Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:127885
Precedence: bulk
MIME-Version: 1.0
References: <CALaXqqRKy4_y3HkO6dVhVcOjoHOp=HYdsU7v3SVZQ8kr1EfgLA@mail.gmail.com>
 <CAAwdEzBEntKfsebADTR70mytCYjEv6MvOg2gPAVfXSCAp=3qnA@mail.gmail.com>
In-Reply-To: <CAAwdEzBEntKfsebADTR70mytCYjEv6MvOg2gPAVfXSCAp=3qnA@mail.gmail.com>
Date: Fri, 4 Jul 2025 15:01:37 -0700
Message-ID: <CALaXqqRzkbp2n60xN6G-sLpXKzdc6Bw46hu5zNVBG4q-RO941g@mail.gmail.com>
Subject: Re: [PHP-DEV] [RFC] [Discussion] #[\DelayedTargetValidation] attribute
To: =?UTF-8?Q?Alexandru_P=C4=83tr=C4=83nescu?= <drealecs@gmail.com>
Cc: php internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary="0000000000003ffb4e063921a58f"
From: daniel.e.scherzer@gmail.com (Daniel Scherzer)

--0000000000003ffb4e063921a58f
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Sun, Jun 22, 2025 at 10:24=E2=80=AFPM Alexandru P=C4=83tr=C4=83nescu <dr=
ealecs@gmail.com>
wrote:

> Hi Daniel, internals,
>
> On Wed, Jun 18, 2025, 02:29 Daniel Scherzer <daniel.e.scherzer@gmail.com>
> wrote:
>
>> Hi internals,
>>
>> I'd like to start the discussion for a new RFC about adding a
>> `#[\DelayedTargetValidation]` attribute.
>>
>>
> How about completely disabling errors caused by a bad target at compile
> time?
> And just ignore the attribute, that can be validated at runtime if needed=
.
> IDEs and static code analysis would show the problem and that might be
> enough.
>
> --
> Alex
>


If you mean to always disable those errors, that is exactly what I
responded to above - https://news-web.php.net/php.internals/127734.
Basically, internal attributes are not pure metadata but also trigger
engine behavior, while userland attributes are metadata (and the attributes
don't even need to exist to be used!). Thus, there is a benefit to compile
time errors, since otherwise you don't know that the engine behavior isn't
being triggered.

This attribute completely disables errors caused by a bad target at compile
time *whenever the new #[\DelayedTargetValidation] is applied*. This gives
the best of both worlds

* you get errors if you misuse an internal attribute
* you can suppress those errors intentionally if you have a reason (e.g.
forward compatibility), and just delay the validation until runtime

Since I proposed this RFC, a proposal to support `#[\Override]` on
properties has been discussed (https://news-web.php.net/php.internals/12783=
1),
highlighting the benefits of this #[\DelayedTargetValidation] attribute.
E.g. if we add it in 8.5, then when a later version adds #[\Override], a
library can apply #[\Override] to properties without *requiring* a newer
version of PHP.

-Daniel

--0000000000003ffb4e063921a58f
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div dir=3D"ltr">On Sun, Jun 22, 2025 at 10:24=E2=80=AFPM =
Alexandru P=C4=83tr=C4=83nescu &lt;<a href=3D"mailto:drealecs@gmail.com">dr=
ealecs@gmail.com</a>&gt; wrote:</div><div class=3D"gmail_quote gmail_quote_=
container"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.=
8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"au=
to"><div>Hi Daniel, internals,<br><br><div class=3D"gmail_quote"><div dir=
=3D"ltr" class=3D"gmail_attr">On Wed, Jun 18, 2025, 02:29 Daniel Scherzer &=
lt;<a href=3D"mailto:daniel.e.scherzer@gmail.com" target=3D"_blank">daniel.=
e.scherzer@gmail.com</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quo=
te" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204=
);padding-left:1ex"><div dir=3D"ltr">Hi internals,<div><br></div><div>I&#39=
;d like to start the discussion for a new RFC about adding a `#[\DelayedTar=
getValidation]` attribute.</div><div><br></div><div></div></div></blockquot=
e></div></div><div dir=3D"auto"><br></div><div dir=3D"auto">How about compl=
etely disabling errors caused by a bad target at compile time?</div><div di=
r=3D"auto">And just ignore the attribute, that can be validated at runtime =
if needed.</div><div dir=3D"auto">IDEs and static code analysis would show =
the problem and that might be enough.</div><div dir=3D"auto"><br></div><div=
 dir=3D"auto">--=C2=A0</div><div dir=3D"auto">Alex</div></div></blockquote>=
<div><br></div><div><br></div><div>If you mean to always disable those erro=
rs, that is exactly what I responded to above -=C2=A0<a href=3D"https://new=
s-web.php.net/php.internals/127734">https://news-web.php.net/php.internals/=
127734</a>. Basically, internal attributes are not pure metadata but also t=
rigger engine behavior, while userland attributes are metadata (and the att=
ributes don&#39;t even need to exist to be used!). Thus, there is a benefit=
 to compile time errors, since otherwise you don&#39;t know that the engine=
 behavior isn&#39;t being triggered.</div><div><br></div><div>This attribut=
e completely disables errors caused by a bad target at compile time *whenev=
er the new #[\DelayedTargetValidation] is applied*. This gives the best of =
both worlds</div><div><br></div><div>* you get errors if you misuse an inte=
rnal attribute</div><div>* you can suppress those errors intentionally if y=
ou have a reason (e.g. forward compatibility), and just delay the validatio=
n until runtime</div><div><br></div><div>Since I proposed this RFC, a propo=
sal to support `#[\Override]` on properties has been discussed (<a href=3D"=
https://news-web.php.net/php.internals/127831">https://news-web.php.net/php=
.internals/127831</a>), highlighting the benefits of this #[\DelayedTargetV=
alidation] attribute. E.g. if we add it in 8.5, then when a later version a=
dds #[\Override], a library can apply #[\Override] to properties without *r=
equiring* a newer version of PHP.</div><div><br></div><div>-Daniel=C2=A0</d=
iv></div></div>

--0000000000003ffb4e063921a58f--