Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:60558
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain sugarcrm.com designates 67.192.241.131 as permitted sender)
Message-ID: <4FB04675.6000307@sugarcrm.com>
Date: Sun, 13 May 2012 16:40:37 -0700
Organization: SugarCRM
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:12.0) Gecko/20120428 Thunderbird/12.0.1
MIME-Version: 1.0
To: Seva Lapsha <seva.lapsha@gmail.com>
CC: "internals@lists.php.net" <internals@lists.php.net>
References: <CAOtCo3rn=XqaFn+ZGOV-0Az_pOVik4eBhNesXmHgU_d3WsyZZw@mail.gmail.com>
In-Reply-To: <CAOtCo3rn=XqaFn+ZGOV-0Az_pOVik4eBhNesXmHgU_d3WsyZZw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] [RFC] Custom Casting
From: smalyshev@sugarcrm.com (Stas Malyshev)

Hi!

> Please be kind to review and comment my proposal for custom casting in PHP
> (or let me know if a similar proposal was already discussed).
> 
> http://pastebin.com/sPb0i8U6

I think there's an issue with this idea. As far as I understand, what is
proposed is kind of cast-constructor paradigm. However, the result of
(ClassName)$var would be expected to be an object of type ClassName.
That is, however, not what cast() returns - it returns integer $var.
Since there's no way for foo(ClassName $var) to know where $var came
from, the result of $var = (ClassName)$var; is just a simple integer and
foo() would reject it since it's not an object of type ClassName.

Of course, you could just create this instead:

class PositiveInteger {
  private $i;
  function __construct($i) {
     if(intval($i) < 1) $i = 1;
     $this->i = $i;
  }
  function intval() {
     return $this->i;
  }
}

function foo(PositiveInteger $i) { return 2*sqrt($i->intval()); }

and then:

foo(new PositiveInteger(42));

But this is doable right now, even if sounds a bit of overkill for me. I
wouldn't mind also having (int)$i done with some magic methods, as
proposed in RFCs you mentioned.

-- 
Stanislav Malyshev, Software Architect
SugarCRM: http://www.sugarcrm.com/
(408)454-6900 ext. 227