bpo-31861: Add aiter and anext to builtins (#23847)
Co-authored-by: jab <jab@users.noreply.github.com>
Co-authored-by: Daniel Pope <mauve@mauveweb.co.uk>
Co-authored-by: Justin Wang <justin39@gmail.com>
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 4cd5910..fcfe2db 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2738,6 +2738,26 @@ PyObject_GetIter(PyObject *o)
}
}
+PyObject *
+PyObject_GetAiter(PyObject *o) {
+ PyTypeObject *t = Py_TYPE(o);
+ unaryfunc f;
+
+ if (t->tp_as_async == NULL || t->tp_as_async->am_aiter == NULL) {
+ return type_error("'%.200s' object is not an AsyncIterable", o);
+ }
+ f = t->tp_as_async->am_aiter;
+ PyObject *it = (*f)(o);
+ if (it != NULL && !PyAiter_Check(it)) {
+ PyErr_Format(PyExc_TypeError,
+ "aiter() returned non-AsyncIterator of type '%.100s'",
+ Py_TYPE(it)->tp_name);
+ Py_DECREF(it);
+ it = NULL;
+ }
+ return it;
+}
+
int
PyIter_Check(PyObject *obj)
{
@@ -2746,6 +2766,17 @@ PyIter_Check(PyObject *obj)
tp->tp_iternext != &_PyObject_NextNotImplemented);
}
+int
+PyAiter_Check(PyObject *obj)
+{
+ PyTypeObject *tp = Py_TYPE(obj);
+ return (tp->tp_as_async != NULL &&
+ tp->tp_as_async->am_aiter != NULL &&
+ tp->tp_as_async->am_aiter != &_PyObject_NextNotImplemented &&
+ tp->tp_as_async->am_anext != NULL &&
+ tp->tp_as_async->am_anext != &_PyObject_NextNotImplemented);
+}
+
/* Return next item.
* If an error occurs, return NULL. PyErr_Occurred() will be true.
* If the iteration terminates normally, return NULL and clear the
diff --git a/Objects/iterobject.c b/Objects/iterobject.c
index 6cac41a..06a6da5 100644
--- a/Objects/iterobject.c
+++ b/Objects/iterobject.c
@@ -157,7 +157,7 @@ PyTypeObject PySeqIter_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
0, /* tp_doc */
(traverseproc)iter_traverse, /* tp_traverse */
0, /* tp_clear */
@@ -276,7 +276,7 @@ PyTypeObject PyCallIter_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
0, /* tp_doc */
(traverseproc)calliter_traverse, /* tp_traverse */
0, /* tp_clear */
@@ -288,3 +288,91 @@ PyTypeObject PyCallIter_Type = {
};
+/* -------------------------------------- */
+
+typedef struct {
+ PyObject_HEAD
+ PyObject *wrapped;
+ PyObject *default_value;
+} anextawaitableobject;
+
+static void
+anextawaitable_dealloc(anextawaitableobject *obj)
+{
+ _PyObject_GC_UNTRACK(obj);
+ Py_XDECREF(obj->wrapped);
+ Py_XDECREF(obj->default_value);
+ PyObject_GC_Del(obj);
+}
+
+static int
+anextawaitable_traverse(anextawaitableobject *obj, visitproc visit, void *arg)
+{
+ Py_VISIT(obj->wrapped);
+ Py_VISIT(obj->default_value);
+ return 0;
+}
+
+static PyObject *
+anextawaitable_iternext(anextawaitableobject *obj)
+{
+ PyObject *result = PyIter_Next(obj->wrapped);
+ if (result != NULL) {
+ return result;
+ }
+ if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)) {
+ _PyGen_SetStopIterationValue(obj->default_value);
+ }
+ return NULL;
+}
+
+static PyAsyncMethods anextawaitable_as_async = {
+ PyObject_SelfIter, /* am_await */
+ 0, /* am_aiter */
+ 0, /* am_anext */
+ 0, /* am_send */
+};
+
+PyTypeObject PyAnextAwaitable_Type = {
+ PyVarObject_HEAD_INIT(&PyType_Type, 0)
+ "anext_awaitable", /* tp_name */
+ sizeof(anextawaitableobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)anextawaitable_dealloc, /* tp_dealloc */
+ 0, /* tp_vectorcall_offset */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ &anextawaitable_as_async, /* tp_as_async */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
+ 0, /* tp_doc */
+ (traverseproc)anextawaitable_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ PyObject_SelfIter, /* tp_iter */
+ (unaryfunc)anextawaitable_iternext, /* tp_iternext */
+ 0, /* tp_methods */
+};
+
+PyObject *
+PyAnextAwaitable_New(PyObject *awaitable, PyObject *default_value)
+{
+ anextawaitableobject *anext = PyObject_GC_New(anextawaitableobject, &PyAnextAwaitable_Type);
+ Py_INCREF(awaitable);
+ anext->wrapped = awaitable;
+ Py_INCREF(default_value);
+ anext->default_value = default_value;
+ _PyObject_GC_TRACK(anext);
+ return (PyObject *)anext;
+}