 end

lib/chronic/handlers/general.rb

@@ -115,5 +115,16 @@ def handle_sn
       @precision = :season
     end
 
+    # Handle keyword-q/scalar
+    # formats: Qs
+    def handle_q_s
+      next_tag # Q
+      @quarter = @tokens[@index].get_tag(Scalar).type
+      @number = @quarter
+      @index += 1
+      @precision = :quarter
+      @unit = :quarter
+    end
+
   end
 end

lib/chronic/objects/anchor_object.rb

@@ -20,7 +20,7 @@ def is_valid?
     end
 
     def to_s
-      "grabber #{@grabber.inspect}, unit #{@unit.inspect}, season #{@season.inspect}, month #{@month.inspect}, wday #{@wday.inspect}, day special #{@day_special.inspect}, time special #{@time_special.inspect}, count #{@count.inspect}"
+      "grabber #{@grabber.inspect}, unit #{@unit.inspect}, season #{@season.inspect}, quarter #{@quarter.inspect}, month #{@month.inspect}, wday #{@wday.inspect}, day special #{@day_special.inspect}, time special #{@time_special.inspect}, count #{@count.inspect}"
     end
 
     def to_span(span = nil, time = nil, timezone = nil)
@@ -53,6 +53,15 @@ def to_span(span = nil, time = nil, timezone = nil)
         end_year, next_season = Date::add_season(year, @season)
         end_month, end_day = Date::SEASON_DATES[next_season]
         hour = minute = second = end_hour = end_minute = end_second = 0
+      elsif @quarter
+        quarter = Date::get_quarter_index(month)
+        diff = Date::quarter_diff(quarter, @quarter, modifier, sign)
+        year, quarter = Date::add_quarter(year, quarter, diff)
+        month = Date::QUARTERS[@quarter]
+        end_year, next_quarter = Date::add_quarter(year, @quarter)
+        end_month = Date::QUARTERS[next_quarter]
+        day = end_day = 1
+        hour = minute = second = end_hour = end_minute = end_second = 0
       elsif @month
         diff = Date::month_diff(month, @month, modifier, sign)
         year, month = Date::add_month(year, month, diff)
@@ -115,6 +124,19 @@ def to_span(span = nil, time = nil, timezone = nil)
             end_day = 1
             end_hour = end_minute = end_second = 0
           end
+        when :quarter
+          year, quarter = Date::add_quarter(year, Date::get_quarter_index(month), modifier)
+          month = Date::QUARTERS[quarter]
+          unless modifier.zero? and @context == :future
+            day = 1
+            hour = minute = second = 0
+          end
+          unless modifier.zero? and @context == :past
+            end_year, next_quarter = Date::add_quarter(year, quarter)
+            end_month = Date::QUARTERS[next_quarter]
+            end_day = 1
+            end_hour = end_minute = end_second = 0
+          end
         when :month
           year, month = Date::add_month(year, month, modifier)
           unless modifier.zero? and @context == :future

lib/chronic/objects/narrow_object.rb

@@ -41,6 +41,16 @@ def to_span(span = nil, timezone = nil)
         when :season
           # TODO
           raise "Not Implemented NarrowObject #{@unit.inspect}"
+        when :quarter
+          this_quarter = Date::get_quarter_index(start.month)
+          diff = Date::quarter_diff(this_quarter, @number, modifier, sign)
+          year, quarter = Date::add_quarter(start.year, this_quarter, diff)
+          year = start.year if span
+          month = Date::QUARTERS[quarter]
+          end_year, next_quarter = Date::add_quarter(year, quarter)
+          end_month = Date::QUARTERS[next_quarter]
+          day = end_day = 1
+          hour = minute = second = 0
         when :month
           day = start.day
           year, month = Date::add_month(start.year, start.month, @number - 1)

lib/chronic/parser.rb

@@ -91,7 +91,11 @@ def pre_proccess(text)
     #
     # Returns a new String ready for Chronic to parse.
     def pre_normalize(text)
+      text.gsub!(/\b(quarters?)\b/, '<=\1=>') # workaround for Numerizer
+      text.gsub!(/\b\s+third\b/, ' 3rd')
+      text.gsub!(/\b\s+fourth\b/, ' 4th')
       text = Numerizer.numerize(text)
+      text.gsub!(/<=(quarters?)=>/, '\1')
       text
     end
 

lib/chronic/tags/keyword.rb

@@ -15,6 +15,7 @@ def self.scan(tokens, options)
         token.tag scan_for(token, KeywordOn,  { 'on'        => :on  })
         token.tag scan_for(token, KeywordAnd, { 'and'       => :and })
         token.tag scan_for(token, KeywordTo,  { 'to'        => :to  })
+        token.tag scan_for(token, KeywordQ,   { :Q          => :Q   })
       end
     end
 
@@ -53,4 +54,10 @@ def to_s
     end
   end
 
+  class KeywordQ < Keyword #:nodoc:
+    def to_s
+      super << '-q'
+    end
+  end
+
 end

lib/chronic/tags/unit.rb

@@ -32,6 +32,7 @@ def self.patterns
       @@paterns ||= {
         /^years?$/i               => :year,
         /^seasons?$/i             => :season,
+        /^quarters?$/i            => :quarter,
         /^months?$/i              => :month,
         /^fortnights?$/i          => :fortnight,
         /^weeks?$/i               => :week,