Re: E_RECOVERABLE_ERROR for object to string conversion

On 27.09.2017 at 14:45, Marlies Heijkoop wrote: > Hi Internals, > > I stumbled upon a difference in behavior between PHP >=7.0 and HHVM when it comes to > object-to-string conversion for objects not implementing a ³bÊW–%z¬z > «çJSY__toString which caught me by surprise. > > It's probably a pretty common scenario, especially for inexperienced PHP developers, as > all it takes is to accidentally name your method _toString() or > toString() rather than __toString(). > > When trying to use an object which does not implement a __toString(), PHP will emit an > E_RECOVERABLE_ERROR where HHVM throws an Error. > See https://3v4l.org/WtJff for a minimal example. HHVM's > behavior makes more sense to me here. > > To me, PHP's behavior is especially unexpected if you consider the behavior in > https://3v4l.org/lF7gR where PHP *does* throw a (Type)Error because > of the typehint. Note this example works if you change $a for an > instance of something with a proper __toString()-method. > > I searched through the discussions on the original 'Exceptions in the engine' RFC and > couldn't find any mention of this specific case so I was wondering if anyone remembers if this > was deliberately kept this way? I'm not sure if I have the skill to write a patch, I'm > willing to try, but it'd be a waste of time if there is some good reason for having kept this > an E_RECOVERABLE_ERROR I'm unaware of. I assume that this is closely related to the fact that PHP can't throw from inside of __toString(), see <https://3v4l.org/BhPiN> and <http://markmail.org/message/lkpmpnhrvcbafhkd>. -- Christoph M. Becker