def add(self, rule, method, target, name=None):
        ''' Add a new route or replace the target for an existing route. '''
        if rule in self.rules:
            self.rules[rule][method] = target
            if name: self.builder[name] = self.builder[rule]
            return

        target = self.rules[rule] = {method: target}

        # Build pattern and other structures for dynamic routes
        anons = 0      # Number of anonymous wildcards
        pattern = ''   # Regular expression  pattern
        filters = []   # Lists of wildcard input filters
        builder = []   # Data structure for the URL builder
        is_static = True
        for key, mode, conf in self.parse_rule(rule):
            if mode:
                is_static = False
                mask, in_filter, out_filter = self.filters[mode](conf)
                if key:
                    pattern += '(?P<%s>%s)' % (key, mask)
                else:
                    pattern += '(?:%s)' % mask
                    key = 'anon%d' % anons; anons += 1
                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[self.build(rule)] = target
            return

        def fpat_sub(m):
            return m.group(0) if len(m.group(1)) % 2 else m.group(1) + '(?:'
        flat_pattern = re.sub(r'(\\*)(\(\?P<[^>]*>|\((?!\?))', fpat_sub, pattern)

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

        def match(path):
            """ Return an url-argument dictionary. """
            url_args = re_match(path).groupdict()
            for name, wildcard_filter in filters:
                try:
                    url_args[name] = wildcard_filter(url_args[name])
                except ValueError:
                    raise HTTPError(400, 'Path has wrong format.')
            return url_args

        try:
            combined = '%s|(^%s$)' % (self.dynamic[-1][0].pattern, flat_pattern)
            self.dynamic[-1] = (re.compile(combined), self.dynamic[-1][1])
            self.dynamic[-1][1].append((match, target))
        except (__HOLE__, IndexError): # AssertionError: Too many groups
            self.dynamic.append((re.compile('(^%s$)' % flat_pattern),
                                [(match, target)]))
        return match
dataset/ETHPy150Open adampresley/bottlepy-bootstrap/app/bottle.py/Router.add