nice C# like formattin structure in js

keeper.js

/**
     * Format all arguments into the first argument.  This is a
     * convenience function similar to the C sprintf function, though
     * only with simple replacements.  Replacements are formatted like
     * #{i} where i is a zero based index into the additional
     * arguments passed in to format beyond the first.
     *
     * Additional parameters not used will be ignored.
     *
     * Including formatting requests for parameters that don't exist
     * will throw an exception.
     *
     * The first argument must be the string that needs to be
     * formatted.  Additional arguments are formatted into that
     * string.
     *
     * If any of the arguments to the format string include a string
     * that matches the #{i} format, the result could be erroneous.
     *
     * Example: $.guards.format("#{2} #{0} #{1}", "hello", "world", 3); // "3 hello world"
     * Example: $.guards.format("#{0} #{1}", "hello", "world", 3);      // "hello world".
     * Example: $.guards.format("#{2} #{0} #{1}", "hello", "world");    // throws exception
     */
    $.Guards.prototype.format = function() {
        var str = arguments[0];

        if (arguments.length > 1) {
            for (var i = 1; i < arguments.length; i++) {
                var regex = "\\#\\{" + (i - 1) + "\\}";
                str = str.replace(new RegExp(regex, "g"), arguments[i]);
            }
        }

        if (/\#\{\d+\}/.test(str)) {
            throw new Error("Unmatched formatting found!");
        }

        return str;
    };