Merge: Date Lib

les fonctions ce trouve dans le module date_f.nit.

Pull-Request: #1100
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>
Reviewed-by: Jean Privat <jean@pryen.org>

diff --git a/lib/date.nit b/lib/date.nit
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+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Services to manipulate `Date`, `Time` and `DateTime`
+#
+# The services are split in 2 classes:
+#
+# * `Date` handles the year, month and day parts of the date.
+# * `Time` handles the time in hours, minutes and seconds.
+#
+# These are united in `DateTime` for a precise time in a precise day.
+#
+# ~~~
+# var now = new Time.now
+# var midnight = new Time(0, 0, 0)
+# assert now > midnight
+#
+# var nine_thirty = new Time(9, 30, 0)
+# var eleven_twenty = new Time(11, 20, 0)
+# assert eleven_twenty > nine_thirty
+#
+# var pi_day = new Date(2015, 03, 14)
+# var may_the_fourth = new Date(2015, 5, 4)
+# assert pi_day < may_the_fourth
+#
+# var now_t = new DateTime.now
+# var epoch = new DateTime(1970, 1, 1, 0, 0, 0)
+# assert now_t > epoch
+# ~~~
+#
+module date
+
+# A time of the day, composed of an `hour`, a `minute` and a `second` count
+class Time
+       super Comparable
+       redef type OTHER: Time
+
+       # The hour part of this time, between 0 and 23
+       var hour: Int
+
+       # The minute within the hour, between 0 and 59
+       var minute: Int
+
+       # The second within the minute, between 0 and 59
+       var second: Int
+
+       # Get the current time of the day
+       init now do
+               var tm = new Tm.localtime
+               hour = tm.hour
+               minute = tm.min
+               second = tm.sec
+       end
+
+       # Get the difference between two times in second
+       fun diff_time(other: Time): Int do
+               return (hour * 3600 + minute * 60 + second) -
+                       (other.hour * 3600 + other.minute * 60 + other.second)
+       end
+
+       redef fun ==(d) do return d isa Time and time_eq(d)
+
+       redef fun <(d) do return self.diff_time(d) < 0
+
+       redef fun hash do return hour * 1024 + minute * 64 + second
+
+       private fun time_eq(other: Time): Bool
+       do
+               return hour * 3600 + minute * 60 + second ==
+                       other.hour * 3600 + other.minute * 60 + other.second
+       end
+end
+
+# A date, composed by a `year`, a `month` and a `day`
+class Date
+       super Comparable
+       redef type OTHER: Date
+
+       # Year, ex: 1989
+       var year: Int
+
+       # Month as an integer, `1` for January, `2` for February, etc.
+       var month: Int
+
+       # Day of the month
+       var day: Int
+
+       # UTC time zone
+       #
+       # FIXME this value is not yet applied
+       var time_zone = "Z"
+
+       # The date of this day
+       init today do
+               var tm = new Tm.localtime
+               year = 1900 + tm.year
+               month = tm.mon + 1
+               day = tm.mday
+       end
+
+       # `self` formatted according to ISO 8601
+       redef fun to_s do return "{year}-{month}-{day}"
+
+       # Difference in days between `self` and `other`
+       fun diff_days(other: Date): Int
+       do
+               var y_out = year - other.year
+               y_out = y_out * 365
+               var m_out = month - other.month
+               m_out = m_out * 30 # FIXME
+               return day - other.day + m_out + y_out
+       end
+
+       # Difference in months between `self` and `other`
+       fun diff_months(other: Date): Int
+       do
+               var y_out = year - other.year
+               y_out = y_out * 12
+               return month - other.month + y_out
+       end
+
+       # Difference in years between `self` and `other`
+       fun diff_years(other: Date): Int do return year - other.year
+
+       redef fun ==(d) do return d isa Date and self.diff_days(d) == 0
+
+       redef fun hash do return year + month * 1024 + day * 2048
+
+       redef fun <(d) do return self.diff_days(d) < 0
+
+       # Is `self` is between the years of `a` and `b`?
+       private fun is_between_years(a, b: Date): Bool
+       do
+               return (a.year > year and b.year < year) or (b.year > year and a.year < year) or (a.year == year or b.year == year)
+       end
+
+       # Is `self` is between the months of `a` and `b`?
+       private fun is_between_months(a, b: Date) : Bool
+       do
+               if not self.is_between_years(a,b) then return false
+               return (a.month > month and b.month < month) or (b.month > month and a.month < month) or (a.month == month or b.month == month)
+       end
+
+       # Is `self` between `a` and `b`?
+       redef fun is_between(a, b)
+       do
+               if not self.is_between_months(a, b) then return false
+               return (a.day > day and b.day < day) or (b.day > day and a.day < day) or (a.day == day or b.day == day)
+       end
+end
+
+# A `Time` in a `Date`
+class DateTime
+       super Date
+       super Time
+       redef type OTHER: DateTime
+       autoinit year, month, day, hour, minute, second
+
+       # Get the current `DateTime`
+       init now
+       do
+               super
+               today
+       end
+
+       redef fun ==(other) do return other isa DateTime and diff_days(other) == 0 and time_eq(other)
+
+       redef fun to_s do return "{super} {hour}:{minute}:{second}{time_zone}"
+end