/src/cpython/Objects/iterobject.c

Source
/* Iterator objects */

#include "Python.h"
#include "pycore_abstract.h"      // _PyObject_HasLen()
#include "pycore_call.h"          // _PyObject_CallNoArgs()
#include "pycore_ceval.h"         // _PyEval_GetBuiltin()
#include "pycore_genobject.h"     // _PyCoro_GetAwaitableIter()
#include "pycore_object.h"        // _PyObject_GC_TRACK()


typedef struct {
    PyObject_HEAD
    Py_ssize_t it_index;
    PyObject *it_seq; /* Set to NULL when iterator is exhausted */
} seqiterobject;

PyObject *
PySeqIter_New(PyObject *seq)
{
    seqiterobject *it;

    if (!PySequence_Check(seq)) {
        PyErr_BadInternalCall();
        return NULL;
    }
    it = PyObject_GC_New(seqiterobject, &PySeqIter_Type);
    if (it == NULL)
        return NULL;
    it->it_index = 0;
    it->it_seq = Py_NewRef(seq);
    _PyObject_GC_TRACK(it);
    return (PyObject *)it;
}

static void
iter_dealloc(PyObject *op)
{
    seqiterobject *it = (seqiterobject*)op;
    _PyObject_GC_UNTRACK(it);
    Py_XDECREF(it->it_seq);
    PyObject_GC_Del(it);
}

static int
iter_traverse(PyObject *op, visitproc visit, void *arg)
{
    seqiterobject *it = (seqiterobject*)op;
    Py_VISIT(it->it_seq);
    return 0;
}

static PyObject *
iter_iternext(PyObject *iterator)
{
    seqiterobject *it;
    PyObject *seq;
    PyObject *result;

    assert(PySeqIter_Check(iterator));
    it = (seqiterobject *)iterator;
    seq = it->it_seq;
    if (seq == NULL)
        return NULL;
    if (it->it_index == PY_SSIZE_T_MAX) {
        PyErr_SetString(PyExc_OverflowError,
                        "iter index too large");
        return NULL;
    }

    result = PySequence_GetItem(seq, it->it_index);
    if (result != NULL) {
        it->it_index++;
        return result;
    }
    if (PyErr_ExceptionMatches(PyExc_IndexError) ||
        PyErr_ExceptionMatches(PyExc_StopIteration))
    {
        PyErr_Clear();
        it->it_seq = NULL;
        Py_DECREF(seq);
    }
    return NULL;
}

static PyObject *
iter_len(PyObject *op, PyObject *Py_UNUSED(ignored))
{
    seqiterobject *it = (seqiterobject*)op;
    Py_ssize_t seqsize, len;

    if (it->it_seq) {
        if (_PyObject_HasLen(it->it_seq)) {
            seqsize = PySequence_Size(it->it_seq);
            if (seqsize == -1)
                return NULL;
        }
        else {
            Py_RETURN_NOTIMPLEMENTED;
        }
        len = seqsize - it->it_index;
        if (len >= 0)
            return PyLong_FromSsize_t(len);
    }
    return PyLong_FromLong(0);
}

PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");

static PyObject *
iter_reduce(PyObject *op, PyObject *Py_UNUSED(ignored))
{
    seqiterobject *it = (seqiterobject*)op;
    PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));

    /* _PyEval_GetBuiltin can invoke arbitrary code,
     * call must be before access of iterator pointers.
     * see issue #101765 */

    if (it->it_seq != NULL)
        return Py_BuildValue("N(O)n", iter, it->it_seq, it->it_index);
    else
        return Py_BuildValue("N(())", iter);
}

PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");

static PyObject *
iter_setstate(PyObject *op, PyObject *state)
{
    seqiterobject *it = (seqiterobject*)op;
    Py_ssize_t index = PyLong_AsSsize_t(state);
    if (index == -1 && PyErr_Occurred())
        return NULL;
    if (it->it_seq != NULL) {
        if (index < 0)
            index = 0;
        it->it_index = index;
    }
    Py_RETURN_NONE;
}

PyDoc_STRVAR(setstate_doc, "Set state information for unpickling.");

static PyMethodDef seqiter_methods[] = {
    {"__length_hint__", iter_len, METH_NOARGS, length_hint_doc},
    {"__reduce__", iter_reduce, METH_NOARGS, reduce_doc},
    {"__setstate__", iter_setstate, METH_O, setstate_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PySeqIter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "iterator",                                 /* tp_name */
    sizeof(seqiterobject),                      /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    iter_dealloc,                               /* tp_dealloc */
    0,                                          /* tp_vectorcall_offset */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* 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 */
    iter_traverse,                              /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    iter_iternext,                              /* tp_iternext */
    seqiter_methods,                            /* tp_methods */
    0,                                          /* tp_members */
};

/* -------------------------------------- */

typedef struct {
    PyObject_HEAD
    PyObject *it_callable; /* Set to NULL when iterator is exhausted */
    PyObject *it_sentinel; /* Set to NULL when iterator is exhausted */
} calliterobject;

PyObject *
PyCallIter_New(PyObject *callable, PyObject *sentinel)
{
    calliterobject *it;
    it = PyObject_GC_New(calliterobject, &PyCallIter_Type);
    if (it == NULL)
        return NULL;
    it->it_callable = Py_NewRef(callable);
    it->it_sentinel = Py_NewRef(sentinel);
    _PyObject_GC_TRACK(it);
    return (PyObject *)it;
}
static void
calliter_dealloc(PyObject *op)
{
    calliterobject *it = (calliterobject*)op;
    _PyObject_GC_UNTRACK(it);
    Py_XDECREF(it->it_callable);
    Py_XDECREF(it->it_sentinel);
    PyObject_GC_Del(it);
}

static int
calliter_traverse(PyObject *op, visitproc visit, void *arg)
{
    calliterobject *it = (calliterobject*)op;
    Py_VISIT(it->it_callable);
    Py_VISIT(it->it_sentinel);
    return 0;
}

static PyObject *
calliter_iternext(PyObject *op)
{
    calliterobject *it = (calliterobject*)op;
    PyObject *result;

    if (it->it_callable == NULL) {
        return NULL;
    }

    result = _PyObject_CallNoArgs(it->it_callable);
    if (result != NULL && it->it_sentinel != NULL){
        int ok;

        ok = PyObject_RichCompareBool(it->it_sentinel, result, Py_EQ);
        if (ok == 0) {
            return result; /* Common case, fast path */
        }

        if (ok > 0) {
            Py_CLEAR(it->it_callable);
            Py_CLEAR(it->it_sentinel);
        }
    }
    else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
        PyErr_Clear();
        Py_CLEAR(it->it_callable);
        Py_CLEAR(it->it_sentinel);
    }
    Py_XDECREF(result);
    return NULL;
}

static PyObject *
calliter_reduce(PyObject *op, PyObject *Py_UNUSED(ignored))
{
    calliterobject *it = (calliterobject*)op;
    PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));

    /* _PyEval_GetBuiltin can invoke arbitrary code,
     * call must be before access of iterator pointers.
     * see issue #101765 */

    if (it->it_callable != NULL && it->it_sentinel != NULL)
        return Py_BuildValue("N(OO)", iter, it->it_callable, it->it_sentinel);
    else
        return Py_BuildValue("N(())", iter);
}

static PyMethodDef calliter_methods[] = {
    {"__reduce__", calliter_reduce, METH_NOARGS, reduce_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PyCallIter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "callable_iterator",                        /* tp_name */
    sizeof(calliterobject),                     /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    calliter_dealloc,                           /* tp_dealloc */
    0,                                          /* tp_vectorcall_offset */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* 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 */
    calliter_traverse,                          /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    calliter_iternext,                          /* tp_iternext */
    calliter_methods,                           /* tp_methods */
};


/* -------------------------------------- */

typedef struct {
    PyObject_HEAD
    PyObject *wrapped;
    PyObject *default_value;
} anextawaitableobject;

#define anextawaitableobject_CAST(op)   ((anextawaitableobject *)(op))

static void
anextawaitable_dealloc(PyObject *op)
{
    anextawaitableobject *obj = anextawaitableobject_CAST(op);
    _PyObject_GC_UNTRACK(obj);
    Py_XDECREF(obj->wrapped);
    Py_XDECREF(obj->default_value);
    PyObject_GC_Del(obj);
}

static int
anextawaitable_traverse(PyObject *op, visitproc visit, void *arg)
{
    anextawaitableobject *obj = anextawaitableobject_CAST(op);
    Py_VISIT(obj->wrapped);
    Py_VISIT(obj->default_value);
    return 0;
}

static PyObject *
anextawaitable_getiter(anextawaitableobject *obj)
{
    assert(obj->wrapped != NULL);
    PyObject *awaitable = _PyCoro_GetAwaitableIter(obj->wrapped);
    if (awaitable == NULL) {
        return NULL;
    }
    if (Py_TYPE(awaitable)->tp_iternext == NULL) {
        /* _PyCoro_GetAwaitableIter returns a Coroutine, a Generator,
         * or an iterator. Of these, only coroutines lack tp_iternext.
         */
        assert(PyCoro_CheckExact(awaitable));
        unaryfunc getter = Py_TYPE(awaitable)->tp_as_async->am_await;
        PyObject *new_awaitable = getter(awaitable);
        if (new_awaitable == NULL) {
            Py_DECREF(awaitable);
            return NULL;
        }
        Py_SETREF(awaitable, new_awaitable);
        if (!PyIter_Check(awaitable)) {
            PyErr_Format(PyExc_TypeError,
                         "%T.__await__() must return an iterable, not %T",
                         obj, awaitable);
            Py_DECREF(awaitable);
            return NULL;
        }
    }
    return awaitable;
}

static PyObject *
anextawaitable_iternext(PyObject *op)
{
    /* Consider the following class:
     *
     *     class A:
     *         async def __anext__(self):
     *             ...
     *     a = A()
     *
     * Then `await anext(a)` should call
     * a.__anext__().__await__().__next__()
     *
     * On the other hand, given
     *
     *     async def agen():
     *         yield 1
     *         yield 2
     *     gen = agen()
     *
     * Then `await anext(gen)` can just call
     * gen.__anext__().__next__()
     */
    anextawaitableobject *obj = anextawaitableobject_CAST(op);
    PyObject *awaitable = anextawaitable_getiter(obj);
    if (awaitable == NULL) {
        return NULL;
    }
    PyObject *result = (*Py_TYPE(awaitable)->tp_iternext)(awaitable);
    Py_DECREF(awaitable);
    if (result != NULL) {
        return result;
    }
    if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)) {
        PyErr_Clear();
        _PyGen_SetStopIterationValue(obj->default_value);
    }
    return NULL;
}


static PyObject *
anextawaitable_proxy(anextawaitableobject *obj, char *meth, PyObject *arg)
{
    PyObject *awaitable = anextawaitable_getiter(obj);
    if (awaitable == NULL) {
        return NULL;
    }
    // When specified, 'arg' may be a tuple (if coming from a METH_VARARGS
    // method) or a single object (if coming from a METH_O method).
    PyObject *ret = arg == NULL
        ? PyObject_CallMethod(awaitable, meth, NULL)
        : PyObject_CallMethod(awaitable, meth, "O", arg);
    Py_DECREF(awaitable);
    if (ret != NULL) {
        return ret;
    }
    if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)) {
        /* `anextawaitableobject` is only used by `anext()` when
         * a default value is provided. So when we have a StopAsyncIteration
         * exception we replace it with a `StopIteration(default)`, as if
         * it was the return value of `__anext__()` coroutine.
         */
        PyErr_Clear();
        _PyGen_SetStopIterationValue(obj->default_value);
    }
    return NULL;
}


static PyObject *
anextawaitable_send(PyObject *op, PyObject *arg)
{
    anextawaitableobject *obj = anextawaitableobject_CAST(op);
    return anextawaitable_proxy(obj, "send", arg);
}


static PyObject *
anextawaitable_throw(PyObject *op, PyObject *args)
{
    anextawaitableobject *obj = anextawaitableobject_CAST(op);
    return anextawaitable_proxy(obj, "throw", args);
}


static PyObject *
anextawaitable_close(PyObject *op, PyObject *Py_UNUSED(dummy))
{
    anextawaitableobject *obj = anextawaitableobject_CAST(op);
    return anextawaitable_proxy(obj, "close", NULL);
}


PyDoc_STRVAR(send_doc,
"send(arg) -> send 'arg' into the wrapped iterator,\n\
return next yielded value or raise StopIteration.");


PyDoc_STRVAR(throw_doc,
"throw(value)\n\
throw(typ[,val[,tb]])\n\
\n\
raise exception in the wrapped iterator, return next yielded value\n\
or raise StopIteration.\n\
the (type, val, tb) signature is deprecated, \n\
and may be removed in a future version of Python.");


PyDoc_STRVAR(close_doc,
"close() -> raise GeneratorExit inside generator.");


static PyMethodDef anextawaitable_methods[] = {
    {"send", anextawaitable_send, METH_O, send_doc},
    {"throw", anextawaitable_throw, METH_VARARGS, throw_doc},
    {"close", anextawaitable_close, METH_NOARGS, close_doc},
    {NULL, NULL}        /* Sentinel */
};


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 */
    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 */
    anextawaitable_traverse,                    /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    anextawaitable_iternext,                    /* tp_iternext */
    anextawaitable_methods,                     /* tp_methods */
};

PyObject *
PyAnextAwaitable_New(PyObject *awaitable, PyObject *default_value)
{
    anextawaitableobject *anext = PyObject_GC_New(
            anextawaitableobject, &_PyAnextAwaitable_Type);
    if (anext == NULL) {
        return NULL;
    }
    anext->wrapped = Py_NewRef(awaitable);
    anext->default_value = Py_NewRef(default_value);
    _PyObject_GC_TRACK(anext);
    return (PyObject *)anext;
}

Coverage Report

Created: 2025-11-11 06:44

Line	Count	Source
1		/* Iterator objects */
2
3		#include "Python.h"
4		#include "pycore_abstract.h" // _PyObject_HasLen()
5		#include "pycore_call.h" // _PyObject_CallNoArgs()
6		#include "pycore_ceval.h" // _PyEval_GetBuiltin()
7		#include "pycore_genobject.h" // _PyCoro_GetAwaitableIter()
8		#include "pycore_object.h" // _PyObject_GC_TRACK()
9
10
11		typedef struct {
12		PyObject_HEAD
13		Py_ssize_t it_index;
14		PyObject it_seq; / Set to NULL when iterator is exhausted */
15		} seqiterobject;
16
17		PyObject *
18		PySeqIter_New(PyObject *seq)
19	746	{
20	746	seqiterobject *it;
21
22	746	if (!PySequence_Check(seq)) {
23	0	PyErr_BadInternalCall();
24	0	return NULL;
25	0	}
26	746	it = PyObject_GC_New(seqiterobject, &PySeqIter_Type);
27	746	if (it == NULL)
28	0	return NULL;
29	746	it->it_index = 0;
30	746	it->it_seq = Py_NewRef(seq);
31	746	_PyObject_GC_TRACK(it);
32	746	return (PyObject *)it;
33	746	}
34
35		static void
36		iter_dealloc(PyObject *op)
37	746	{
38	746	seqiterobject it = (seqiterobject)op;
39	746	_PyObject_GC_UNTRACK(it);
40	746	Py_XDECREF(it->it_seq);
41	746	PyObject_GC_Del(it);
42	746	}
43
44		static int
45		iter_traverse(PyObject op, visitproc visit, void arg)
46	0	{
47	0	seqiterobject it = (seqiterobject)op;
48	0	Py_VISIT(it->it_seq);
49	0	return 0;
50	0	}
51
52		static PyObject *
53		iter_iternext(PyObject *iterator)
54	1.76k	{
55	1.76k	seqiterobject *it;
56	1.76k	PyObject *seq;
57	1.76k	PyObject *result;
58
59	1.76k	assert(PySeqIter_Check(iterator));
60	1.76k	it = (seqiterobject *)iterator;
61	1.76k	seq = it->it_seq;
62	1.76k	if (seq == NULL)
63	0	return NULL;
64	1.76k	if (it->it_index == PY_SSIZE_T_MAX) {
65	0	PyErr_SetString(PyExc_OverflowError,
66	0	"iter index too large");
67	0	return NULL;
68	0	}
69
70	1.76k	result = PySequence_GetItem(seq, it->it_index);
71	1.76k	if (result != NULL) {
72	1.02k	it->it_index++;
73	1.02k	return result;
74	1.02k	}
75	746	if (PyErr_ExceptionMatches(PyExc_IndexError) \|\|
76	0	PyErr_ExceptionMatches(PyExc_StopIteration))
77	746	{
78	746	PyErr_Clear();
79	746	it->it_seq = NULL;
80	746	Py_DECREF(seq);
81	746	}
82	746	return NULL;
83	1.76k	}
84
85		static PyObject *
86		iter_len(PyObject op, PyObject Py_UNUSED(ignored))
87	14	{
88	14	seqiterobject it = (seqiterobject)op;
89	14	Py_ssize_t seqsize, len;
90
91	14	if (it->it_seq) {
92	14	if (_PyObject_HasLen(it->it_seq)) {
93	14	seqsize = PySequence_Size(it->it_seq);
94	14	if (seqsize == -1)
95	0	return NULL;
96	14	}
97	0	else {
98	0	Py_RETURN_NOTIMPLEMENTED;
99	0	}
100	14	len = seqsize - it->it_index;
101	14	if (len >= 0)
102	14	return PyLong_FromSsize_t(len);
103	14	}
104	0	return PyLong_FromLong(0);
105	14	}
106
107		PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
108
109		static PyObject *
110		iter_reduce(PyObject op, PyObject Py_UNUSED(ignored))
111	0	{
112	0	seqiterobject it = (seqiterobject)op;
113	0	PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));
114
115		/* _PyEval_GetBuiltin can invoke arbitrary code,
116		* call must be before access of iterator pointers.
117		* see issue #101765 */
118
119	0	if (it->it_seq != NULL)
120	0	return Py_BuildValue("N(O)n", iter, it->it_seq, it->it_index);
121	0	else
122	0	return Py_BuildValue("N(())", iter);
123	0	}
124
125		PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
126
127		static PyObject *
128		iter_setstate(PyObject op, PyObject state)
129	0	{
130	0	seqiterobject it = (seqiterobject)op;
131	0	Py_ssize_t index = PyLong_AsSsize_t(state);
132	0	if (index == -1 && PyErr_Occurred())
133	0	return NULL;
134	0	if (it->it_seq != NULL) {
135	0	if (index < 0)
136	0	index = 0;
137	0	it->it_index = index;
138	0	}
139	0	Py_RETURN_NONE;
140	0	}
141
142		PyDoc_STRVAR(setstate_doc, "Set state information for unpickling.");
143
144		static PyMethodDef seqiter_methods[] = {
145		{"__length_hint__", iter_len, METH_NOARGS, length_hint_doc},
146		{"__reduce__", iter_reduce, METH_NOARGS, reduce_doc},
147		{"__setstate__", iter_setstate, METH_O, setstate_doc},
148		{NULL, NULL} /* sentinel */
149		};
150
151		PyTypeObject PySeqIter_Type = {
152		PyVarObject_HEAD_INIT(&PyType_Type, 0)
153		"iterator", /* tp_name */
154		sizeof(seqiterobject), /* tp_basicsize */
155		0, /* tp_itemsize */
156		/* methods */
157		iter_dealloc, /* tp_dealloc */
158		0, /* tp_vectorcall_offset */
159		0, /* tp_getattr */
160		0, /* tp_setattr */
161		0, /* tp_as_async */
162		0, /* tp_repr */
163		0, /* tp_as_number */
164		0, /* tp_as_sequence */
165		0, /* tp_as_mapping */
166		0, /* tp_hash */
167		0, /* tp_call */
168		0, /* tp_str */
169		PyObject_GenericGetAttr, /* tp_getattro */
170		0, /* tp_setattro */
171		0, /* tp_as_buffer */
172		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC, /* tp_flags */
173		0, /* tp_doc */
174		iter_traverse, /* tp_traverse */
175		0, /* tp_clear */
176		0, /* tp_richcompare */
177		0, /* tp_weaklistoffset */
178		PyObject_SelfIter, /* tp_iter */
179		iter_iternext, /* tp_iternext */
180		seqiter_methods, /* tp_methods */
181		0, /* tp_members */
182		};
183
184		/* -------------------------------------- */
185
186		typedef struct {
187		PyObject_HEAD
188		PyObject it_callable; / Set to NULL when iterator is exhausted */
189		PyObject it_sentinel; / Set to NULL when iterator is exhausted */
190		} calliterobject;
191
192		PyObject *
193		PyCallIter_New(PyObject callable, PyObject sentinel)
194	541k	{
195	541k	calliterobject *it;
196	541k	it = PyObject_GC_New(calliterobject, &PyCallIter_Type);
197	541k	if (it == NULL)
198	0	return NULL;
199	541k	it->it_callable = Py_NewRef(callable);
200	541k	it->it_sentinel = Py_NewRef(sentinel);
201	541k	_PyObject_GC_TRACK(it);
202	541k	return (PyObject *)it;
203	541k	}
204		static void
205		calliter_dealloc(PyObject *op)
206	541k	{
207	541k	calliterobject it = (calliterobject)op;
208	541k	_PyObject_GC_UNTRACK(it);
209	541k	Py_XDECREF(it->it_callable);
210	541k	Py_XDECREF(it->it_sentinel);
211	541k	PyObject_GC_Del(it);
212	541k	}
213
214		static int
215		calliter_traverse(PyObject op, visitproc visit, void arg)
216	177	{
217	177	calliterobject it = (calliterobject)op;
218	177	Py_VISIT(it->it_callable);
219	177	Py_VISIT(it->it_sentinel);
220	177	return 0;
221	177	}
222
223		static PyObject *
224		calliter_iternext(PyObject *op)
225	4.20M	{
226	4.20M	calliterobject it = (calliterobject)op;
227	4.20M	PyObject *result;
228
229	4.20M	if (it->it_callable == NULL) {
230	0	return NULL;
231	0	}
232
233	4.20M	result = _PyObject_CallNoArgs(it->it_callable);
234	4.20M	if (result != NULL && it->it_sentinel != NULL){
235	4.20M	int ok;
236
237	4.20M	ok = PyObject_RichCompareBool(it->it_sentinel, result, Py_EQ);
238	4.20M	if (ok == 0) {
239	3.66M	return result; /* Common case, fast path */
240	3.66M	}
241
242	541k	if (ok > 0) {
243	541k	Py_CLEAR(it->it_callable);
244	541k	Py_CLEAR(it->it_sentinel);
245	541k	}
246	541k	}
247	0	else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
248	0	PyErr_Clear();
249	0	Py_CLEAR(it->it_callable);
250	0	Py_CLEAR(it->it_sentinel);
251	0	}
252	541k	Py_XDECREF(result);
253	541k	return NULL;
254	4.20M	}
255
256		static PyObject *
257		calliter_reduce(PyObject op, PyObject Py_UNUSED(ignored))
258	0	{
259	0	calliterobject it = (calliterobject)op;
260	0	PyObject *iter = _PyEval_GetBuiltin(&_Py_ID(iter));
261
262		/* _PyEval_GetBuiltin can invoke arbitrary code,
263		* call must be before access of iterator pointers.
264		* see issue #101765 */
265
266	0	if (it->it_callable != NULL && it->it_sentinel != NULL)
267	0	return Py_BuildValue("N(OO)", iter, it->it_callable, it->it_sentinel);
268	0	else
269	0	return Py_BuildValue("N(())", iter);
270	0	}
271
272		static PyMethodDef calliter_methods[] = {
273		{"__reduce__", calliter_reduce, METH_NOARGS, reduce_doc},
274		{NULL, NULL} /* sentinel */
275		};
276
277		PyTypeObject PyCallIter_Type = {
278		PyVarObject_HEAD_INIT(&PyType_Type, 0)
279		"callable_iterator", /* tp_name */
280		sizeof(calliterobject), /* tp_basicsize */
281		0, /* tp_itemsize */
282		/* methods */
283		calliter_dealloc, /* tp_dealloc */
284		0, /* tp_vectorcall_offset */
285		0, /* tp_getattr */
286		0, /* tp_setattr */
287		0, /* tp_as_async */
288		0, /* tp_repr */
289		0, /* tp_as_number */
290		0, /* tp_as_sequence */
291		0, /* tp_as_mapping */
292		0, /* tp_hash */
293		0, /* tp_call */
294		0, /* tp_str */
295		PyObject_GenericGetAttr, /* tp_getattro */
296		0, /* tp_setattro */
297		0, /* tp_as_buffer */
298		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC, /* tp_flags */
299		0, /* tp_doc */
300		calliter_traverse, /* tp_traverse */
301		0, /* tp_clear */
302		0, /* tp_richcompare */
303		0, /* tp_weaklistoffset */
304		PyObject_SelfIter, /* tp_iter */
305		calliter_iternext, /* tp_iternext */
306		calliter_methods, /* tp_methods */
307		};
308
309
310		/* -------------------------------------- */
311
312		typedef struct {
313		PyObject_HEAD
314		PyObject *wrapped;
315		PyObject *default_value;
316		} anextawaitableobject;
317
318	0	#define anextawaitableobject_CAST(op) ((anextawaitableobject *)(op))
319
320		static void
321		anextawaitable_dealloc(PyObject *op)
322	0	{
323	0	anextawaitableobject *obj = anextawaitableobject_CAST(op);
324	0	_PyObject_GC_UNTRACK(obj);
325	0	Py_XDECREF(obj->wrapped);
326	0	Py_XDECREF(obj->default_value);
327	0	PyObject_GC_Del(obj);
328	0	}
329
330		static int
331		anextawaitable_traverse(PyObject op, visitproc visit, void arg)
332	0	{
333	0	anextawaitableobject *obj = anextawaitableobject_CAST(op);
334	0	Py_VISIT(obj->wrapped);
335	0	Py_VISIT(obj->default_value);
336	0	return 0;
337	0	}
338
339		static PyObject *
340		anextawaitable_getiter(anextawaitableobject *obj)
341	0	{
342	0	assert(obj->wrapped != NULL);
343	0	PyObject *awaitable = _PyCoro_GetAwaitableIter(obj->wrapped);
344	0	if (awaitable == NULL) {
345	0	return NULL;
346	0	}
347	0	if (Py_TYPE(awaitable)->tp_iternext == NULL) {
348		/* _PyCoro_GetAwaitableIter returns a Coroutine, a Generator,
349		* or an iterator. Of these, only coroutines lack tp_iternext.
350		*/
351	0	assert(PyCoro_CheckExact(awaitable));
352	0	unaryfunc getter = Py_TYPE(awaitable)->tp_as_async->am_await;
353	0	PyObject *new_awaitable = getter(awaitable);
354	0	if (new_awaitable == NULL) {
355	0	Py_DECREF(awaitable);
356	0	return NULL;
357	0	}
358	0	Py_SETREF(awaitable, new_awaitable);
359	0	if (!PyIter_Check(awaitable)) {
360	0	PyErr_Format(PyExc_TypeError,
361	0	"%T.__await__() must return an iterable, not %T",
362	0	obj, awaitable);
363	0	Py_DECREF(awaitable);
364	0	return NULL;
365	0	}
366	0	}
367	0	return awaitable;
368	0	}
369
370		static PyObject *
371		anextawaitable_iternext(PyObject *op)
372	0	{
373		/* Consider the following class:
374		*
375		* class A:
376		* async def __anext__(self):
377		* ...
378		* a = A()
379		*
380		* Then `await anext(a)` should call
381		* a.__anext__().__await__().__next__()
382		*
383		* On the other hand, given
384		*
385		* async def agen():
386		* yield 1
387		* yield 2
388		* gen = agen()
389		*
390		* Then `await anext(gen)` can just call
391		* gen.__anext__().__next__()
392		*/
393	0	anextawaitableobject *obj = anextawaitableobject_CAST(op);
394	0	PyObject *awaitable = anextawaitable_getiter(obj);
395	0	if (awaitable == NULL) {
396	0	return NULL;
397	0	}
398	0	PyObject result = (Py_TYPE(awaitable)->tp_iternext)(awaitable);
399	0	Py_DECREF(awaitable);
400	0	if (result != NULL) {
401	0	return result;
402	0	}
403	0	if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)) {
404	0	PyErr_Clear();
405	0	_PyGen_SetStopIterationValue(obj->default_value);
406	0	}
407	0	return NULL;
408	0	}
409
410
411		static PyObject *
412		anextawaitable_proxy(anextawaitableobject obj, char meth, PyObject *arg)
413	0	{
414	0	PyObject *awaitable = anextawaitable_getiter(obj);
415	0	if (awaitable == NULL) {
416	0	return NULL;
417	0	}
418		// When specified, 'arg' may be a tuple (if coming from a METH_VARARGS
419		// method) or a single object (if coming from a METH_O method).
420	0	PyObject *ret = arg == NULL
421	0	? PyObject_CallMethod(awaitable, meth, NULL)
422	0	: PyObject_CallMethod(awaitable, meth, "O", arg);
423	0	Py_DECREF(awaitable);
424	0	if (ret != NULL) {
425	0	return ret;
426	0	}
427	0	if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration)) {
428		/* `anextawaitableobject` is only used by `anext()` when
429		* a default value is provided. So when we have a StopAsyncIteration
430		* exception we replace it with a `StopIteration(default)`, as if
431		* it was the return value of `__anext__()` coroutine.
432		*/
433	0	PyErr_Clear();
434	0	_PyGen_SetStopIterationValue(obj->default_value);
435	0	}
436	0	return NULL;
437	0	}
438
439
440		static PyObject *
441		anextawaitable_send(PyObject op, PyObject arg)
442	0	{
443	0	anextawaitableobject *obj = anextawaitableobject_CAST(op);
444	0	return anextawaitable_proxy(obj, "send", arg);
445	0	}
446
447
448		static PyObject *
449		anextawaitable_throw(PyObject op, PyObject args)
450	0	{
451	0	anextawaitableobject *obj = anextawaitableobject_CAST(op);
452	0	return anextawaitable_proxy(obj, "throw", args);
453	0	}
454
455
456		static PyObject *
457		anextawaitable_close(PyObject op, PyObject Py_UNUSED(dummy))
458	0	{
459	0	anextawaitableobject *obj = anextawaitableobject_CAST(op);
460	0	return anextawaitable_proxy(obj, "close", NULL);
461	0	}
462
463
464		PyDoc_STRVAR(send_doc,
465		"send(arg) -> send 'arg' into the wrapped iterator,\n\
466		return next yielded value or raise StopIteration.");
467
468
469		PyDoc_STRVAR(throw_doc,
470		"throw(value)\n\
471		throw(typ[,val[,tb]])\n\
472		\n\
473		raise exception in the wrapped iterator, return next yielded value\n\
474		or raise StopIteration.\n\
475		the (type, val, tb) signature is deprecated, \n\
476		and may be removed in a future version of Python.");
477
478
479		PyDoc_STRVAR(close_doc,
480		"close() -> raise GeneratorExit inside generator.");
481
482
483		static PyMethodDef anextawaitable_methods[] = {
484		{"send", anextawaitable_send, METH_O, send_doc},
485		{"throw", anextawaitable_throw, METH_VARARGS, throw_doc},
486		{"close", anextawaitable_close, METH_NOARGS, close_doc},
487		{NULL, NULL} /* Sentinel */
488		};
489
490
491		static PyAsyncMethods anextawaitable_as_async = {
492		PyObject_SelfIter, /* am_await */
493		0, /* am_aiter */
494		0, /* am_anext */
495		0, /* am_send */
496		};
497
498		PyTypeObject _PyAnextAwaitable_Type = {
499		PyVarObject_HEAD_INIT(&PyType_Type, 0)
500		"anext_awaitable", /* tp_name */
501		sizeof(anextawaitableobject), /* tp_basicsize */
502		0, /* tp_itemsize */
503		/* methods */
504		anextawaitable_dealloc, /* tp_dealloc */
505		0, /* tp_vectorcall_offset */
506		0, /* tp_getattr */
507		0, /* tp_setattr */
508		&anextawaitable_as_async, /* tp_as_async */
509		0, /* tp_repr */
510		0, /* tp_as_number */
511		0, /* tp_as_sequence */
512		0, /* tp_as_mapping */
513		0, /* tp_hash */
514		0, /* tp_call */
515		0, /* tp_str */
516		PyObject_GenericGetAttr, /* tp_getattro */
517		0, /* tp_setattro */
518		0, /* tp_as_buffer */
519		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC, /* tp_flags */
520		0, /* tp_doc */
521		anextawaitable_traverse, /* tp_traverse */
522		0, /* tp_clear */
523		0, /* tp_richcompare */
524		0, /* tp_weaklistoffset */
525		PyObject_SelfIter, /* tp_iter */
526		anextawaitable_iternext, /* tp_iternext */
527		anextawaitable_methods, /* tp_methods */
528		};
529
530		PyObject *
531		PyAnextAwaitable_New(PyObject awaitable, PyObject default_value)
532	0	{
533	0	anextawaitableobject *anext = PyObject_GC_New(
534	0	anextawaitableobject, &_PyAnextAwaitable_Type);
535	0	if (anext == NULL) {
536	0	return NULL;
537	0	}
538	0	anext->wrapped = Py_NewRef(awaitable);
539	0	anext->default_value = Py_NewRef(default_value);
540	0	_PyObject_GC_TRACK(anext);
541	0	return (PyObject *)anext;
542	0	}