/**
* Matches a route and HTTP method/s against the request path, and if successful, invokes a controller and **exits**.
*
* When a route and method/s are matched, the HTTP response code is automatically set to `200`.
* The controller is then invoked and responsible for the response code from then on.
*
* Otherwise a response code of either `404` or `405` is set.
*
* This also means that within a subrouter the HTTP response can go from an initial `200` to `404`/`405` if those subroutes fail.
*
* To allow safe fallthrough, a `404` response code will not replace an existing `405`.
*
* @param string[] $methods HTTP request methods, or empty to accept any method.
* @param string $route A literal path with leading slash, or a regular expression.
* Regular expressions are enclosed by anything other than a slash, since slashes are used for literal paths.
* @param callable $controller Given either the [preg_match()](http://php.net/preg-match) array, or the literal path.
* The controller can output content directly if it chooses, but it must also output headers and **exit**.
* If not, the return value is given to {@link \H\O::mixed()}, which **exits**.
*/
public static function route($methods, $route, callable $controller)
{
$match = $path = I::path();
if ($route === $path or $route[0] !== '/' && preg_match($route, $path, $match)) {
if (empty($methods) or in_array(I::method(), $methods)) {
O::code(200);
O::mixed(call_user_func($controller, $match));
// exits
} else {
O::code(405);
}
} elseif (O::code() !== 405) {
O::code(404);
}
}