Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:90541
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 74.125.82.51 as permitted sender)
References: <CAML1Pf7ti=CG1DRfpPYw0yeyRCUC0ca=ZkKkm3xEHFB_P3_ruw@mail.gmail.com>
 <5693B6BB.9020607@gmail.com>
 <CAML1Pf5-P3XtyetnPwiDOLTOdMHjretKGtpa1hxuZzY45Fgb7Q@mail.gmail.com>
To: internals@lists.php.net
Message-ID: <5694E119.3070308@gmail.com>
Date: Tue, 12 Jan 2016 11:18:49 +0000
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.5.1
MIME-Version: 1.0
In-Reply-To: <CAML1Pf5-P3XtyetnPwiDOLTOdMHjretKGtpa1hxuZzY45Fgb7Q@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] Throwable and Error exceptions break existing PHP 5.x
 code
From: rowan.collins@gmail.com (Rowan Collins)

Giovanni Giacobbi wrote on 12/01/2016 09:37:
> But the fact is that it did NOT exist, so when you say "other than the 
> specific transition to PHP 7", well I think it is a big deal and 
> motivates the introduction of a new feature just for that.

I guess what I meant was, once everyone has been using PHP 7 for years, 
it would be a shame to have features lying around in the language that 
existed only to ease the transition, and aren't even "legacy" in the 
sense of matching PHP 5.


> 1) Check the handler's signature compatibility before calling it.
> Indeed there is no reason to fix a my_hnd(Exception $e) and not a 
> my_hnd(ExceptionA $e) where class ExceptionA extends Exception, so 
> this proposal would be to simply ignore the set_handler_exception()'s 
> callback if it is not compatible, or maybe even better issue an 
> E_NOTICE or E_STRICT in such case.

I like this idea. Although I can't think of many cases outside the 
transition where it would be deliberately used, generating a fatal error 
when calling an error handler is not particular helpful, so just falling 
through and acting as though no handler existed would seem like a more 
useful fallback. I don't know how simple it would be to implement in the 
engine though...


Just on a general point, there's actually surprisingly *few* BC breaks 
in PHP 7, in my opinion. I don't think it's fair to extrapolate from 
this a "general attitude to the community" - I think it's an unfortunate 
BC break which could have had more attention, either to ensure it was 
clearly signalled, or to look at mitigation ideas like we are in this 
thread. An honest mistake, rather than somebody not caring.

Regards,
-- 
Rowan Collins
[IMSoP]