[E014] Error: missing type for readonly property `foo::$s`
   ,-[code.php:5:25]
   |
 3 | class foo {
   *       ^^^  
   *             
   * 
 5 |         readonly public $s = "h",
   *         ^^^^^^^^        ^|  
   *                          `-- try adding a type before `$s`
   *                             
   *                              
---'