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Date: Mon, 03 Oct 2005 07:31:37 -0700
To: Marcus Boerger <helly@php.net>,Dmitry Stogov <dmitry@zend.com>
Cc: 'Derick Rethans' <derick@php.net>,
	'PHP Developers Mailing List' <internals@lists.php.net>
In-Reply-To: <774652170.20051003161344@marcus-boerger.de>
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Subject: Re: [PHP-DEV] $ref =& $this;
From: andi@zend.com (Andi Gutmans)

See my note regarding the fixes we did in the past 1-2 weeks 
regarding references. It's a huge BC break, and quite frankly, it's 
not the kind of thing that forces you not to write good code because 
it's supported.

Andi

At 07:13 AM 10/3/2005, Marcus Boerger wrote:
>Hello Dmitry,
>
>   that IS NOT proper code and it wasn't in php 4 either, it was only a
>workaround that is no longer needed. Had the php 4 design been correct in
>the first place that wouldn't have been allowed in 4 either. Since BC is not
>working out anyway i see absolutley no reason to encourage people to
>continue to missuse php.
>
>marcus
>
>Monday, October 3, 2005, 4:05:56 PM, you wrote:
>
> > Hi,
>
> > At first $ref =& $this; produced fatal error because of the bug (not by
> > design).
> > For example $ref->prop =& $this; worked and works without errors.
>
> > So my patch shouldn't be reverted in any case.
>
> > At second disallowing such assignments and passign $this by reference will
> > breake a lot of PHP4 code (Mamaba CMS).
> > In PHP4 passing $object by refernce and by value had completely different
> > semantic.
>
> > I don't see any reason to disallow 100% proper code (like the the
> > following).
>
> > class Child {
> >   function Child($parent) {
> >     $parent->children[] =& $this;
> >   }
> > }
>
> > Of course using "=& $this" user can breake $this value, but other languages
> > (C++) allows this too.
> > I don't think we should be paranoiacs.
>
> > Thanks. Dmitry.
>
>
> >> -----Original Message-----
> >> From: Derick Rethans [mailto:derick@php.net]
> >> Sent: Monday, October 03, 2005 5:09 PM
> >> To: PHP Developers Mailing List
> >> Subject: [PHP-DEV] $ref =& $this;
> >>
> >>
> >> Hello,
> >>
> >> Dmitry committed a fix earlier to ignore the & in the
> >> statement above. I
> >> think this is not a good thing to do as it's simply
> >> conceptually wrong.
> >> The first thing is that ignoring syntax without issuing a warning is
> >> dubious because people might think it does actually work, and
> >> secondly
> >> because I think that the code above is wrong anyway - somewhat in the
> >> same way that "$this = new foo();" is wrong.
> >>
> >> There is never any need to assign $this by reference, nor to
> >> pass it by
> >> reference to a function as it's an object anyway, making the
> >> references
> >> pointless - I would even go as far as disallowing passing $this by
> >> references to a function - where the reference has to be
> >> ignored again,
> >> otherwise it allows you to chantge $this to a different object with:
> >>
> >> class Foo {
> >>       function byRef(&$f) {
> >>               $f = new Bar();
> >>       }
> >>
> >>       function modifyThis() {
> >>               $this->byRef($this);
> >>       }
> >> }
> >>
> >> I think we should prevent people from writing syntax like
> >> this, as it is
> >> not obvious what is going to happen. This means that we should revert
> >> Dmitry's patch.
> >>
> >> regards,
> >> Derick
> >>
> >> --
> >> Derick Rethans
> >> http://derickrethans.nl | http://ez.no | http://xdebug.org
> >>
> >> --
> >> PHP Internals - PHP Runtime Development Mailing List
> >> To unsubscribe, visit: http://www.php.net/unsub.php
> >>
> >>
>
>
>
>
>Best regards,
>  Marcus
>
>--
>PHP Internals - PHP Runtime Development Mailing List
>To unsubscribe, visit: http://www.php.net/unsub.php


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