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Date: Wed, 15 Mar 2023 11:10:32 +0100
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To: Rowan Tommins <rowan.collins@gmail.com>
Cc: internals@lists.php.net
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Subject: Re: [PHP-DEV] Brainstorming idea: inline syntax for lexical
 (captured) variables
From: landers.robert@gmail.com (Robert Landers)

On Wed, Mar 15, 2023 at 8:38=E2=80=AFAM Rowan Tommins <rowan.collins@gmail.=
com> wrote:
>
> On 15 March 2023 03:28:39 GMT, "Alexandru P=C4=83tr=C4=83nescu" <drealecs=
@gmail.com> wrote:
>
> >How about first implementing use() for anonymous classes first?
> >Something like:
> >
> >function foo(int $outer) {
> >     return new class() use($outer) {
> >         public function getIt() {
> >             return $outer;
> >         }
> >     };
> >}
>
>
> I think it's a lot less clear exactly where the variable is being importe=
d to that way. Would you still be able to overwrite $outer as a normal loca=
l variable in that function scope? Would it return to its captured value ev=
ery time the function runs? It's different from capturing into a function, =
because you're not just adding a variable to a single existing scope.
>
> Just allowing the captured var for property initialisation would be less =
ambiguous, but having to list it in use() and then in the property list wou=
ld be the same amount of code as you can currently get to with constructor =
promotion (see my first example in the thread).
>
> From what Ilija has pointed out, the implementation of actually getting t=
he values into the right place is going to be harder than handling the synt=
ax anyway. My current feeling is that if it's possible at all, it will end =
up as a shorthand for that constructor example: declaring normal properties=
, and populating them as the instance is initialised.
>
> Regards,
>
> --
> Rowan Tommins
> [IMSoP]
>
> --
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: https://www.php.net/unsub.php
>

> The outer variable would be captured by value, and carried around with
> the instance, like existing closures.

For what its worth, there are ways to get references inside values:

https://3v4l.org/5q93F

Other than pointing that out, I like it.