Bug #60161 [Opn]: Implementing an interface extending Traversable is order dependent

Edit report at https://bugs.php.net/bug.php?id=60161&edit=1 ID: 60161 Updated by: levim@php.net Reported by: nikic@php.net Summary: Implementing an interface extending Traversable is order dependent Status: Open Type: Bug Package: Scripting Engine problem PHP Version: 5.4.0beta2 Block user comment: N Private report: N New Comment: I don't care as much about the abstract issue (it's filed separately: https://bugs.php.net/bug.php?id=62609) but I'd really like to see the order restriction be relaxed on interfaces. Previous Comments: ------------------------------------------------------------------------ [2013-10-12 17:57:02] maciej dot sz at gmail dot com The order dependency of interface names is a minor drawback, but same thing happens when one tries to put an abstract class between the interface and specific implementation. And this is a big problem: <?php interface IFoo extends \Traversable {} abstract class AFoo implements IFoo {} ?> Throws: Class AFoo must implement interface Traversable as part of either Iterator or IteratorAggregate in Unknown on line 0 ------------------------------------------------------------------------ [2011-11-02 17:50:13] nikic@php.net Yes, exactly. That's what I was trying to do when I encountered the issue. ------------------------------------------------------------------------ [2011-11-02 17:16:29] johannes@php.net You mean for a type hint which says "traversable and having that function"? That might indeed be a valid reason I didn't think about .. ------------------------------------------------------------------------ [2011-11-02 14:44:55] nikic@php.net @johannes: How could you then hint that a class must be Traversable in some way (either Iterator or Aggregate)? Or shouldn't that be possible at all? ------------------------------------------------------------------------ [2011-11-02 12:21:47] johannes@php.net Actually we should forbid extending Traversable. This should only only only be used by internal classes (Iterator, iteratorAggregate or classes providing the C get_iterator hooks) ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=60161 -- Edit this bug report at https://bugs.php.net/bug.php?id=60161&edit=1