* lib/date.rb, lib/date/format.rb: introduced some constants

	  (for internal use) and aliases (minute and second).

	* sample/cal.rb: trivial adjustments.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14903 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 82 insertions, 59 deletions

diff --git a/lib/date.rb b/lib/date.rb
index dec02967f2..8ef1b1fe59 100644
--- a/lib/date.rb
+++ b/lib/date.rb
@@ -1,12 +1,12 @@
 #
 # date.rb - date and time library
 #
-# Author: Tadayoshi Funaba 1998-2007
+# Author: Tadayoshi Funaba 1998-2008
 #
 # Documentation: William Webber <william@williamwebber.com>
 #
 #--
-# $Id: date.rb,v 2.34 2007-12-30 21:45:27+09 tadf Exp $
+# $Id: date.rb,v 2.35 2008-01-06 08:42:17+09 tadf Exp $
 #++
 #
 # == Overview
@@ -313,7 +313,20 @@ class Date
   # Gregorian calendar.
   GREGORIAN = -Infinity.new
 
-  UNIXEPOCH = 2440588 # 1970-01-01 :nodoc:
+  HALF_DAYS_IN_DAY       = Rational(1, 2) # :nodoc:
+  HOURS_IN_DAY           = Rational(1, 24) # :nodoc:
+  MINUTES_IN_DAY         = Rational(1, 1440) # :nodoc:
+  SECONDS_IN_DAY         = Rational(1, 86400) # :nodoc:
+  MILLISECONDS_IN_DAY    = Rational(1, 86400*10**3) # :nodoc:
+  NANOSECONDS_IN_DAY     = Rational(1, 86400*10**9) # :nodoc:
+  MILLISECONDS_IN_SECOND = Rational(1, 10**3) # :nodoc:
+  NANOSECONDS_IN_SECOND  = Rational(1, 10**9) # :nodoc:
+
+  MJD_EPOCH_IN_AJD       = Rational(4800001, 2) # 1858-11-17 # :nodoc:
+  UNIX_EPOCH_IN_AJD      = Rational(4881175, 2) # 1970-01-01 # :nodoc:
+  MJD_EPOCH_IN_CJD       = 2400001 # :nodoc:
+  UNIX_EPOCH_IN_CJD      = 2440588 # :nodoc:
+  LD_EPOCH_IN_CJD        = 2299160 # :nodoc:
 
   t = Module.new do
 
@@ -487,7 +500,7 @@ class Date
     #
     # Returns the (civil) Julian Day Number as [day_number,
     # fraction] where +fraction+ is always 1/2.
-    def ajd_to_jd(ajd, of=0) (ajd + of + 1.to_r/2).divmod(1) end # :nodoc:
+    def ajd_to_jd(ajd, of=0) (ajd + of + HALF_DAYS_IN_DAY).divmod(1) end # :nodoc:
 
     # Convert a (civil) Julian Day Number to an Astronomical Julian
     # Day Number.
@@ -498,46 +511,54 @@ class Date
     #
     # Returns the Astronomical Julian Day Number as a single
     # numeric value.
-    def jd_to_ajd(jd, fr, of=0) jd + fr - of - 1.to_r/2 end # :nodoc:
+    def jd_to_ajd(jd, fr, of=0) jd + fr - of - HALF_DAYS_IN_DAY end # :nodoc:
 
     # Convert a fractional day +fr+ to [hours, minutes, seconds,
     # fraction_of_a_second]
     def day_fraction_to_time(fr) # :nodoc:
-      h,   fr = fr.divmod(1.to_r/24)
-      min, fr = fr.divmod(1.to_r/1440)
-      s,   fr = fr.divmod(1.to_r/86400)
+      h,   fr = fr.divmod(HOURS_IN_DAY)
+      min, fr = fr.divmod(MINUTES_IN_DAY)
+      s,   fr = fr.divmod(SECONDS_IN_DAY)
       return h, min, s, fr * 86400
     end
 
     # Convert an +h+ hour, +min+ minutes, +s+ seconds period
     # to a fractional day.
-    def time_to_day_fraction(h, min, s) # :nodoc:
-      h.to_r/24 + min.to_r/1440 + s.to_r/86400
+    begin
+      Rational(Rational(1, 2), 2) # a challenge
+
+      def time_to_day_fraction(h, min, s) # :nodoc:
+	Rational(h, 24) + Rational(min, 1440) + Rational(s, 86400)
+      end
+    rescue
+      def time_to_day_fraction(h, min, s) # :nodoc:
+	h.to_r/24 + min.to_r/1440 + s.to_r/86400
+      end
     end
 
     # Convert an Astronomical Modified Julian Day Number to an
     # Astronomical Julian Day Number.
-    def amjd_to_ajd(amjd) amjd + 4800001.to_r/2 end # :nodoc:
+    def amjd_to_ajd(amjd) amjd + MJD_EPOCH_IN_AJD end # :nodoc:
 
     # Convert an Astronomical Julian Day Number to an
     # Astronomical Modified Julian Day Number.
-    def ajd_to_amjd(ajd) ajd - 4800001.to_r/2 end # :nodoc:
+    def ajd_to_amjd(ajd) ajd - MJD_EPOCH_IN_AJD end # :nodoc:
 
     # Convert a Modified Julian Day Number to a Julian
     # Day Number.
-    def mjd_to_jd(mjd) mjd + 2400001 end # :nodoc:
+    def mjd_to_jd(mjd) mjd + MJD_EPOCH_IN_CJD end # :nodoc:
 
     # Convert a Julian Day Number to a Modified Julian Day
     # Number.
-    def jd_to_mjd(jd) jd - 2400001 end # :nodoc:
+    def jd_to_mjd(jd) jd - MJD_EPOCH_IN_CJD end # :nodoc:
 
     # Convert a count of the number of days since the adoption
     # of the Gregorian Calendar (in Italy) to a Julian Day Number.
-    def ld_to_jd(ld) ld + 2299160 end # :nodoc:
+    def ld_to_jd(ld) ld +  LD_EPOCH_IN_CJD end # :nodoc:
 
     # Convert a Julian Day Number to the number of days since
     # the adoption of the Gregorian Calendar (in Italy).
-    def jd_to_ld(jd) jd - 2299160 end # :nodoc:
+    def jd_to_ld(jd) jd -  LD_EPOCH_IN_CJD end # :nodoc:
 
     # Convert a Julian Day Number to the day of the week.
     #
@@ -835,7 +856,7 @@ class Date
       h,   fr = fr.divmod(3600)
       min, fr = fr.divmod(60)
       s,   fr = fr.divmod(1)
-      elem[:jd] = UNIXEPOCH + d
+      elem[:jd] = UNIX_EPOCH_IN_CJD + d
       elem[:hour] = h
       elem[:min] = min
       elem[:sec] = s
@@ -1194,7 +1215,12 @@ class Date
   # Get the fraction-of-a-second of this date.
   def sec_fraction() time[3] end
 
-  private :hour, :min, :sec, :sec_fraction
+  alias_method :minute, :min
+  alias_method :second, :sec
+  alias_method :second_fraction, :sec_fraction
+
+  private :hour, :min, :sec, :sec_fraction,
+	  :minute, :second, :second_fraction
 
   def zone() strftime('%:z') end
 
@@ -1285,7 +1311,7 @@ class Date
 
   def new_offset(of=0)
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     self.class.new!(@ajd, of, @sg)
   end
@@ -1522,7 +1548,7 @@ class DateTime < Date
       raise ArgumentError, 'invalid date'
     end
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
@@ -1547,7 +1573,7 @@ class DateTime < Date
       raise ArgumentError, 'invalid date'
     end
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
@@ -1572,7 +1598,7 @@ class DateTime < Date
       raise ArgumentError, 'invalid date'
     end
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
@@ -1600,7 +1626,7 @@ class DateTime < Date
       raise ArgumentError, 'invalid date'
     end
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
@@ -1611,7 +1637,7 @@ class DateTime < Date
       raise ArgumentError, 'invalid date'
     end
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
@@ -1624,7 +1650,7 @@ class DateTime < Date
       raise ArgumentError, 'invalid date'
     end
     if String === of
-      of = (zone_to_diff(of) || 0).to_r/86400
+      of = Rational(zone_to_diff(of) || 0, 86400)
     end
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
@@ -1638,10 +1664,8 @@ class DateTime < Date
 	   (fr = valid_time_frags?(elem))
       raise ArgumentError, 'invalid date'
     end
-    sf = (elem[:sec_fraction] || 0)
-    fr += sf/86400
-    of = (elem[:offset] || 0)
-    of = of.to_r/86400
+    fr += (elem[:sec_fraction] || 0) / 86400
+    of = Rational(elem[:offset] || 0, 86400)
     new!(jd_to_ajd(jd, fr, of), of, sg)
   end
 
@@ -1718,7 +1742,8 @@ class DateTime < Date
     new_by_frags(elem, sg)
   end
 
-  public :hour, :min, :sec, :sec_fraction, :zone, :offset, :new_offset
+  public :hour, :min, :sec, :sec_fraction, :zone, :offset, :new_offset,
+	 :minute, :second, :second_fraction
 
 end
 
@@ -1734,8 +1759,8 @@ class Time
   def to_datetime
     jd = DateTime.__send__(:civil_to_jd, year, mon, mday, DateTime::ITALY)
     fr = DateTime.__send__(:time_to_day_fraction, hour, min, [sec, 59].min) +
-      nsec.to_r/86400_000_000_000
-    of = utc_offset.to_r/86400
+      Rational(nsec, 86400_000_000_000)
+    of = Rational(utc_offset, 86400)
     DateTime.new!(DateTime.__send__(:jd_to_ajd, jd, fr, of),
 		  of, DateTime::ITALY)
   end
diff --git a/lib/date/format.rb b/lib/date/format.rb
index abc58acb48..8e47eda590 100644
--- a/lib/date/format.rb
+++ b/lib/date/format.rb
@@ -1,5 +1,5 @@
-# format.rb: Written by Tadayoshi Funaba 1999-2007
-# $Id: format.rb,v 2.40 2007-09-09 08:28:03+09 tadf Exp $
+# format.rb: Written by Tadayoshi Funaba 1999-2008
+# $Id: format.rb,v 2.41 2008-01-06 08:42:17+09 tadf Exp $
 
 require 'rational'
 
@@ -257,25 +257,23 @@ class Date
       when 'j'; emit_n(yday, 3, f)
       when 'k'; emit_a(hour, 2, f)
       when 'L'
-	emit_n((sec_fraction / (1.to_r/(10**3))).round, 3, f)
+	emit_n((sec_fraction / MILLISECONDS_IN_SECOND).round, 3, f)
       when 'l'; emit_a((hour % 12).nonzero? || 12, 2, f)
       when 'M', 'OM'; emit_n(min, 2, f)
       when 'm', 'Om'; emit_n(mon, 2, f)
       when 'N'
-	emit_n((sec_fraction / (1.to_r/(10**9))).round, 9, f)
+	emit_n((sec_fraction / NANOSECONDS_IN_SECOND).round, 9, f)
       when 'n'; "\n"
       when 'P'; emit_ad(strftime('%p').downcase, 0, f)
       when 'p'; emit_au(if hour < 12 then 'AM' else 'PM' end, 0, f)
       when 'Q'
-	d = ajd - jd_to_ajd(self.class::UNIXEPOCH, 0)
-	s = (d * 86400*10**3).to_i
+	s = ((ajd - UNIX_EPOCH_IN_AJD) / MILLISECONDS_IN_DAY).round
 	emit_sn(s, 1, f)
       when 'R'; emit_a(strftime('%H:%M'), 0, f)
       when 'r'; emit_a(strftime('%I:%M:%S %p'), 0, f)
       when 'S', 'OS'; emit_n(sec, 2, f)
       when 's'
-	d = ajd - jd_to_ajd(self.class::UNIXEPOCH, 0)
-	s = (d * 86400).to_i
+	s = ((ajd - UNIX_EPOCH_IN_AJD) / SECONDS_IN_DAY).round
 	emit_sn(s, 1, f)
       when 'T'
 	if m == '%T'
@@ -299,9 +297,9 @@ class Date
 	t = $1.size
 	sign = if offset < 0 then -1 else +1 end
 	fr = offset.abs
-	hh, fr = fr.divmod(1.to_r/24)
-	mm, fr = fr.divmod(1.to_r/1440)
-	ss, fr = fr.divmod(1.to_r/86400)
+	hh, fr = fr.divmod(HOURS_IN_DAY)
+	mm, fr = fr.divmod(MINUTES_IN_DAY)
+	ss, fr = fr.divmod(SECONDS_IN_DAY)
 	if t == 3
 	  if    ss.nonzero? then t =  2
 	  elsif mm.nonzero? then t =  1
@@ -372,12 +370,12 @@ class Date
 
 =begin
   def beat(n=0)
-    i, f = (new_offset(1.to_r/24).day_fraction * 1000).divmod(1)
+    i, f = (new_offset(HOURS_IN_DAY).day_fraction * 1000).divmod(1)
     ('@%03d' % i) +
       if n < 1
 	''
       else
-	'.%0*d' % [n, (f / (1.to_r/(10**n))).round]
+	'.%0*d' % [n, (f / Rational(1, 10**n)).round]
       end
   end
 =end
@@ -456,8 +454,8 @@ class Date
 				 then /\A([-+]?\d{1,3})/
 				 else /\A([-+]?\d{1,})/
 				 end, '')
-#	  val = $1.to_i.to_r / (10**3)
-	  val = $1.to_i.to_r / (10**$1.size)
+#	  val = Rational($1.to_i, 10**3)
+	  val = Rational($1.to_i, 10**$1.size)
 	  e.sec_fraction = val
 	when 'M', 'OM'
 	  return unless str.sub!(/\A(\d{1,2})/, '')
@@ -474,8 +472,8 @@ class Date
 				 then /\A([-+]?\d{1,9})/
 				 else /\A([-+]?\d{1,})/
 				 end, '')
-#	  val = $1.to_i.to_r / (10**9)
-	  val = $1.to_i.to_r / (10**$1.size)
+#	  val = Rational($1.to_i, 10**9)
+	  val = Rational($1.to_i, 10**$1.size)
 	  e.sec_fraction = val
 	when 'n', 't'
 	  return unless _strptime_i(str, "\s", e)
@@ -484,7 +482,7 @@ class Date
 	  e._merid = if $1.downcase == 'a' then 0 else 12 end
 	when 'Q'
 	  return unless str.sub!(/\A(-?\d{1,})/, '')
-	  val = $1.to_i.to_r / 10**3
+	  val = Rational($1.to_i, 10**3)
 	  e.seconds = val
 	when 'R'
 	  return unless _strptime_i(str, '%H:%M', e)
@@ -723,7 +721,7 @@ class Date
       e.hour = $1.to_i
       e.min = $2.to_i if $2
       e.sec = $3.to_i if $3
-      e.sec_fraction = $4.to_i.to_r / (10**$4.size) if $4
+      e.sec_fraction = Rational($4.to_i, 10**$4.size) if $4
 
       if $5
 	e.hour %= 12
@@ -738,9 +736,9 @@ class Date
 =begin
   def self._parse_beat(str, e) # :nodoc:
     if str.sub!(/@\s*(\d+)(?:[,.](\d*))?/, ' ')
-      beat = $1.to_i.to_r
-      beat += $2.to_i.to_r / (10**$2.size) if $2
-      secs = beat.to_r / 1000
+      beat = Rational($1.to_i)
+      beat += Rational($2.to_i, 10**$2.size) if $2
+      secs = Rational(beat, 1000)
       h, min, s, fr = self.day_fraction_to_time(secs)
       e.hour = h
       e.min = min
@@ -1063,7 +1061,7 @@ class Date
 	end
       end
       if $4
-	e.sec_fraction = $4.to_i.to_r / (10**$4.size)
+	e.sec_fraction = Rational($4.to_i, 10**$4.size)
       end
       if $5
 	e.zone = $5
@@ -1280,7 +1278,7 @@ class Date
       e.hour = $4.to_i if $4
       e.min = $5.to_i if $5
       e.sec = $6.to_i if $6
-      e.sec_fraction = $7.to_i.to_r / (10**$7.size) if $7
+      e.sec_fraction = Rational($7.to_i, 10**$7.size) if $7
       if $8
 	e.zone = $8
 	e.offset = zone_to_diff($8)
@@ -1292,7 +1290,7 @@ class Date
       e.hour = $1.to_i if $1
       e.min = $2.to_i if $2
       e.sec = $3.to_i if $3
-      e.sec_fraction = $4.to_i.to_r / (10**$4.size) if $4
+      e.sec_fraction = Rational($4.to_i, 10**$4.size) if $4
       if $5
 	e.zone = $5
 	e.offset = zone_to_diff($5)
@@ -1390,7 +1388,7 @@ class Date
 	  hour, min, sec, = zone.split(':')
 	elsif zone.include?(',') || zone.include?('.')
 	  hour, fr, = zone.split(/[,.]/)
-	  min = fr.to_i.to_r / (10**fr.size) * 60
+	  min = Rational(fr.to_i, 10**fr.size) * 60
 	else
 	  case zone.size
 	  when 3
@@ -1430,7 +1428,7 @@ class DateTime < Date
 	     if n < 1
 	       ''
 	     else
-	       '.%0*d' % [n, (sec_fraction / (1.to_r/(10**n))).round]
+	       '.%0*d' % [n, (sec_fraction / Rational(1, 10**n)).round]
 	     end +
 	     '%:z')
   end