Re: extending interfaces - fringe behavior

At 07:55 16/02/2004, Hans Lellelid wrote:

I have a need in a current application to extend interfaces and possibly re-define (change signature) some of the inherited methods in the child interface. e.g. interface Foo {

        public function __construct(MyCls $var);
        public function myFunction();

} interface Bar extends Foo {

        public function __construct(MyCls $var, $var2 = null);
        public function myOtherFunction();

} class A implements Bar {

        public function __construct(MyCls $var, $var2 = null) {
                // ...
        }
        public function myFunction() {
                // ...
        }
        public function myOtherFunction() {
                // ...
        }

} This is not currently possible in PHP5b4, due to the (new?) "Can't inherit abstract function" errors generated by the engine. I.e. if I try to redefine __construct() I will get an error. The need for this capability is probably not that mainstream, but it'd be very nice. Is there any chance of having support for this behavior? I don't know anything about the underlying mechanism for supporting interface extension, so I don't know if what I'm asking is trivial or not.

You're not supposed to change the signature when you're extending/implementing interfaces. I'll try to see if it's feasible to improve the checks so that they compare signatures in a smarter way (i.e., func($arg1, $arg2=null) is compatible with func($arg1), and currently it's not detected that way). Zeev