I want to make an anonymous function that is based off a string i get from a database

anonymous function

// so i have two strings i get from a database, an action, and a callback function name
// let's say the action = 'comment_post', and the function name is 'my_comment_post'
// i want to add an action that is basically add_action( 'comment_post', 'my_comment_post' );
// but i want to do this dynamically for any and all entries i have in the database
// how?

// in my plugin init i had this code, but it wasn't working
// $results->callback would be "my_comment_post"
// $results->hook would be 'comment_post'

${$results->callback} = function () {
    // get the current user
    $current_user = wp_get_current_user();
    if ( 0 == $current_user->ID ) {
        // Not logged in.
        return;
    } else {
        // add the point value to their point meta
        update_user_meta( $current_user->ID, 'some_key', 'some_value' );
    }
};

add_action( "$results->hook", "$results->callback" );

my sample

$results = (object) array(
	'callback' => 'my_wp_head',
	'hook' => 'wp_head',
);

${$results->callback} = function () {
	?>
	<script>alert('here');</script>
	<?php
};

add_action( "$results->hook", ${$results->callback} );