Introduce InternalIterator

Userland classes that implement Traversable must do so either
through Iterator or IteratorAggregate. The same requirement does
not exist for internal classes: They can implement the internal
get_iterator mechanism, without exposing either the Iterator or
IteratorAggregate APIs. This makes them usable in get_iterator(),
but incompatible with any Iterator based APIs.

A lot of internal classes do this, because exposing the userland
APIs is simply a lot of work. This patch alleviates this issue by
providing a generic InternalIterator class, which acts as an
adapater between get_iterator and Iterator, and can be easily
used by many internal classes. At the same time, we extend the
requirement that Traversable implies Iterator or IteratorAggregate
to internal classes as well.

Closes GH-5216.

1 files changed, 3 insertions, 1 deletions

diff --git a/Zend/zend_weakrefs.stub.php b/Zend/zend_weakrefs.stub.php
index 4cf189b064..8cf0df5cf6 100644
--- a/Zend/zend_weakrefs.stub.php
+++ b/Zend/zend_weakrefs.stub.php
@@ -11,7 +11,7 @@ final class WeakReference
     public function get(): ?object {}
 }
 
-final class WeakMap implements ArrayAccess, Countable, Traversable
+final class WeakMap implements ArrayAccess, Countable, IteratorAggregate
 {
     /**
      * @param object $object
@@ -32,4 +32,6 @@ final class WeakMap implements ArrayAccess, Countable, Traversable
     public function offsetUnset($object): void {}
 
     public function count(): int {}
+
+    public function getIterator(): Iterator {}
 }