Re: Generic classes and methods RFC

Hi, On 05.09.2015 21:48, John LeSueur wrote:

Hi Ben, Now that I have substantive questions, including the list :) In the following: class SomeList<Bar> {

     public static function fromArray<Baz>(array $a): SomeList<Baz> {
         $list = new SomeList<Baz>();
         $list2 = new SomeList<Bar>();
         return $list;
     }

} $list = SomeList<int>::fromArray([1, 2]); When fromArray() executes, what type is $list2? or is that an error? If it's an error, what advantage is there to having distinct generic types on the class vs. the method? How do I specify the two generic types I want to use?

The $list2 line would definitely be an error, since the <Bar> hint is not known in the static context. The advantage is simply that you can pass a type through the a static method to create an object with a specific type for you.

Another thing I'd like to make sure I understand, how does this interact with strict types (and non-strict)? new Entry<int, string>(1, 2);//I assume it should type-juggle declare(strict_types = 1); new Entry<int, string>(1, 2);//I assume it should throw error

I didn't think too much about this, but I guess you are right that for scalar types, the strict_type declaration should apply in the user context.

I'm interested to see if PHP can get generics going. I hope hashing out some more details might garner more interest. Thanks, John

-- Ben Scholzen http://www.dasprids.de

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