Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:91848
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain telia.com from 81.236.60.154 cause and error)
To: Rowan Collins <rowan.collins@gmail.com>
References: <CABDNdAHwgx+LJRc_gi9citiypxxWVGFMB+6hrmU+vVYDWCDV_g@mail.gmail.com>
 <1458149992.3969.2.camel@kuechenschabe>
 <BLU436-SMTP1394648F9BABA2FA74BFC4DE28A0@phx.gbl>
 <1458151531.3969.8.camel@kuechenschabe>
 <BLU436-SMTP2092DD6AFBC93D83397A3C7E28A0@phx.gbl>
 <1458153695.3969.16.camel@kuechenschabe> <3F.70.02405.6803BE65@pb1.pair.com>
 <56F01545.8080008@gmail.com>
 <CAF+90c-Z82kBT18ivvKejD5_dBf=dtbNYN-cZcyO1K=0C1WcLA@mail.gmail.com>
 <56F14572.701@gmail.com>
Cc: PHP internals <internals@lists.php.net>
Message-ID: <56F15EF5.80006@telia.com>
Date: Tue, 22 Mar 2016 16:04:21 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.7.0
MIME-Version: 1.0
In-Reply-To: <56F14572.701@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Subject: Re: [PHP-DEV] [RFC Discussion] Typed Properties
From: bjorn.x.larsson@telia.com (=?UTF-8?Q?Bj=c3=b6rn_Larsson?=)

Den 2016-03-22 kl. 14:15, skrev Rowan Collins:
> Nikita Popov wrote on 21/03/2016 17:05:
>> While it is no secret that we don't particularly like references, 
>> this is not the reason why they are forbidden. There is no conspiracy 
>> to punish users of references by denying them use of new typing 
>> features. No, the reasons here are technical. Let me illustrate some 
>> of the issues involved in more detail.
>
>
> Thanks for the detailed explanation of the problems, which are indeed 
> deeper than I'd appreciated. To be clear, I never thought it was the 
> intention to dissuade users from using references, but a couple of 
> people have implied that they consider it no bad thing.
>
>
> For me, the restriction on setting references makes this whole feature 
> a no-go for the language as it stands. I don't think it is at all 
> reasonable for the following code to produce a TypeError:
>
> class Sorter {
>     private array $data;
>     public function __construct(array $data) {
>         $this->data = $data;
>         sort($this->data);
>     }
> }
> new Sorter([1,3,6,5,2,4]);
>
>
> It may be that we've reached the limit of how much typing we can add 
> to the language incrementally, and need actual typed variables, so 
> that references could be made only between variables with the same 
> type hint, e.g.
>
> class A { public int $foo=42; }
> $a = new A;
> int $ref =& $a->foo;
>
> The sort() example would work in this scenario because the expected 
> parameter type is array, so the reference being created is of the 
> matching type.
>
> Obviously, this would be a huge change to the language, and no doubt 
> have all sorts of impacts and problems of its own, but I don't think 
> it makes sense to say "you can typehint your property names, but you 
> lose some existing functionality if you do so, for technical reasons".
>
> Regards,

Hm... In Hack the above code works, see:
https://3v4l.org/nsA5W

Well they have a different implementation as mentioned in
the RFC, so no wonder. But they do have typed porperties in
the language.

Regards //Björn Larsson