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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 /* Portions Copyright Norbert Lindenberg 2011-2012. */

 /*global JSMSG_INTL_OBJECT_NOT_INITED: false, JSMSG_INVALID_LOCALES_ELEMENT: false,

          JSMSG_INVALID_LANGUAGE_TAG: false, JSMSG_INVALID_LOCALE_MATCHER: false,

          JSMSG_INVALID_OPTION_VALUE: false, JSMSG_INVALID_DIGITS_VALUE: false,

          JSMSG_INTL_OBJECT_REINITED: false, JSMSG_INVALID_CURRENCY_CODE: false,

          JSMSG_UNDEFINED_CURRENCY: false, JSMSG_INVALID_TIME_ZONE: false,

          JSMSG_DATE_NOT_FINITE: false,

          intl_Collator_availableLocales: false,

          intl_availableCollations: false,

          intl_CompareStrings: false,

          intl_NumberFormat_availableLocales: false,

          intl_numberingSystem: false,

          intl_FormatNumber: false,

          intl_DateTimeFormat_availableLocales: false,

          intl_availableCalendars: false,

          intl_patternForSkeleton: false,

          intl_FormatDateTime: false,

 */

 /*

  * The Intl module specified by standard ECMA-402,

  * ECMAScript Internationalization API Specification.

  */

 /********** Locales, Time Zones, and Currencies **********/

 /**

  * Convert s to upper case, but limited to characters a-z.

  *

  * Spec: ECMAScript Internationalization API Specification, 6.1.

  */

 function toASCIIUpperCase(s) {

     assert(typeof s === "string", "toASCIIUpperCase");

     // String.prototype.toUpperCase may map non-ASCII characters into ASCII,

     // so go character by character (actually code unit by code unit, but

     // since we only care about ASCII characters here, that's OK).

     var result = "";

     for (var i = 0; i < s.length; i++) {

         var c = s[i];

         if ("a" <= c && c <= "z")

             c = callFunction(std_String_toUpperCase, c);

         result += c;

     }

     return result;

 }

 /**

  * Regular expression matching a "Unicode locale extension sequence", which the

  * specification defines as: "any substring of a language tag that starts with

  * a separator '-' and the singleton 'u' and includes the maximum sequence of

  * following non-singleton subtags and their preceding '-' separators."

  *

  * Alternatively, this may be defined as: the components of a language tag that

  * match the extension production in RFC 5646, where the singleton component is

  * "u".

  *

  * Spec: ECMAScript Internationalization API Specification, 6.2.1.

  */

 var unicodeLocaleExtensionSequence = "-u(-[a-z0-9]{2,8})+";

 var unicodeLocaleExtensionSequenceRE = new RegExp(unicodeLocaleExtensionSequence);

 /**

  * Removes Unicode locale extension sequences from the given language tag.

  */

 function removeUnicodeExtensions(locale) {

     // Don't use std_String_replace directly with a regular expression,

     // as that would set RegExp statics.

     var extensions;

     while ((extensions = regexp_exec_no_statics(unicodeLocaleExtensionSequenceRE, locale)) !== null) {

         locale = callFunction(std_String_replace, locale, extensions[0], "");

         unicodeLocaleExtensionSequenceRE.lastIndex = 0;

     }

     return locale;

 }

 /**

  * Regular expression defining BCP 47 language tags.

  *

  * Spec: RFC 5646 section 2.1.

  */

 var languageTagRE = (function () {

     // RFC 5234 section B.1

     // ALPHA          =  %x41-5A / %x61-7A   ; A-Z / a-z

     var ALPHA = "[a-zA-Z]";

     // DIGIT          =  %x30-39

     //                        ; 0-9

     var DIGIT = "[0-9]";

     // RFC 5646 section 2.1

     // alphanum      = (ALPHA / DIGIT)     ; letters and numbers

     var alphanum = "(?:" + ALPHA + "|" + DIGIT + ")";

     // regular       = "art-lojban"        ; these tags match the 'langtag'

     //               / "cel-gaulish"       ; production, but their subtags

     //               / "no-bok"            ; are not extended language

     //               / "no-nyn"            ; or variant subtags: their meaning

     //               / "zh-guoyu"          ; is defined by their registration

     //               / "zh-hakka"          ; and all of these are deprecated

     //               / "zh-min"            ; in favor of a more modern

     //               / "zh-min-nan"        ; subtag or sequence of subtags

     //               / "zh-xiang"

     var regular = "(?:art-lojban|cel-gaulish|no-bok|no-nyn|zh-guoyu|zh-hakka|zh-min|zh-min-nan|zh-xiang)";

     // irregular     = "en-GB-oed"         ; irregular tags do not match

     //                / "i-ami"             ; the 'langtag' production and

     //                / "i-bnn"             ; would not otherwise be

     //                / "i-default"         ; considered 'well-formed'

     //                / "i-enochian"        ; These tags are all valid,

     //                / "i-hak"             ; but most are deprecated

     //                / "i-klingon"         ; in favor of more modern

     //                / "i-lux"             ; subtags or subtag

     //                / "i-mingo"           ; combination

     //                / "i-navajo"

     //                / "i-pwn"

     //                / "i-tao"

     //                / "i-tay"

     //                / "i-tsu"

     //                / "sgn-BE-FR"

     //                / "sgn-BE-NL"

     //                / "sgn-CH-DE"

     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)";

     // grandfathered = irregular           ; non-redundant tags registered

     //               / regular             ; during the RFC 3066 era

     var grandfathered = "(?:" + irregular + "|" + regular + ")";

     // privateuse    = "x" 1*("-" (1*8alphanum))

     var privateuse = "(?:x(?:-[a-z0-9]{1,8})+)";

     // singleton     = DIGIT               ; 0 - 9

     //               / %x41-57             ; A - W

     //               / %x59-5A             ; Y - Z

     //               / %x61-77             ; a - w

     //               / %x79-7A             ; y - z

     var singleton = "(?:" + DIGIT + "|[A-WY-Za-wy-z])";

     // extension     = singleton 1*("-" (2*8alphanum))

     var extension = "(?:" + singleton + "(?:-" + alphanum + "{2,8})+)";

     // variant       = 5*8alphanum         ; registered variants

     //               / (DIGIT 3alphanum)

     var variant = "(?:" + alphanum + "{5,8}|(?:" + DIGIT + alphanum + "{3}))";

     // region        = 2ALPHA              ; ISO 3166-1 code

     //               / 3DIGIT              ; UN M.49 code

     var region = "(?:" + ALPHA + "{2}|" + DIGIT + "{3})";

     // script        = 4ALPHA              ; ISO 15924 code

     var script = "(?:" + ALPHA + "{4})";

     // extlang       = 3ALPHA              ; selected ISO 639 codes

     //                 *2("-" 3ALPHA)      ; permanently reserved

     var extlang = "(?:" + ALPHA + "{3}(?:-" + ALPHA + "{3}){0,2})";

     // language      = 2*3ALPHA            ; shortest ISO 639 code

     //                 ["-" extlang]       ; sometimes followed by

     //                                     ; extended language subtags

     //               / 4ALPHA              ; or reserved for future use

     //               / 5*8ALPHA            ; or registered language subtag

     var language = "(?:" + ALPHA + "{2,3}(?:-" + extlang + ")?|" + ALPHA + "{4}|" + ALPHA + "{5,8})";

     // langtag       = language

     //                 ["-" script]

     //                 ["-" region]

     //                 *("-" variant)

     //                 *("-" extension)

     //                 ["-" privateuse]

     var langtag = language + "(?:-" + script + ")?(?:-" + region + ")?(?:-" +

                   variant + ")*(?:-" + extension + ")*(?:-" + privateuse + ")?";

     // Language-Tag  = langtag             ; normal language tags

     //               / privateuse          ; private use tag

     //               / grandfathered       ; grandfathered tags

     var languageTag = "^(?:" + langtag + "|" + privateuse + "|" + grandfathered + ")$";

     // Language tags are case insensitive (RFC 5646 section 2.1.1).

     return new RegExp(languageTag, "i");

 }());

 var duplicateVariantRE = (function () {

     // RFC 5234 section B.1

     // ALPHA          =  %x41-5A / %x61-7A   ; A-Z / a-z

     var ALPHA = "[a-zA-Z]";

     // DIGIT          =  %x30-39

     //                        ; 0-9

     var DIGIT = "[0-9]";

     // RFC 5646 section 2.1

     // alphanum      = (ALPHA / DIGIT)     ; letters and numbers

     var alphanum = "(?:" + ALPHA + "|" + DIGIT + ")";

     // variant       = 5*8alphanum         ; registered variants

     //               / (DIGIT 3alphanum)

     var variant = "(?:" + alphanum + "{5,8}|(?:" + DIGIT + alphanum + "{3}))";

     // Match a langtag that contains a duplicate variant.

     var duplicateVariant =

         // Match everything in a langtag prior to any variants, and maybe some

         // of the variants as well (which makes this pattern inefficient but

         // not wrong, for our purposes);

         "(?:" + alphanum + "{2,8}-)+" +

         // a variant, parenthesised so that we can refer back to it later;

         "(" + variant + ")-" +

         // zero or more subtags at least two characters long (thus stopping

         // before extension and privateuse components);

         "(?:" + alphanum + "{2,8}-)*" +

         // and the same variant again

         "\\1" +

         // ...but not followed by any characters that would turn it into a

         // different subtag.

         "(?!" + alphanum + ")";

     // Language tags are case insensitive (RFC 5646 section 2.1.1), but for

     // this regular expression that's covered by having its character classes

     // list both upper- and lower-case characters.

     return new RegExp(duplicateVariant);

 }());

 var duplicateSingletonRE = (function () {

     // RFC 5234 section B.1

     // ALPHA          =  %x41-5A / %x61-7A   ; A-Z / a-z

     var ALPHA = "[a-zA-Z]";

     // DIGIT          =  %x30-39

     //                        ; 0-9

     var DIGIT = "[0-9]";

     // RFC 5646 section 2.1

     // alphanum      = (ALPHA / DIGIT)     ; letters and numbers

     var alphanum = "(?:" + ALPHA + "|" + DIGIT + ")";

     // singleton     = DIGIT               ; 0 - 9

     //               / %x41-57             ; A - W

     //               / %x59-5A             ; Y - Z

     //               / %x61-77             ; a - w

     //               / %x79-7A             ; y - z

     var singleton = "(?:" + DIGIT + "|[A-WY-Za-wy-z])";

     // Match a langtag that contains a duplicate singleton.

     var duplicateSingleton =

         // Match a singleton subtag, parenthesised so that we can refer back to

         // it later;

         "-(" + singleton + ")-" +

         // then zero or more subtags;

         "(?:" + alphanum + "+-)*" +

         // and the same singleton again

         "\\1" +

         // ...but not followed by any characters that would turn it into a

         // different subtag.

         "(?!" + alphanum + ")";

     // Language tags are case insensitive (RFC 5646 section 2.1.1), but for

     // this regular expression that's covered by having its character classes

     // list both upper- and lower-case characters.

     return new RegExp(duplicateSingleton);

 }());

 /**

  * Verifies that the given string is a well-formed BCP 47 language tag

  * with no duplicate variant or singleton subtags.

  *

  * Spec: ECMAScript Internationalization API Specification, 6.2.2.

  */

 function IsStructurallyValidLanguageTag(locale) {

     assert(typeof locale === "string", "IsStructurallyValidLanguageTag");

     if (!regexp_test_no_statics(languageTagRE, locale))

         return false;

     // Before checking for duplicate variant or singleton subtags with

     // regular expressions, we have to get private use subtag sequences

     // out of the picture.

     if (callFunction(std_String_startsWith, locale, "x-"))

         return true;

     var pos = callFunction(std_String_indexOf, locale, "-x-");

     if (pos !== -1)

         locale = callFunction(std_String_substring, locale, 0, pos);

     // Check for duplicate variant or singleton subtags.

     return !regexp_test_no_statics(duplicateVariantRE, locale) &&

            !regexp_test_no_statics(duplicateSingletonRE, locale);

 }

 /**

  * Canonicalizes the given structurally valid BCP 47 language tag, including

  * regularized case of subtags. For example, the language tag

  * Zh-NAN-haNS-bu-variant2-Variant1-u-ca-chinese-t-Zh-laTN-x-PRIVATE, where

  *

  *     Zh             ; 2*3ALPHA

  *     -NAN           ; ["-" extlang]

  *     -haNS          ; ["-" script]

  *     -bu            ; ["-" region]

  *     -variant2      ; *("-" variant)

  *     -Variant1

  *     -u-ca-chinese  ; *("-" extension)

  *     -t-Zh-laTN

  *     -x-PRIVATE     ; ["-" privateuse]

  *

  * becomes nan-Hans-mm-variant2-variant1-t-zh-latn-u-ca-chinese-x-private

  *

  * Spec: ECMAScript Internationalization API Specification, 6.2.3.

  * Spec: RFC 5646, section 4.5.

  */

 function CanonicalizeLanguageTag(locale) {

     assert(IsStructurallyValidLanguageTag(locale), "CanonicalizeLanguageTag");

     // The input

     // "Zh-NAN-haNS-bu-variant2-Variant1-u-ca-chinese-t-Zh-laTN-x-PRIVATE"

     // will be used throughout this method to illustrate how it works.

     // Language tags are compared and processed case-insensitively, so

     // technically it's not necessary to adjust case. But for easier processing,

     // and because the canonical form for most subtags is lower case, we start

     // with lower case for all.

     // "Zh-NAN-haNS-bu-variant2-Variant1-u-ca-chinese-t-Zh-laTN-x-PRIVATE" ->

     // "zh-nan-hans-bu-variant2-variant1-u-ca-chinese-t-zh-latn-x-private"

     locale = callFunction(std_String_toLowerCase, locale);

     // Handle mappings for complete tags.

     if (callFunction(std_Object_hasOwnProperty, langTagMappings, locale))

         return langTagMappings[locale];

     var subtags = callFunction(std_String_split, locale, "-");

     var i = 0;

     // Handle the standard part: All subtags before the first singleton or "x".

     // "zh-nan-hans-bu-variant2-variant1"

     while (i < subtags.length) {

         var subtag = subtags[i];

         // If we reach the start of an extension sequence or private use part,

         // we're done with this loop. We have to check for i > 0 because for

         // irregular language tags, such as i-klingon, the single-character

         // subtag "i" is not the start of an extension sequence.

         // In the example, we break at "u".

         if (subtag.length === 1 && (i > 0 || subtag === "x"))

             break;

         if (subtag.length === 4) {

             // 4-character subtags are script codes; their first character

             // needs to be capitalized. "hans" -> "Hans"

             subtag = callFunction(std_String_toUpperCase, subtag[0]) +

                      callFunction(std_String_substring, subtag, 1);

         } else if (i !== 0 && subtag.length === 2) {

             // 2-character subtags that are not in initial position are region

             // codes; they need to be upper case. "bu" -> "BU"

             subtag = callFunction(std_String_toUpperCase, subtag);

         }

         if (callFunction(std_Object_hasOwnProperty, langSubtagMappings, subtag)) {

             // Replace deprecated subtags with their preferred values.

             // "BU" -> "MM"

             // This has to come after we capitalize region codes because

             // otherwise some language and region codes could be confused.

             // For example, "in" is an obsolete language code for Indonesian,

             // but "IN" is the country code for India.

             // Note that the script generating langSubtagMappings makes sure

             // that no regular subtag mapping will replace an extlang code.

             subtag = langSubtagMappings[subtag];

         } else if (callFunction(std_Object_hasOwnProperty, extlangMappings, subtag)) {

             // Replace deprecated extlang subtags with their preferred values,

             // and remove the preceding subtag if it's a redundant prefix.

             // "zh-nan" -> "nan"

             // Note that the script generating extlangMappings makes sure that

             // no extlang mapping will replace a normal language code.

             subtag = extlangMappings[subtag].preferred;

             if (i === 1 && extlangMappings[subtag].prefix === subtags[0]) {

                 callFunction(std_Array_shift, subtags);

                 i--;

             }

         }

         subtags[i] = subtag;

         i++;

     }

     var normal = callFunction(std_Array_join, callFunction(std_Array_slice, subtags, 0, i), "-");

     // Extension sequences are sorted by their singleton characters.

     // "u-ca-chinese-t-zh-latn" -> "t-zh-latn-u-ca-chinese"

     var extensions = new List();

     while (i < subtags.length && subtags[i] !== "x") {

         var extensionStart = i;

         i++;

         while (i < subtags.length && subtags[i].length > 1)

             i++;

         var extension = callFunction(std_Array_join, callFunction(std_Array_slice, subtags, extensionStart, i), "-");

         extensions.push(extension);

     }

     extensions.sort();

     // Private use sequences are left as is. "x-private"

     var privateUse = "";

     if (i < subtags.length)

         privateUse = callFunction(std_Array_join, callFunction(std_Array_slice, subtags, i), "-");

     // Put everything back together.

     var canonical = normal;

     if (extensions.length > 0)

         canonical += "-" + extensions.join("-");

     if (privateUse.length > 0) {

         // Be careful of a Language-Tag that is entirely privateuse.

         if (canonical.length > 0)

             canonical += "-" + privateUse;

         else

             canonical = privateUse;

     }

     return canonical;

 }

 // mappings from some commonly used old-style language tags to current flavors

 // with script codes

 var oldStyleLanguageTagMappings = {

     "pa-PK": "pa-Arab-PK",

     "zh-CN": "zh-Hans-CN",

     "zh-HK": "zh-Hant-HK",

     "zh-SG": "zh-Hans-SG",

     "zh-TW": "zh-Hant-TW"

 };

 /**

  * Returns the BCP 47 language tag for the host environment's current locale.

  *

  * Spec: ECMAScript Internationalization API Specification, 6.2.4.

  */

 function DefaultLocale() {

     // The locale of last resort is used if none of the available locales

     // satisfies a request. "en-GB" is used based on the assumptions that

     // English is the most common second language, that both en-GB and en-US

     // are normally available in an implementation, and that en-GB is more

     // representative of the English used in other locales.

     var localeOfLastResort = "en-GB";

     var locale = RuntimeDefaultLocale();

     if (!IsStructurallyValidLanguageTag(locale))

         return localeOfLastResort;

     locale = CanonicalizeLanguageTag(locale);

     if (callFunction(std_Object_hasOwnProperty, oldStyleLanguageTagMappings, locale))

         locale = oldStyleLanguageTagMappings[locale];

     if (!(collatorInternalProperties.availableLocales()[locale] &&

           numberFormatInternalProperties.availableLocales()[locale] &&

           dateTimeFormatInternalProperties.availableLocales()[locale]))

     {

         locale = localeOfLastResort;

     }

     return locale;

 }

 /**

  * Verifies that the given string is a well-formed ISO 4217 currency code.

  *

  * Spec: ECMAScript Internationalization API Specification, 6.3.1.

  */

 function IsWellFormedCurrencyCode(currency) {

     var c = ToString(currency);

     var normalized = toASCIIUpperCase(c);

     if (normalized.length !== 3)

         return false;

     return !regexp_test_no_statics(/[^A-Z]/, normalized);

 }

 /********** Locale and Parameter Negotiation **********/

 /**

  * Add old-style language tags without script code for locales that in current

  * usage would include a script subtag. Returns the availableLocales argument

  * provided.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.1.

  */

 function addOldStyleLanguageTags(availableLocales) {

     var oldStyleLocales = std_Object_getOwnPropertyNames(oldStyleLanguageTagMappings);

     for (var i = 0; i < oldStyleLocales.length; i++) {

         var oldStyleLocale = oldStyleLocales[i];

         if (availableLocales[oldStyleLanguageTagMappings[oldStyleLocale]])

             availableLocales[oldStyleLocale] = true;

     }

     return availableLocales;

 }

 /**

  * Canonicalizes a locale list.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.1.

  */

 function CanonicalizeLocaleList(locales) {

     if (locales === undefined)

         return new List();

     var seen = new List();

     if (typeof locales === "string")

         locales = [locales];

     var O = ToObject(locales);

     var len = TO_UINT32(O.length);

     var k = 0;

     while (k < len) {

         // Don't call ToString(k) - SpiderMonkey is faster with integers.

         var kPresent = HasProperty(O, k);

         if (kPresent) {

             var kValue = O[k];

             if (!(typeof kValue === "string" || IsObject(kValue)))

                 ThrowError(JSMSG_INVALID_LOCALES_ELEMENT);

             var tag = ToString(kValue);

             if (!IsStructurallyValidLanguageTag(tag))

                 ThrowError(JSMSG_INVALID_LANGUAGE_TAG, tag);

             tag = CanonicalizeLanguageTag(tag);

             if (seen.indexOf(tag) === -1)

                 seen.push(tag);

         }

         k++;

     }

     return seen;

 }

 /**

  * Compares a BCP 47 language tag against the locales in availableLocales

  * and returns the best available match. Uses the fallback

  * mechanism of RFC 4647, section 3.4.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.2.

  * Spec: RFC 4647, section 3.4.

  */

 function BestAvailableLocale(availableLocales, locale) {

     assert(IsStructurallyValidLanguageTag(locale), "invalid BestAvailableLocale locale structure");

     assert(locale === CanonicalizeLanguageTag(locale), "non-canonical BestAvailableLocale locale");

     assert(callFunction(std_String_indexOf, locale, "-u-") === -1, "locale shouldn't contain -u-");

     var candidate = locale;

     while (true) {

         if (availableLocales[candidate])

             return candidate;

         var pos = callFunction(std_String_lastIndexOf, candidate, "-");

         if (pos === -1)

             return undefined;

         if (pos >= 2 && candidate[pos - 2] === "-")

             pos -= 2;

         candidate = callFunction(std_String_substring, candidate, 0, pos);

     }

 }

 /**

  * Compares a BCP 47 language priority list against the set of locales in

  * availableLocales and determines the best available language to meet the

  * request. Options specified through Unicode extension subsequences are

  * ignored in the lookup, but information about such subsequences is returned

  * separately.

  *

  * This variant is based on the Lookup algorithm of RFC 4647 section 3.4.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.3.

  * Spec: RFC 4647, section 3.4.

  */

 function LookupMatcher(availableLocales, requestedLocales) {

     var i = 0;

     var len = requestedLocales.length;

     var availableLocale;

     var locale, noExtensionsLocale;

     while (i < len && availableLocale === undefined) {

         locale = requestedLocales[i];

         noExtensionsLocale = removeUnicodeExtensions(locale);

         availableLocale = BestAvailableLocale(availableLocales, noExtensionsLocale);

         i++;

     }

     var result = new Record();

     if (availableLocale !== undefined) {

         result.locale = availableLocale;

         if (locale !== noExtensionsLocale) {

             var extensionMatch = regexp_exec_no_statics(unicodeLocaleExtensionSequenceRE, locale);

             var extension = extensionMatch[0];

             var extensionIndex = extensionMatch.index;

             result.extension = extension;

             result.extensionIndex = extensionIndex;

         }

     } else {

         result.locale = DefaultLocale();

     }

     return result;

 }

 /**

  * Compares a BCP 47 language priority list against the set of locales in

  * availableLocales and determines the best available language to meet the

  * request. Options specified through Unicode extension subsequences are

  * ignored in the lookup, but information about such subsequences is returned

  * separately.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.4.

  */

 function BestFitMatcher(availableLocales, requestedLocales) {

     // this implementation doesn't have anything better

     return LookupMatcher(availableLocales, requestedLocales);

 }

 /**

  * Compares a BCP 47 language priority list against availableLocales and

  * determines the best available language to meet the request. Options specified

  * through Unicode extension subsequences are negotiated separately, taking the

  * caller's relevant extensions and locale data as well as client-provided

  * options into consideration.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.5.

  */

 function ResolveLocale(availableLocales, requestedLocales, options, relevantExtensionKeys, localeData) {

     /*jshint laxbreak: true */

     // Steps 1-3.

     var matcher = options.localeMatcher;

     var r = (matcher === "lookup")

             ? LookupMatcher(availableLocales, requestedLocales)

             : BestFitMatcher(availableLocales, requestedLocales);

     // Step 4.

     var foundLocale = r.locale;

     // Step 5.a.

     var extension = r.extension;

     var extensionIndex, extensionSubtags, extensionSubtagsLength;

     // Step 5.

     if (extension !== undefined) {

         // Step 5.b.

         extensionIndex = r.extensionIndex;

         // Steps 5.d-e.

         extensionSubtags = callFunction(std_String_split, extension, "-");

         extensionSubtagsLength = extensionSubtags.length;

     }

     // Steps 6-7.

     var result = new Record();

     result.dataLocale = foundLocale;

     // Step 8.

     var supportedExtension = "-u";

     // Steps 9-11.

     var i = 0;

     var len = relevantExtensionKeys.length;

     while (i < len) {

         // Steps 11.a-c.

         var key = relevantExtensionKeys[i];

         // In this implementation, localeData is a function, not an object.

         var foundLocaleData = localeData(foundLocale);

         var keyLocaleData = foundLocaleData[key];

         // Locale data provides default value.

         // Step 11.d.

         var value = keyLocaleData[0];

         // Locale tag may override.

         // Step 11.e.

         var supportedExtensionAddition = "";

         // Step 11.f is implemented by Utilities.js.

         var valuePos;

         // Step 11.g.

         if (extensionSubtags !== undefined) {

             // Step 11.g.i.

             var keyPos = callFunction(std_Array_indexOf, extensionSubtags, key);

             // Step 11.g.ii.

             if (keyPos !== -1) {

                 // Step 11.g.ii.1.

                 if (keyPos + 1 < extensionSubtagsLength &&

                     extensionSubtags[keyPos + 1].length > 2)

                 {

                     // Step 11.g.ii.1.a.

                     var requestedValue = extensionSubtags[keyPos + 1];

                     // Step 11.g.ii.1.b.

                     valuePos = callFunction(std_Array_indexOf, keyLocaleData, requestedValue);

                     // Step 11.g.ii.1.c.

                     if (valuePos !== -1) {

                         value = requestedValue;

                         supportedExtensionAddition = "-" + key + "-" + value;

                     }

                 } else {

                     // Step 11.g.ii.2.

                     // According to the LDML spec, if there's no type value,

                     // and true is an allowed value, it's used.

                     // Step 11.g.ii.2.a.

                     valuePos = callFunction(std_Array_indexOf, keyLocaleData, "true");

                     // Step 11.g.ii.2.b.

                     if (valuePos !== -1)

                         value = "true";

                 }

             }

         }

         // Options override all.

         // Step 11.h.i.

         var optionsValue = options[key];

         // Step 11.h, 11.h.ii.

         if (optionsValue !== undefined &&

             callFunction(std_Array_indexOf, keyLocaleData, optionsValue) !== -1)

         {

             // Step 11.h.ii.1.

             if (optionsValue !== value) {

                 value = optionsValue;

                 supportedExtensionAddition = "";

             }

         }

         // Steps 11.i-k.

         result[key] = value;

         supportedExtension += supportedExtensionAddition;

         i++;

     }

     // Step 12.

     if (supportedExtension.length > 2) {

         var preExtension = callFunction(std_String_substring, foundLocale, 0, extensionIndex);

         var postExtension = callFunction(std_String_substring, foundLocale, extensionIndex);

         foundLocale = preExtension + supportedExtension + postExtension;

     }

     // Steps 13-14.

     result.locale = foundLocale;

     return result;

 }

 /**

  * Returns the subset of requestedLocales for which availableLocales has a

  * matching (possibly fallback) locale. Locales appear in the same order in the

  * returned list as in the input list.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.6.

  */

 function LookupSupportedLocales(availableLocales, requestedLocales) {

     // Steps 1-2.

     var len = requestedLocales.length;

     var subset = new List();

     // Steps 3-4.

     var k = 0;

     while (k < len) {

         // Steps 4.a-b.

         var locale = requestedLocales[k];

         var noExtensionsLocale = removeUnicodeExtensions(locale);

         // Step 4.c-d.

         var availableLocale = BestAvailableLocale(availableLocales, noExtensionsLocale);

         if (availableLocale !== undefined)

             subset.push(locale);

         // Step 4.e.

         k++;

     }

     // Steps 5-6.

     return subset.slice(0);

 }

 /**

  * Returns the subset of requestedLocales for which availableLocales has a

  * matching (possibly fallback) locale. Locales appear in the same order in the

  * returned list as in the input list.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.7.

  */

 function BestFitSupportedLocales(availableLocales, requestedLocales) {

     // don't have anything better

     return LookupSupportedLocales(availableLocales, requestedLocales);

 }

 /**

  * Returns the subset of requestedLocales for which availableLocales has a

  * matching (possibly fallback) locale. Locales appear in the same order in the

  * returned list as in the input list.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.8.

  */

 function SupportedLocales(availableLocales, requestedLocales, options) {

     /*jshint laxbreak: true */

     // Step 1.

     var matcher;

     if (options !== undefined) {

         // Steps 1.a-b.

         options = ToObject(options);

         matcher = options.localeMatcher;

         // Step 1.c.

         if (matcher !== undefined) {

             matcher = ToString(matcher);

             if (matcher !== "lookup" && matcher !== "best fit")

                 ThrowError(JSMSG_INVALID_LOCALE_MATCHER, matcher);

         }

     }

     // Steps 2-3.

     var subset = (matcher === undefined || matcher === "best fit")

                  ? BestFitSupportedLocales(availableLocales, requestedLocales)

                  : LookupSupportedLocales(availableLocales, requestedLocales);

     // Step 4.

     for (var i = 0; i < subset.length; i++) {

         _DefineValueProperty(subset, i, subset[i],

                              ATTR_ENUMERABLE | ATTR_NONCONFIGURABLE | ATTR_NONWRITABLE);

     }

     _DefineValueProperty(subset, "length", subset.length,

                          ATTR_NONENUMERABLE | ATTR_NONCONFIGURABLE | ATTR_NONWRITABLE);

     // Step 5.

     return subset;

 }

 /**

  * Extracts a property value from the provided options object, converts it to

  * the required type, checks whether it is one of a list of allowed values,

  * and fills in a fallback value if necessary.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.9.

  */

 function GetOption(options, property, type, values, fallback) {

     // Step 1.

     var value = options[property];

     // Step 2.

     if (value !== undefined) {

         // Steps 2.a-c.

         if (type === "boolean")

             value = ToBoolean(value);

         else if (type === "string")

             value = ToString(value);

         else

             assert(false, "GetOption");

         // Step 2.d.

         if (values !== undefined && callFunction(std_Array_indexOf, values, value) === -1)

             ThrowError(JSMSG_INVALID_OPTION_VALUE, property, value);

         // Step 2.e.

         return value;

     }

     // Step 3.

     return fallback;

 }

 /**

  * Extracts a property value from the provided options object, converts it to a

  * Number value, checks whether it is in the allowed range, and fills in a

  * fallback value if necessary.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.2.10.

  */

 function GetNumberOption(options, property, minimum, maximum, fallback) {

     assert(typeof minimum === "number", "GetNumberOption");

     assert(typeof maximum === "number", "GetNumberOption");

     assert(fallback === undefined || (fallback >= minimum && fallback <= maximum), "GetNumberOption");

     // Step 1.

     var value = options[property];

     // Step 2.

     if (value !== undefined) {

         value = ToNumber(value);

         if (std_isNaN(value) || value < minimum || value > maximum)

             ThrowError(JSMSG_INVALID_DIGITS_VALUE, value);

         return std_Math_floor(value);

     }

     // Step 3.

     return fallback;

 }

 /********** Property access for Intl objects **********/

 /**

  * Set a normal public property p of o to value v, but use Object.defineProperty

  * to avoid interference from setters on Object.prototype.

  */

 function defineProperty(o, p, v) {

     _DefineValueProperty(o, p, v, ATTR_ENUMERABLE | ATTR_CONFIGURABLE | ATTR_WRITABLE);

 }

 /**

  * Weak map used to track the initialize-as-Intl status (and, if an object has

  * been so initialized, the Intl-specific internal properties) of all objects.

  * Presence of an object as a key within this map indicates that the object has

  * its [[initializedIntlObject]] internal property set to true.  The associated

  * value is an object whose structure is documented in |initializeIntlObject|

  * below.

  *

  * Ideally we'd be using private symbols for internal properties, but

  * SpiderMonkey doesn't have those yet.

  */

 var internalsMap = new WeakMap();

 /**

  * Set the [[initializedIntlObject]] internal property of |obj| to true.

  */

 function initializeIntlObject(obj) {

     assert(IsObject(obj), "Non-object passed to initializeIntlObject");

     // Intl-initialized objects are weird.  They have [[initializedIntlObject]]

     // set on them, but they don't *necessarily* have any other properties.

     var internals = std_Object_create(null);

     // The meaning of an internals object for an object |obj| is as follows.

     //

     // If the .type is "partial", |obj| has [[initializedIntlObject]] set but

     // nothing else.  No other property of |internals| can be used.  (This

     // occurs when InitializeCollator or similar marks an object as

     // [[initializedIntlObject]] but fails before marking it as the appropriate

     // more-specific type ["Collator", "DateTimeFormat", "NumberFormat"].)

     //

     // Otherwise, the .type indicates the type of Intl object that |obj| is:

     // "Collator", "DateTimeFormat", or "NumberFormat" (likely with more coming

     // in future Intl specs).  In these cases |obj| *conceptually* also has

     // [[initializedCollator]] or similar set, and all the other properties

     // implied by that.

     //

     // If |internals| doesn't have a "partial" .type, two additional properties

     // have meaning.  The .lazyData property stores information needed to

     // compute -- without observable side effects -- the actual internal Intl

     // properties of |obj|.  If it is non-null, then the actual internal

     // properties haven't been computed, and .lazyData must be processed by

     // |setInternalProperties| before internal Intl property values are

     // available.  If it is null, then the .internalProps property contains an

     // object whose properties are the internal Intl properties of |obj|.

     internals.type = "partial";

     internals.lazyData = null;

     internals.internalProps = null;

     callFunction(std_WeakMap_set, internalsMap, obj, internals);

     return internals;

 }

 /**

  * Mark |internals| as having the given type and lazy data.

  */

 function setLazyData(internals, type, lazyData)

 {

     assert(internals.type === "partial", "can't set lazy data for anything but a newborn");

     assert(type === "Collator" || type === "DateTimeFormat" || type == "NumberFormat", "bad type");

     assert(IsObject(lazyData), "non-object lazy data");

     // Set in reverse order so that the .type change is a barrier.

     internals.lazyData = lazyData;

     internals.type = type;

 }

 /**

  * Set the internal properties object for an |internals| object previously

  * associated with lazy data.

  */

 function setInternalProperties(internals, internalProps)

 {

     assert(internals.type !== "partial", "newborn internals can't have computed internals");

     assert(IsObject(internals.lazyData), "lazy data must exist already");

     assert(IsObject(internalProps), "internalProps argument should be an object");

     // Set in reverse order so that the .lazyData nulling is a barrier.

     internals.internalProps = internalProps;

     internals.lazyData = null;

 }

 /**

  * Get the existing internal properties out of a non-newborn |internals|, or

  * null if none have been computed.

  */

 function maybeInternalProperties(internals)

 {

     assert(IsObject(internals), "non-object passed to maybeInternalProperties");

     assert(internals.type !== "partial", "maybeInternalProperties must only be used on completely-initialized internals objects");

     var lazyData = internals.lazyData;

     if (lazyData)

         return null;

     assert(IsObject(internals.internalProps), "missing lazy data and computed internals");

     return internals.internalProps;

 }

 /**

  * Return whether |obj| has an[[initializedIntlObject]] property set to true.

  */

 function isInitializedIntlObject(obj) {

 #ifdef DEBUG

     var internals = callFunction(std_WeakMap_get, internalsMap, obj);

     if (IsObject(internals)) {

         assert(callFunction(std_Object_hasOwnProperty, internals, "type"), "missing type");

         var type = internals.type;

         assert(type === "partial" || type === "Collator" || type === "DateTimeFormat" || type === "NumberFormat", "unexpected type");

         assert(callFunction(std_Object_hasOwnProperty, internals, "lazyData"), "missing lazyData");

         assert(callFunction(std_Object_hasOwnProperty, internals, "internalProps"), "missing internalProps");

     } else {

         assert(internals === undefined, "bad mapping for |obj|");

     }

 #endif

     return callFunction(std_WeakMap_has, internalsMap, obj);

 }

 /**

  * Check that |obj| meets the requirements for "this Collator object", "this

  * NumberFormat object", or "this DateTimeFormat object" as used in the method

  * with the given name.  Throw a TypeError if |obj| doesn't meet these

  * requirements.  But if it does, return |obj|'s internals object (*not* the

  * object holding its internal properties!), associated with it by

  * |internalsMap|, with structure specified above.

  *

  * Spec: ECMAScript Internationalization API Specification, 10.3.

  * Spec: ECMAScript Internationalization API Specification, 11.3.

  * Spec: ECMAScript Internationalization API Specification, 12.3.

  */

 function getIntlObjectInternals(obj, className, methodName) {

     assert(typeof className === "string", "bad className for getIntlObjectInternals");

     var internals = callFunction(std_WeakMap_get, internalsMap, obj);

     assert(internals === undefined || isInitializedIntlObject(obj), "bad mapping in internalsMap");

     if (internals === undefined || internals.type !== className)

         ThrowError(JSMSG_INTL_OBJECT_NOT_INITED, className, methodName, className);

     return internals;

 }

 /**

  * Get the internal properties of known-Intl object |obj|.  For use only by

  * C++ code that knows what it's doing!

  */

 function getInternals(obj)

 {

     assert(isInitializedIntlObject(obj), "for use only on guaranteed Intl objects");

     var internals = callFunction(std_WeakMap_get, internalsMap, obj);

     assert(internals.type !== "partial", "must have been successfully initialized");

     var lazyData = internals.lazyData;

     if (!lazyData)

         return internals.internalProps;

     var internalProps;

     var type = internals.type;

     if (type === "Collator")

         internalProps = resolveCollatorInternals(lazyData)

     else if (type === "DateTimeFormat")

         internalProps = resolveDateTimeFormatInternals(lazyData)

     else

         internalProps = resolveNumberFormatInternals(lazyData);

     setInternalProperties(internals, internalProps);

     return internalProps;

 }

 /********** Intl.Collator **********/

 /**

  * Mapping from Unicode extension keys for collation to options properties,

  * their types and permissible values.

  *

  * Spec: ECMAScript Internationalization API Specification, 10.1.1.

  */

 var collatorKeyMappings = {

     kn: {property: "numeric", type: "boolean"},

     kf: {property: "caseFirst", type: "string", values: ["upper", "lower", "false"]}

 };

 /**

  * Compute an internal properties object from |lazyCollatorData|.

  */

 function resolveCollatorInternals(lazyCollatorData)

 {

     assert(IsObject(lazyCollatorData), "lazy data not an object?");

     var internalProps = std_Object_create(null);

     // Step 7.

     internalProps.usage = lazyCollatorData.usage;

     // Step 8.

     var Collator = collatorInternalProperties;

     // Step 9.

     var collatorIsSorting = lazyCollatorData.usage === "sort";

     var localeData = collatorIsSorting

                      ? Collator.sortLocaleData

                      : Collator.searchLocaleData;

     // Compute effective locale.

     // Step 14.

     var relevantExtensionKeys = Collator.relevantExtensionKeys;

     // Step 15.

     var r = ResolveLocale(Collator.availableLocales(),

                           lazyCollatorData.requestedLocales,

                           lazyCollatorData.opt,

                           relevantExtensionKeys,

                           localeData);

     // Step 16.

     internalProps.locale = r.locale;

     // Steps 17-19.

     var key, property, value, mapping;

     var i = 0, len = relevantExtensionKeys.length;

     while (i < len) {

         // Step 19.a.

         key = relevantExtensionKeys[i];

         if (key === "co") {

             // Step 19.b.

             property = "collation";

             value = r.co === null ? "default" : r.co;

         } else {

             // Step 19.c.

             mapping = collatorKeyMappings[key];

             property = mapping.property;

             value = r[key];

             if (mapping.type === "boolean")

                 value = value === "true";

         }

         // Step 19.d.

         internalProps[property] = value;

         // Step 19.e.

         i++;

     }

     // Compute remaining collation options.

     // Steps 21-22.

     var s = lazyCollatorData.rawSensitivity;

     if (s === undefined) {

         if (collatorIsSorting) {

             // Step 21.a.

             s = "variant";

         } else {

             // Step 21.b.

             var dataLocale = r.dataLocale;

             var dataLocaleData = localeData(dataLocale);

             s = dataLocaleData.sensitivity;

         }

     }

     internalProps.sensitivity = s;

     // Step 24.

     internalProps.ignorePunctuation = lazyCollatorData.ignorePunctuation;

     // Step 25.

     internalProps.boundFormat = undefined;

     // The caller is responsible for associating |internalProps| with the right

     // object using |setInternalProperties|.

     return internalProps;

 }

 /**

  * Returns an object containing the Collator internal properties of |obj|, or

  * throws a TypeError if |obj| isn't Collator-initialized.

  */

 function getCollatorInternals(obj, methodName) {

     var internals = getIntlObjectInternals(obj, "Collator", methodName);

     assert(internals.type === "Collator", "bad type escaped getIntlObjectInternals");

     // If internal properties have already been computed, use them.

     var internalProps = maybeInternalProperties(internals);

     if (internalProps)

         return internalProps;

     // Otherwise it's time to fully create them.

     internalProps = resolveCollatorInternals(internals.lazyData);

     setInternalProperties(internals, internalProps);

     return internalProps;

 }

 /**

  * Initializes an object as a Collator.

  *

  * This method is complicated a moderate bit by its implementing initialization

  * as a *lazy* concept.  Everything that must happen now, does -- but we defer

  * all the work we can until the object is actually used as a Collator.  This

  * later work occurs in |resolveCollatorInternals|; steps not noted here occur

  * there.

  *

  * Spec: ECMAScript Internationalization API Specification, 10.1.1.

  */

 function InitializeCollator(collator, locales, options) {

     assert(IsObject(collator), "InitializeCollator");

     // Step 1.

     if (isInitializedIntlObject(collator))

         ThrowError(JSMSG_INTL_OBJECT_REINITED);

     // Step 2.

     var internals = initializeIntlObject(collator);

     // Lazy Collator data has the following structure:

     //

     //   {

     //     requestedLocales: List of locales,

     //     usage: "sort" / "search",

     //     opt: // opt object computed in InitializeCollator

     //       {

     //         localeMatcher: "lookup" / "best fit",

     //         kn: true / false / undefined,

     //         kf: "upper" / "lower" / "false" / undefined

     //       }

     //     rawSensitivity: "base" / "accent" / "case" / "variant" / undefined,

     //     ignorePunctuation: true / false

     //   }

     //

     // Note that lazy data is only installed as a final step of initialization,

     // so every Collator lazy data object has *all* these properties, never a

     // subset of them.

     var lazyCollatorData = std_Object_create(null);

     // Step 3.

     var requestedLocales = CanonicalizeLocaleList(locales);

     lazyCollatorData.requestedLocales = requestedLocales;

     // Steps 4-5.

     //

     // If we ever need more speed here at startup, we should try to detect the

     // case where |options === undefined| and Object.prototype hasn't been

     // mucked with.  (|options| is fully consumed in this method, so it's not a

     // concern that Object.prototype might be touched between now and when

     // |resolveCollatorInternals| is called.)  For now, just keep it simple.

     if (options === undefined)

         options = {};

     else

         options = ToObject(options);

     // Compute options that impact interpretation of locale.

     // Step 6.

     var u = GetOption(options, "usage", "string", ["sort", "search"], "sort");

     lazyCollatorData.usage = u;

     // Step 10.

     var opt = new Record();

     lazyCollatorData.opt = opt;

     // Steps 11-12.

     var matcher = GetOption(options, "localeMatcher", "string", ["lookup", "best fit"], "best fit");

     opt.localeMatcher = matcher;

     // Step 13, unrolled.

     var numericValue = GetOption(options, "numeric", "boolean", undefined, undefined);

     if (numericValue !== undefined)

         numericValue = callFunction(std_Boolean_toString, numericValue);

     opt.kn = numericValue;

     var caseFirstValue = GetOption(options, "caseFirst", "string", ["upper", "lower", "false"], undefined);

     opt.kf = caseFirstValue;

     // Compute remaining collation options.

     // Step 20.

     var s = GetOption(options, "sensitivity", "string",

                       ["base", "accent", "case", "variant"], undefined);

     lazyCollatorData.rawSensitivity = s;

     // Step 23.

     var ip = GetOption(options, "ignorePunctuation", "boolean", undefined, false);

     lazyCollatorData.ignorePunctuation = ip;

     // Step 26.

     //

     // We've done everything that must be done now: mark the lazy data as fully

     // computed and install it.

     setLazyData(internals, "Collator", lazyCollatorData);

 }

 /**

  * Returns the subset of the given locale list for which this locale list has a

  * matching (possibly fallback) locale. Locales appear in the same order in the

  * returned list as in the input list.

  *

  * Spec: ECMAScript Internationalization API Specification, 10.2.2.

  */

 function Intl_Collator_supportedLocalesOf(locales /*, options*/) {

     var options = arguments.length > 1 ? arguments[1] : undefined;

     var availableLocales = collatorInternalProperties.availableLocales();

     var requestedLocales = CanonicalizeLocaleList(locales);

     return SupportedLocales(availableLocales, requestedLocales, options);

 }

 /**

  * Collator internal properties.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.1 and 10.2.3.

  */

 var collatorInternalProperties = {

     sortLocaleData: collatorSortLocaleData,

     searchLocaleData: collatorSearchLocaleData,

     _availableLocales: null,

     availableLocales: function()

     {

         var locales = this._availableLocales;

         if (locales)

             return locales;

         return (this._availableLocales =

           addOldStyleLanguageTags(intl_Collator_availableLocales()));

     },

     relevantExtensionKeys: ["co", "kn"]

 };

 function collatorSortLocaleData(locale) {

     var collations = intl_availableCollations(locale);

     callFunction(std_Array_unshift, collations, null);

     return {

         co: collations,

         kn: ["false", "true"]

     };

 }

 function collatorSearchLocaleData(locale) {

     return {

         co: [null],

         kn: ["false", "true"],

         // In theory the default sensitivity is locale dependent;

         // in reality the CLDR/ICU default strength is always tertiary.

         sensitivity: "variant"

     };

 }

 /**

  * Function to be bound and returned by Intl.Collator.prototype.format.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.3.2.

  */

 function collatorCompareToBind(x, y) {

     // Steps 1.a.i-ii implemented by ECMAScript declaration binding instantiation,

     // ES5.1 10.5, step 4.d.ii.

     // Step 1.a.iii-v.

     var X = ToString(x);

     var Y = ToString(y);

     return intl_CompareStrings(this, X, Y);

 }

 /**

  * Returns a function bound to this Collator that compares x (converted to a

  * String value) and y (converted to a String value),

  * and returns a number less than 0 if x < y, 0 if x = y, or a number greater

  * than 0 if x > y according to the sort order for the locale and collation

  * options of this Collator object.

  *

  * Spec: ECMAScript Internationalization API Specification, 10.3.2.

  */

 function Intl_Collator_compare_get() {

     // Check "this Collator object" per introduction of section 10.3.

     var internals = getCollatorInternals(this, "compare");

     // Step 1.

     if (internals.boundCompare === undefined) {

         // Step 1.a.

         var F = collatorCompareToBind;

         // Step 1.b-d.

         var bc = callFunction(std_Function_bind, F, this);

         internals.boundCompare = bc;

     }

     // Step 2.

     return internals.boundCompare;

 }

 /**

  * Returns the resolved options for a Collator object.

  *

  * Spec: ECMAScript Internationalization API Specification, 10.3.3 and 10.4.

  */

 function Intl_Collator_resolvedOptions() {

     // Check "this Collator object" per introduction of section 10.3.

     var internals = getCollatorInternals(this, "resolvedOptions");

     var result = {

         locale: internals.locale,

         usage: internals.usage,

         sensitivity: internals.sensitivity,

         ignorePunctuation: internals.ignorePunctuation

     };

     var relevantExtensionKeys = collatorInternalProperties.relevantExtensionKeys;

     for (var i = 0; i < relevantExtensionKeys.length; i++) {

         var key = relevantExtensionKeys[i];

         var property = (key === "co") ? "collation" : collatorKeyMappings[key].property;

         defineProperty(result, property, internals[property]);

     }

     return result;

 }

 /********** Intl.NumberFormat **********/

 /**

  * NumberFormat internal properties.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.1 and 11.2.3.

  */

 var numberFormatInternalProperties = {

     localeData: numberFormatLocaleData,

     _availableLocales: null,

     availableLocales: function()

     {

         var locales = this._availableLocales;

         if (locales)

             return locales;

         return (this._availableLocales =

           addOldStyleLanguageTags(intl_NumberFormat_availableLocales()));

     },

     relevantExtensionKeys: ["nu"]

 };

 /**

  * Compute an internal properties object from |lazyNumberFormatData|.

  */

 function resolveNumberFormatInternals(lazyNumberFormatData) {

     assert(IsObject(lazyNumberFormatData), "lazy data not an object?");

     var internalProps = std_Object_create(null);

     // Step 3.

     var requestedLocales = lazyNumberFormatData.requestedLocales;

     // Compute options that impact interpretation of locale.

     // Step 6.

     var opt = lazyNumberFormatData.opt;

     // Compute effective locale.

     // Step 9.

     var NumberFormat = numberFormatInternalProperties;

     // Step 10.

     var localeData = NumberFormat.localeData;

     // Step 11.

     var r = ResolveLocale(NumberFormat.availableLocales(),

                           lazyNumberFormatData.requestedLocales,

                           lazyNumberFormatData.opt,

                           NumberFormat.relevantExtensionKeys,

                           localeData);

     // Steps 12-13.  (Step 14 is not relevant to our implementation.)

     internalProps.locale = r.locale;

     internalProps.numberingSystem = r.nu;

     // Compute formatting options.

     // Step 16.

     var s = lazyNumberFormatData.style;

     internalProps.style = s;

     // Steps 20, 22.

     if (s === "currency") {

         internalProps.currency = lazyNumberFormatData.currency;

         internalProps.currencyDisplay = lazyNumberFormatData.currencyDisplay;

     }

     // Step 24.

     internalProps.minimumIntegerDigits = lazyNumberFormatData.minimumIntegerDigits;

     // Steps 27.

     internalProps.minimumFractionDigits = lazyNumberFormatData.minimumFractionDigits;

     // Step 30.

     internalProps.maximumFractionDigits = lazyNumberFormatData.maximumFractionDigits;

     // Step 33.

     if ("minimumSignificantDigits" in lazyNumberFormatData) {

         // Note: Intl.NumberFormat.prototype.resolvedOptions() exposes the

         // actual presence (versus undefined-ness) of these properties.

         assert("maximumSignificantDigits" in lazyNumberFormatData, "min/max sig digits mismatch");

         internalProps.minimumSignificantDigits = lazyNumberFormatData.minimumSignificantDigits;

         internalProps.maximumSignificantDigits = lazyNumberFormatData.maximumSignificantDigits;

     }

     // Step 35.

     internalProps.useGrouping = lazyNumberFormatData.useGrouping;

     // Step 42.

     internalProps.boundFormat = undefined;

     // The caller is responsible for associating |internalProps| with the right

     // object using |setInternalProperties|.

     return internalProps;

 }

 /**

  * Returns an object containing the NumberFormat internal properties of |obj|,

  * or throws a TypeError if |obj| isn't NumberFormat-initialized.

  */

 function getNumberFormatInternals(obj, methodName) {

     var internals = getIntlObjectInternals(obj, "NumberFormat", methodName);

     assert(internals.type === "NumberFormat", "bad type escaped getIntlObjectInternals");

     // If internal properties have already been computed, use them.

     var internalProps = maybeInternalProperties(internals);

     if (internalProps)

         return internalProps;

     // Otherwise it's time to fully create them.

     internalProps = resolveNumberFormatInternals(internals.lazyData);

     setInternalProperties(internals, internalProps);

     return internalProps;

 }

 /**

  * Initializes an object as a NumberFormat.

  *

  * This method is complicated a moderate bit by its implementing initialization

  * as a *lazy* concept.  Everything that must happen now, does -- but we defer

  * all the work we can until the object is actually used as a NumberFormat.

  * This later work occurs in |resolveNumberFormatInternals|; steps not noted

  * here occur there.

  *

  * Spec: ECMAScript Internationalization API Specification, 11.1.1.

  */

 function InitializeNumberFormat(numberFormat, locales, options) {

     assert(IsObject(numberFormat), "InitializeNumberFormat");

     // Step 1.

     if (isInitializedIntlObject(numberFormat))

         ThrowError(JSMSG_INTL_OBJECT_REINITED);

     // Step 2.

     var internals = initializeIntlObject(numberFormat);

     // Lazy NumberFormat data has the following structure:

     //

     //   {

     //     requestedLocales: List of locales,

     //     style: "decimal" / "percent" / "currency",

     //

     //     // fields present only if style === "currency":

     //     currency: a well-formed currency code (IsWellFormedCurrencyCode),

     //     currencyDisplay: "code" / "symbol" / "name",

     //

     //     opt: // opt object computed in InitializeNumberFormat

     //       {

     //         localeMatcher: "lookup" / "best fit",

     //       }

     //

     //     minimumIntegerDigits: integer ∈ [1, 21],

     //     minimumFractionDigits: integer ∈ [0, 20],

     //     maximumFractionDigits: integer ∈ [0, 20],

     //

     //     // optional

     //     minimumSignificantDigits: integer ∈ [1, 21],

     //     maximumSignificantDigits: integer ∈ [1, 21],

     //

     //     useGrouping: true / false,

     //   }

     //

     // Note that lazy data is only installed as a final step of initialization,

     // so every Collator lazy data object has *all* these properties, never a

     // subset of them.

     var lazyNumberFormatData = std_Object_create(null);

     // Step 3.

     var requestedLocales = CanonicalizeLocaleList(locales);

     lazyNumberFormatData.requestedLocales = requestedLocales;

     // Steps 4-5.

     //

     // If we ever need more speed here at startup, we should try to detect the

     // case where |options === undefined| and Object.prototype hasn't been

     // mucked with.  (|options| is fully consumed in this method, so it's not a

     // concern that Object.prototype might be touched between now and when

     // |resolveNumberFormatInternals| is called.)  For now just keep it simple.

     if (options === undefined)

         options = {};

     else

         options = ToObject(options);

     // Compute options that impact interpretation of locale.

     // Step 6.

     var opt = new Record();

     lazyNumberFormatData.opt = opt;

     // Steps 7-8.

     var matcher = GetOption(options, "localeMatcher", "string", ["lookup", "best fit"], "best fit");

     opt.localeMatcher = matcher;

     // Compute formatting options.

     // Step 15.

     var s = GetOption(options, "style", "string", ["decimal", "percent", "currency"], "decimal");

     lazyNumberFormatData.style = s;

     // Steps 17-20.

     var c = GetOption(options, "currency", "string", undefined, undefined);

     if (c !== undefined && !IsWellFormedCurrencyCode(c))

         ThrowError(JSMSG_INVALID_CURRENCY_CODE, c);

     var cDigits;

     if (s === "currency") {

         if (c === undefined)

             ThrowError(JSMSG_UNDEFINED_CURRENCY);

         // Steps 20.a-c.

         c = toASCIIUpperCase(c);

         lazyNumberFormatData.currency = c;

         cDigits = CurrencyDigits(c);

     }

     // Step 21.

     var cd = GetOption(options, "currencyDisplay", "string", ["code", "symbol", "name"], "symbol");

     if (s === "currency")

         lazyNumberFormatData.currencyDisplay = cd;

     // Step 23.

     var mnid = GetNumberOption(options, "minimumIntegerDigits", 1, 21, 1);

     lazyNumberFormatData.minimumIntegerDigits = mnid;

     // Steps 25-26.

     var mnfdDefault = (s === "currency") ? cDigits : 0;

     var mnfd = GetNumberOption(options, "minimumFractionDigits", 0, 20, mnfdDefault);

     lazyNumberFormatData.minimumFractionDigits = mnfd;

     // Steps 28-29.

     var mxfdDefault;

     if (s === "currency")

         mxfdDefault = std_Math_max(mnfd, cDigits);

     else if (s === "percent")

         mxfdDefault = std_Math_max(mnfd, 0);

     else

         mxfdDefault = std_Math_max(mnfd, 3);

     var mxfd = GetNumberOption(options, "maximumFractionDigits", mnfd, 20, mxfdDefault);

     lazyNumberFormatData.maximumFractionDigits = mxfd;

     // Steps 31-32.

     var mnsd = options.minimumSignificantDigits;

     var mxsd = options.maximumSignificantDigits;

     // Step 33.

     if (mnsd !== undefined || mxsd !== undefined) {

         mnsd = GetNumberOption(options, "minimumSignificantDigits", 1, 21, 1);

         mxsd = GetNumberOption(options, "maximumSignificantDigits", mnsd, 21, 21);

         lazyNumberFormatData.minimumSignificantDigits = mnsd;

         lazyNumberFormatData.maximumSignificantDigits = mxsd;

     }

     // Step 34.

     var g = GetOption(options, "useGrouping", "boolean", undefined, true);

     lazyNumberFormatData.useGrouping = g;

     // Step 43.

     //

     // We've done everything that must be done now: mark the lazy data as fully

     // computed and install it.

     setLazyData(internals, "NumberFormat", lazyNumberFormatData);

 }

 /**

  * Mapping from currency codes to the number of decimal digits used for them.

  * Default is 2 digits.

  *

  * Spec: ISO 4217 Currency and Funds Code List.

  * http://www.currency-iso.org/en/home/tables/table-a1.html

  */

 var currencyDigits = {

     BHD: 3,

     BIF: 0,

     BYR: 0,

     CLF: 0,

     CLP: 0,

     DJF: 0,

     IQD: 3,

     GNF: 0,

     ISK: 0,

     JOD: 3,

     JPY: 0,

     KMF: 0,

     KRW: 0,

     KWD: 3,

     LYD: 3,

     OMR: 3,

     PYG: 0,

     RWF: 0,

     TND: 3,

     UGX: 0,

     UYI: 0,

     VND: 0,

     VUV: 0,

     XAF: 0,

     XOF: 0,

     XPF: 0

 };

 /**

  * Returns the number of decimal digits to be used for the given currency.

  *

  * Spec: ECMAScript Internationalization API Specification, 11.1.1.

  */

 function CurrencyDigits(currency) {

     assert(typeof currency === "string", "CurrencyDigits");

     assert(regexp_test_no_statics(/^[A-Z]{3}$/, currency), "CurrencyDigits");

     if (callFunction(std_Object_hasOwnProperty, currencyDigits, currency))

         return currencyDigits[currency];

     return 2;

 }

 /**

  * Returns the subset of the given locale list for which this locale list has a

  * matching (possibly fallback) locale. Locales appear in the same order in the

  * returned list as in the input list.

  *

  * Spec: ECMAScript Internationalization API Specification, 11.2.2.

  */

 function Intl_NumberFormat_supportedLocalesOf(locales /*, options*/) {

     var options = arguments.length > 1 ? arguments[1] : undefined;

     var availableLocales = numberFormatInternalProperties.availableLocales();

     var requestedLocales = CanonicalizeLocaleList(locales);

     return SupportedLocales(availableLocales, requestedLocales, options);

 }

 function getNumberingSystems(locale) {

     // ICU doesn't have an API to determine the set of numbering systems

     // supported for a locale; it generally pretends that any numbering system

     // can be used with any locale. Supporting a decimal numbering system

     // (where only the digits are replaced) is easy, so we offer them all here.

     // Algorithmic numbering systems are typically tied to one locale, so for

     // lack of information we don't offer them. To increase chances that

     // other software will process output correctly, we further restrict to

     // those decimal numbering systems explicitly listed in table 2 of

     // the ECMAScript Internationalization API Specification, 11.3.2, which

     // in turn are those with full specifications in version 21 of Unicode

     // Technical Standard #35 using digits that were defined in Unicode 5.0,

     // the Unicode version supported in Windows Vista.

     // The one thing we can find out from ICU is the default numbering system

     // for a locale.

     var defaultNumberingSystem = intl_numberingSystem(locale);

     return [

         defaultNumberingSystem,

         "arab", "arabext", "bali", "beng", "deva",

         "fullwide", "gujr", "guru", "hanidec", "khmr",

         "knda", "laoo", "latn", "limb", "mlym",

         "mong", "mymr", "orya", "tamldec", "telu",

         "thai", "tibt"

     ];

 }

 function numberFormatLocaleData(locale) {

     return {

         nu: getNumberingSystems(locale)

     };

 }

 /**

  * Function to be bound and returned by Intl.NumberFormat.prototype.format.

  *

  * Spec: ECMAScript Internationalization API Specification, 11.3.2.

  */

 function numberFormatFormatToBind(value) {

     // Steps 1.a.i implemented by ECMAScript declaration binding instantiation,

     // ES5.1 10.5, step 4.d.ii.

     // Step 1.a.ii-iii.

     var x = ToNumber(value);

     return intl_FormatNumber(this, x);

 }

 /**

  * Returns a function bound to this NumberFormat that returns a String value

  * representing the result of calling ToNumber(value) according to the

  * effective locale and the formatting options of this NumberFormat.

  *

  * Spec: ECMAScript Internationalization API Specification, 11.3.2.

  */

 function Intl_NumberFormat_format_get() {

     // Check "this NumberFormat object" per introduction of section 11.3.

     var internals = getNumberFormatInternals(this, "format");

     // Step 1.

     if (internals.boundFormat === undefined) {

         // Step 1.a.

         var F = numberFormatFormatToBind;

         // Step 1.b-d.

         var bf = callFunction(std_Function_bind, F, this);

         internals.boundFormat = bf;

     }

     // Step 2.

     return internals.boundFormat;

 }

 /**

  * Returns the resolved options for a NumberFormat object.

  *

  * Spec: ECMAScript Internationalization API Specification, 11.3.3 and 11.4.

  */

 function Intl_NumberFormat_resolvedOptions() {

     // Check "this NumberFormat object" per introduction of section 11.3.

     var internals = getNumberFormatInternals(this, "resolvedOptions");

     var result = {

         locale: internals.locale,

         numberingSystem: internals.numberingSystem,

         style: internals.style,

         minimumIntegerDigits: internals.minimumIntegerDigits,

         minimumFractionDigits: internals.minimumFractionDigits,

         maximumFractionDigits: internals.maximumFractionDigits,

         useGrouping: internals.useGrouping

     };

     var optionalProperties = [

         "currency",

         "currencyDisplay",

         "minimumSignificantDigits",

         "maximumSignificantDigits"

     ];

     for (var i = 0; i < optionalProperties.length; i++) {

         var p = optionalProperties[i];

         if (callFunction(std_Object_hasOwnProperty, internals, p))

             defineProperty(result, p, internals[p]);

     }

     return result;

 }

 /********** Intl.DateTimeFormat **********/

 /**

  * Compute an internal properties object from |lazyDateTimeFormatData|.

  */

 function resolveDateTimeFormatInternals(lazyDateTimeFormatData) {

     assert(IsObject(lazyDateTimeFormatData), "lazy data not an object?");

     // Lazy DateTimeFormat data has the following structure:

     //

     //   {

     //     requestedLocales: List of locales,

     //

     //     localeOpt: // *first* opt computed in InitializeDateTimeFormat

     //       {

     //         localeMatcher: "lookup" / "best fit",

     //

     //         hour12: true / false,  // optional

     //       }

     //

     //     timeZone: undefined / "UTC",

     //

     //     formatOpt: // *second* opt computed in InitializeDateTimeFormat

     //       {

     //         // all the properties/values listed in Table 3

     //         // (weekday, era, year, month, day, &c.)

     //       }

     //

     //     formatMatcher: "basic" / "best fit",

     //   }

     //

     // Note that lazy data is only installed as a final step of initialization,

     // so every DateTimeFormat lazy data object has *all* these properties,

     // never a subset of them.

     var internalProps = std_Object_create(null);

     // Compute effective locale.

     // Step 8.

     var DateTimeFormat = dateTimeFormatInternalProperties;

     // Step 9.

     var localeData = DateTimeFormat.localeData;

     // Step 10.

     var r = ResolveLocale(DateTimeFormat.availableLocales(),

                           lazyDateTimeFormatData.requestedLocales,

                           lazyDateTimeFormatData.localeOpt,

                           DateTimeFormat.relevantExtensionKeys,

                           localeData);

     // Steps 11-13.

     internalProps.locale = r.locale;

     internalProps.calendar = r.ca;

     internalProps.numberingSystem = r.nu;

     // Compute formatting options.

     // Step 14.

     var dataLocale = r.dataLocale;

     // Steps 15-17.

     internalProps.timeZone = lazyDateTimeFormatData.timeZone;

     // Step 18.

     var formatOpt = lazyDateTimeFormatData.formatOpt;

     // Steps 27-28, more or less - see comment after this function.

     var pattern = toBestICUPattern(dataLocale, formatOpt);

     // Step 29.

     internalProps.pattern = pattern;

     // Step 30.

     internalProps.boundFormat = undefined;

     // The caller is responsible for associating |internalProps| with the right

     // object using |setInternalProperties|.

     return internalProps;

 }

 /**

  * Returns an object containing the DateTimeFormat internal properties of |obj|,

  * or throws a TypeError if |obj| isn't DateTimeFormat-initialized.

  */

 function getDateTimeFormatInternals(obj, methodName) {

     var internals = getIntlObjectInternals(obj, "DateTimeFormat", methodName);

     assert(internals.type === "DateTimeFormat", "bad type escaped getIntlObjectInternals");

     // If internal properties have already been computed, use them.

     var internalProps = maybeInternalProperties(internals);

     if (internalProps)

         return internalProps;

     // Otherwise it's time to fully create them.

     internalProps = resolveDateTimeFormatInternals(internals.lazyData);

     setInternalProperties(internals, internalProps);

     return internalProps;

 }

 /**

  * Components of date and time formats and their values.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.1.1.

  */

 var dateTimeComponentValues = {

     weekday: ["narrow", "short", "long"],

     era: ["narrow", "short", "long"],

     year: ["2-digit", "numeric"],

     month: ["2-digit", "numeric", "narrow", "short", "long"],

     day: ["2-digit", "numeric"],

     hour: ["2-digit", "numeric"],

     minute: ["2-digit", "numeric"],

     second: ["2-digit", "numeric"],

     timeZoneName: ["short", "long"]

 };

 var dateTimeComponents = std_Object_getOwnPropertyNames(dateTimeComponentValues);

 /**

  * Initializes an object as a DateTimeFormat.

  *

  * This method is complicated a moderate bit by its implementing initialization

  * as a *lazy* concept.  Everything that must happen now, does -- but we defer

  * all the work we can until the object is actually used as a DateTimeFormat.

  * This later work occurs in |resolveDateTimeFormatInternals|; steps not noted

  * here occur there.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.1.1.

  */

 function InitializeDateTimeFormat(dateTimeFormat, locales, options) {

     assert(IsObject(dateTimeFormat), "InitializeDateTimeFormat");

     // Step 1.

     if (isInitializedIntlObject(dateTimeFormat))

         ThrowError(JSMSG_INTL_OBJECT_REINITED);

     // Step 2.

     var internals = initializeIntlObject(dateTimeFormat);

     // Lazy DateTimeFormat data has the following structure:

     //

     //   {

     //     requestedLocales: List of locales,

     //

     //     localeOpt: // *first* opt computed in InitializeDateTimeFormat

     //       {

     //         localeMatcher: "lookup" / "best fit",

     //       }

     //

     //     timeZone: undefined / "UTC",

     //

     //     formatOpt: // *second* opt computed in InitializeDateTimeFormat

     //       {

     //         // all the properties/values listed in Table 3

     //         // (weekday, era, year, month, day, &c.)

     //

     //         hour12: true / false  // optional

     //       }

     //

     //     formatMatcher: "basic" / "best fit",

     //   }

     //

     // Note that lazy data is only installed as a final step of initialization,

     // so every DateTimeFormat lazy data object has *all* these properties,

     // never a subset of them.

     var lazyDateTimeFormatData = std_Object_create(null);

     // Step 3.

     var requestedLocales = CanonicalizeLocaleList(locales);

     lazyDateTimeFormatData.requestedLocales = requestedLocales;

     // Step 4.

     options = ToDateTimeOptions(options, "any", "date");

     // Compute options that impact interpretation of locale.

     // Step 5.

     var localeOpt = new Record();

     lazyDateTimeFormatData.localeOpt = localeOpt;

     // Steps 6-7.

     var localeMatcher =

         GetOption(options, "localeMatcher", "string", ["lookup", "best fit"],

                   "best fit");

     localeOpt.localeMatcher = localeMatcher;

     // Steps 15-17.

     var tz = options.timeZone;

     if (tz !== undefined) {

         tz = toASCIIUpperCase(ToString(tz));

         if (tz !== "UTC")

             ThrowError(JSMSG_INVALID_TIME_ZONE, tz);

     }

     lazyDateTimeFormatData.timeZone = tz;

     // Step 18.

     var formatOpt = new Record();

     lazyDateTimeFormatData.formatOpt = formatOpt;

     // Step 19.

     var i, prop;

     for (i = 0; i < dateTimeComponents.length; i++) {

         prop = dateTimeComponents[i];

         var value = GetOption(options, prop, "string", dateTimeComponentValues[prop], undefined);

         formatOpt[prop] = value;

     }

     // Steps 20-21 provided by ICU - see comment after this function.

     // Step 22.

     //

     // For some reason (ICU not exposing enough interface?) we drop the

     // requested format matcher on the floor after this.  In any case, even if

     // doing so is justified, we have to do this work here in case it triggers

     // getters or similar.

     var formatMatcher =

         GetOption(options, "formatMatcher", "string", ["basic", "best fit"],

                   "best fit");

     // Steps 23-25 provided by ICU, more or less - see comment after this function.

     // Step 26.

     var hr12  = GetOption(options, "hour12", "boolean", undefined, undefined);

     // Pass hr12 on to ICU.

     if (hr12 !== undefined)

         formatOpt.hour12 = hr12;

     // Step 31.

     //

     // We've done everything that must be done now: mark the lazy data as fully

     // computed and install it.

     setLazyData(internals, "DateTimeFormat", lazyDateTimeFormatData);

 }

 // Intl.DateTimeFormat and ICU skeletons and patterns

 // ==================================================

 //

 // Different locales have different ways to display dates using the same

 // basic components. For example, en-US might use "Sept. 24, 2012" while

 // fr-FR might use "24 Sept. 2012". The intent of Intl.DateTimeFormat is to

 // permit production of a format for the locale that best matches the

 // set of date-time components and their desired representation as specified

 // by the API client.

 //

 // ICU supports specification of date and time formats in three ways:

 //

 // 1) A style is just one of the identifiers FULL, LONG, MEDIUM, or SHORT.

 //    The date-time components included in each style and their representation

 //    are defined by ICU using CLDR locale data (CLDR is the Unicode

 //    Consortium's Common Locale Data Repository).

 //

 // 2) A skeleton is a string specifying which date-time components to include,

 //    and which representations to use for them. For example, "yyyyMMMMdd"

 //    specifies a year with at least four digits, a full month name, and a

 //    two-digit day. It does not specify in which order the components appear,

 //    how they are separated, the localized strings for textual components

 //    (such as weekday or month), whether the month is in format or

 //    stand-alone form¹, or the numbering system used for numeric components.

 //    All that information is filled in by ICU using CLDR locale data.

 //    ¹ The format form is the one used in formatted strings that include a

 //    day; the stand-alone form is used when not including days, e.g., in

 //    calendar headers. The two forms differ at least in some Slavic languages,

 //    e.g. Russian: "22 марта 2013 г." vs. "Март 2013".

 //

 // 3) A pattern is a string specifying which date-time components to include,

 //    in which order, with which separators, in which grammatical case. For

 //    example, "EEEE, d MMMM y" specifies the full localized weekday name,

 //    followed by comma and space, followed by the day, followed by space,

 //    followed by the full month name in format form, followed by space,

 //    followed by the full year. It

 //    still does not specify localized strings for textual components and the

 //    numbering system - these are determined by ICU using CLDR locale data or

 //    possibly API parameters.

 //

 // All actual formatting in ICU is done with patterns; styles and skeletons

 // have to be mapped to patterns before processing.

 //

 // The options of DateTimeFormat most closely correspond to ICU skeletons. This

 // implementation therefore, in the toBestICUPattern function, converts

 // DateTimeFormat options to ICU skeletons, and then lets ICU map skeletons to

 // actual ICU patterns. The pattern may not directly correspond to what the

 // skeleton requests, as the mapper (UDateTimePatternGenerator) is constrained

 // by the available locale data for the locale. The resulting ICU pattern is

 // kept as the DateTimeFormat's [[pattern]] internal property and passed to ICU

 // in the format method.

 //

 // An ICU pattern represents the information of the following DateTimeFormat

 // internal properties described in the specification, which therefore don't

 // exist separately in the implementation:

 // - [[weekday]], [[era]], [[year]], [[month]], [[day]], [[hour]], [[minute]],

 //   [[second]], [[timeZoneName]]

 // - [[hour12]]

 // - [[hourNo0]]

 // When needed for the resolvedOptions method, the resolveICUPattern function

 // maps the instance's ICU pattern back to the specified properties of the

 // object returned by resolvedOptions.

 //

 // ICU date-time skeletons and patterns aren't fully documented in the ICU

 // documentation (see http://bugs.icu-project.org/trac/ticket/9627). The best

 // documentation at this point is in UTR 35:

 // http://unicode.org/reports/tr35/tr35-dates.html#Date_Format_Patterns

 /**

  * Returns an ICU pattern string for the given locale and representing the

  * specified options as closely as possible given available locale data.

  */

 function toBestICUPattern(locale, options) {

     // Create an ICU skeleton representing the specified options. See

     // http://unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table

     var skeleton = "";

     switch (options.weekday) {

     case "narrow":

         skeleton += "EEEEE";

         break;

     case "short":

         skeleton += "E";

         break;

     case "long":

         skeleton += "EEEE";

     }

     switch (options.era) {

     case "narrow":

         skeleton += "GGGGG";

         break;

     case "short":

         skeleton += "G";

         break;

     case "long":

         skeleton += "GGGG";

         break;

     }

     switch (options.year) {

     case "2-digit":

         skeleton += "yy";

         break;

     case "numeric":

         skeleton += "y";

         break;

     }

     switch (options.month) {

     case "2-digit":

         skeleton += "MM";

         break;

     case "numeric":

         skeleton += "M";

         break;

     case "narrow":

         skeleton += "MMMMM";

         break;

     case "short":

         skeleton += "MMM";

         break;

     case "long":

         skeleton += "MMMM";

         break;

     }

     switch (options.day) {

     case "2-digit":

         skeleton += "dd";

         break;

     case "numeric":

         skeleton += "d";

         break;

     }

     var hourSkeletonChar = "j";

     if (options.hour12 !== undefined) {

         if (options.hour12)

             hourSkeletonChar = "h";

         else

             hourSkeletonChar = "H";

     }

     switch (options.hour) {

     case "2-digit":

         skeleton += hourSkeletonChar + hourSkeletonChar;

         break;

     case "numeric":

         skeleton += hourSkeletonChar;

         break;

     }

     switch (options.minute) {

     case "2-digit":

         skeleton += "mm";

         break;

     case "numeric":

         skeleton += "m";

         break;

     }

     switch (options.second) {

     case "2-digit":

         skeleton += "ss";

         break;

     case "numeric":

         skeleton += "s";

         break;

     }

     switch (options.timeZoneName) {

     case "short":

         skeleton += "z";

         break;

     case "long":

         skeleton += "zzzz";

         break;

     }

     // Let ICU convert the ICU skeleton to an ICU pattern for the given locale.

     return intl_patternForSkeleton(locale, skeleton);

 }

 /**

  * Returns a new options object that includes the provided options (if any)

  * and fills in default components if required components are not defined.

  * Required can be "date", "time", or "any".

  * Defaults can be "date", "time", or "all".

  *

  * Spec: ECMAScript Internationalization API Specification, 12.1.1.

  */

 function ToDateTimeOptions(options, required, defaults) {

     assert(typeof required === "string", "ToDateTimeOptions");

     assert(typeof defaults === "string", "ToDateTimeOptions");

     // Steps 1-3.

     if (options === undefined)

         options = null;

     else

         options = ToObject(options);

     options = std_Object_create(options);

     // Step 4.

     var needDefaults = true;

     // Step 5.

     if ((required === "date" || required === "any") &&

         (options.weekday !== undefined || options.year !== undefined ||

          options.month !== undefined || options.day !== undefined))

     {

         needDefaults = false;

     }

     // Step 6.

     if ((required === "time" || required === "any") &&

         (options.hour !== undefined || options.minute !== undefined ||

          options.second !== undefined))

     {

         needDefaults = false;

     }

     // Step 7.

     if (needDefaults && (defaults === "date" || defaults === "all")) {

         // The specification says to call [[DefineOwnProperty]] with false for

         // the Throw parameter, while Object.defineProperty uses true. For the

         // calls here, the difference doesn't matter because we're adding

         // properties to a new object.

         defineProperty(options, "year", "numeric");

         defineProperty(options, "month", "numeric");

         defineProperty(options, "day", "numeric");

     }

     // Step 8.

     if (needDefaults && (defaults === "time" || defaults === "all")) {

         // See comment for step 7.

         defineProperty(options, "hour", "numeric");

         defineProperty(options, "minute", "numeric");

         defineProperty(options, "second", "numeric");

     }

     // Step 9.

     return options;

 }

 /**

  * Compares the date and time components requested by options with the available

  * date and time formats in formats, and selects the best match according

  * to a specified basic matching algorithm.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.1.1.

  */

 function BasicFormatMatcher(options, formats) {

     // Steps 1-6.

     var removalPenalty = 120,

         additionPenalty = 20,

         longLessPenalty = 8,

         longMorePenalty = 6,

         shortLessPenalty = 6,

         shortMorePenalty = 3;

     // Table 3.

     var properties = ["weekday", "era", "year", "month", "day",

         "hour", "minute", "second", "timeZoneName"];

     // Step 11.c.vi.1.

     var values = ["2-digit", "numeric", "narrow", "short", "long"];

     // Steps 7-8.

     var bestScore = -Infinity;

     var bestFormat;

     // Steps 9-11.

     var i = 0;

     var len = formats.length;

     while (i < len) {

         // Steps 11.a-b.

         var format = formats[i];

         var score = 0;

         // Step 11.c.

         var formatProp;

         for (var j = 0; j < properties.length; j++) {

             var property = properties[j];

             // Step 11.c.i.

             var optionsProp = options[property];

             // Step missing from spec.

             // https://bugs.ecmascript.org/show_bug.cgi?id=1254

             formatProp = undefined;

             // Steps 11.c.ii-iii.

             if (callFunction(std_Object_hasOwnProperty, format, property))

                 formatProp = format[property];

             if (optionsProp === undefined && formatProp !== undefined) {

                 // Step 11.c.iv.

                 score -= additionPenalty;

             } else if (optionsProp !== undefined && formatProp === undefined) {

                 // Step 11.c.v.

                 score -= removalPenalty;

             } else {

                 // Step 11.c.vi.

                 var optionsPropIndex = callFunction(std_Array_indexOf, values, optionsProp);

                 var formatPropIndex = callFunction(std_Array_indexOf, values, formatProp);

                 var delta = std_Math_max(std_Math_min(formatPropIndex - optionsPropIndex, 2), -2);

                 if (delta === 2)

                     score -= longMorePenalty;

                 else if (delta === 1)

                     score -= shortMorePenalty;

                 else if (delta === -1)

                     score -= shortLessPenalty;

                 else if (delta === -2)

                     score -= longLessPenalty;

             }

         }

         // Step 11.d.

         if (score > bestScore) {

             bestScore = score;

             bestFormat = format;

         }

         // Step 11.e.

         i++;

     }

     // Step 12.

     return bestFormat;

 }

 /**

  * Compares the date and time components requested by options with the available

  * date and time formats in formats, and selects the best match according

  * to an unspecified best-fit matching algorithm.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.1.1.

  */

 function BestFitFormatMatcher(options, formats) {

     // this implementation doesn't have anything better

     return BasicFormatMatcher(options, formats);

 }

 /**

  * Returns the subset of the given locale list for which this locale list has a

  * matching (possibly fallback) locale. Locales appear in the same order in the

  * returned list as in the input list.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.2.2.

  */

 function Intl_DateTimeFormat_supportedLocalesOf(locales /*, options*/) {

     var options = arguments.length > 1 ? arguments[1] : undefined;

     var availableLocales = dateTimeFormatInternalProperties.availableLocales();

     var requestedLocales = CanonicalizeLocaleList(locales);

     return SupportedLocales(availableLocales, requestedLocales, options);

 }

 /**

  * DateTimeFormat internal properties.

  *

  * Spec: ECMAScript Internationalization API Specification, 9.1 and 12.2.3.

  */

 var dateTimeFormatInternalProperties = {

     localeData: dateTimeFormatLocaleData,

     _availableLocales: null,

     availableLocales: function()

     {

         var locales = this._availableLocales;

         if (locales)

             return locales;

         return (this._availableLocales =

           addOldStyleLanguageTags(intl_DateTimeFormat_availableLocales()));

     },

     relevantExtensionKeys: ["ca", "nu"]

 };

 function dateTimeFormatLocaleData(locale) {

     return {

         ca: intl_availableCalendars(locale),

         nu: getNumberingSystems(locale)

     };

 }

 /**

  * Function to be bound and returned by Intl.DateTimeFormat.prototype.format.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.3.2.

  */

 function dateTimeFormatFormatToBind() {

     // Steps 1.a.i-ii

     var date = arguments.length > 0 ? arguments[0] : undefined;

     var x = (date === undefined) ? std_Date_now() : ToNumber(date);

     // Step 1.a.iii.

     return intl_FormatDateTime(this, x);

 }

 /**

  * Returns a function bound to this DateTimeFormat that returns a String value

  * representing the result of calling ToNumber(date) according to the

  * effective locale and the formatting options of this DateTimeFormat.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.3.2.

  */

 function Intl_DateTimeFormat_format_get() {

     // Check "this DateTimeFormat object" per introduction of section 12.3.

     var internals = getDateTimeFormatInternals(this, "format");

     // Step 1.

     if (internals.boundFormat === undefined) {

         // Step 1.a.

         var F = dateTimeFormatFormatToBind;

         // Step 1.b-d.

         var bf = callFunction(std_Function_bind, F, this);

         internals.boundFormat = bf;

     }

     // Step 2.

     return internals.boundFormat;

 }

 /**

  * Returns the resolved options for a DateTimeFormat object.

  *

  * Spec: ECMAScript Internationalization API Specification, 12.3.3 and 12.4.

  */

 function Intl_DateTimeFormat_resolvedOptions() {

     // Check "this DateTimeFormat object" per introduction of section 12.3.

     var internals = getDateTimeFormatInternals(this, "resolvedOptions");

     var result = {

         locale: internals.locale,

         calendar: internals.calendar,

         numberingSystem: internals.numberingSystem,

         timeZone: internals.timeZone

     };

     resolveICUPattern(internals.pattern, result);

     return result;

 }

 // Table mapping ICU pattern characters back to the corresponding date-time

 // components of DateTimeFormat. See

 // http://unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table

 var icuPatternCharToComponent = {

     E: "weekday",

     G: "era",

     y: "year",

     M: "month",

     L: "month",

     d: "day",

     h: "hour",

     H: "hour",

     k: "hour",

     K: "hour",

     m: "minute",

     s: "second",

     z: "timeZoneName",

     v: "timeZoneName",

     V: "timeZoneName"

 };

 /**

  * Maps an ICU pattern string to a corresponding set of date-time components

  * and their values, and adds properties for these components to the result

  * object, which will be returned by the resolvedOptions method. For the

  * interpretation of ICU pattern characters, see

  * http://unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table

  */

 function resolveICUPattern(pattern, result) {

     assert(IsObject(result), "resolveICUPattern");

     var i = 0;

     while (i < pattern.length) {

         var c = pattern[i++];

         if (c === "'") {

             while (i < pattern.length && pattern[i] !== "'")

                 i++;

             i++;

         } else {

             var count = 1;

             while (i < pattern.length && pattern[i] === c) {

                 i++;

                 count++;

             }

             var value;

             switch (c) {

             // "text" cases

             case "G":

             case "E":

             case "z":

             case "v":

             case "V":

                 if (count <= 3)

                     value = "short";

                 else if (count === 4)

                     value = "long";

                 else

                     value = "narrow";

                 break;

             // "number" cases

             case "y":

             case "d":

             case "h":

             case "H":

             case "m":

             case "s":

             case "k":

             case "K":

                 if (count === 2)

                     value = "2-digit";

                 else

                     value = "numeric";

                 break;

             // "text & number" cases

             case "M":

             case "L":

                 if (count === 1)

                     value = "numeric";

                 else if (count === 2)

                     value = "2-digit";

                 else if (count === 3)

                     value = "short";

                 else if (count === 4)

                     value = "long";

                 else

                     value = "narrow";

                 break;

             default:

                 // skip other pattern characters and literal text

             }

             if (callFunction(std_Object_hasOwnProperty, icuPatternCharToComponent, c))

                 defineProperty(result, icuPatternCharToComponent[c], value);

             if (c === "h" || c === "K")

                 defineProperty(result, "hour12", true);

             else if (c === "H" || c === "k")

                 defineProperty(result, "hour12", false);

         }

     }

 }