/**
* Emits a value from the contained Emitter object.
*
* @coroutine
*
* @param mixed $value If $value is an instance of \Icicle\Awaitable\Awaitable, the fulfillment value is used
* as the value to emit or the rejection reason is thrown from this coroutine. If $value is an instance of
* \Generator, it is used to create a coroutine which is then used as an awaitable.
*
* @return \Generator
*
* @resolve mixed The emitted value (the resolution value of $value)
*
* @throws \Icicle\Observable\Exception\CompletedError If the observable has been completed.
* @throws \Icicle\Observable\Exception\BusyError If the observable is still busy emitting a value.
* @throws \Icicle\Observable\Exception\DisposedException If no listeners remain on the observable.
*/
public function emit($value = null) : \Generator
{
if (null === $this->emit) {
$this->emit = (yield $this->started);
}
if (!$this->delayed->isPending()) {
if ($this->delayed->isRejected()) {
(yield $this->delayed);
// Throws failure reason.
}
throw new CompletedError('The observable was marked as completed.');
}
return yield from ($this->emit)($value);
}
