Detect if PHP generator accepts send()?

Hi! Is it possible to somehow detect if a generator can accept any send() command? That is, if it has any line like this: $gen = yield; Use-case is when generators are used to factor out side-effects (as in redux-saga). If no expression depends on the result of any side-effect, all side-effects can be run concurrently (non-blocking IO). Otherwise, the code should wait. Example: yield $io->db->query('UPDATE table ...'); // Don't wait, run as async $result = yield $io->db->query('SELECT id FROM ...'); // Wait for result I've looked into Amphp but didn't find any way to do this yet. Maybe async()/await() functions (not language constructs) would work? Thank you for any feedback. Olle