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

From: Date: Wed, 10 Dec 2014 16:17:00 +0000
Subject: AW: [PHP-DEV] [RFC] Nullsafe calls
References: 1  Groups: php.internals 
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Hi,

> -----Ursprüngliche Nachricht-----
> Von: Josh Watzman [mailto:[email protected]]
> Gesendet: Mittwoch, 10. Dezember 2014 00:08
> An: PHP internals
> Betreff: [PHP-DEV] [RFC] Nullsafe calls
> 
> Hey internals! A useful feature that Hack picked up in the last few months are "nullsafe
> calls", a way of propagating
failure
> forward in a series of chained method calls to the end of the whole computation, getting rid of
> a lot of the
boilerplate in the
> middle. I think the feature would be a good one for PHP as well, so I'm submitting this
> RFC to add it -- you can see
the RFC
> itself for a full discussion of the motivation for the feature, as well as the feature itself:
> 
> https://wiki.php.net/rfc/nullsafe_calls
> 
> Josh Watzman
> 
> 
> --
> PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php

First of all, I like the RFC, I think as well that it is a useful feature for PHP and I already have
it on my wish list
;)

Yet, either I misunderstand the section about short circuiting or I propose to change the behaviour.

"If $obj is null, when $obj?->foo(..) executes, the arguments will still be evaluated."

IMO that is wrong. It should not evaluate the arguments since the nullsafe operator (sometimes
called "safe navigation"
operator in other languages - which is the better wording IMO, maybe change it? But that is just a
detail) is just
syntactic sugar for making the call only if $bj is not null. So the following:

$obj = null;
$obj?->foo($a, $b);

should be the same as 

$obj = null;
If($obj !== null){
 $obj->foo($a, $b);
}

hence PHP will not complain that $a and $b where not defined.



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