/**
  * Outputs DDL for differences in functions
  *
  * @param $ofs1       stage1 output pointer
  * @param $ofs3       stage3 output pointer
  * @param $old_schema original schema
  * @param $new_schema new schema
  */
 public static function diff_functions($ofs1, $ofs3, $old_schema, $new_schema)
 {
     // drop functions that no longer exist in stage 3
     if ($old_schema != null) {
         foreach (dbx::get_functions($old_schema) as $old_function) {
             if (!mysql5_schema::contains_function($new_schema, mysql5_function::get_declaration($new_schema, $old_function))) {
                 $ofs3->write(mysql5_function::get_drop_sql($old_schema, $old_function) . "\n");
             }
         }
     }
     // Add new functions and replace modified functions
     foreach (dbx::get_functions($new_schema) as $new_function) {
         $old_function = null;
         if ($old_schema != null) {
             $old_function = dbx::get_function($old_schema, $new_function['name'], mysql5_function::get_declaration($new_schema, $new_function));
         }
         if ($old_function == null || !mysql5_function::equals($new_schema, $new_function, $old_function, mysql5_diff::$ignore_function_whitespace)) {
             $ofs1->write(mysql5_function::get_creation_sql($new_schema, $new_function) . "\n");
         } else {
             if (isset($new_function['forceRedefine']) && strcasecmp($new_function['forceRedefine'], 'true') == 0) {
                 $ofs1->write("-- DBSteward insists on function recreation: {$new_schema['name']}.{$new_function['name']} has forceRedefine set to true\n");
                 $ofs1->write(mysql5_function::get_creation_sql($new_schema, $new_function) . "\n");
             } else {
                 if (mysql5_schema::contains_type($new_schema, $new_function['returns']) && mysql5_schema::contains_type($old_schema, $new_function['returns']) && !mysql5_type::equals(dbx::get_type($old_schema, $new_function['returns']), dbx::get_type($new_schema, $new_function['returns']))) {
                     $ofs1->write("-- Force function re-creation {$new_function['name']} for type: {$new_function['returns']}\n");
                     $ofs1->write(mysql5_function::get_creation_sql($new_schema, $new_function) . "\n");
                 }
             }
         }
     }
 }