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Date: Wed, 10 Dec 2014 17:17:00 +0100
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Subject: AW: [PHP-DEV] [RFC] Nullsafe calls
From: php@tutteli.ch ("Robert Stoll")

Hi,

> -----Urspr=FCngliche Nachricht-----
> Von: Josh Watzman [mailto:jwatzman@fb.com]
> Gesendet: Mittwoch, 10. Dezember 2014 00:08
> An: PHP internals
> Betreff: [PHP-DEV] [RFC] Nullsafe calls
>=20
> 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:
>=20
> https://wiki.php.net/rfc/nullsafe_calls
>=20
> Josh Watzman
>=20
>=20
> --
> 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 =3D null;
$obj?->foo($a, $b);

should be the same as=20

$obj =3D null;
If($obj !=3D=3D null){
 $obj->foo($a, $b);
}

hence PHP will not complain that $a and $b where not defined.