Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:81422
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain phcomp.co.uk designates 78.32.209.33 as permitted sender)
Date: Fri, 30 Jan 2015 11:07:16 +0000
To: internals@lists.php.net
Message-ID: <20150130110716.GA18357@phcomp.co.uk>
Mail-Followup-To: internals@lists.php.net
References: <CA+9eiLsqy8NWA6dp733NN5O+dDwHxDPV2DBK-jHxp90BA6uKZQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CA+9eiLsqy8NWA6dp733NN5O+dDwHxDPV2DBK-jHxp90BA6uKZQ@mail.gmail.com>
Organization: Parliament Hill Computers Ltd
User-Agent: Mutt/1.5.20 (2009-12-10)
Subject: Re: [PHP-DEV] [RFC] Fix "foreach" behavior
From: addw@phcomp.co.uk (Alain Williams)

On Fri, Jan 30, 2015 at 11:23:19AM +0400, Dmitry Stogov wrote:
> Hi,
> 
> I'd like to start discussion about fixing inconsistent "foreach" statement
> behavior.
> The implementation is almost done. It not only fixes inconsistencies in a
> defined by RFC way but also improves performance in most usual cases,
> because now foreach by value over array doesn't require array duplication.
> 
> https://wiki.php.net/rfc/php7_foreach
> 
> https://github.com/php/php-src/pull/1034
> 
> I'm going to continue work on implementation improvement and may be fixing
> related behavior of some internal functions when they used on array
> iterated by foreach by reference (e.g. array_unshift()). However, the
> conceptual behavior defined in RFC is not going to be changed anymore.

I think that I am raising a concern that is not real, but I'll do so anyway.

You write:

    This will lead to copy-on-write on attempt of array modification inside the
    loop.  As result, we will always iterate over elements of array originally
    passed to foreach, ignoring any possible array changes.

I think that you mean modification of the array and that this does not relate to
modification of array elements. Ie will code like the following still work:

foreach($_POST as &$v)
    $v = trim($v);

Otherwise - good.

-- 
Alain Williams
Linux/GNU Consultant - Mail systems, Web sites, Networking, Programmer, IT Lecturer.
+44 (0) 787 668 0256  http://www.phcomp.co.uk/
Parliament Hill Computers Ltd. Registration Information: http://www.phcomp.co.uk/contact.php
#include <std_disclaimer.h>