Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:126273
Precedence: bulk
MIME-Version: 1.0
References: <CAPzBOBMh5DR9opccsXHaijBFYG7gk=gAOBpnHFRVHKh6+Mzh8A@mail.gmail.com>
 <878EED34-B28D-48FE-8EBE-5929841C12BD@gmail.com>
In-Reply-To: <878EED34-B28D-48FE-8EBE-5929841C12BD@gmail.com>
Date: Sun, 2 Feb 2025 21:56:54 +0100
Message-ID: <CAPyj-LD9sASB9Vscm_H0qWOwddtHkgt71E7Szw8aGQS1ZKwozw@mail.gmail.com>
Subject: Re: [PHP-DEV] Re: Discussion: making continue and break into an expression
To: internals <internals@lists.php.net>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
From: tovilo.ilija@gmail.com (Ilija Tovilo)

Hi Dmitrii

On Sun, Feb 2, 2025 at 2:36=E2=80=AFPM Dmitry Derepko <xepozzd@gmail.com> w=
rote:
>
> I had similar idea to make `break`, `continue` and `return` be expression=
s instead of statements to simplify almost the same cases as Robert describ=
ed above.
>
> Grammar corrections in the PR. https://github.com/php/php-src/pull/17647
> Ilija pointed to memory leaking problems as well.
>
> Thinking about Ilija memory leaking case:
> new Foo + return 1
>
> I think we may have a workaround here, by allowing all of these construct=
ions only available at some specific points:
> - <point> as the statement now
> - $cond ? <point> : <point>;
> - match ($v) { =E2=80=A6 =3D> <point> }
>
> So it will deny such cases:
> - operand OPERATOR <point> (1 + return; $cond && break; etc)
>
> It may prevent memory leaking problems. Isn=E2=80=99t it?

Note that technical discussions don't need to happen on the internals
mailing list. It has a lot of recipients and they are usually not
interesting to the majority of people. GH is a better place for that.

This alone will not be sufficient, because the ?: and match
expressions themselves may be nested in other expressions that create
temporary variables. E.g. new Foo + ($cond ? $x : break) will create
the same issue. Restricting control flow statements fully to a
combination of these expressions would work, however is also less
useful and thus less persuasive. In my experience, incomprehensible
limitations are generally not well received by internals.

Ilija