"return new copy of default base router"
    router = Storage(
        default_application = 'init',
            applications = 'ALL',
        default_controller = 'default',
            controllers = 'DEFAULT',
        default_function = 'index',
            functions = dict(),
        default_language = None,
            languages = None,
        root_static = ['favicon.ico', 'robots.txt'],
        domains = None,
        exclusive_domain = False,
        map_hyphen = False,
        acfe_match = r'\w+$',              # legal app/ctlr/fcn/ext

        for key in router.keys():
            if key not in ROUTER_KEYS:
                raise SyntaxError, "unknown key '%s' in router '%s'" % (key, app)
        if not router.controllers:
            router.controllers = set()
        elif not isinstance(router.controllers, str):
            router.controllers = set(router.controllers)




        if router.languages:
            router.languages = set(router.languages)
        else:
            router.languages = set()
        if app != 'BASE':
            for base_only in ROUTER_BASE_KEYS:
                router.pop(base_only, None)
            if 'domain' in router:
                routers.BASE.domains[router.domain] = app
            if isinstance(router.controllers, str) and router.controllers == 'DEFAULT':
                router.controllers = set()
                if os.path.isdir(abspath('applications', app)):
                    cpath = abspath('applications', app, 'controllers')
                    for cname in os.listdir(cpath):
                        if os.path.isfile(abspath(cpath, cname)) and cname.endswith('.py'):
                            router.controllers.add(cname[:-3])
            if router.controllers:
                router.controllers.add('static')
                router.controllers.add(router.default_controller)
            if router.functions:
                if isinstance(router.functions, (set, tuple, list)):
                    functions = set(router.functions)
                    if isinstance(router.default_function, str):
                        functions.add(router.default_function)  # legacy compatibility
                    router.functions = { router.default_controller: functions }
                for controller in router.functions:
                    router.functions[controller] = set(router.functions[controller])
            else:
                router.functions = dict()

    if isinstance(routers.BASE.applications, str) and routers.BASE.applications == 'ALL':
        routers.BASE.applications = list(all_apps)
    if routers.BASE.applications:
        routers.BASE.applications = set(routers.BASE.applications)
    else:
        routers.BASE.applications = set()

    domains = dict()
    if routers.BASE.domains:
        for (domain, app) in [(d.strip(':'), a.strip('/')) for (d, a) in routers.BASE.domains.items()]:
            port = None
            if ':' in domain:
                (domain, port) = domain.split(':')
            ctlr = None
            fcn = None
            if '/' in app:
                (app, ctlr) = app.split('/', 1)
            if ctlr and '/' in ctlr:
                (ctlr, fcn) = ctlr.split('/')
            if app not in all_apps and app not in routers:
                raise SyntaxError, "unknown app '%s' in domains" % app
            domains[(domain, port)] = (app, ctlr, fcn)
    routers.BASE.domains = domains

def regex_uri(e, regexes, tag, default=None):
    "filter incoming URI against a list of regexes"
    path = e['PATH_INFO']
    host = e.get('HTTP_HOST', 'localhost').lower()
    i = host.find(':')

        self.application = None
        self.language = None
        self.controller = None
        self.function = None
        self.extension = 'html'

        self.controllers = set()
        self.functions = dict()
        self.languages = set()
        self.default_language = None
        self.map_hyphen = False
        self.exclusive_domain = False

        path = self.env['PATH_INFO']
        self.query = self.env.get('QUERY_STRING', None)

            self.args = List(self.args[prefixlen:]) # strip the prefix

    def map_app(self):
        "determine application name"
        base = routers.BASE  # base router
        self.domain_application = None
        self.domain_controller = None
        self.domain_function = None
        arg0 = self.harg0


        if (self.host, self.port) in base.domains:
            (self.application, self.domain_controller, self.domain_function) = base.domains[(self.host, self.port)]
            self.env['domain_application'] = self.application
            self.env['domain_controller'] = self.domain_controller
            self.env['domain_function'] = self.domain_function
        elif (self.host, None) in base.domains:
            (self.application, self.domain_controller, self.domain_function) = base.domains[(self.host, None)]
            self.env['domain_application'] = self.application
            self.env['domain_controller'] = self.domain_controller
            self.env['domain_function'] = self.domain_function
        elif base.applications and arg0 in base.applications:
            self.application = arg0
        elif arg0 and not base.applications:
            self.application = arg0
        else:
            self.application = base.default_application or ''
        self.pop_arg_if(self.application == arg0)

        if not base._acfe_match.match(self.application):

                                   'static', file)
        logger.debug("route: static=%s" % static_file)
        return static_file

    def map_function(self):
        "handle function.extension"
        arg0 = self.harg0    # map hyphens
        functions = self.functions.get(self.controller, set())
        if isinstance(self.router.default_function, dict):
            default_function = self.router.default_function.get(self.controller, None)
        else:
            default_function = self.router.default_function # str or None
        default_function = self.domain_function or default_function
        if not arg0 or functions and arg0 not in functions:
            self.function = default_function or ""
            self.pop_arg_if(arg0 and self.function == arg0)
        else:
            func_ext = arg0.split('.')
            if len(func_ext) > 1:
                self.function = func_ext[0]
                self.extension = func_ext[-1]
            else:

        self.other = other
        self.scheme = scheme
        self.host = host
        self.port = port

        self.applications = routers.BASE.applications
        self.controllers = self.router.controllers
        self.functions = self.router.functions.get(self.controller, set())
        self.languages = self.router.languages
        self.default_language = self.router.default_language
        self.exclusive_domain = self.router.exclusive_domain
        self.map_hyphen = self.router.map_hyphen
        self.map_static = self.router.map_static
        self.path_prefix = routers.BASE.path_prefix

        self.domain_application = request and self.request.env.domain_application
        self.domain_controller = request and self.request.env.domain_controller
        if isinstance(self.router.default_function, dict):
            self.default_function = self.router.default_function.get(self.controller, None)
        else:
            self.default_function = self.router.default_function

        if (self.router.exclusive_domain and self.domain_application and self.domain_application != self.application and not self.host):
            raise SyntaxError, 'cross-domain conflict: must specify host'

        lang = request and request.uri_language
        if lang and self.languages and lang in self.languages:
            self.language = lang

    def omit_acf(self):
        "omit what we can of a/c/f"

        router = self.router

        #  Handle the easy no-args case of tail-defaults: /a/c  /a  /
        #
        if not self.args and self.function == self.default_function:
            self.omit_function = True
            if self.controller == router.default_controller:
                self.omit_controller = True
                if self.application == self.default_application:
                    self.omit_application = True

        #  omit default application
        #  (which might be the domain default application)
        #
        default_application = self.domain_application or self.default_application
        if self.application == default_application:
            self.omit_application = True

        #  omit controller if default controller
        #
        default_controller = ((self.application == self.domain_application) and self.domain_controller) or router.default_controller or ''
        if self.controller == default_controller:
            self.omit_controller = True

        #  omit function if possible
        #
        if self.functions and self.function in self.functions and self.function == self.default_function:
            self.omit_function = True

        #  prohibit ambiguous cases
        #
        #  because we presume the lang string to be unambiguous, its presence protects application omission
        #
        if self.omit_language:

    We would also like to be able to strip the default application or application/controller
    from URLs with function/args present, thus:

        /da/c/f/args  => /c/f/args
        /da/dc/f/args => /f/args

    We use [applications] and [controllers] and {functions} to suppress ambiguous omissions.

    We assume that language names do not collide with a/c/f names.
    '''
    map = MapUrlOut(request, env, application, controller, function, args, other, scheme, host, port)
    return map.acf()

def get_effective_router(appname):
    "return a private copy of the effective router for the specified application"
    if not routers or appname not in routers:
        return None
    return Storage(routers[appname])  # return a copy