/* 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);
var unicodeLocaleExtensionSequenceGlobalRE = new RegExp(unicodeLocaleExtensionSequence, "g");


/**
 * 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 (!callFunction(std_RegExp_test, 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 !callFunction(std_RegExp_test, duplicateVariantRE, locale) &&
           !callFunction(std_RegExp_test, 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 !callFunction(std_RegExp_test, /[^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), "BestAvailableLocale");
    assert(locale === CanonicalizeLanguageTag(locale), "BestAvailableLocale");
    assert(callFunction(std_String_indexOf, locale, "-u-") === -1, "BestAvailableLocale");

    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 = callFunction(std_String_replace, locale, unicodeLocaleExtensionSequenceGlobalRE, "");
        availableLocale = BestAvailableLocale(availableLocales, noExtensionsLocale);
        i++;
    }

    var result = new Record();
    if (availableLocale !== undefined) {
        result.locale = availableLocale;
        if (locale !== noExtensionsLocale) {
            var extensionMatch = callFunction(std_String_match, locale, unicodeLocaleExtensionSequenceRE);
            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 = callFunction(std_String_replace, locale, unicodeLocaleExtensionSequenceGlobalRE, "");

        // 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++)
        std_Object_defineProperty(subset, i, {value: subset[i], writable: false, enumerable: true, configurable: false});
    std_Object_defineProperty(subset, "length", {value: subset.length, writable: false, enumerable: false, configurable: false});

    // 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) {
    std_Object_defineProperty(o, p, {value: v, writable: true, enumerable: true, configurable: true});
}


/**
 * Weak map holding objects with the properties specified as "internal" for
 * all Intl API objects. Presence of an object as a key within this map is
 * considered equivalent to having the [[initializedIntlObject]] internal
 * property set to true on this object.
 *
 * Ideally we'd be using private symbols for internal properties, but
 * SpiderMonkey doesn't have those yet.
 */
var internalsMap = new WeakMap();


/**
 * Create an object holding the properties specified as "internal" for
 * an Intl API object. This call is equivalent to setting the
 * [[initializedIntlObject]] internal property of o to true.
 */
function initializeIntlObject(o) {
    assert(IsObject(o), "initializeIntlObject");
    var internals = std_Object_create(null);
    callFunction(std_WeakMap_set, internalsMap, o, internals);
    return internals;
}


/**
 * Return whether the object has been initialized as an Intl object, equivalent
 * to testing whether the [[initializedIntlObject]] internal property of o is
 * true.
 */
function isInitializedIntlObject(o) {
    return callFunction(std_WeakMap_has, internalsMap, o);
}


/**
 * Returns the object holding the internal properties of o.
 */
function getInternals(o) {
    return callFunction(std_WeakMap_get, internalsMap, o);
}


/**
 * Check that the object on which certain functions are called
 * meet the requirements for "this Collator object", "this NumberFormat object",
 * "this DateTimeFormat object". If it meets the requirements, return the
 * object holding its internal properties.
 *
 * Spec: ECMAScript Internationalization API Specification, 10.3.
 * Spec: ECMAScript Internationalization API Specification, 11.3.
 * Spec: ECMAScript Internationalization API Specification, 12.3.
 */
function checkIntlAPIObject(o, className, methodName) {
    assert(typeof className === "string", "checkIntlAPIObject");
    var internals = getInternals(o);
    if (internals === undefined || internals["initialized" + className] !== true)
        ThrowError(JSMSG_INTL_OBJECT_NOT_INITED, className, methodName, className);
    assert(IsObject(o), "checkIntlAPIObject");
    return internals;
}


/********** 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"]}
};


/**
 * Initializes an object as a Collator.
 *
 * 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);

    // Step 3.
    var requestedLocales = CanonicalizeLocaleList(locales);

    // Steps 4-5.
    if (options === undefined)
        options = {};
    else
        options = ToObject(options);

    // Compute options that impact interpretation of locale.
    // Steps 6-7.
    var u = GetOption(options, "usage", "string", ["sort", "search"], "sort");
    internals.usage = u;

    // Step 8.
    var Collator = collatorInternalProperties;

    // Step 9.
    var localeData = u === "sort" ? Collator.sortLocaleData : Collator.searchLocaleData;

    // Step 10.
    var opt = new Record();

    // Steps 11-12.
    var matcher = GetOption(options, "localeMatcher", "string", ["lookup", "best fit"], "best fit");
    opt.localeMatcher = matcher;

    // Check all allowed options properties and convert them to extension keys.
    // Steps 13-13.a.
    var key, mapping, property, value;
    for (key in collatorKeyMappings) {
        if (callFunction(std_Object_hasOwnProperty, collatorKeyMappings, key)) {
            mapping = collatorKeyMappings[key];

            // Step 13.b.
            value = GetOption(options, mapping.property, mapping.type, mapping.values, undefined);

            // Step 13.c.
            if (mapping.type === "boolean" && value !== undefined)
                value = callFunction(std_Boolean_toString, value);

            // Step 13.d.
            opt[key] = value;
        }
    }

    // Compute effective locale.
    // Step 14.
    var relevantExtensionKeys = Collator.relevantExtensionKeys;

    // Step 15.
    var r = ResolveLocale(Collator.availableLocales,
                          requestedLocales, opt,
                          relevantExtensionKeys,
                          localeData);
    // Step 16.
    internals.locale = r.locale;

    // Steps 17-19.
    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.
        internals[property] = value;

        // Step 19.e.
        i++;
    }

    // Compute remaining collation options.
    // Steps 20-21.
    var s = GetOption(options, "sensitivity", "string",
                      ["base", "accent", "case", "variant"], undefined);
    if (s === undefined) {
        if (u === "sort") {
            // Step 21.a.
            s = "variant";
        } else {
            // Step 21.b.
            var dataLocale = r.dataLocale;
            var dataLocaleData = localeData(dataLocale);
            s = dataLocaleData.sensitivity;
        }
    }

    // Step 22.
    internals.sensitivity = s;

    // Steps 23-24.
    var ip = GetOption(options, "ignorePunctuation", "boolean", undefined, false);
    internals.ignorePunctuation = ip;

    // Step 25.
    internals.boundFormat = undefined;

    // Step 26.
    internals.initializedCollator = true;
}


/**
 * 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: 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 = checkIntlAPIObject(this, "Collator", "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 = checkIntlAPIObject(this, "Collator", "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 **********/


/**
 * Initializes an object as a NumberFormat.
 *
 * 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);

    // Step 3.
    var requestedLocales = CanonicalizeLocaleList(locales);

    // Steps 4-5.
    if (options === undefined)
        options = {};
    else
        options = ToObject(options);

    // Compute options that impact interpretation of locale.
    // Step 6.
    var opt = new Record();

    // Steps 7-8.
    var matcher = GetOption(options, "localeMatcher", "string", ["lookup", "best fit"], "best fit");
    opt.localeMatcher = matcher;

    // Compute effective locale.
    // Step 9.
    var NumberFormat = numberFormatInternalProperties;

    // Step 10.
    var localeData = NumberFormat.localeData;

    // Step 11.
    var r = ResolveLocale(NumberFormat.availableLocales,
                          requestedLocales, opt,
                          NumberFormat.relevantExtensionKeys,
                          localeData);

    // Steps 12-14.
    internals.locale = r.locale;
    internals.numberingSystem = r.nu;
    var dataLocale = r.dataLocale;

    // Compute formatting options.
    // Steps 15-16.
    var s = GetOption(options, "style", "string", ["decimal", "percent", "currency"], "decimal");
    internals.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);
        internals.currency = c;
        cDigits = CurrencyDigits(c);
    }

    // Steps 21-22.
    var cd = GetOption(options, "currencyDisplay", "string", ["code", "symbol", "name"], "symbol");
    if (s === "currency")
        internals.currencyDisplay = cd;

    // Steps 23-24.
    var mnid = GetNumberOption(options, "minimumIntegerDigits", 1, 21, 1);
    internals.minimumIntegerDigits = mnid;

    // Steps 25-27.
    var mnfdDefault = (s === "currency") ? cDigits : 0;
    var mnfd = GetNumberOption(options, "minimumFractionDigits", 0, 20, mnfdDefault);
    internals.minimumFractionDigits = mnfd;

    // Steps 28-30.
    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);
    internals.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);
        internals.minimumSignificantDigits = mnsd;
        internals.maximumSignificantDigits = mxsd;
    }

    // Steps 34-35.
    var g = GetOption(options, "useGrouping", "boolean", undefined, true);
    internals.useGrouping = g;

    // ??? Steps 36-41 to be provided by concrete implementation.

    // Step 42.
    internals.boundFormat = undefined;

    // Step 43.
    internals.initializedNumberFormat = true;
}


/**
 * 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(callFunction(std_RegExp_test, /^[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);
}


/**
 * NumberFormat internal properties.
 *
 * Spec: ECMAScript Internationalization API Specification, 9.1 and 11.2.3.
 */
var numberFormatInternalProperties = {
    localeData: numberFormatLocaleData,
    availableLocales: addOldStyleLanguageTags(intl_NumberFormat_availableLocales()),
    relevantExtensionKeys: ["nu"]
};


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 = checkIntlAPIObject(this, "NumberFormat", "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 = checkIntlAPIObject(this, "NumberFormat", "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 **********/


/**
 * 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.
 *
 * 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);

    // Step 3.
    var requestedLocales = CanonicalizeLocaleList(locales);

    // Step 4.
    options = ToDateTimeOptions(options, "any", "date");

    // Compute options that impact interpretation of locale.
    // Step 5.
    var opt = new Record();

    // Steps 6-7.
    var matcher = GetOption(options, "localeMatcher", "string", ["lookup", "best fit"], "best fit");
    opt.localeMatcher = matcher;

    // Compute effective locale.
    // Step 8.
    var DateTimeFormat = dateTimeFormatInternalProperties;

    // Step 9.
    var localeData = DateTimeFormat.localeData;

    // Step 10.
    var r = ResolveLocale(DateTimeFormat.availableLocales,
                          requestedLocales, opt,
                          DateTimeFormat.relevantExtensionKeys,
                          localeData);

    // Steps 11-13.
    internals.locale = r.locale;
    internals.calendar = r.ca;
    internals.numberingSystem = r.nu;

    // Compute formatting options.
    // Step 14.
    var dataLocale = r.dataLocale;

    // Steps 15-17.
    var tz = options.timeZone;
    if (tz !== undefined) {
        tz = toASCIIUpperCase(ToString(tz));
        if (tz !== "UTC")
            ThrowError(JSMSG_INVALID_TIME_ZONE, tz);
    }
    internals.timeZone = tz;

    // Step 18.
    opt = new Record();

    // Step 19.
    var i, prop;
    for (i = 0; i < dateTimeComponents.length; i++) {
        prop = dateTimeComponents[i];
        var value = GetOption(options, prop, "string", dateTimeComponentValues[prop], undefined);
        opt[prop] = value;
    }

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

    // Step 22.
    matcher = 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)
        opt.hour12 = hr12;

    // Steps 27-28, more or less - see comment after this function.
    var pattern = toBestICUPattern(dataLocale, opt);

    // Step 29.
    internals.pattern = pattern;

    // Step 30.
    internals.boundFormat = undefined;

    // Step 31.
    internals.initializedDateTimeFormat = true;
}


// 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: 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 = checkIntlAPIObject(this, "DateTimeFormat", "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 = checkIntlAPIObject(this, "DateTimeFormat", "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);
        }
    }
}