Re: __invokeStatic() method

On 18/03/2013, at 6:07 PM, Matīss Roberts Treinis <mrtreinis@gmail.com> wrote: > Not only that. This potentially might break compatibility with many > software products already out there. Also, this might lead to many > misunderstandings and, in fact, ambiguous code. Consider the sample. > > $name = 'something'; > $something = $name(); // What is this - a function call or object? > > Fact is, we can not know that unless a) do a search in code b) var_dump? > > > 2013/3/18 Pierre du Plessis <pierre@pcservice.co.za> > >> On Mar 18, 2013 2:41 AM, "Thomas Bley" <thbley+php@gmail.com> wrote: >>> >>> On Sat, Mar 16, 2013 at 9:33 PM, Pierre du Plessis >>> <pierre@pcservice.co.za> wrote: >>>> On Mar 16, 2013 9:35 PM, "Daniele Orlando" <dnl.rlnd@gmail.com> >>>> wrote: >>>>> >>>>> Hi List, >>>>> >>>>> I'm interested in proposing an RFC and I would know your opinion. >>>>> >>>>> === Current Situation === >>>>> Since PHP 5.3 we can use an object instance, who defines the >> __invoke() >>>>> method, as a callable object. >>>>> Example: >>>>> >>>>> // PHP Code. >>>>> class Runnable >>>>> { >>>>> public function __invoke() >>>>> { >>>>> echo "Runned"; >>>>> } >>>>> } >>>>> >>>>> $r = new Runnable(); >>>>> $r(); >>>>> >>>>> // Output >>>>> Runned >>>>> >>>>> === The Idea === >>>>> In Python, when you construct an object, you don't need to use the >> "new" >>>>> keyword but you just invoke the class name followed by "()", like the >>>> class >>>>> is a function. >>>>> Example: >>>>> >>>>> // Python Code. >>>>> class A: >>>>> pass >>>>> >>>>> A() >>>>> >>>>> // Output. >>>>> <__main__.A instance at %address> >>>>> >>>>> Now, would be interesting to extend the PHP __invoke() method adding >> an >>>>> __invokeStatic() method, like happens with __call() and __callStatic() >>>>> methods. >>>>> In this way could be possible to use a class name to invoke the >>>>> __invokeStatic() method. >>>>> Example: >>>>> >>>>> // PHP Code. >>>>> class TrueRunnable >>>>> { >>>>> public static function __invokeStatic() >>>>> { >>>>> echo "Runned"; >>>>> } >>>>> } >>>>> >>>>> TrueRunnable(); >>>>> >>>>> // Output. >>>>> Runned >>>>> >>>>> But the possibility are endless: >>>>> >>>>> class A >>>>> { >>>>> public static function __invokeStatic() >>>>> { >>>>> return new A(); >>>>> } >>>>> public method m() {} >>>>> } >>>>> >>>>> A()->m(); >>>>> >>>>> // or >>>>> >>>>> class A >>>>> { >>>>> private $_instance; >>>>> public static function __invokeStatic() >>>>> { >>>>> // Singleton pattern. >>>>> if (self::$_instance) { >>>>> return self::$_instance; >>>>> } >>>>> >>>>> return self::$_instance = new A(); >>>>> } >>>>> public method m() {} >>>>> } >>>>> >>>>> A()->m(); >>>>> >>>>> >>>>> === Conclusion === >>>>> This feature makes the __invoke() method consistent with the __call() >> and >>>>> __callStatic() methods, >>>>> and opens the door to many cool stuff. >>>>> >>>>> Any feedback is appreciated. >>>>> >>>>> Daniele Orlando >>>> >>>> I don't really see a use case for this, as you can already use the >> syntax >>>> A::method(); >>>> >>>> E.G class A { public static function invoke() { return new A; } >>>> >>>> public function m() { echo 'Runned'; } >>>> >>>> A::invoke()->m(); >>>> >>>> Your example above only saves a few characters to type and can lead to >> a >>>> lot of problems if you have a function with the same name as the class. >>> >>> Using A::invoke(), you need to know the name of "invoke()" and it's >>> hard to force users always to use the invoke() function. >>> Using A() would be more clean since all the static init(), factory(), >>> invoke(), getInstance() are gone. >>> Having __call(), __callStatic(), __invoke() and invokeStatic() would >>> make the overloading concept more consistent. >>> >>> Regards, >>> Thomas >>> >>> -- >>> PHP Internals - PHP Runtime Development Mailing List >>> To unsubscribe, visit: http://www.php.net/unsub.php >> >> Using A() looks too much like a function call. And there is still the issue >> with having a function name the same as the class name. >> This works well in languages like JavaScript where functions are objects. As much as I like the feature there, I'm not sure it's a great fit for PHP. David Sent from my iPhone