Revert 12494.

lib/core/duration.dart

 // Copyright (c) 2011, 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.
 
 /**
  * A [Duration] represents a time span. A duration can be negative.
  */
-class Duration implements Comparable, Hashable {
-  static const int MILLISECONDS_PER_SECOND = 1000;
-  static const int SECONDS_PER_MINUTE = 60;
-  static const int MINUTES_PER_HOUR = 60;
-  static const int HOURS_PER_DAY = 24;
-
-  static const int MILLISECONDS_PER_MINUTE =
-      MILLISECONDS_PER_SECOND * SECONDS_PER_MINUTE;
-  static const int MILLISECONDS_PER_HOUR =
-      MILLISECONDS_PER_MINUTE * MINUTES_PER_HOUR;
-  static const int MILLISECONDS_PER_DAY =
-      MILLISECONDS_PER_HOUR * HOURS_PER_DAY;
-
-  static const int SECONDS_PER_HOUR = SECONDS_PER_MINUTE * MINUTES_PER_HOUR;
-  static const int SECONDS_PER_DAY = SECONDS_PER_HOUR * HOURS_PER_DAY;
-
-  static const int MINUTES_PER_DAY = MINUTES_PER_HOUR * HOURS_PER_DAY;
-
-  /**
-   * This [Duration] in milliseconds.
-   */
-  final int inMilliseconds;
-
+interface Duration extends Comparable default DurationImplementation {
   /**
    * The duration is the sum of all individual parts. This means that individual
    * parts don't need to be less than the next-bigger unit. For example [hours]
    * is allowed to have a value greater than 23.
    *
    * All individual parts are allowed to be negative.
    * All arguments are by default 0.
    */
-  const Duration({int days: 0,
-                  int hours: 0,
-                  int minutes: 0,
-                  int seconds: 0,
-                  int milliseconds: 0})
-      : inMilliseconds = days * Duration.MILLISECONDS_PER_DAY +
-                         hours * Duration.MILLISECONDS_PER_HOUR +
-                         minutes * Duration.MILLISECONDS_PER_MINUTE +
-                         seconds * Duration.MILLISECONDS_PER_SECOND +
-                         milliseconds;
+  const Duration({int days, int hours, int minutes, int seconds,
+                  int milliseconds});
 
   /**
-   * This [Duration] in days. Incomplete days are discarded
+   * Returns this [Duration] in days. Incomplete days are discarded.
    */
-  int get inDays {
-    return inMilliseconds ~/ Duration.MILLISECONDS_PER_DAY;
-  }
+  int get inDays;
 
   /**
-   * This [Duration] in hours. Incomplete hours are discarded.
+   * Returns this [Duration] in hours. Incomplete hours are discarded.
    * The returned value can be greater than 23.
    */
-  int get inHours {
-    return inMilliseconds ~/ Duration.MILLISECONDS_PER_HOUR;
-  }
+  int get inHours;
 
   /**
-   * This [Duration] in minutes. Incomplete minutes are discarded.
+   * Returns this [Duration] in minutes. Incomplete minutes are discarded.
    * The returned value can be greater than 59.
    */
-  int get inMinutes {
-    return inMilliseconds ~/ Duration.MILLISECONDS_PER_MINUTE;
-  }
+  int get inMinutes;
 
   /**
-   * This [Duration] in seconds. Incomplete seconds are discarded.
+   * Returns this [Duration] in seconds. Incomplete seconds are discarded.
    * The returned value can be greater than 59.
    */
-  int get inSeconds {
-    return inMilliseconds ~/ Duration.MILLISECONDS_PER_SECOND;
-  }
+  int get inSeconds;
 
-  bool operator ==(other) {
-    if (other is !Duration) return false;
-    return inMilliseconds == other.inMilliseconds;
-  }
+  /**
+   * Returns this [Duration] in milliseconds.
+   */
+  int get inMilliseconds;
 
-  int hashCode() {
-    return inMilliseconds.hashCode();
-  }
+  static const int MILLISECONDS_PER_SECOND = 1000;
+  static const int SECONDS_PER_MINUTE = 60;
+  static const int MINUTES_PER_HOUR = 60;
+  static const int HOURS_PER_DAY = 24;
 
-  int compareTo(Duration other) {
-    return inMilliseconds.compareTo(other.inMilliseconds);
-  }
+  static const int MILLISECONDS_PER_MINUTE =
+      MILLISECONDS_PER_SECOND * SECONDS_PER_MINUTE;
+  static const int MILLISECONDS_PER_HOUR =
+      MILLISECONDS_PER_MINUTE * MINUTES_PER_HOUR;
+  static const int MILLISECONDS_PER_DAY =
+      MILLISECONDS_PER_HOUR * HOURS_PER_DAY;
 
-  String toString() {
-    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";
-    }
+  static const int SECONDS_PER_HOUR = SECONDS_PER_MINUTE * MINUTES_PER_HOUR;
+  static const int SECONDS_PER_DAY = SECONDS_PER_HOUR * HOURS_PER_DAY;
 
-    if (inMilliseconds < 0) {
-      Duration duration =
-          new Duration(milliseconds: -inMilliseconds);
-      return "-$duration";
-    }
-    String twoDigitMinutes =
-        twoDigits(inMinutes.remainder(Duration.MINUTES_PER_HOUR));
-    String twoDigitSeconds =
-        twoDigits(inSeconds.remainder(Duration.SECONDS_PER_MINUTE));
-    String threeDigitMs =
-        threeDigits(inMilliseconds.remainder(Duration.MILLISECONDS_PER_SECOND));
-    return "$inHours:$twoDigitMinutes:$twoDigitSeconds.$threeDigitMs";
-  }
+  static const int MINUTES_PER_DAY = MINUTES_PER_HOUR * HOURS_PER_DAY;
 }