/**
 * XRegExp 0.6.1
 * (c) 2007-2008 Steven Levithan
 * <http://stevenlevithan.com/regex/xregexp/>
 * MIT License
 * 
 * provides an augmented, cross-browser implementation of regular expressions
 * including support for additional modifiers and syntax. several convenience
 * methods and a recursive-construct parser are also included.
 */

// prevent running twice, which would break references to native globals
if (!window.XRegExp) {
// anonymous function to avoid global variables
(function () {
// copy various native globals for reference. can't use the name ``native``
// because it's a reserved JavaScript keyword.
var real = {
        exec:    RegExp.prototype.exec,
        match:   String.prototype.match,
        replace: String.prototype.replace,
        split:   String.prototype.split
    },
    /* regex syntax parsing with support for all the necessary cross-
       browser and context issues (escapings, character classes, etc.) */
    lib = {
        part:       /(?:[^\\([#\s.]+|\\(?!k<[\w$]+>|[pP]{[^}]+})[\S\s]?|\((?=\?(?!#|<[\w$]+>)))+|(\()(?:\?(?:(#)[^)]*\)|<([$\w]+)>))?|\\(?:k<([\w$]+)>|[pP]{([^}]+)})|(\[\^?)|([\S\s])/g,
        replaceVar: /(?:[^$]+|\$(?![1-9$&`']|{[$\w]+}))+|\$(?:([1-9]\d*|[$&`'])|{([$\w]+)})/g,
        extended:   /^(?:\s+|#.*)+/,
        quantifier: /^(?:[?*+]|{\d+(?:,\d*)?})/,
        classLeft:  /&&\[\^?/g,
        classRight: /]/g
    },
    indexOf = function (array, item, from) {
        for (var i = from || 0; i < array.length; i++)
            if (array[i] === item) return i;
        return -1;
    },
    brokenExecUndef = /()??/.exec("")[1] !== undefined,
    plugins = {};

/**
 * Accepts a pattern and flags, returns a new, extended RegExp object.
 * differs from a native regex in that additional flags and syntax are
 * supported and browser inconsistencies are ameliorated.
 * @ignore
 */
XRegExp = function (pattern, flags) {
    if (pattern instanceof RegExp) {
        if (flags !== undefined)
            throw TypeError("can't supply flags when constructing one RegExp from another");
        return pattern.addFlags(); // new copy
    }

    var flags           = flags || "",
        singleline      = flags.indexOf("s") > -1,
        extended        = flags.indexOf("x") > -1,
        hasNamedCapture = false,
        captureNames    = [],
        output          = [],
        part            = lib.part,
        match, cc, len, index, regex;

    part.lastIndex = 0; // in case the last XRegExp compilation threw an error (unbalanced character class)

    while (match = real.exec.call(part, pattern)) {
        // comment pattern. this check must come before the capturing group check,
        // because both match[1] and match[2] will be non-empty.
        if (match[2]) {
            // keep tokens separated unless the following token is a quantifier
            if (!lib.quantifier.test(pattern.slice(part.lastIndex)))
                output.push("(?:)");
        // capturing group
        } else if (match[1]) {
            captureNames.push(match[3] || null);
            if (match[3])
                hasNamedCapture = true;
            output.push("(");
        // named backreference
        } else if (match[4]) {
            index = indexOf(captureNames, match[4]);
            // keep backreferences separate from subsequent literal numbers
            // preserve backreferences to named groups that are undefined at this point as literal strings
            output.push(index > -1 ?
                "\\" + (index + 1) + (isNaN(pattern.charAt(part.lastIndex)) ? "" : "(?:)") :
                match[0]
            );
        // unicode element (requires plugin)
        } else if (match[5]) {
            output.push(plugins.unicode ?
                plugins.unicode.get(match[5], match[0].charAt(1) === "P") :
                match[0]
            );
        // character class opening delimiter ("[" or "[^")
        // (non-native unicode elements are not supported within character classes)
        } else if (match[6]) {
            if (pattern.charAt(part.lastIndex) === "]") {
                // for cross-browser compatibility with ECMA-262 v3 behavior,
                // convert [] to (?!) and [^] to [\S\s].
                output.push(match[6] === "[" ? "(?!)" : "[\\S\\s]");
                part.lastIndex++;
            } else {
                // parse the character class with support for inner escapes and
                // ES4's infinitely nesting intersection syntax ([&&[^&&[]]]).
                cc = XRegExp.matchRecursive("&&" + pattern.slice(match.index), lib.classLeft, lib.classRight, "", {escapeChar: "\\"})[0];
                output.push(match[6] + cc + "]");
                part.lastIndex += cc.length + 1;
            }
        // dot ("."), pound sign ("#"), or whitespace character
        } else if (match[7]) {
            if (singleline && match[7] === ".") {
                output.push("[\\S\\s]");
            } else if (extended && lib.extended.test(match[7])) {
                len = real.exec.call(lib.extended, pattern.slice(part.lastIndex - 1))[0].length;
                // keep tokens separated unless the following token is a quantifier
                if (!lib.quantifier.test(pattern.slice(part.lastIndex - 1 + len)))
                    output.push("(?:)");
                part.lastIndex += len - 1;
            } else {
                output.push(match[7]);
            }
        } else {
            output.push(match[0]);
        }
    }

    regex = RegExp(output.join(""), real.replace.call(flags, /[sx]+/g, ""));
    regex._x = {
        source:       pattern,
        captureNames: hasNamedCapture ? captureNames : null
    };
    return regex;
};

/**
 * Barebones plugin support for now (intentionally undocumented)
 * @ignore
 * @param {Object} name
 * @param {Object} o
 */
XRegExp.addPlugin = function (name, o) {
    plugins[name] = o;
};

/**
 * Adds named capture support, with values returned as ``result.name``.
 * 
 * Also fixes two cross-browser issues, following the ECMA-262 v3 spec:
 *  - captured values for non-participating capturing groups should be returned
 *    as ``undefined``, rather than the empty string.
 *  - the regex's ``lastIndex`` should not be incremented after zero-length
 *    matches.
 * @ignore
 */
RegExp.prototype.exec = function (str) {
    var match = real.exec.call(this, str),
        name, i, r2;
    if (match) {
        // fix browsers whose exec methods don't consistently return
        // undefined for non-participating capturing groups
        if (brokenExecUndef && match.length > 1) {
            // r2 doesn't need /g or /y, but they shouldn't hurt
            r2 = new RegExp("^" + this.source + "$(?!\\s)", this.getNativeFlags());
            real.replace.call(match[0], r2, function () {
                for (i = 1; i < arguments.length - 2; i++) {
                    if (arguments[i] === undefined) match[i] = undefined;
                }
            });
        }
        // attach named capture properties
        if (this._x && this._x.captureNames) {
            for (i = 1; i < match.length; i++) {
                name = this._x.captureNames[i - 1];
                if (name) match[name] = match[i];
            }
        }
        // fix browsers that increment lastIndex after zero-length matches
        if (this.global && this.lastIndex > (match.index + match[0].length))
            this.lastIndex--;
    }
    return match;
};
})(); // end anonymous function
} // end if(!window.XRegExp)

/**
 * intentionally undocumented
 * @ignore
 */
RegExp.prototype.getNativeFlags = function () {
    return (this.global     ? "g" : "") +
           (this.ignoreCase ? "i" : "") +
           (this.multiline  ? "m" : "") +
           (this.extended   ? "x" : "") +
           (this.sticky     ? "y" : "");
};

/**
 * Accepts flags; returns a new XRegExp object generated by recompiling
 * the regex with the additional flags (may include non-native flags).
 * The original regex object is not altered.
 * @ignore
 */
RegExp.prototype.addFlags = function (flags) {
    var regex = new XRegExp(this.source, (flags || "") + this.getNativeFlags());
    if (this._x) {
        regex._x = {
            source:       this._x.source,
            captureNames: this._x.captureNames ? this._x.captureNames.slice(0) : null
        };
    }
    return regex;
};

/**
 * Accepts a context object and string; returns the result of calling
 * ``exec`` with the provided string. the context is ignored but is
 * accepted for congruity with ``Function.prototype.call``.
 * @ignore
 */
RegExp.prototype.call = function (context, str) {
    return this.exec(str);
};

/**
 * Accepts a context object and arguments array; returns the result of
 * calling ``exec`` with the first value in the arguments array. the context
 * is ignored but is accepted for congruity with ``Function.prototype.apply``.
 * @ignore
 */
RegExp.prototype.apply = function (context, args) {
    return this.exec(args[0]);
};

/**
 * Accepts a pattern and flags; returns an XRegExp object. if the pattern
 * and flag combination has previously been cached, the cached copy is
 * returned, otherwise the new object is cached.
 * @ignore
 */
XRegExp.cache = function (pattern, flags) {
    var key = "/" + pattern + "/" + (flags || "");
    return XRegExp.cache[key] || (XRegExp.cache[key] = new XRegExp(pattern, flags));
};

/**
 * Accepts a string; returns the string with regex metacharacters escaped.
 * the returned string can safely be used within a regex to match a literal
 * string. escaped characters are [, ], {, }, (, ), -, *, +, ?, ., \, ^, $,
 * |, #, [comma], and whitespace.
 * @ignore
 */
XRegExp.escape = function (str) {
    return str.replace(/[-[\]{}()*+?.\\^$|,#\s]/g, "\\$&");
};

/**
 * Accepts a string to search, left and right delimiters as regex pattern
 * strings, optional regex flags (may include non-native s, x, and y flags),
 * and an options object which allows setting an escape character and changing
 * the return format from an array of matches to a two-dimensional array of
 * string parts with extended position data. returns an array of matches
 * (optionally with extended data), allowing nested instances of left and right
 * delimiters. use the g flag to return all matches, otherwise only the first
 * is returned. if delimiters are unbalanced within the subject data, an error
 * is thrown.
 * 
 * This function admittedly pushes the boundaries of what can be accomplished
 * sensibly without a "real" parser. however, by doing so it provides flexible
 * and powerful recursive parsing capabilities with minimal code weight.
 * 
 * Warning: the ``escapeChar`` option is considered experimental and might be
 * changed or removed in future versions of XRegExp.
 * 
 * unsupported features:
 *  - backreferences within delimiter patterns when using ``escapeChar``.
 *  - although providing delimiters as regex objects adds the minor feature of
 *    independent delimiter flags, it introduces other limitations and is only
 *    intended to be done by the ``XRegExp`` constructor (which can't call
 *    itself while building a regex).
 * 
 * @ignore
 */
XRegExp.matchRecursive = function (str, left, right, flags, options) {
    var options      = options || {},
        escapeChar   = options.escapeChar,
        vN           = options.valueNames,
        flags        = flags || "",
        global       = flags.indexOf("g") > -1,
        ignoreCase   = flags.indexOf("i") > -1,
        multiline    = flags.indexOf("m") > -1,
        sticky       = flags.indexOf("y") > -1,
        /* sticky mode has its own handling in this function, which means you
           can use flag "y" even in browsers which don't support it natively */
        flags        = flags.replace(/y/g, ""),
        left         = left  instanceof RegExp ? (left.global  ? left  : left.addFlags("g"))  : new XRegExp(left,  "g" + flags),
        right        = right instanceof RegExp ? (right.global ? right : right.addFlags("g")) : new XRegExp(right, "g" + flags),
        output       = [],
        openTokens   = 0,
        delimStart   = 0,
        delimEnd     = 0,
        lastOuterEnd = 0,
        outerStart, innerStart, leftMatch, rightMatch, escaped, esc;

    if (escapeChar) {
        if (escapeChar.length > 1) throw SyntaxError("can't supply more than one escape character");
        if (multiline)             throw TypeError("can't supply escape character when using the multiline flag");
        escaped = XRegExp.escape(escapeChar);
        /* Escape pattern modifiers:
            /g - not needed here
            /i - included
            /m - **unsupported**, throws error
            /s - handled by XRegExp when delimiters are provided as strings
            /x - handled by XRegExp when delimiters are provided as strings
            /y - not needed here; supported by other handling in this function
        */
        esc = new RegExp(
            "^(?:" + escaped + "[\\S\\s]|(?:(?!" + left.source + "|" + right.source + ")[^" + escaped + "])+)+",
            ignoreCase ? "i" : ""
        );
    }

    while (true) {
        /* advance the starting search position to the end of the last delimiter match.
           a couple special cases are also covered:
            - if using an escape character, advance to the next delimiter's starting position,
              skipping any escaped characters
            - first time through, reset lastIndex in case delimiters were provided as regexes
        */
        left.lastIndex = right.lastIndex = delimEnd +
            (escapeChar ? (esc.exec(str.slice(delimEnd)) || [""])[0].length : 0);

        leftMatch  = left.exec(str);
        rightMatch = right.exec(str);

        // only keep the result which matched earlier in the string
        if (leftMatch && rightMatch) {
            if (leftMatch.index <= rightMatch.index)
                 rightMatch = null;
            else leftMatch  = null;
        }

        /* paths*:
        leftMatch | rightMatch | openTokens | result
        1         | 0          | 1          | ...
        1         | 0          | 0          | ...
        0         | 1          | 1          | ...
        0         | 1          | 0          | throw
        0         | 0          | 1          | throw
        0         | 0          | 0          | break
        * - does not include the sticky mode special case
          - the loop ends after the first completed match if not in global mode
        */

        if (leftMatch || rightMatch) {
            delimStart = (leftMatch || rightMatch).index;
            delimEnd   = (leftMatch ? left : right).lastIndex;
        } else if (!openTokens) {
            break;
        }

        if (sticky && !openTokens && delimStart > lastOuterEnd)
            break;

        if (leftMatch) {
            if (!openTokens++) {
                outerStart = delimStart;
                innerStart = delimEnd;
            }
        } else if (rightMatch && openTokens) {
            if (!--openTokens) {
                if (vN) {
                    if (vN[0] && outerStart > lastOuterEnd)
                               output.push([vN[0], str.slice(lastOuterEnd, outerStart), lastOuterEnd, outerStart]);
                    if (vN[1]) output.push([vN[1], str.slice(outerStart,   innerStart), outerStart,   innerStart]);
                    if (vN[2]) output.push([vN[2], str.slice(innerStart,   delimStart), innerStart,   delimStart]);
                    if (vN[3]) output.push([vN[3], str.slice(delimStart,   delimEnd),   delimStart,   delimEnd]);
                } else {
                    output.push(str.slice(innerStart, delimStart));
                }
                lastOuterEnd = delimEnd;
                if (!global)
                    break;
            }
        } else {
            // reset lastIndex in case delimiters were provided as regexes
            left.lastIndex = right.lastIndex = 0;
            throw Error("subject data contains unbalanced delimiters");
        }

        // if the delimiter matched an empty string, advance delimEnd to avoid an infinite loop
        if (delimStart === delimEnd)
            delimEnd++;
    }

    if (global && !sticky && vN && vN[0] && str.length > lastOuterEnd)
        output.push([vN[0], str.slice(lastOuterEnd), lastOuterEnd, str.length]);

    // reset lastIndex in case delimiters were provided as regexes
    left.lastIndex = right.lastIndex = 0;

    return output;
};