Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:100639
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.223.173 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <097578bf-ab74-44cf-a465-dc6fdd50930f@Spark>
References: <097578bf-ab74-44cf-a465-dc6fdd50930f@Spark>
Date: Fri, 15 Sep 2017 11:30:44 -0600
Message-ID: <CAObuZdtSUwyJi-qmg8cDjHJvqGtecTJ8U5J8tm_Oe765m5vDPw@mail.gmail.com>
To: ilija.tovilo@me.com
Cc: PHP internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary="001a113ce3f4c300e605593dc07d"
Subject: Re: [PHP-DEV] [RFC] Deprecate the extract function in PHP 7.3
From: derokorian@gmail.com (Ryan Pallas)

--001a113ce3f4c300e605593dc07d
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Sep 15, 2017 11:22 AM, <ilija.tovilo@me.com> wrote:

Hi!

The `extract` function takes an associative array and puts it into the
local symbol table.
http://php.net/manual/en/function.extract.php

```
$array =3D [
    =E2=80=98foo=E2=80=99 =3D> =E2=80=98foo=E2=80=99,
    =E2=80=98bar=E2=80=99 =3D> =E2=80=98bar=E2=80=99,
];

extract($array);

print $foo; // "foo"
```

As a second parameter the `extract` function takes some options to make
this function less dangerous, like `EXTR_SKIP` that prevents an existing
local variable of being overwritten. There=E2=80=99s a few more options, go=
 ahead
and take a look at the documentation. `EXTR_OVERWRITE` is the default one
though. You can also pass a prefix for the variable names as a third
argument.

I seriously doubt the usefulness of this function, especially looking at
the potential risks. The fact that overwriting the local variables is the
default behaviour doesn=E2=80=99t make it any better. I suggest deprecating=
 it in
PHP 7.3 and removing it in 8.

In a whole Symfony-Stack (3.4) with all of it=E2=80=99s dependencies I coul=
d only
find two usages of this function, both of which could be easily rewritten
in vanilla PHP:
https://github.com/symfony/symfony/blob/master/src/
Symfony/Component/Templating/PhpEngine.php#L148
https://github.com/symfony/symfony/blob/master/src/
Symfony/Component/Templating/PhpEngine.php#L158

Only downside: A polyfill is probably impossible since you cannot mutate
the local symbol table of the callee (as far as I=E2=80=99m aware).

Any thoughts?


I see no gain by removing this function. I've also seen it used for
templating quite often. Yes the functionality could be changed not to use
extract and end up working the same to the consumer but why make people
rewrite these things for no apparent gain (and likely a small performance
hit)?


Regards

--001a113ce3f4c300e605593dc07d--