Bug #43200 [Opn]: Interface implementation / inheritence not possible in abstract classes

Edit report at https://bugs.php.net/bug.php?id=43200&edit=1 ID: 43200 Updated by: lsmith@php.net Reported by: smith at pooteeweet dot org Summary: Interface implementation / inheritence not possible in abstract classes Status: Open Type: Bug Package: Scripting Engine problem Operating System: Linux PHP Version: 5.3CVS-2007-11-05 (CVS) Block user comment: N Private report: N New Comment: I should also clarify that the issue also exist when simply dealing with interfaces only aka when an interface extends another interface. I am aware that we do not support polymorphism, but again when dealing with legacy interfaces there will be overlaps with signatures that are identical. Previous Comments: ------------------------------------------------------------------------ [2011-10-02 21:16:11] aharvey@php.net Revert the various field changes that crept in. I'll let one of the engine developers figure out if this should be left open or re-bogused. ------------------------------------------------------------------------ [2011-10-01 07:55:33] lsmith@php.net This is not bogus and it should be fixed. In many cases I in the end managed to work around this, but its not always possible, like when dealing with legacy interfaces that one cannot change etc, but that are being superseded by newer ones (f.e. https://github.com/symfony/symfony/pull/2244). ------------------------------------------------------------------------ [2010-12-16 00:38:40] kucho86 at gmail dot com Are you planning to cover this bug?? It's pretty simple to fix and since interfaces define behaviours and classes implements them, this should be possible. It goes against Object Oriented Programming concepts. ------------------------------------------------------------------------ [2007-11-05 16:34:21] cellog@php.net <?php interface A { function foo(); } abstract class B implements A { } class C extends B { public function foo() { echo 'works'; } } $o = new C(); $o->foo(); ?> If you don't want to implement a method from an interface, don't redeclare it, and the code will work as intended. ------------------------------------------------------------------------ [2007-11-05 15:50:30] smith at pooteeweet dot org Description: ------------ PHP 5.3.0-dev (cli) (built: Nov 5 2007 16:42:56) from todays CVS HEAD. The implementation of interfaces in concrete abstract classes and their inheritence is not possible: Reproduce code: --------------- <?php interface A { function foo(); } abstract class B implements A { abstract public function foo(); } class C extends B { public function foo() { echo 'works'; } } $o = new C(); $o->foo(); ?> Expected result: ---------------- Echoing "works" Actual result: -------------- Fatal error: Can't inherit abstract function A::foo() (previously declared abstract in B) in ... ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=43200&edit=1