AW: [PHP-DEV] [RFC] Nullsafe calls

> -----Ursprüngliche Nachricht----- > Von: Andrea Faulds [mailto:ajf@ajf.me] > Gesendet: Mittwoch, 10. Dezember 2014 20:21 > An: Josh Watzman > Cc: PHP internals > Betreff: Re: [PHP-DEV] [RFC] Nullsafe calls > > Hi again. > > > On 10 Dec 2014, at 19:11, Josh Watzman <jwatzman@fb.com> wrote: > > > > On Dec 10, 2014, at 9:19 AM, Andrea Faulds <ajf@ajf.me> wrote: > > > >> First, how is this substantially different from catching an exception? With Nikita’s > >> Exceptions in the Engine RFC, > something like this would be possible: > >> > >> try { > >> return $foo->bar()->qux()->elePHPant()->dance(); > >> } catch (EngineException $e) { > >> return NULL; > >> } > >> > >> That would essentially do the same as what you’re proposing: > >> > >> return $foo?->bar()?->qux()?->elePHPant()?->dance(); > >> > >> Are there many instances where there’d be a substantial benefit to using ?-> > >> versus catching an exception? > > > > It's an API decision up to the implementors of the object. If you like > > using exceptions for *every* failure, then go for it, this syntax > > won't cost you anything or get in your way :) > > > > However, for a lot of failures, I don't feel that exceptions are appropriate. I tend > > to only use them for exceptional > behavior -- usually, some failure that needs to be propagated up a few levels up the stack, to > an appropriate error > boundary. This doesn't necessarily mean a completely unrecoverable error, but it's > *locally* unrecoverable. For things that > are completely recoverable, returning null might be more appropriate and more lightweight, and > then this nullsafe > operator would be useful at that point. > > …huh? I’m not talking about exceptions the object itself throws. In PHP 7, if Nikita’s RFC > passes, trying to call a method on > NULL will throw an exception. That largely negates the need for a special operator, since you > can just catch the exception. > > Thanks. > -- > Andrea Faulds > http://ajf.me/ > > -- > PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: > http://www.php.net/unsub.php I think it is a matter of taste whether you use try/catch as control structure or only as exception handling. I for myself usually try to avoid using it as control structure and thus would write something like: if($a !== null){ $a->foo(bar()); } And for this case the ?-> operator seems perfect for me - as long as it does not evaluate bar().