I was trying to create a WordPress function that altered the post_name. My final function is:

function edit_permalink( $post_id ) {

    if ( 'ratings' === get_post_type( $post_id ) ) {

        remove_action( 'save_post', 'edit_permalink' );
        $slug = get_post_field('post_title', $post_id);
        $slug = urlencode($slug);
        $date = get_field( 'date_of_rating', $post_id );
        $location = wp_get_post_terms( $post_id, 'areas' ); 

        wp_update_post(array('ID' => $post_id, 'post_name' => $slug . "_" . $date->name . "_" . $location[0]->slug));
        add_action( 'save_post', 'edit_permalink' );
        }


}

add_filter( 'save_post', 'edit_permalink', 10, 2 );

HOWEVER – somewhere along the way, I created a function that is just spewing out multiple posts every second. I’m now up 4000 – still going on – and I can’t stop it!! I’ve tried switching themes, wp_die() – what else can I do!?!