Re: References challenge with PHP4

2007/3/23, Jochem Maas <jochem@iamjochem.com>:

Martin Alterisio wrote: 2007/3/20, Jochem Maas <jochem@iamjochem.com <mailto: jochem@iamjochem.com>>:

    Robert Cummings wrote:

On Tue, 2007-03-20 at 11:52 +0100, Jochem Maas wrote:

ok, I tried it in a whole number of variations - no joy. you should use php5 if you want this kind of reference stuff - in php5 it just works, php 4 will give you big headaches.

Now now, don't be calling PHP5 "ALL THAT" when it can't do it right either (or did you not check it using PHP5 ;) ;)

    god knows what I did - obviously something different to what I

thought

    I was testing :-/

Everything works fine in PHP4 (also for PHP5 in this case if you just understand that static vars are buggy *lol* -- and this is first time I've noticed this

    bug).

    I have never run into this bug before ... nice catch, seems like
    a viable item for a bug report.

Actually, is not a bug, is expected behaviour and documented in the manual http://php.net/static See the last section, named "references with global and static variables" I have 2 issues with this: 1. the docs specify php4/ZendEngine1 which suggests php5 is not prone to this implementation error, the following code seems to suggest that from the user's POV the problem no longer exists (as long as there is no use of the reference operator inconjunction with objects) in php5 (using the erf operator in php5 with objects is almost always wrong anyway): class Test { public $foo; private static $inst; function get() { if(!isset(self::$inst)) self::$inst = new self; return self::$inst; } } $foo = Test::get(); $foo2 = Test::get(); $foo->foo = "foo"; var_dump($foo, $foo2, ($foo === $foo2)); $foo2->foo = "bar"; var_dump($foo, $foo2); 2. should I have to care about the way something is implemented internally in order to use a given piece of language functionality without running into problems that have a serious wtf factor? I feel not. oh well. static and global are implemented internally as references, that makes storing references into static variables impossible (which can be solved by using arrays of references as seen in Robert Cummings example). 100% behind you. I suffered enough because of this when trying to make code

that works for both php4 and php5 (unsuccesfully most of the times), and that's why I knew about this "expected behaviour". And if you ever tried to work with recursion in both functions and abstract data types in older versions of PHP you'll find the WTF factor being more annoying than ever (most of the problems have been solved but I still have nigthmares about $foo =& $foo->next; causing segmentation faults).