def add(self, rule, method, target, name=None):
        """ Add a new rule or replace the target for an existing rule. """
        anons = 0  # Number of anonymous wildcards found
        keys = []  # Names of keys
        pattern = ''  # Regular expression pattern with named groups
        filters = []  # Lists of wildcard input filters
        builder = []  # Data structure for the URL builder
        is_static = True

        for key, mode, conf in self._itertokens(rule):
            if mode:
                is_static = False
                if mode == 'default': mode = self.default_filter
                mask, in_filter, out_filter = self.filters[mode](conf)
                if not key:
                    pattern += '(?:%s)' % mask
                    key = 'anon%d' % anons
                    anons += 1
                else:
                    pattern += '(?P<%s>%s)' % (key, mask)
                    keys.append(key)
                if in_filter: filters.append((key, in_filter))
                builder.append((key, out_filter or str))
            elif key:
                pattern += re.escape(key)
                builder.append((None, key))

        self.builder[rule] = builder
        if name: self.builder[name] = builder

        if is_static and not self.strict_order:
            self.static.setdefault(method, {})
            self.static[method][self.build(rule)] = (target, None)
            return

        try:
            re_pattern = re.compile('^(%s)$' % pattern)
            re_match = re_pattern.match
        except re.error:
            raise RouteSyntaxError("Could not add Route: %s (%s)" %
                                   (rule, _e()))

        if filters:

            def getargs(path):
                url_args = re_match(path).groupdict()
                for name, wildcard_filter in filters:
                    try:
                        url_args[name] = wildcard_filter(url_args[name])
                    except __HOLE__:
                        raise HTTPError(400, 'Path has wrong format.')
                return url_args
        elif re_pattern.groupindex:

            def getargs(path):
                return re_match(path).groupdict()
        else:
            getargs = None

        flatpat = _re_flatten(pattern)
        whole_rule = (rule, flatpat, target, getargs)

        if (flatpat, method) in self._groups:
            if DEBUG:
                msg = 'Route <%s %s> overwrites a previously defined route'
                warnings.warn(msg % (method, rule), RuntimeWarning)
            self.dyna_routes[method][
                self._groups[flatpat, method]] = whole_rule
        else:
            self.dyna_routes.setdefault(method, []).append(whole_rule)
            self._groups[flatpat, method] = len(self.dyna_routes[method]) - 1

        self._compile(method)
dataset/ETHPy150Open Arelle/Arelle/arelle/webserver/bottle.py/Router.add