Edit report at https://bugs.php.net/bug.php?id=62464&edit=1
ID: 62464
Comment by: valderrama dot christopher at gmail dot com
Reported by: j dot henge-ernst at interexa dot de
Summary: implementing two interfaces with same signature no
longer gives a fatal error
Status: Open
Type: Bug
Package: Scripting Engine problem
Operating System: linux
PHP Version: 5.3Git-2012-07-02 (Git)
Block user comment: N
Private report: N
New Comment:
The certification guide states that a object can't implement two interfaces
that
share the same method, but the code still runs ok.
So if classes are going to be allowed two implement two interfaces that share
the
same method, I think that the certification exam should be changed to reflect
this change.
Previous Comments:
------------------------------------------------------------------------
[2012-07-02 22:11:54] j dot henge-ernst at interexa dot de
Your example is ok and should work correctly as both interfaces extend the same
base interface and add different methods. In my given example AInterface and
BInterface do not extend from a common interface. So the class which implements
RewindableIterator, ReversableIterator must implement
from Iterator:
function current();
function key();
function next();
function valid();
from RewindableIterator:
function rewind();
from ReversableIterator:
function prev();
So lets change my example to:
interface AInterface {
/** @return Aclass[] */
public function getObjects();
}
interface BInterface {
/** @return Bclass[] */
public function getObjects();
}
class CClass implements AInterface, BInterface
{
public function getObjects() {
return ???;
}
}
class AClass {
public function foo() { echo "foo";}
}
class BClass {
public function bar() { echo "bar";}
}
------------------------------------------------------------------------
[2012-07-02 17:50:10] ni...@php.net
I'm not sure I see the problem. If the class satisfies both interfaces, why
should there be an error?
E.g., consider:
interface Iterator {
function current();
function key();
function next();
function valid();
}
interface RewindableIterator extends Iterator {
function rewind();
}
interface ReversableIterator extends Iterator {
function prev();
}
class Foo implements RewindableIterator, ReversableIterator {
// ...
}
Why shouldn't the class be able to implement both, as long as the method
declarations don't disagree?
------------------------------------------------------------------------
[2012-07-02 16:11:52] j dot henge-ernst at interexa dot de
Description:
------------
having two different interfaces with same method no longer causes a fatal error
like in php 5.3.8. With fix for bug #43200 (my guess) it is now possible to
inherit another interface which has the same method signature as a previous
interface.
implementing an interface with methods which collide with a method name which
is already implemented by another interface should cause an error.
>From my point of OOP it does not make sense as the meaning of the colliding
>interface method do not express the same, else both interfaces with the same
>signature part should extend that base interface.
It's the opposite of bug #46705
Such a change of the language should not be done in a minor release.
Test script:
---------------
<?php
interface AInterface {
public function getLogicalKey();
}
interface BInterface {
public function getLogicalKey();
}
class AClass implements AInterface {
public function getLogicalKey() { return 1; }
}
class BClass extends AClass implements BInterface { }
Expected result:
----------------
Fatal error: Can't inherit abstract function BInterface::getLogicalKey()
(previously declared abstract in AInterface) in x.php on line 12
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=62464&edit=1
