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