从匹配的路由中提取通配符字符串

Question

我现有的代码：

    // Define the routes
    $routes = [
        '/programs',
        '/programs/{}',
        '/programs/{}/{}',
        '/programs/{}/test/{}'
    ];

    // Example URL
    $url = '/programs/part_1/test/part_2';

    /*
     * Split the URL at /
     * Remove the first and last value from the returned array
    */
    $parts = array_values( array_filter( preg_split( "/\//", $url ) ) );

    // Define valid routes array
    $valid_routes = $routes;

    // Loop over the defined routes
    foreach($routes as $route){
        // Split the route into parts, like we do with the url
        $route_parts = array_values( array_filter( preg_split( "/\//", $route ) ) );

        /*
         * If the route parts is more than the parts of the url
         * then continue to the next value in the routes array
         */
        if( sizeof( $route_parts ) != sizeof( $parts ) ){
            // Remove the route from the valid routes array
            $valid_routes = array_values( array_diff( $valid_routes, [$route] ) );
        }

        // Loop over the route parts
        for( $i=0; $i<sizeof( $route_parts ); $i++ ) {
            /*
             * Compare the route part to the url part and see if they match
             * or if the route part is {}
             */
            if ( $i >= sizeof( $parts ) || ( $route_parts[ $i ] != '{}' & $route_parts[ $i ] != $parts[ $i ] ) ){
                // Remove the route from the valid routes array
                $valid_routes = array_values( array_diff( $valid_routes, [$route] ) );
            }
        }
    }

    // Find the route with the least occurrence of the {} characters
    $route = $this->leastOccurrence( $valid_routes, '{}' );

    if( $route != null ){
        // Route found, output the route
        echo 'Found route: ' . $route;
    } else {
        // No route found, 404
        echo '404, not found';
    }

这-简单来说-将给定的URL匹配到路由。输出为：

  

找到的路径：/ programs / {} / test / {}

我的程序的下一步是提取通配符字符串，本例中为'part_1'和'part_2'。我遇到的问题是我只是不知道从哪里开始，我没有任何逻辑可以解决，而这正是我真正想要的-与编码答案相反。