Zend incompatibility: Generator::send returns null

[jeskew]

Generator::send appears to return null instead of the value yielded. This breaks Guzzle coroutines, which yield out promises and expect the value which fulfills each promise to be sent back in.

Reproduction script: https://3v4l.org/fMsKp
With more verbose output: https://3v4l.org/mMvOC

[jeskew]

This issue makes advanced features of the AWS SDK for PHP and Guzzle 6 incompatible with HHVM. Any chance this could at least be acknowledged and labeled as a Zend incompatibility?

[wulftone]

Just ran into this and noticed it's a year old... is this on the roadmap to fix?

[effeks]

This is still an issue, even with later HHVM-versions, right?

[lexidor]

Yep it still is, but the hhi notes that it returns void (null).

[lexidor]

Hi, I am reading HHVM issues to see which issues are unlikely to be fixed.

This issue was created because HHVM's behavior was/is different from PHP's. HHVM stopped striving from php compatibility with the release of version 4.0.0.

The current behavior, although different, is not buggy or broken. The HHI also notes that send will return void (which is a null that shouldn't be used). I suspect all Hack code out there is aware of this and uses ->current() to get the value from the generator.