Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:78811
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 74.125.82.42 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <13E1F1B8-D2DB-4BAF-95FD-E9AB7A7D1AA5@ajf.me>
References: <CAHpw9Ac0oapNSV=y4Gj3WCdZ1ckik+WOJt-yMdMjGt3u7iJpJg@mail.gmail.com>
 <545B3900.6070208@sugarcrm.com> <CAHpw9AeNHLKFPmAF8AmZUeauz4_x+p7ayyN-pi2PBnZ6wV=CYg@mail.gmail.com>
 <6FB6D82E-CF77-462D-8420-A1E37915EA13@ajf.me> <CAHpw9AcDaThJ_rx3U+xpH6LYpWfGdVP-cz6XwZTKQZWXt4WJVA@mail.gmail.com>
 <13E1F1B8-D2DB-4BAF-95FD-E9AB7A7D1AA5@ajf.me>
Date: Thu, 6 Nov 2014 15:55:13 +0400
Message-ID: <CAHpw9AdkruXiDGOEYEY4CH2-KqwdzCYSK7a-NtcHdheE5FMzNA@mail.gmail.com>
To: Andrea Faulds <ajf@ajf.me>
Cc: Stas Malyshev <smalyshev@sugarcrm.com>, PHP internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=001a1133c8fab3b55a05072f5f17
Subject: Re: [PHP-DEV] Allow arbitrary expressions when using instanceof operator
From: drgomesp@gmail.com (Daniel Ribeiro)

--001a1133c8fab3b55a05072f5f17
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

On Thu, Nov 6, 2014 at 3:49 PM, Andrea Faulds <ajf@ajf.me> wrote:

> By merging the symbol tables, you could reference classes like constants
> (perhaps it=E2=80=99d return some sort of ReflectionClass-like thing?):
>
>     $x =3D SomeClass;
>     $foo =3D new $x;
>
> Currently, because SomeClass above would resolve to a constant, you have
> to use the weird pseudo-constant ::class:
>
>     $x =3D SomeClass::class;
>
> It also would mean instanceof could accept arbitrary expressions, as
> there=E2=80=99d be no syntactic ambiguity:
>
>     class Foo {}
>     const Bar =3D =E2=80=98Foo';
>     $x =3D (new Foo) instanceof Bar; // works (Bar resolves to =E2=80=98F=
oo=E2=80=99, valid
> class name)
>     $x =3D (new Foo) instanceof Foo; // works (Foo is a class)
>     const Foo;                     // Not allowed, conflicts with class
>

Yeah, that makes perfect sense.

Also, I just realized that HHVM accepts expressions wrapped in parenthesis.
I might need to take a look at how it's done there.


Daniel Ribeiro
http://danielribeiro.org

--001a1133c8fab3b55a05072f5f17--