gistfile1.js

function unescapeJSString(string) {
    var named = {b: "\b", f: "\f", n: "\n", r: "\r", t: "\t", v: "\v"};
    return string.replace(/\\(?:([bfnrtv])|u([0-9a-fA-F]{4})|x([0-9a-fA-F]{2})|([0-3][0-7]{0,2}|[0-7]{1,2})|([^]))/g, function(seq, name, hex4, hex2, oct, char) {
        var hex;
        if (name) { // e.g. \n
            return named[name];
        } else if (char) { // e.g. \"
            return char;
        } else if (hex = hex4 || hex2) { // e.g. \u0022 or \x22
            return String.fromCharCode(parseInt(hex, 16));
        } else if (oct) { // e.g. \42
            return String.fromCharCode(parseInt(oct, 8));
        } else {
            // this case doesn't happen actually
            return seq;
        }
    });
}