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Date: Thu, 20 Nov 2025 15:21:55 +0100
Message-ID: <CAP1Jc1215HK6CyzOPgZEYUpsxCjuLYMHbnh5_Fe-CNfiO+gRCA@mail.gmail.com>
Subject: Re: [PHP-DEV] First-class constructor callables
To: Valentin Udaltsov <udaltsov.valentin@gmail.com>
Cc: php internals <internals@lists.php.net>
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From: arnaud.lb@gmail.com (Arnaud Le Blanc)

Hi Valentin,

On Thu, Nov 20, 2025 at 2:20=E2=80=AFPM Valentin Udaltsov
<udaltsov.valentin@gmail.com> wrote:
> Question for Larry and Arnaud:
>
> In PFA v2, you note that constructor references pose significant technica=
l challenges.
> Could you elaborate on what those challenges are and whether they are fun=
damental, or potentially addressable with a more limited or explicit syntax=
 such as `new Foo(...)`?

One issue is that partial application needs to resolve the function
being applied, but constructors can not be resolved without
instantiating the class first (at least, not on all classes). So `new
Foo(...)` would need to instantiate Foo, resolve the constructor, and
discard the instance, before creating the PFA.

This is something that could be addressed as a follow up to PFA v2.

Best Regards,
Arnaud