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Date: Wed, 21 Sep 2011 09:57:35 -0400
Message-ID: <8C.A0.17510.E4DE97E4@pb1.pair.com>
To: internals@lists.php.net
References: <4E790B82.6090805@akbkhome.com>
User-Agent: slrn/pre1.0.0-18 (Linux)
Subject: Re: is_a() - again - a better fix
From: weierophinney@php.net (Matthew Weier O'Phinney)

On 2011-09-20, Alan Knowles <alan@akbkhome.com> wrote:
> Let's try and close this one.
>
> https://bugs.php.net/bug.php?id=55475
>
> I've just added a patch that adds is_class_of(), which is identical to 
> is_subclass_of, and has the new feature of supporting strings and using 
> the autoloader.

is_class_of() has a very different semantic meaning (in natural
language) than is_subclass_of() -- I know I wouldn't expect the behavior
it exhibits by looking at the name.

> It then reverts is_a() back to the previous behavior, and clarifies the 
> documentation.

Reverting at this point adds a BC break on top of a BC break. Yes, the
original perhaps should not have happened (and likely wouldn't have, if
people had actually been testing the RCs...), but I'll argue again: the
new behavior is more correct. 

Reverting at this point is simply going to cause more headaches:
"package X works for PHP versions X.Y - 5.3.6, and from 5.3.9 to
5.3.last" -- what a nightmare! 

> This solves the BC issues, and also solves potential security issues 
> with existing code accidentally passing $url's to the autoloader, and 
> gives anyone who needs this new behavior a solution.

I'd argue that this fix also highlights the need for autoloaders to test
their arguments to see if they are getting something that looks like a
class name.

> Let's at least try and respect the new release RFC, and our users who 
> appreciate PHP's efforts over the years to try and maintain BC. (it's 
> one of it's few advantages these days...)

To respect the release RFC, we shouldn't introduce a new BC break
(breaking behavior with something already released).

-- 
Matthew Weier O'Phinney
Project Lead            | matthew@zend.com
Zend Framework          | http://framework.zend.com/
PGP key: http://framework.zend.com/zf-matthew-pgp-key.asc