String.prototype.split = function()

in ext/syntaxhighlighter/scripts/XRegExp.js [421:475]
45 lines of code
19 McCabe index (conditional complexity)

    String.prototype.split = function (s /* separator */, limit) {
        // If separator `s` is not a regex, use the native `split`
        if (!XRegExp.isRegExp(s))
            return real.split.apply(this, arguments);

        var str = this + "", // Type conversion
            output = [],
            lastLastIndex = 0,
            match, lastLength;

        // Behavior for `limit`: if it's...
        // - `undefined`: No limit
        // - `NaN` or zero: Return an empty array
        // - A positive number: Use `Math.floor(limit)`
        // - A negative number: No limit
        // - Other: Type-convert, then use the above rules
        if (limit === undefined || +limit < 0) {
            limit = Infinity;
        } else {
            limit = Math.floor(+limit);
            if (!limit)
                return [];
        }

        // This is required if not `s.global`, and it avoids needing to set `s.lastIndex` to zero
        // and restore it to its original value when we're done using the regex
        s = XRegExp.copyAsGlobal(s);

        while (match = s.exec(str)) { // Run the altered `exec` (required for `lastIndex` fix, etc.)
            if (s.lastIndex > lastLastIndex) {
                output.push(str.slice(lastLastIndex, match.index));

                if (match.length > 1 && match.index < str.length)
                    Array.prototype.push.apply(output, match.slice(1));

                lastLength = match[0].length;
                lastLastIndex = s.lastIndex;

                if (output.length >= limit)
                    break;
            }

            if (s.lastIndex === match.index)
                s.lastIndex++;
        }

        if (lastLastIndex === str.length) {
            if (!real.test.call(s, "") || lastLength)
                output.push("");
        } else {
            output.push(str.slice(lastLastIndex));
        }

        return output.length > limit ? output.slice(0, limit) : output;
    };