Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:120038
Date: Fri, 14 Apr 2023 07:52:22 +0100
To: internals@lists.php.net
User-Agent: K-9 Mail for Android
In-Reply-To: <CABdc3WoSgKnjE9gktLB4xzjiqg6X1+quMb3-G67xppkar3zBcQ@mail.gmail.com>
References: <8a9a04b3-45e6-47dd-dee8-0f524e49bd37@gmail.com> <CAOWwgpnPxDg0VWCtwn9ALAdiHNn1SFjLAsvVJiMaR-QQc0fU2A@mail.gmail.com> <CALKiJKrCXgWmBzWB_HfcqbrA8G4xLDzdryOkcy+JjUCWm4fC5Q@mail.gmail.com> <CAOWwgpmOFek0oZt9aOg44nCbcbcY7J3T-Ghw=UvFFd6Ugr=pRA@mail.gmail.com> <c17185c0-9bbb-43be-9127-6dfc5ea6e33d@gmail.com> <c694900b-5f0d-493f-a454-9d51acd09ac4@app.fastmail.com> <52a5a80d-f03f-5e96-4188-272a705e3fdd@gmail.com> <b366ccc1-cb3a-4f1d-9f90-dc7043cbb588@app.fastmail.com> <CAOWwgpmudjArTFMxUsYL_1SDT+yEQAYKRa-6MTUqOUxxi0sa=g@mail.gmail.com> <CABdc3WoSgKnjE9gktLB4xzjiqg6X1+quMb3-G67xppkar3zBcQ@mail.gmail.com>
Message-ID: <6D8558DF-FDD1-4B04-920F-7EDDC38DE532@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: quoted-printable
Subject: =?US-ASCII?Q?Re=3A_=5BPHP-DEV=5D_Brainstorming_idea=3A_inline?= =?US-ASCII?Q?_syntax_for_lexical_=28captured=29_variables?=
From: rowan.collins@gmail.com (Rowan Tommins)

On 14 April 2023 05:35:39 BST, "Micha=C5=82 Marcin Brzuchalski" <michal=2Eb=
rzuchalski@gmail=2Ecom> wrote:

>Have you thought about not populating property by default but instead:
>* adding "use" language construct as default to all methods?
>* adding ability to assign variable values from "use" to property if need=
ed?
>
>Like desugar to
>$c =3D class ($a, $b) use ($c) {
>    private $c =3D $c; // optional, not required, no conflicts
>    public function __construct(private int $a, private int $b) use ($c) =
{
>        $this->c =3D $c % 2 ? 3 : 5;
>    }
>    public function something() use ($c) {
>        return $c;
>    }
>}


This is closer to what I originally proposed, but with different syntax=2E

The challenge, as was pointed out to me, is that the anonymous class is co=
mpiled as a reusable class definition on first use, and a new instance cons=
truction on each execution, so you have to think about what happens at each=
 stage=2E

In this example, you've got to first compile something where $c is an open=
 parameter of some sort, and make it available to all the contexts where it=
 might be used; then, when you create the instance, supply a value for $c, =
and attach it to the instance somewhere; and finally, when something() is c=
alled, look up that attached value and make it available to the method=2E

In other words, the use() clause on the class ends up acting like a constr=
uctor parameter, and the references in methods end up acting like property =
references=2E It's a lot of extra complication to duplicate things the lang=
uage already has=2E

Having played with it a bit while implementing, I also like the concisenes=
s of objects with no explicit body at all:

$who =3D new class use ($firstName as string, $lastName as string) {};
echo $who->firstName;

Regards,

--=20
Rowan Tommins
[IMSoP]