Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:126294
Precedence: bulk
MIME-Version: 1.0
References: <CAJWOiuN7uO_gYhqcwD7UPC=z8VC_A_f1-yAoddBVAt-+p9ZCgA@mail.gmail.com>
In-Reply-To: <CAJWOiuN7uO_gYhqcwD7UPC=z8VC_A_f1-yAoddBVAt-+p9ZCgA@mail.gmail.com>
Date: Wed, 5 Feb 2025 13:07:24 +0100
Message-ID: <CAPyj-LAnSfcPd8Qgix+crNY3QpTrwj5U2k-7ruH7LU8UZqQE7Q@mail.gmail.com>
Subject: Re: [PHP-DEV] RFC: Not Null Assertion Operator
To: PHP internals <internals@lists.php.net>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
From: tovilo.ilija@gmail.com (Ilija Tovilo)

Hi Mihail

Thanks for your proposal.

On Wed, Feb 5, 2025 at 9:24=E2=80=AFAM Mihail Liahimov <91liahim@gmail.com>=
 wrote:
>
> Good afternoon. I would like to create an RFC on the implementation of th=
e NOT null assertion operator. Do you think it makes sense to create it? I =
was able to implement the operator. I've already posted a draft in my githu=
b - https://github.com/rekmixa/php-src/tree/feature/not_null_assertion_oper=
ator
> An example of the implementation of this operator can be viewed in kotlin=
 or in typescript. The point of it is that in places where we did not expec=
t null, we should not make additional checks, but use this operator. It wil=
l also be convenient for highlighting in the IDE.

First off, it would be useful if you show some examples in your
proposals. Especially for people who don't know Kotlin, it's not clear
how such a feature would work. Looking at your patch, you're
introducing the !-> operator, which presumably would error on
(null)!->foo. A few thoughts:

* This approach/patch seems unnecessarily limiting and complex. it
would be easier to create a postfix operator ! that works on all
expressions, and simply errors if null. This won't require much
special handling in the engine. It would also allow you to do
foo($bar!). TBH, this seems most useful for static analysis, but
assert($bar) will do there too, so I'm not particularly convinced we
need such a feature.
* Especially in the case of property access on null, it would be worth
considering whether we ever want to make this error by default, which
seems like the general trajectory PHP has been taking. This is
currently a warning (since PHP 8, and a notice since 5.0). If we rule
that out, the feature might make more sense.

Ilija