Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:125028
Content-Type: text/plain;
	charset=utf-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk
Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3776.700.51\))
Subject: Re: [PHP-DEV] Should there be a `get_declared_enums()` function ?
Date: Sat, 17 Aug 2024 19:31:40 +0200
References: <66BD5F05.8010409@adviesenzo.nl>
 <8dc51539-20bb-4017-b859-76066e2287e5@gmx.de>
 <CANLbj-oEjsJrpVcxG53Vg5rJOcMb3W3xksH2Z+gR1awDW2bSdQ@mail.gmail.com>
 <66BFF486.3020707@adviesenzo.nl>
 <c5cb6473-5cda-4dff-b897-346b09288447@app.fastmail.com>
To: php internals <internals@lists.php.net>
In-Reply-To: <c5cb6473-5cda-4dff-b897-346b09288447@app.fastmail.com>
Message-ID: <DCDB5885-FD6B-4FCA-8F1D-43953B09039C@gmail.com>
From: claude.pache@gmail.com (Claude Pache)



> Le 17 ao=C3=BBt 2024 =C3=A0 15:17, Larry Garfield =
<larry@garfieldtech.com> a =C3=A9crit :
>=20
> On Fri, Aug 16, 2024, at 7:53 PM, Juliette Reinders Folmer wrote:
>> On 16-8-2024 17:01, Ayesh Karunaratne wrote:
>>> I went ahead and created PR =
https://github.com/php/php-src/pull/15443 along with tests, UPGRADE =
notice, etc. I think having a `get_declared_enums` function will be =
helpful. The implementation is simple and straightforward too.
>> Thanks for creating the PR Ayesh!
>>=20
>> I'm presuming it's too late for PHP 8.4, what with feature freeze=20
>> having come & gone this week.
>>=20
>> Based on the mostly supportive responses on the list, I wonder =
whether=20
>> an RFC is needed. If so, I'd be happy to create an initial draft (for=20=

>> PHP 8.5).
>>=20
>> Smile,
>> Juliette
>=20
> I would prefer to have an RFC for this, even if it's short.  I'm not =
against it, I just think there's enough non-trivial questions (eg, =
impact on get_declared_classes()) that it warrants an RFC =
process/discussion.
>=20
> --Larry Garfield

Hi,

I concur with Larry, it should not be rushed into PHP 8.4, but carefully =
considered if it is really the correct function to define. Enums were =
introduced three years ago, and until three days ago, there has been =
apparently no complaint of the missing function, and it has been =
proposed less because of a need than because of an apparent lack of =
symmetry with other `get_declared_*()` functions. So, there is no =
urgency.

Now, the proposed design for `get_declared_enums()` is problematic, =
because it will bring (or sustain) confusion. An enum is (imo =
rightfully) considered as a class for the purpose of =
`class_exists(...)`; and following the same logic, the proposed =
`get_declared_enums()` returns (rightfully) a subset of the names =
returned by `get_declared_classes()`. On the other hand, in the mind of =
many people =E2=80=93 as it can be seen in several messages in this =
thread, and citing the original poster =E2=80=93, there are four =
different OO structures in PHP: classes, interfaces, traits, and enums. =
For example, one is tempted to write na=C3=AFvely:

```php
function get_declared_symbols(): array {
    return [ ...get_declared_classes(), ...get_declared_interfaces(), =
...get_declared_traits(), ...get_declared_enums() ];
}
```

not realising that enums will appear twice in the returned list.

An alternative design that is less confusing could be the following. I =
am not really proposing it (as I am personally not convinced that =
`get_declared_classes()` filtered by `enum_exists()` is not sufficient), =
but I merely give it as an illustrative example of an api thought to =
avoid or reduce confusion. We could add an optional parameter to the =
existing `get_declared_classes()` function, specifying what sort of =
classes they are interested in:

```php
const SIMPLE_CLASS =3D 1;
const ABSTRACT_CLASS =3D 2;
const ANONYMOUS_CLASS =3D 4;
const ENUM =3D 8;

function get_declared_classes(int $type =3D SIMPLE_CLASS | =
ABSTRACT_CLASS | ANONYMOUS_CLASS | ENUM): array { /* ... */ }
```

=E2=80=94Claude