/src/Python-3.8.3/Objects/enumobject.c

Source
/* enumerate object */

#include "Python.h"

#include "clinic/enumobject.c.h"

/*[clinic input]
class enumerate "enumobject *" "&PyEnum_Type"
class reversed "reversedobject *" "&PyReversed_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=d2dfdf1a88c88975]*/

typedef struct {
    PyObject_HEAD
    Py_ssize_t en_index;           /* current index of enumeration */
    PyObject* en_sit;          /* secondary iterator of enumeration */
    PyObject* en_result;           /* result tuple  */
    PyObject* en_longindex;        /* index for sequences >= PY_SSIZE_T_MAX */
} enumobject;


/*[clinic input]
@classmethod
enumerate.__new__ as enum_new

    iterable: object
        an object supporting iteration
    start: object = 0

Return an enumerate object.

The enumerate object yields pairs containing a count (from start, which
defaults to zero) and a value yielded by the iterable argument.

enumerate is useful for obtaining an indexed list:
    (0, seq[0]), (1, seq[1]), (2, seq[2]), ...
[clinic start generated code]*/

static PyObject *
enum_new_impl(PyTypeObject *type, PyObject *iterable, PyObject *start)
/*[clinic end generated code: output=e95e6e439f812c10 input=782e4911efcb8acf]*/
{
    enumobject *en;

    en = (enumobject *)type->tp_alloc(type, 0);
    if (en == NULL)
        return NULL;
    if (start != NULL) {
        start = PyNumber_Index(start);
        if (start == NULL) {
            Py_DECREF(en);
            return NULL;
        }
        assert(PyLong_Check(start));
        en->en_index = PyLong_AsSsize_t(start);
        if (en->en_index == -1 && PyErr_Occurred()) {
            PyErr_Clear();
            en->en_index = PY_SSIZE_T_MAX;
            en->en_longindex = start;
        } else {
            en->en_longindex = NULL;
            Py_DECREF(start);
        }
    } else {
        en->en_index = 0;
        en->en_longindex = NULL;
    }
    en->en_sit = PyObject_GetIter(iterable);
    if (en->en_sit == NULL) {
        Py_DECREF(en);
        return NULL;
    }
    en->en_result = PyTuple_Pack(2, Py_None, Py_None);
    if (en->en_result == NULL) {
        Py_DECREF(en);
        return NULL;
    }
    return (PyObject *)en;
}

static void
enum_dealloc(enumobject *en)
{
    PyObject_GC_UnTrack(en);
    Py_XDECREF(en->en_sit);
    Py_XDECREF(en->en_result);
    Py_XDECREF(en->en_longindex);
    Py_TYPE(en)->tp_free(en);
}

static int
enum_traverse(enumobject *en, visitproc visit, void *arg)
{
    Py_VISIT(en->en_sit);
    Py_VISIT(en->en_result);
    Py_VISIT(en->en_longindex);
    return 0;
}

static PyObject *
enum_next_long(enumobject *en, PyObject* next_item)
{
    PyObject *result = en->en_result;
    PyObject *next_index;
    PyObject *stepped_up;
    PyObject *old_index;
    PyObject *old_item;

    if (en->en_longindex == NULL) {
        en->en_longindex = PyLong_FromSsize_t(PY_SSIZE_T_MAX);
        if (en->en_longindex == NULL) {
            Py_DECREF(next_item);
            return NULL;
        }
    }
    next_index = en->en_longindex;
    assert(next_index != NULL);
    stepped_up = PyNumber_Add(next_index, _PyLong_One);
    if (stepped_up == NULL) {
        Py_DECREF(next_item);
        return NULL;
    }
    en->en_longindex = stepped_up;

    if (result->ob_refcnt == 1) {
        Py_INCREF(result);
        old_index = PyTuple_GET_ITEM(result, 0);
        old_item = PyTuple_GET_ITEM(result, 1);
        PyTuple_SET_ITEM(result, 0, next_index);
        PyTuple_SET_ITEM(result, 1, next_item);
        Py_DECREF(old_index);
        Py_DECREF(old_item);
        return result;
    }
    result = PyTuple_New(2);
    if (result == NULL) {
        Py_DECREF(next_index);
        Py_DECREF(next_item);
        return NULL;
    }
    PyTuple_SET_ITEM(result, 0, next_index);
    PyTuple_SET_ITEM(result, 1, next_item);
    return result;
}

static PyObject *
enum_next(enumobject *en)
{
    PyObject *next_index;
    PyObject *next_item;
    PyObject *result = en->en_result;
    PyObject *it = en->en_sit;
    PyObject *old_index;
    PyObject *old_item;

    next_item = (*Py_TYPE(it)->tp_iternext)(it);
    if (next_item == NULL)
        return NULL;

    if (en->en_index == PY_SSIZE_T_MAX)
        return enum_next_long(en, next_item);

    next_index = PyLong_FromSsize_t(en->en_index);
    if (next_index == NULL) {
        Py_DECREF(next_item);
        return NULL;
    }
    en->en_index++;

    if (result->ob_refcnt == 1) {
        Py_INCREF(result);
        old_index = PyTuple_GET_ITEM(result, 0);
        old_item = PyTuple_GET_ITEM(result, 1);
        PyTuple_SET_ITEM(result, 0, next_index);
        PyTuple_SET_ITEM(result, 1, next_item);
        Py_DECREF(old_index);
        Py_DECREF(old_item);
        return result;
    }
    result = PyTuple_New(2);
    if (result == NULL) {
        Py_DECREF(next_index);
        Py_DECREF(next_item);
        return NULL;
    }
    PyTuple_SET_ITEM(result, 0, next_index);
    PyTuple_SET_ITEM(result, 1, next_item);
    return result;
}

static PyObject *
enum_reduce(enumobject *en, PyObject *Py_UNUSED(ignored))
{
    if (en->en_longindex != NULL)
        return Py_BuildValue("O(OO)", Py_TYPE(en), en->en_sit, en->en_longindex);
    else
        return Py_BuildValue("O(On)", Py_TYPE(en), en->en_sit, en->en_index);
}

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

static PyMethodDef enum_methods[] = {
    {"__reduce__", (PyCFunction)enum_reduce, METH_NOARGS, reduce_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PyEnum_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "enumerate",                    /* tp_name */
    sizeof(enumobject),             /* tp_basicsize */
    0,                              /* tp_itemsize */
    /* methods */
    (destructor)enum_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 |
        Py_TPFLAGS_BASETYPE,        /* tp_flags */
    enum_new__doc__,                /* tp_doc */
    (traverseproc)enum_traverse,    /* tp_traverse */
    0,                              /* tp_clear */
    0,                              /* tp_richcompare */
    0,                              /* tp_weaklistoffset */
    PyObject_SelfIter,              /* tp_iter */
    (iternextfunc)enum_next,        /* tp_iternext */
    enum_methods,                   /* tp_methods */
    0,                              /* tp_members */
    0,                              /* tp_getset */
    0,                              /* tp_base */
    0,                              /* tp_dict */
    0,                              /* tp_descr_get */
    0,                              /* tp_descr_set */
    0,                              /* tp_dictoffset */
    0,                              /* tp_init */
    PyType_GenericAlloc,            /* tp_alloc */
    enum_new,                       /* tp_new */
    PyObject_GC_Del,                /* tp_free */
};

/* Reversed Object ***************************************************************/

typedef struct {
    PyObject_HEAD
    Py_ssize_t      index;
    PyObject* seq;
} reversedobject;

/*[clinic input]
@classmethod
reversed.__new__ as reversed_new

    sequence as seq: object
    /

Return a reverse iterator over the values of the given sequence.
[clinic start generated code]*/

static PyObject *
reversed_new_impl(PyTypeObject *type, PyObject *seq)
/*[clinic end generated code: output=f7854cc1df26f570 input=aeb720361e5e3f1d]*/
{
    Py_ssize_t n;
    PyObject *reversed_meth;
    reversedobject *ro;
    _Py_IDENTIFIER(__reversed__);

    reversed_meth = _PyObject_LookupSpecial(seq, &PyId___reversed__);
    if (reversed_meth == Py_None) {
        Py_DECREF(reversed_meth);
        PyErr_Format(PyExc_TypeError,
                     "'%.200s' object is not reversible",
                     Py_TYPE(seq)->tp_name);
        return NULL;
    }
    if (reversed_meth != NULL) {
        PyObject *res = _PyObject_CallNoArg(reversed_meth);
        Py_DECREF(reversed_meth);
        return res;
    }
    else if (PyErr_Occurred())
        return NULL;

    if (!PySequence_Check(seq)) {
        PyErr_Format(PyExc_TypeError,
                     "'%.200s' object is not reversible",
                     Py_TYPE(seq)->tp_name);
        return NULL;
    }

    n = PySequence_Size(seq);
    if (n == -1)
        return NULL;

    ro = (reversedobject *)type->tp_alloc(type, 0);
    if (ro == NULL)
        return NULL;

    ro->index = n-1;
    Py_INCREF(seq);
    ro->seq = seq;
    return (PyObject *)ro;
}

static void
reversed_dealloc(reversedobject *ro)
{
    PyObject_GC_UnTrack(ro);
    Py_XDECREF(ro->seq);
    Py_TYPE(ro)->tp_free(ro);
}

static int
reversed_traverse(reversedobject *ro, visitproc visit, void *arg)
{
    Py_VISIT(ro->seq);
    return 0;
}

static PyObject *
reversed_next(reversedobject *ro)
{
    PyObject *item;
    Py_ssize_t index = ro->index;

    if (index >= 0) {
        item = PySequence_GetItem(ro->seq, index);
        if (item != NULL) {
            ro->index--;
            return item;
        }
        if (PyErr_ExceptionMatches(PyExc_IndexError) ||
            PyErr_ExceptionMatches(PyExc_StopIteration))
            PyErr_Clear();
    }
    ro->index = -1;
    Py_CLEAR(ro->seq);
    return NULL;
}

static PyObject *
reversed_len(reversedobject *ro, PyObject *Py_UNUSED(ignored))
{
    Py_ssize_t position, seqsize;

    if (ro->seq == NULL)
        return PyLong_FromLong(0);
    seqsize = PySequence_Size(ro->seq);
    if (seqsize == -1)
        return NULL;
    position = ro->index + 1;
    return PyLong_FromSsize_t((seqsize < position)  ?  0  :  position);
}

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

static PyObject *
reversed_reduce(reversedobject *ro, PyObject *Py_UNUSED(ignored))
{
    if (ro->seq)
        return Py_BuildValue("O(O)n", Py_TYPE(ro), ro->seq, ro->index);
    else
        return Py_BuildValue("O(())", Py_TYPE(ro));
}

static PyObject *
reversed_setstate(reversedobject *ro, PyObject *state)
{
    Py_ssize_t index = PyLong_AsSsize_t(state);
    if (index == -1 && PyErr_Occurred())
        return NULL;
    if (ro->seq != 0) {
        Py_ssize_t n = PySequence_Size(ro->seq);
        if (n < 0)
            return NULL;
        if (index < -1)
            index = -1;
        else if (index > n-1)
            index = n-1;
        ro->index = index;
    }
    Py_RETURN_NONE;
}

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

static PyMethodDef reversediter_methods[] = {
    {"__length_hint__", (PyCFunction)reversed_len, METH_NOARGS, length_hint_doc},
    {"__reduce__", (PyCFunction)reversed_reduce, METH_NOARGS, reduce_doc},
    {"__setstate__", (PyCFunction)reversed_setstate, METH_O, setstate_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PyReversed_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "reversed",                     /* tp_name */
    sizeof(reversedobject),         /* tp_basicsize */
    0,                              /* tp_itemsize */
    /* methods */
    (destructor)reversed_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 |
        Py_TPFLAGS_BASETYPE,        /* tp_flags */
    reversed_new__doc__,            /* tp_doc */
    (traverseproc)reversed_traverse,/* tp_traverse */
    0,                              /* tp_clear */
    0,                              /* tp_richcompare */
    0,                              /* tp_weaklistoffset */
    PyObject_SelfIter,              /* tp_iter */
    (iternextfunc)reversed_next,    /* tp_iternext */
    reversediter_methods,           /* tp_methods */
    0,                              /* tp_members */
    0,                              /* tp_getset */
    0,                              /* tp_base */
    0,                              /* tp_dict */
    0,                              /* tp_descr_get */
    0,                              /* tp_descr_set */
    0,                              /* tp_dictoffset */
    0,                              /* tp_init */
    PyType_GenericAlloc,            /* tp_alloc */
    reversed_new,                   /* tp_new */
    PyObject_GC_Del,                /* tp_free */
};

Coverage Report

Created: 2025-10-27 06:40

Line	Count	Source
1		/* enumerate object */
2
3		#include "Python.h"
4
5		#include "clinic/enumobject.c.h"
6
7		/*[clinic input]
8		class enumerate "enumobject *" "&PyEnum_Type"
9		class reversed "reversedobject *" "&PyReversed_Type"
10		[clinic start generated code]*/
11		/[clinic end generated code: output=da39a3ee5e6b4b0d input=d2dfdf1a88c88975]/
12
13		typedef struct {
14		PyObject_HEAD
15		Py_ssize_t en_index; /* current index of enumeration */
16		PyObject* en_sit; /* secondary iterator of enumeration */
17		PyObject* en_result; /* result tuple */
18		PyObject* en_longindex; /* index for sequences >= PY_SSIZE_T_MAX */
19		} enumobject;
20
21
22		/*[clinic input]
23		@classmethod
24		enumerate.__new__ as enum_new
25
26		iterable: object
27		an object supporting iteration
28		start: object = 0
29
30		Return an enumerate object.
31
32		The enumerate object yields pairs containing a count (from start, which
33		defaults to zero) and a value yielded by the iterable argument.
34
35		enumerate is useful for obtaining an indexed list:
36		(0, seq[0]), (1, seq[1]), (2, seq[2]), ...
37		[clinic start generated code]*/
38
39		static PyObject *
40		enum_new_impl(PyTypeObject type, PyObject iterable, PyObject *start)
41		/[clinic end generated code: output=e95e6e439f812c10 input=782e4911efcb8acf]/
42	5	{
43	5	enumobject *en;
44
45	5	en = (enumobject *)type->tp_alloc(type, 0);
46	5	if (en == NULL)
47	0	return NULL;
48	5	if (start != NULL) {
49	0	start = PyNumber_Index(start);
50	0	if (start == NULL) {
51	0	Py_DECREF(en);
52	0	return NULL;
53	0	}
54	0	assert(PyLong_Check(start));
55	0	en->en_index = PyLong_AsSsize_t(start);
56	0	if (en->en_index == -1 && PyErr_Occurred()) {
57	0	PyErr_Clear();
58	0	en->en_index = PY_SSIZE_T_MAX;
59	0	en->en_longindex = start;
60	0	} else {
61	0	en->en_longindex = NULL;
62	0	Py_DECREF(start);
63	0	}
64	5	} else {
65	5	en->en_index = 0;
66	5	en->en_longindex = NULL;
67	5	}
68	5	en->en_sit = PyObject_GetIter(iterable);
69	5	if (en->en_sit == NULL) {
70	0	Py_DECREF(en);
71	0	return NULL;
72	0	}
73	5	en->en_result = PyTuple_Pack(2, Py_None, Py_None);
74	5	if (en->en_result == NULL) {
75	0	Py_DECREF(en);
76	0	return NULL;
77	0	}
78	5	return (PyObject *)en;
79	5	}
80
81		static void
82		enum_dealloc(enumobject *en)
83	5	{
84	5	PyObject_GC_UnTrack(en);
85	5	Py_XDECREF(en->en_sit);
86	5	Py_XDECREF(en->en_result);
87	5	Py_XDECREF(en->en_longindex);
88	5	Py_TYPE(en)->tp_free(en);
89	5	}
90
91		static int
92		enum_traverse(enumobject en, visitproc visit, void arg)
93	0	{
94	0	Py_VISIT(en->en_sit);
95	0	Py_VISIT(en->en_result);
96	0	Py_VISIT(en->en_longindex);
97	0	return 0;
98	0	}
99
100		static PyObject *
101		enum_next_long(enumobject en, PyObject next_item)
102	0	{
103	0	PyObject *result = en->en_result;
104	0	PyObject *next_index;
105	0	PyObject *stepped_up;
106	0	PyObject *old_index;
107	0	PyObject *old_item;
108
109	0	if (en->en_longindex == NULL) {
110	0	en->en_longindex = PyLong_FromSsize_t(PY_SSIZE_T_MAX);
111	0	if (en->en_longindex == NULL) {
112	0	Py_DECREF(next_item);
113	0	return NULL;
114	0	}
115	0	}
116	0	next_index = en->en_longindex;
117	0	assert(next_index != NULL);
118	0	stepped_up = PyNumber_Add(next_index, _PyLong_One);
119	0	if (stepped_up == NULL) {
120	0	Py_DECREF(next_item);
121	0	return NULL;
122	0	}
123	0	en->en_longindex = stepped_up;
124
125	0	if (result->ob_refcnt == 1) {
126	0	Py_INCREF(result);
127	0	old_index = PyTuple_GET_ITEM(result, 0);
128	0	old_item = PyTuple_GET_ITEM(result, 1);
129	0	PyTuple_SET_ITEM(result, 0, next_index);
130	0	PyTuple_SET_ITEM(result, 1, next_item);
131	0	Py_DECREF(old_index);
132	0	Py_DECREF(old_item);
133	0	return result;
134	0	}
135	0	result = PyTuple_New(2);
136	0	if (result == NULL) {
137	0	Py_DECREF(next_index);
138	0	Py_DECREF(next_item);
139	0	return NULL;
140	0	}
141	0	PyTuple_SET_ITEM(result, 0, next_index);
142	0	PyTuple_SET_ITEM(result, 1, next_item);
143	0	return result;
144	0	}
145
146		static PyObject *
147		enum_next(enumobject *en)
148	87	{
149	87	PyObject *next_index;
150	87	PyObject *next_item;
151	87	PyObject *result = en->en_result;
152	87	PyObject *it = en->en_sit;
153	87	PyObject *old_index;
154	87	PyObject *old_item;
155
156	87	next_item = (*Py_TYPE(it)->tp_iternext)(it);
157	87	if (next_item == NULL)
158	5	return NULL;
159
160	82	if (en->en_index == PY_SSIZE_T_MAX)
161	0	return enum_next_long(en, next_item);
162
163	82	next_index = PyLong_FromSsize_t(en->en_index);
164	82	if (next_index == NULL) {
165	0	Py_DECREF(next_item);
166	0	return NULL;
167	0	}
168	82	en->en_index++;
169
170	82	if (result->ob_refcnt == 1) {
171	82	Py_INCREF(result);
172	82	old_index = PyTuple_GET_ITEM(result, 0);
173	82	old_item = PyTuple_GET_ITEM(result, 1);
174	82	PyTuple_SET_ITEM(result, 0, next_index);
175	82	PyTuple_SET_ITEM(result, 1, next_item);
176	82	Py_DECREF(old_index);
177	82	Py_DECREF(old_item);
178	82	return result;
179	82	}
180	0	result = PyTuple_New(2);
181	0	if (result == NULL) {
182	0	Py_DECREF(next_index);
183	0	Py_DECREF(next_item);
184	0	return NULL;
185	0	}
186	0	PyTuple_SET_ITEM(result, 0, next_index);
187	0	PyTuple_SET_ITEM(result, 1, next_item);
188	0	return result;
189	0	}
190
191		static PyObject *
192		enum_reduce(enumobject en, PyObject Py_UNUSED(ignored))
193	0	{
194	0	if (en->en_longindex != NULL)
195	0	return Py_BuildValue("O(OO)", Py_TYPE(en), en->en_sit, en->en_longindex);
196	0	else
197	0	return Py_BuildValue("O(On)", Py_TYPE(en), en->en_sit, en->en_index);
198	0	}
199
200		PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
201
202		static PyMethodDef enum_methods[] = {
203		{"__reduce__", (PyCFunction)enum_reduce, METH_NOARGS, reduce_doc},
204		{NULL, NULL} /* sentinel */
205		};
206
207		PyTypeObject PyEnum_Type = {
208		PyVarObject_HEAD_INIT(&PyType_Type, 0)
209		"enumerate", /* tp_name */
210		sizeof(enumobject), /* tp_basicsize */
211		0, /* tp_itemsize */
212		/* methods */
213		(destructor)enum_dealloc, /* tp_dealloc */
214		0, /* tp_vectorcall_offset */
215		0, /* tp_getattr */
216		0, /* tp_setattr */
217		0, /* tp_as_async */
218		0, /* tp_repr */
219		0, /* tp_as_number */
220		0, /* tp_as_sequence */
221		0, /* tp_as_mapping */
222		0, /* tp_hash */
223		0, /* tp_call */
224		0, /* tp_str */
225		PyObject_GenericGetAttr, /* tp_getattro */
226		0, /* tp_setattro */
227		0, /* tp_as_buffer */
228		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC \|
229		Py_TPFLAGS_BASETYPE, /* tp_flags */
230		enum_new__doc__, /* tp_doc */
231		(traverseproc)enum_traverse, /* tp_traverse */
232		0, /* tp_clear */
233		0, /* tp_richcompare */
234		0, /* tp_weaklistoffset */
235		PyObject_SelfIter, /* tp_iter */
236		(iternextfunc)enum_next, /* tp_iternext */
237		enum_methods, /* tp_methods */
238		0, /* tp_members */
239		0, /* tp_getset */
240		0, /* tp_base */
241		0, /* tp_dict */
242		0, /* tp_descr_get */
243		0, /* tp_descr_set */
244		0, /* tp_dictoffset */
245		0, /* tp_init */
246		PyType_GenericAlloc, /* tp_alloc */
247		enum_new, /* tp_new */
248		PyObject_GC_Del, /* tp_free */
249		};
250
251		/* Reversed Object ***************************************************************/
252
253		typedef struct {
254		PyObject_HEAD
255		Py_ssize_t index;
256		PyObject* seq;
257		} reversedobject;
258
259		/*[clinic input]
260		@classmethod
261		reversed.__new__ as reversed_new
262
263		sequence as seq: object
264		/
265
266		Return a reverse iterator over the values of the given sequence.
267		[clinic start generated code]*/
268
269		static PyObject *
270		reversed_new_impl(PyTypeObject type, PyObject seq)
271		/[clinic end generated code: output=f7854cc1df26f570 input=aeb720361e5e3f1d]/
272	16	{
273	16	Py_ssize_t n;
274	16	PyObject *reversed_meth;
275	16	reversedobject *ro;
276	16	_Py_IDENTIFIER(__reversed__);
277
278	16	reversed_meth = _PyObject_LookupSpecial(seq, &PyId___reversed__);
279	16	if (reversed_meth == Py_None) {
280	0	Py_DECREF(reversed_meth);
281	0	PyErr_Format(PyExc_TypeError,
282	0	"'%.200s' object is not reversible",
283	0	Py_TYPE(seq)->tp_name);
284	0	return NULL;
285	0	}
286	16	if (reversed_meth != NULL) {
287	16	PyObject *res = _PyObject_CallNoArg(reversed_meth);
288	16	Py_DECREF(reversed_meth);
289	16	return res;
290	16	}
291	0	else if (PyErr_Occurred())
292	0	return NULL;
293
294	0	if (!PySequence_Check(seq)) {
295	0	PyErr_Format(PyExc_TypeError,
296	0	"'%.200s' object is not reversible",
297	0	Py_TYPE(seq)->tp_name);
298	0	return NULL;
299	0	}
300
301	0	n = PySequence_Size(seq);
302	0	if (n == -1)
303	0	return NULL;
304
305	0	ro = (reversedobject *)type->tp_alloc(type, 0);
306	0	if (ro == NULL)
307	0	return NULL;
308
309	0	ro->index = n-1;
310	0	Py_INCREF(seq);
311	0	ro->seq = seq;
312	0	return (PyObject *)ro;
313	0	}
314
315		static void
316		reversed_dealloc(reversedobject *ro)
317	0	{
318	0	PyObject_GC_UnTrack(ro);
319	0	Py_XDECREF(ro->seq);
320	0	Py_TYPE(ro)->tp_free(ro);
321	0	}
322
323		static int
324		reversed_traverse(reversedobject ro, visitproc visit, void arg)
325	0	{
326	0	Py_VISIT(ro->seq);
327	0	return 0;
328	0	}
329
330		static PyObject *
331		reversed_next(reversedobject *ro)
332	0	{
333	0	PyObject *item;
334	0	Py_ssize_t index = ro->index;
335
336	0	if (index >= 0) {
337	0	item = PySequence_GetItem(ro->seq, index);
338	0	if (item != NULL) {
339	0	ro->index--;
340	0	return item;
341	0	}
342	0	if (PyErr_ExceptionMatches(PyExc_IndexError) \|\|
343	0	PyErr_ExceptionMatches(PyExc_StopIteration))
344	0	PyErr_Clear();
345	0	}
346	0	ro->index = -1;
347	0	Py_CLEAR(ro->seq);
348	0	return NULL;
349	0	}
350
351		static PyObject *
352		reversed_len(reversedobject ro, PyObject Py_UNUSED(ignored))
353	0	{
354	0	Py_ssize_t position, seqsize;
355
356	0	if (ro->seq == NULL)
357	0	return PyLong_FromLong(0);
358	0	seqsize = PySequence_Size(ro->seq);
359	0	if (seqsize == -1)
360	0	return NULL;
361	0	position = ro->index + 1;
362	0	return PyLong_FromSsize_t((seqsize < position) ? 0 : position);
363	0	}
364
365		PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
366
367		static PyObject *
368		reversed_reduce(reversedobject ro, PyObject Py_UNUSED(ignored))
369	0	{
370	0	if (ro->seq)
371	0	return Py_BuildValue("O(O)n", Py_TYPE(ro), ro->seq, ro->index);
372	0	else
373	0	return Py_BuildValue("O(())", Py_TYPE(ro));
374	0	}
375
376		static PyObject *
377		reversed_setstate(reversedobject ro, PyObject state)
378	0	{
379	0	Py_ssize_t index = PyLong_AsSsize_t(state);
380	0	if (index == -1 && PyErr_Occurred())
381	0	return NULL;
382	0	if (ro->seq != 0) {
383	0	Py_ssize_t n = PySequence_Size(ro->seq);
384	0	if (n < 0)
385	0	return NULL;
386	0	if (index < -1)
387	0	index = -1;
388	0	else if (index > n-1)
389	0	index = n-1;
390	0	ro->index = index;
391	0	}
392	0	Py_RETURN_NONE;
393	0	}
394
395		PyDoc_STRVAR(setstate_doc, "Set state information for unpickling.");
396
397		static PyMethodDef reversediter_methods[] = {
398		{"__length_hint__", (PyCFunction)reversed_len, METH_NOARGS, length_hint_doc},
399		{"__reduce__", (PyCFunction)reversed_reduce, METH_NOARGS, reduce_doc},
400		{"__setstate__", (PyCFunction)reversed_setstate, METH_O, setstate_doc},
401		{NULL, NULL} /* sentinel */
402		};
403
404		PyTypeObject PyReversed_Type = {
405		PyVarObject_HEAD_INIT(&PyType_Type, 0)
406		"reversed", /* tp_name */
407		sizeof(reversedobject), /* tp_basicsize */
408		0, /* tp_itemsize */
409		/* methods */
410		(destructor)reversed_dealloc, /* tp_dealloc */
411		0, /* tp_vectorcall_offset */
412		0, /* tp_getattr */
413		0, /* tp_setattr */
414		0, /* tp_as_async */
415		0, /* tp_repr */
416		0, /* tp_as_number */
417		0, /* tp_as_sequence */
418		0, /* tp_as_mapping */
419		0, /* tp_hash */
420		0, /* tp_call */
421		0, /* tp_str */
422		PyObject_GenericGetAttr, /* tp_getattro */
423		0, /* tp_setattro */
424		0, /* tp_as_buffer */
425		Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC \|
426		Py_TPFLAGS_BASETYPE, /* tp_flags */
427		reversed_new__doc__, /* tp_doc */
428		(traverseproc)reversed_traverse,/* tp_traverse */
429		0, /* tp_clear */
430		0, /* tp_richcompare */
431		0, /* tp_weaklistoffset */
432		PyObject_SelfIter, /* tp_iter */
433		(iternextfunc)reversed_next, /* tp_iternext */
434		reversediter_methods, /* tp_methods */
435		0, /* tp_members */
436		0, /* tp_getset */
437		0, /* tp_base */
438		0, /* tp_dict */
439		0, /* tp_descr_get */
440		0, /* tp_descr_set */
441		0, /* tp_dictoffset */
442		0, /* tp_init */
443		PyType_GenericAlloc, /* tp_alloc */
444		reversed_new, /* tp_new */
445		PyObject_GC_Del, /* tp_free */
446		};