/* 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/. */


if (typeof isHighSurrogate === 'undefined') {
    var isHighSurrogate = function isHighSurrogate(s) {
        var c = s.charCodeAt(0);
        return c >= 0xD800 && c <= 0xDBFF;
    }
}

if (typeof isLowSurrogate === 'undefined') {
    var isLowSurrogate = function isLowSurrogate(s) {
        var c = s.charCodeAt(0);
        return c >= 0xDC00 && c <= 0xDFFF;
    }
}

if (typeof isSurrogatePair === 'undefined') {
    var isSurrogatePair = function isSurrogatePair(s) {
        return s.length == 2 && isHighSurrogate(s[0]) && isLowSurrogate(s[1]);
    }
}