Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:122701
Feedback-ID: id5114917:Fastmail
Date: Wed, 20 Mar 2024 19:30:18 +0000
To: internals@lists.php.net, Robert Landers <landers.robert@gmail.com>
Subject: Re: [PHP-DEV] Proposal: AS assertions
User-Agent: K-9 Mail for Android
In-Reply-To: <CAPzBOBM8dmP5e-N4WXgM+7xbBYx7b=1DyPyJuV5O6QHX2F2s0w@mail.gmail.com>
References: <CAPzBOBMGe=kWWiJYGLG02qxh+2Pe5yTqodhGtAE3LjdAPmkQUw@mail.gmail.com> <efbffe5a-f57a-42e4-8e0c-b25ab2c441fc@rwec.co.uk> <CAPzBOBM4b5c=hWgcj6uBgK3Lb65X56T-bhGHVGhma_YnCCJuoQ@mail.gmail.com> <CAPzBOBM8dmP5e-N4WXgM+7xbBYx7b=1DyPyJuV5O6QHX2F2s0w@mail.gmail.com>
Message-ID: <3F78A125-1946-42E2-A4F5-A2B282BE2107@rwec.co.uk>
Precedence: bulk
MIME-Version: 1.0
Content-Type: multipart/alternative;
 boundary=----643D0XMZCHIE9CSBDO03GTBC6TPVDS
Content-Transfer-Encoding: 7bit
From: imsop.php@rwec.co.uk ("Rowan Tommins [IMSoP]")

------643D0XMZCHIE9CSBDO03GTBC6TPVDS
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: quoted-printable



On 20 March 2024 12:51:15 GMT, Robert Landers <landers=2Erobert@gmail=2Eco=
m> wrote:

>Oh and there isn't any difference between:
>
>$x as ?Type
>
>or
>
>$x as Type|null


I'm not sure if I've misunderstood your example, or you've misunderstood m=
ine=2E

I'm saying that this should be an error, because the value is neither an i=
nstance of Foo nor null:

$a =3D 42;
$b =3D $a as Foo|null;

Your earlier example implies that would make $b equal null, which feels wr=
ong to me, because it means it wouldn't match this:

$a =3D 42;
$b =3D $a as Foo|Bar;

If we want a short-hand for "set to null on error" that should be separate=
 from the syntax for a nullable type=2E


Regards,
Rowan Tommins
[IMSoP]
------643D0XMZCHIE9CSBDO03GTBC6TPVDS
Content-Type: text/html;
 charset=utf-8
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE html><html><body><div dir=3D"auto"><br><br>On 20 March 2024 12:51=
:15 GMT, Robert Landers &lt;landers=2Erobert@gmail=2Ecom&gt; wrote:<br><br>=
&gt;Oh and there isn't any difference between:<br>&gt;<br>&gt;$x as ?Type<b=
r>&gt;<br>&gt;or<br>&gt;<br>&gt;$x as Type|null<br><br><br>I'm not sure if =
I've misunderstood your example, or you've misunderstood mine=2E<br><br>I'm=
 saying that this should be an error, because the value is neither an insta=
nce of Foo nor null:<br><br>$a =3D 42;<br>$b =3D $a as Foo|null;<br><br>You=
r earlier example implies that would make $b equal null, which feels wrong =
to me, because it means it wouldn't match this:<br><br>$a =3D 42;<br>$b =3D=
 $a as Foo|Bar;<br><br>If we want a short-hand for "set to null on error" t=
hat should be separate from the syntax for a nullable type=2E<br><br><br>Re=
gards,</div><div dir=3D"auto">Rowan Tommins<br>[IMSoP]</div></body></html>
------643D0XMZCHIE9CSBDO03GTBC6TPVDS--