Re: interface inheritance

Nathan Nobbe schreef:

all, previously, on this list and elsewhere, i have raised the topic of interface inheritance, lamenting that php is void of the feature. to my utter amazement i discovered that php does in fact support interface inheritance, reading through some of Marcus Boergers' code in SPL.. i noticed RecursiveIterator extends Iterator, which is an internal interface (part of the zend engine), so i thought to myself, perhaps only internal interfaces can be extended, but then a quick test proved my suspicions wrong. in fact, interfaces can even extend multiple parent interfaces, just like java (*ducks*). here is the sample code so you can see for yourself: <?php interface Somethingable {

        public function doSomething();

} interface Crazyfiable {

        public function getCrazy();

} interface Extendable extends Somethingable, Crazyfiable {

        public function extend();

} class SuperClass implements Extendable {

        public function doSomething() {
                echo 'i did something ..' . PHP_EOL;
        }

        public function extend() {
                echo 'i extended something..' . PHP_EOL;
        }

        public function getCrazy() {
                echo 'im a crazy bastard now!' . PHP_EOL;
        }

} /* * TEST HERE */ $sc = new SuperClass(); $sc->doSomething(); $sc->extend(); $sc->getCrazy(); ?> and the output: nathan@trident /usr/share/php5/splExperiment/tests $ php testInterfaceInheritence.php i did something .. i extended something.. im a crazy bastard now! i for one am quite excited. heres to happy adventures in oop-land w/ php!

nice bit of info! as an aside, I often use php -r to test snippets like this e.g.: $> php -r 'echo "foo!";' very handy and saves having to create a file everytime you test something, it does mean your forced to use double quotes only in the code (otherwise the shell misinterprets). I recommend using double quotes in snippets you post in order to make it easier for people to quickly test your gems for themselves :-)

-nathan