Re: [PHP-DEV] Re: Making all Traversables an Iterator or IteratorAggregate

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June 9, 2020 13:23 nikita.ppv@gmail.com (Nikita Popov)
On Tue, May 12, 2020 at 2:49 PM Sara Golemon <pollita@php.net> wrote:

> On Tue, May 12, 2020 at 3:26 AM Nikita Popov ppv@gmail.com> wrote: > > // WeakMap::getIterator(): Iterator > > ZEND_METHOD(WeakMap, getIterator) > > { > > if (zend_parse_parameters_none() == FAILURE) { > > return; > > } > > zend_create_internal_iterator_zval(return_value, ZEND_THIS); > > } > > > Given that the body of this method seems to usually (always?) be the same, > why not define it in InternalIterator and allow it to be inherited? > > > There's some bikeshed potential here regarding the class name. > > > Not personally over-picky, but I do agree that "Internal*" is a bit > awkward. Unfortunately there's not much that's better and appropriate for > exposing to scripts. This might be one of those rare occasions where > exposing "Zend" into userspace makes sense. "PHP" is overloaded into > several meanings that are significant for userspace developers, but > something like "ZendIterator" might convey the right level of "This has to > do with the engine, please move along". Or maybe go verbose: > 'IteratorForExtensionClassImplementations'. :p > > > ZEND_ASSERT(scope->get_iterator != zend_user_it_get_new_iterator); > > Does this mean that if I do `class Foo implements InternalIterator {}` in > a script, I can assert (crash) PHP? I don't see anything obvious (at a > glance) preventing me from inheriting from InternalIterator. >
InternalIterator isn't an interface, so it's not possible to implement it in this way. It's not possible to directly construct an object either. What can happen is that the getIterator() method is replaced in a child class, but this will get picked up automatically, and the get_iterator handler will be changed to zend_user_it_get_new_iterator automatically. Nikita