Import the v8-i18n extension into v8

src/extensions/i18n/locale.js

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// limitations under the License.
+
+// ECMAScript 402 API implementation is broken into separate files for
+// each service. The build system combines them together into one
+// Intl namespace.
+
+/**
+ * Canonicalizes the language tag, or throws in case the tag is invalid.
+ */
+function canonicalizeLanguageTag(localeID) {
+  native function NativeJSCanonicalizeLanguageTag();
+
+  // null is typeof 'object' so we have to do extra check.
+  if (typeof localeID !== 'string' && typeof localeID !== 'object' ||
+      localeID === null) {
+    throw new TypeError('Language ID should be string or object.');
+  }
+
+  var localeString = String(localeID);
+
+  if (isValidLanguageTag(localeString) === false) {
+    throw new RangeError('Invalid language tag: ' + localeString);
+  }
+
+  // This call will strip -kn but not -kn-true extensions.
+  // ICU bug filled - http://bugs.icu-project.org/trac/ticket/9265.
+  // TODO(cira): check if -u-kn-true-kc-true-kh-true still throws after
+  // upgrade to ICU 4.9.
+  var tag = NativeJSCanonicalizeLanguageTag(localeString);
+  if (tag === 'invalid-tag') {
+    throw new RangeError('Invalid language tag: ' + localeString);
+  }
+
+  return tag;
+}
+
+
+/**
+ * Returns an array where all locales are canonicalized and duplicates removed.
+ * Throws on locales that are not well formed BCP47 tags.
+ */
+function initializeLocaleList(locales) {
+  var seen = [];
+  if (locales === undefined) {
+    // Constructor is called without arguments.
+    seen = [];
+  } else {
+    // We allow single string localeID.
+    if (typeof locales === 'string') {
+      seen.push(canonicalizeLanguageTag(locales));
+      return freezeArray(seen);
+    }
+
+    var o = toObject(locales);
+    // Converts it to UInt32 (>>> is shr on 32bit integers).
+    var len = o.length >>> 0;
+
+    for (var k = 0; k < len; k++) {
+      if (k in o) {
+        var value = o[k];
+
+        var tag = canonicalizeLanguageTag(value);
+
+        if (seen.indexOf(tag) === -1) {
+          seen.push(tag);
+        }
+      }
+    }
+  }
+
+  return freezeArray(seen);
+}
+
+
+/**
+ * Validates the language tag. Section 2.2.9 of the bcp47 spec
+ * defines a valid tag.
+ *
+ * ICU is too permissible and lets invalid tags, like
+ * hant-cmn-cn, through.
+ *
+ * Returns false if the language tag is invalid.
+ */
+function isValidLanguageTag(locale) {
+  // Check if it's well-formed, including grandfadered tags.
+  if (LANGUAGE_TAG_RE.test(locale) === false) {
+    return false;
+  }
+
+  // Just return if it's a x- form. It's all private.
+  if (locale.indexOf('x-') === 0) {
+    return true;
+  }
+
+  // Check if there are any duplicate variants or singletons (extensions).
+
+  // Remove private use section.
+  locale = locale.split(/-x-/)[0];
+
+  // Skip language since it can match variant regex, so we start from 1.
+  // We are matching i-klingon here, but that's ok, since i-klingon-klingon
+  // is not valid and would fail LANGUAGE_TAG_RE test.
+  var variants = [];
+  var extensions = [];
+  var parts = locale.split(/-/);
+  for (var i = 1; i < parts.length; i++) {
+    var value = parts[i];
+    if (LANGUAGE_VARIANT_RE.test(value) === true && extensions.length === 0) {
+      if (variants.indexOf(value) === -1) {
+        variants.push(value);
+      } else {
+        return false;
+      }
+    }
+
+    if (LANGUAGE_SINGLETON_RE.test(value) === true) {
+      if (extensions.indexOf(value) === -1) {
+        extensions.push(value);
+      } else {
+        return false;
+      }
+    }
+  }
+
+  return true;
+ }
+
+
+/**
+ * Builds a regular expresion that validates the language tag
+ * against bcp47 spec.
+ * Uses http://tools.ietf.org/html/bcp47, section 2.1, ABNF.
+ * Runs on load and initializes the global REs.
+ */
+(function() {
+  var alpha = '[a-zA-Z]';
+  var digit = '[0-9]';
+  var alphanum = '(' + alpha + '|' + digit + ')';
+  var regular = '(art-lojban|cel-gaulish|no-bok|no-nyn|zh-guoyu|zh-hakka|' +
+                'zh-min|zh-min-nan|zh-xiang)';
+  var irregular = '(en-GB-oed|i-ami|i-bnn|i-default|i-enochian|i-hak|' +
+                  'i-klingon|i-lux|i-mingo|i-navajo|i-pwn|i-tao|i-tay|' +
+                  'i-tsu|sgn-BE-FR|sgn-BE-NL|sgn-CH-DE)';
+  var grandfathered = '(' + irregular + '|' + regular + ')';
+  var privateUse = '(x(-' + alphanum + '{1,8})+)';
+
+  var singleton = '(' + digit + '|[A-WY-Za-wy-z])';
+  LANGUAGE_SINGLETON_RE = new RegExp('^' + singleton + '$', 'i');
+
+  var extension = '(' + singleton + '(-' + alphanum + '{2,8})+)';
+
+  var variant = '(' + alphanum + '{5,8}|(' + digit + alphanum + '{3}))';
+  LANGUAGE_VARIANT_RE = new RegExp('^' + variant + '$', 'i');
+
+  var region = '(' + alpha + '{2}|' + digit + '{3})';
+  var script = '(' + alpha + '{4})';
+  var extLang = '(' + alpha + '{3}(-' + alpha + '{3}){0,2})';
+  var language = '(' + alpha + '{2,3}(-' + extLang + ')?|' + alpha + '{4}|' +
+                 alpha + '{5,8})';
+  var langTag = language + '(-' + script + ')?(-' + region + ')?(-' +
+                variant + ')*(-' + extension + ')*(-' + privateUse + ')?';
+
+  var languageTag =
+      '^(' + langTag + '|' + privateUse + '|' + grandfathered + ')$';
+  LANGUAGE_TAG_RE = new RegExp(languageTag, 'i');
+})();