Add support for yielding keys

Keys are yielded using the

    yield $key => $value

syntax. Currently this is implemented as a statement only and not as an
expression, because conflicts arise considering nesting and use in arrays:

    yield yield $a => $b;
    // could be either
    yield (yield $a) => $b;
    // or
    yield (yield $a => $b);

Once I find some way to resolve these conflicts this should be available
as an expression too.

Also the key yielding code is rather copy-and-past-y for the value yielding
code, so that should be factored out.

1 files changed, 8 insertions, 0 deletions

diff --git a/Zend/zend_generators.c b/Zend/zend_generators.c
index b2fe8af854..d3d4b3f7a8 100644
--- a/Zend/zend_generators.c
+++ b/Zend/zend_generators.c
@@ -92,6 +92,10 @@ void zend_generator_close(zend_generator *generator, zend_bool finished_executio
 		generator->value = NULL;
 	}
 
+	if (generator->key) {
+		zval_ptr_dtor(&generator->key);
+		generator->key = NULL;
+	}
 }
 /* }}} */
 
@@ -269,6 +273,10 @@ ZEND_METHOD(Generator, key)
 	generator = (zend_generator *) zend_object_store_get_object(object TSRMLS_CC);
 
 	zend_generator_ensure_initialized(object, generator TSRMLS_CC);
+
+	if (generator->key) {
+		RETURN_ZVAL(generator->key, 1, 0);
+	}
 }
 /* }}} */