Adding DateTimeFormat class to i18n API.

src/extensions/experimental/i18n.js

Index: src/extensions/experimental/i18n.js
===================================================================
--- src/extensions/experimental/i18n.js	(revision 7878)
+++ src/extensions/experimental/i18n.js	(working copy)
@@ -131,13 +131,88 @@
 /**
  * Creates new Collator based on current locale.
  * @param {Object} - collation flags. See constructor.
- * @returns {Object} - new v8BreakIterator object.
+ * @returns {Object} - new Collator object.
  */
 v8Locale.prototype.createCollator = function(settings) {
   return new v8Locale.Collator(this, settings);
 };
 
 /**
+ * DateTimeFormat class implements locale-aware date and time formatting.
+ * @param {Object} locale - locale object to pass to formatter.
+ * @param {Object} settings - formatting flags:
+ *   - skeleton
+ *   - dateType
+ *   - timeType
+ *   - calendar
+ * @constructor
+ */
+v8Locale.DateTimeFormat = function(locale, settings) {
+  native function NativeJSDateTimeFormat();
+
+  settings = v8Locale.createSettingsOrDefault_(settings, {});
+
+  var shortDate = 'yMMdd';
+  var longDate = 'EEEEyMMMdd';
+  var shortTime = 'jm';
+  var mediumTime = 'jms';
+  var skeleton = shortDate + shortTime;
+  if (settings.hasOwnProperty('skeleton')) {
+    skeleton = settings['skeleton'];
+  } else if (settings.hasOwnProperty('dateType') &&
+             settings.hasOwnProperty('timeType')) {
+    var dt = settings['dateType'];
+    var tt = settings['timeType'];
+    if (dt === 'short' && tt === 'short') {
+      skeleton = shortDate + shortTime;
+    } else if (dt === 'short' && tt === 'medium') {
+      skeleton = shortDate + mediumTime;
+    } else if (dt === 'long' && tt === 'short') {
+      skeleton = longDate + shortTime;
+    } else if (dt === 'long' && tt === 'medium') {
+      skeleton = longDate + mediumTime;
+    }
+  } else if (settings.hasOwnProperty('dateType')) {
+    if (settings['dateType'] === 'short') {
+      skeleton = shortDate;
+    } else if (settings['dateType'] === 'long') {
+      skeleton = longDate;
+    }
+  } else if (settings.hasOwnProperty('timeType')) {
+    if (settings['timeType'] === 'short') {
+      skeleton = shortTime;
+    } else if (settings['timeType'] === 'medium') {
+      skeleton = mediumTime;
+    }
+  }
+
+  locale = v8Locale.createLocaleOrDefault_(locale);
+  var formatter = NativeJSDateTimeFormat(locale.__icuLocaleID__, skeleton);
+
+  /**
+   * Clones existing date time format with possible overrides for some
+   * of the options.
+   * @param {!Object} overrideSettings - overrides for current format settings.
+   * @returns {Object} - new DateTimeFormat object.
+   */
+  formatter.derive = function(overrideSettings) {
+    return new v8Locale.DateTimeFormat(
+        locale, v8Locale.createSettingsOrDefault_(overrideSettings, settings));
+  };
+
+  return formatter;
+};
+
+/**
+ * Creates new DateTimeFormat based on current locale.
+ * @param {Object} - formatting flags. See constructor.
+ * @returns {Object} - new DateTimeFormat object.
+ */
+v8Locale.prototype.createDateTimeFormat = function(settings) {
+  return new v8Locale.DateTimeFormat(this, settings);
+};
+
+/**
  * Merges user settings and defaults.
  * Settings that are not of object type are rejected.
  * Actual property values are not validated, but whitespace is trimmed if they