Reapply "Sharing of sources for corelib date implementation between VM

runtime/lib/date_patch.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 // Dart core library.
 
 // VM implementation of DateImplementation.
-class DateImplementation implements Date {
-  static final int _MAX_MILLISECONDS_SINCE_EPOCH = 8640000000000000;
-
-  DateImplementation(int years,
-                     [int month = 1,
-                      int day = 1,
-                      int hour = 0,
-                      int minute = 0,
-                      int second = 0,
-                      int millisecond = 0,
-                      bool isUtc = false])
+patch class DateImplementation {
+  /* patch */ DateImplementation(int years,
+                                 [int month = 1,
+                                  int day = 1,
+                                  int hour = 0,
+                                  int minute = 0,
+                                  int second = 0,
+                                  int millisecond = 0,
+                                  bool isUtc = false])
       : this.isUtc = isUtc,
         this.millisecondsSinceEpoch = _brokenDownDateToMillisecondsSinceEpoch(
             years, month, day, hour, minute, second, millisecond, isUtc) {
     if (millisecondsSinceEpoch === null) throw new IllegalArgumentException();
     if (isUtc === null) throw new IllegalArgumentException();
   }
 
-  DateImplementation.now()
+  /* patch */ DateImplementation.now()
       : isUtc = false,
         millisecondsSinceEpoch = _getCurrentMs() {
   }
 
-  factory DateImplementation.fromString(String formattedString) {
-    // Read in (a subset of) ISO 8601.
-    // Examples:
-    //    - "2012-02-27 13:27:00"
-    //    - "2012-02-27 13:27:00.423z"
-    //    - "20120227 13:27:00"
-    //    - "20120227T132700"
-    //    - "20120227"
-    //    - "2012-02-27T14Z"
-    //    - "-123450101 00:00:00 Z"  // In the year -12345.
-    final RegExp re = const RegExp(
-        @'^([+-]?\d?\d\d\d\d)-?(\d\d)-?(\d\d)'  // The day part.
-        @'(?:[ T](\d\d)(?::?(\d\d)(?::?(\d\d)(.\d{1,6})?)?)? ?([zZ])?)?$');
-    Match match = re.firstMatch(formattedString);
-    if (match !== null) {
-      int parseIntOrZero(String matched) {
-        // TODO(floitsch): we should not need to test against the empty string.
-        if (matched === null || matched == "") return 0;
-        return Math.parseInt(matched);
-      }
-
-      double parseDoubleOrZero(String matched) {
-        // TODO(floitsch): we should not need to test against the empty string.
-        if (matched === null || matched == "") return 0.0;
-        return Math.parseDouble(matched);
-      }
-
-      int years = Math.parseInt(match[1]);
-      int month = Math.parseInt(match[2]);
-      int day = Math.parseInt(match[3]);
-      int hour = parseIntOrZero(match[4]);
-      int minute = parseIntOrZero(match[5]);
-      int second = parseIntOrZero(match[6]);
-      bool addOneMillisecond = false;
-      int millisecond = (parseDoubleOrZero(match[7]) * 1000).round().toInt();
-      if (millisecond == 1000) {
-        addOneMillisecond = true;
-        millisecond = 999;
-      }
-      // TODO(floitsch): we should not need to test against the empty string.
-      bool isUtc = (match[8] !== null) && (match[8] != "");
-      int millisecondsSinceEpoch = _brokenDownDateToMillisecondsSinceEpoch(
-          years, month, day, hour, minute, second, millisecond, isUtc);
-      if (millisecondsSinceEpoch === null) {
-        throw new IllegalArgumentException(formattedString);
-      }
-      if (addOneMillisecond) millisecondsSinceEpoch++;
-      return new DateImplementation.fromMillisecondsSinceEpoch(
-          millisecondsSinceEpoch, isUtc);
-    } else {
-      throw new IllegalArgumentException(formattedString);
-    }
-  }
-
-  DateImplementation.fromMillisecondsSinceEpoch(
-      int this.millisecondsSinceEpoch, [bool isUtc = false])
-      : this.isUtc = isUtc {
-    if (millisecondsSinceEpoch.abs() > _MAX_MILLISECONDS_SINCE_EPOCH) {
-      throw new IllegalArgumentException(millisecondsSinceEpoch);
-    }
-    if (isUtc === null) {
-      throw new IllegalArgumentException(isUtc);
-    }
-  }
-
-  bool operator ==(Object other) {
-    if (other is !DateImplementation) return false;
-    DateImplementation otherDate = other;
-    return millisecondsSinceEpoch == otherDate.millisecondsSinceEpoch;
-  }
-
-  bool operator <(Date other)
-      => millisecondsSinceEpoch < other.millisecondsSinceEpoch;
-
-  bool operator <=(Date other)
-      => millisecondsSinceEpoch <= other.millisecondsSinceEpoch;
-
-  bool operator >(Date other)
-      => millisecondsSinceEpoch > other.millisecondsSinceEpoch;
-
-  bool operator >=(Date other)
-      => millisecondsSinceEpoch >= other.millisecondsSinceEpoch;
-
-  int compareTo(Date other)
-      => millisecondsSinceEpoch.compareTo(other.millisecondsSinceEpoch);
-
-  int hashCode() => millisecondsSinceEpoch;
-
-  Date toLocal() {
-    if (isUtc) {
-      return new DateImplementation.fromMillisecondsSinceEpoch(
-          millisecondsSinceEpoch, false);
-    }
-    return this;
-  }
-
-  Date toUtc() {
-    if (isUtc) return this;
-    return new DateImplementation.fromMillisecondsSinceEpoch(
-        millisecondsSinceEpoch, true);
-  }
-
-  String get timeZoneName() {
+  /* patch */ String get timeZoneName() {
     if (isUtc) return "UTC";
     return _timeZoneName(millisecondsSinceEpoch);
   }
 
-  Duration get timeZoneOffset() {
+  /* patch */ Duration get timeZoneOffset() {
     if (isUtc) return new Duration(0);
     int offsetInSeconds = _timeZoneOffsetInSeconds(millisecondsSinceEpoch);
     return new Duration(seconds: offsetInSeconds);
   }
 
-  int get year() {
-    return _decomposeIntoYearMonthDay(_localDateInUtcMs)[0];
-  }
+  /* patch */ int get year() => _decomposeIntoYearMonthDay(_localDateInUtcMs)[0];
 
-  int get month() {
-    return _decomposeIntoYearMonthDay(_localDateInUtcMs)[1];
-  }
+  /* patch */ int get month() => _decomposeIntoYearMonthDay(_localDateInUtcMs)[1];
 
-  int get day() {
-    return _decomposeIntoYearMonthDay(_localDateInUtcMs)[2];
-  }
+  /* patch */ int get day() => _decomposeIntoYearMonthDay(_localDateInUtcMs)[2];
 
-  int get hour() {
+  /* patch */ int get hour() {
     int valueInHours = _flooredDivision(_localDateInUtcMs,
                                         Duration.MILLISECONDS_PER_HOUR);
     return valueInHours % Duration.HOURS_PER_DAY;
   }
 
-  int get minute() {
+  /* patch */ int get minute() {
     int valueInMinutes = _flooredDivision(_localDateInUtcMs,
                                           Duration.MILLISECONDS_PER_MINUTE);
     return valueInMinutes % Duration.MINUTES_PER_HOUR;
   }
 
-  int get second() {
+  /* patch */ int get second() {
     // Seconds are unaffected by the timezone the user is in. So we can
     // directly use the millisecondsSinceEpoch and not [_localDateInUtcMs].
     int valueInSeconds =
         _flooredDivision(millisecondsSinceEpoch,
                          Duration.MILLISECONDS_PER_SECOND);
     return valueInSeconds % Duration.SECONDS_PER_MINUTE;
   }
 
-  int get millisecond() {
+  /* patch */ int get millisecond() {
     // Milliseconds are unaffected by the timezone the user is in. So we can
     // directly use the value and not the [_localDateInUtcValue].
     return millisecondsSinceEpoch % Duration.MILLISECONDS_PER_SECOND;
   }
 
   /** Returns the weekday of [this]. In accordance with ISO 8601 a week
     * starts with Monday. Monday has the value 1 up to Sunday with 7. */
-  int get weekday() {
+  /* patch */ int get weekday() {
     int daysSince1970 =
         _flooredDivision(_localDateInUtcMs, Duration.MILLISECONDS_PER_DAY);
     // 1970-1-1 was a Thursday.
     return ((daysSince1970 + Date.THU - Date.MON) % Date.DAYS_IN_WEEK) +
         Date.MON;
   }
 
-  String toString() {
-    String fourDigits(int n) {
-      int absN = n.abs();
-      String sign = n < 0 ? "-" : "";
-      if (absN >= 1000) return "$n";
-      if (absN >= 100) return "${sign}0$absN";
-      if (absN >= 10) return "${sign}00$absN";
-      return "${sign}000$absN";
-    }
-    String threeDigits(int n) {
-      if (n >= 100) return "${n}";
-      if (n >= 10) return "0${n}";
-      return "00${n}";
-    }
-    String twoDigits(int n) {
-      if (n >= 10) return "${n}";
-      return "0${n}";
-    }
-
-    String y = fourDigits(year);
-    String m = twoDigits(month);
-    String d = twoDigits(day);
-    String h = twoDigits(hour);
-    String min = twoDigits(minute);
-    String sec = twoDigits(second);
-    String ms = threeDigits(millisecond);
-    if (isUtc) {
-      return "$y-$m-$d $h:$min:$sec.${ms}Z";
-    } else {
-      return "$y-$m-$d $h:$min:$sec.$ms";
-    }
-  }
-
-  /** Returns a new [Date] with the [duration] added to [this]. */
-  Date add(Duration duration) {
-    int ms = millisecondsSinceEpoch;
-    return new DateImplementation.fromMillisecondsSinceEpoch(
-        ms + duration.inMilliseconds, isUtc);
-  }
-
-  /** Returns a new [Date] with the [duration] subtracted from [this]. */
-  Date subtract(Duration duration) {
-    int ms = millisecondsSinceEpoch;
-    return new DateImplementation.fromMillisecondsSinceEpoch(
-        ms - duration.inMilliseconds, isUtc);
-  }
-
-  /** Returns a [Duration] with the difference of [this] and [other]. */
-  Duration difference(Date other) {
-    int ms = millisecondsSinceEpoch;
-    int otherMs = other.millisecondsSinceEpoch;
-    return new DurationImplementation(milliseconds: ms - otherMs);
-  }
 
   /** The first list contains the days until each month in non-leap years. The
     * second list contains the days in leap years. */
   static final List<List<int>> _DAYS_UNTIL_MONTH =
       const [const [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
              const [0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335]];
 
   // Returns the UTC year, month and day for the corresponding
   // [millisecondsSinceEpoch].
   // Code is adapted from V8.
@@ skipping 126 matching lines @@
       int zoneOffset =
           _timeZoneOffsetInSeconds(millisecondsSinceEpoch - adjustment);
       millisecondsSinceEpoch -= zoneOffset * Duration.MILLISECONDS_PER_SECOND;
     }
     if (millisecondsSinceEpoch.abs() > _MAX_MILLISECONDS_SINCE_EPOCH) {
       return null;
     }
     return millisecondsSinceEpoch;
   }
 
+  static int _weekDay(y) {
+    // 1/1/1970 was a Thursday.
+    return (_dayFromYear(y) + 4) % 7;
+  }
+
   /**
    * Returns a year in the range 2008-2035 matching
    * * leap year, and
    * * week day of first day.
    *
    * Leap seconds are ignored.
    * Adapted from V8's date implementation. See ECMA 262 - 15.9.1.9.
    */
   static _equivalentYear(int year) {
     // Returns the week day (in range 0 - 6).
-    int weekDay(y) {
-      // 1/1/1970 was a Thursday.
-      return (_dayFromYear(y) + 4) % 7;
-    }
     // 1/1/1956 was a Sunday (i.e. weekday 0). 1956 was a leap-year.
     // 1/1/1967 was a Sunday (i.e. weekday 0).
     // Without leap years a subsequent year has a week day + 1 (for example
     // 1/1/1968 was a Monday). With leap-years it jumps over one week day
     // (e.g. 1/1/1957 was a Tuesday).
     // After 12 years the weekdays have advanced by 12 days + 3 leap days =
     // 15 days. 15 % 7 = 1. So after 12 years the week day has always
     // (now independently of leap-years) advanced by one.
     // weekDay * 12 gives thus a year starting with the wanted weekDay.
-    int recentYear = (_isLeapYear(year) ? 1956 : 1967) + (weekDay(year) * 12);
+    int recentYear = (_isLeapYear(year) ? 1956 : 1967) + (_weekDay(year) * 12);
     // Close to the year 2008 the calendar cycles every 4 * 7 years (4 for the
     // leap years, 7 for the weekdays).
     // Find the year in the range 2008..2037 that is equivalent mod 28.
     return 2008 + (recentYear - 2008) % 28;
   }
 
   /**
    * Returns the UTC year for the corresponding [secondsSinceEpoch].
    * It is relatively fast for values in the range 0 to year 2098.
    *
@@ skipping 43 matching lines @@
   static int _timeZoneOffsetInSeconds(int millisecondsSinceEpoch) {
     int equivalentSeconds = _equivalentSeconds(millisecondsSinceEpoch);
     return _timeZoneOffsetInSecondsForClampedSeconds(equivalentSeconds);
   }
 
   static String _timeZoneName(int millisecondsSinceEpoch) {
     int equivalentSeconds = _equivalentSeconds(millisecondsSinceEpoch);
     return _timeZoneNameForClampedSeconds(equivalentSeconds);
   }
 
-  final bool isUtc;
-  final int millisecondsSinceEpoch;
-
   // Natives
   static int _getCurrentMs() native "DateNatives_currentTimeMillis";
 
   static String _timeZoneNameForClampedSeconds(int secondsSinceEpoch)
       native "DateNatives_timeZoneName";
 
   static int _timeZoneOffsetInSecondsForClampedSeconds(int secondsSinceEpoch)
       native "DateNatives_timeZoneOffsetInSeconds";
 
   static int _localTimeZoneAdjustmentInSeconds()
       native "DateNatives_localTimeZoneAdjustmentInSeconds";
 }