#define PY_SSIZE_T_CLEAN

#include "Python.h"

#include "pycore_call.h" // _PyObject_CallNoArgs()

#include "pycore_long.h" // _PyLong_GetZero()

#include "pycore_object.h" // _PyObject_GC_TRACK()

#include "pycore_tuple.h" // _PyTuple_ITEMS()

#include <stddef.h> // offsetof()

/* Itertools module written and maintained

by Raymond D. Hettinger <[email protected]>

*/

/*[clinic input]

module itertools

class itertools.groupby "groupbyobject *" "&groupby_type"

class itertools._grouper "_grouperobject *" "&_grouper_type"

class itertools.teedataobject "teedataobject *" "&teedataobject_type"

class itertools._tee "teeobject *" "&tee_type"

class itertools.cycle "cycleobject *" "&cycle_type"

class itertools.dropwhile "dropwhileobject *" "&dropwhile_type"

class itertools.takewhile "takewhileobject *" "&takewhile_type"

class itertools.starmap "starmapobject *" "&starmap_type"

class itertools.chain "chainobject *" "&chain_type"

class itertools.combinations "combinationsobject *" "&combinations_type"

class itertools.combinations_with_replacement "cwr_object *" "&cwr_type"

class itertools.permutations "permutationsobject *" "&permutations_type"

class itertools.accumulate "accumulateobject *" "&accumulate_type"

class itertools.compress "compressobject *" "&compress_type"

class itertools.filterfalse "filterfalseobject *" "&filterfalse_type"

class itertools.count "countobject *" "&count_type"

class itertools.pairwise "pairwiseobject *" "&pairwise_type"

[clinic start generated code]*/

/*[clinic end generated code: output=da39a3ee5e6b4b0d input=6498ed21fbe1bf94]*/

static PyTypeObject groupby_type;

static PyTypeObject _grouper_type;

static PyTypeObject teedataobject_type;

static PyTypeObject tee_type;

static PyTypeObject cycle_type;

static PyTypeObject dropwhile_type;

static PyTypeObject takewhile_type;

static PyTypeObject starmap_type;

static PyTypeObject combinations_type;

static PyTypeObject cwr_type;

static PyTypeObject permutations_type;

static PyTypeObject accumulate_type;

static PyTypeObject compress_type;

static PyTypeObject filterfalse_type;

static PyTypeObject count_type;

static PyTypeObject pairwise_type;

#include "clinic/itertoolsmodule.c.h"

/* pairwise object ***********************************************************/

typedef struct {

PyObject_HEAD

PyObject *it;

PyObject *old;

} pairwiseobject;

/*[clinic input]

@classmethod

itertools.pairwise.__new__ as pairwise_new

iterable: object

/

Return an iterator of overlapping pairs taken from the input iterator.

s -> (s0,s1), (s1,s2), (s2, s3), ...

[clinic start generated code]*/

static PyObject *

pairwise_new_impl(PyTypeObject *type, PyObject *iterable)

/*[clinic end generated code: output=9f0267062d384456 input=6e7c3cddb431a8d6]*/

{

PyObject *it;

pairwiseobject *po;

it = PyObject_GetIter(iterable);

if (it == NULL) {

return NULL;

}

po = (pairwiseobject *)type->tp_alloc(type, 0);

if (po == NULL) {

Py_DECREF(it);

return NULL;

}

po->it = it;

po->old = NULL;

return (PyObject *)po;

}

static void

pairwise_dealloc(pairwiseobject *po)

{

PyObject_GC_UnTrack(po);

Py_XDECREF(po->it);

Py_XDECREF(po->old);

Py_TYPE(po)->tp_free(po);

}

static int

pairwise_traverse(pairwiseobject *po, visitproc visit, void *arg)

{

Py_VISIT(po->it);

Py_VISIT(po->old);

return 0;

}

static PyObject *

pairwise_next(pairwiseobject *po)

{

PyObject *it = po->it;

PyObject *old = po->old;

PyObject *new, *result;

if (it == NULL) {

return NULL;

}

if (old == NULL) {

po->old = old = (*Py_TYPE(it)->tp_iternext)(it);

if (old == NULL) {

Py_CLEAR(po->it);

return NULL;

}

}

new = (*Py_TYPE(it)->tp_iternext)(it);

if (new == NULL) {

Py_CLEAR(po->it);

Py_CLEAR(po->old);

return NULL;

}

/* Future optimization: Reuse the result tuple as we do in enumerate() */

result = PyTuple_Pack(2, old, new);

Py_SETREF(po->old, new);

return result;

}

static PyTypeObject pairwise_type = {

PyVarObject_HEAD_INIT(&PyType_Type, 0)

"itertools.pairwise", /* tp_name */

sizeof(pairwiseobject), /* tp_basicsize */

0, /* tp_itemsize */

/* methods */

(destructor)pairwise_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 */

pairwise_new__doc__, /* tp_doc */

(traverseproc)pairwise_traverse, /* tp_traverse */

0, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

PyObject_SelfIter, /* tp_iter */

(iternextfunc)pairwise_next, /* tp_iternext */

0, /* 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 */

pairwise_new, /* tp_new */

PyObject_GC_Del, /* tp_free */

};

/* groupby object ************************************************************/

typedef struct {

PyObject_HEAD

PyObject *it;

PyObject *keyfunc;

PyObject *tgtkey;

PyObject *currkey;

PyObject *currvalue;

const void *currgrouper; /* borrowed reference */

} groupbyobject;

static PyObject *_grouper_create(groupbyobject *, PyObject *);

/*[clinic input]

@classmethod

itertools.groupby.__new__

iterable as it: object

Elements to divide into groups according to the key function.

key as keyfunc: object = None

A function for computing the group category for each element.

If the key function is not specified or is None, the element itself

is used for grouping.

make an iterator that returns consecutive keys and groups from the iterable

[clinic start generated code]*/

static PyObject *

itertools_groupby_impl(PyTypeObject *type, PyObject *it, PyObject *keyfunc)

/*[clinic end generated code: output=cbb1ae3a90fd4141 input=6b3d123e87ff65a1]*/

{

groupbyobject *gbo;

gbo = (groupbyobject *)type->tp_alloc(type, 0);

if (gbo == NULL)

return NULL;

gbo->tgtkey = NULL;

gbo->currkey = NULL;

gbo->currvalue = NULL;

gbo->keyfunc = keyfunc;

Py_INCREF(keyfunc);

gbo->it = PyObject_GetIter(it);

if (gbo->it == NULL) {

Py_DECREF(gbo);

return NULL;

}

return (PyObject *)gbo;

}

static void

groupby_dealloc(groupbyobject *gbo)

{

PyObject_GC_UnTrack(gbo);

Py_XDECREF(gbo->it);

Py_XDECREF(gbo->keyfunc);

Py_XDECREF(gbo->tgtkey);

Py_XDECREF(gbo->currkey);

Py_XDECREF(gbo->currvalue);

Py_TYPE(gbo)->tp_free(gbo);

}

static int

groupby_traverse(groupbyobject *gbo, visitproc visit, void *arg)

{

Py_VISIT(gbo->it);

Py_VISIT(gbo->keyfunc);

Py_VISIT(gbo->tgtkey);

Py_VISIT(gbo->currkey);

Py_VISIT(gbo->currvalue);

return 0;

}

Py_LOCAL_INLINE(int)

groupby_step(groupbyobject *gbo)

{

PyObject *newvalue, *newkey, *oldvalue;

newvalue = PyIter_Next(gbo->it);

if (newvalue == NULL)

return -1;

if (gbo->keyfunc == Py_None) {

newkey = newvalue;

Py_INCREF(newvalue);

} else {

newkey = PyObject_CallOneArg(gbo->keyfunc, newvalue);

if (newkey == NULL) {

Py_DECREF(newvalue);

return -1;

}

}

oldvalue = gbo->currvalue;

gbo->currvalue = newvalue;

Py_XSETREF(gbo->currkey, newkey);

Py_XDECREF(oldvalue);

return 0;

}

static PyObject *

groupby_next(groupbyobject *gbo)

{

PyObject *r, *grouper;

gbo->currgrouper = NULL;

/* skip to next iteration group */

for (;;) {

if (gbo->currkey == NULL)

/* pass */;

else if (gbo->tgtkey == NULL)

break;

else {

int rcmp;

rcmp = PyObject_RichCompareBool(gbo->tgtkey, gbo->currkey, Py_EQ);

if (rcmp == -1)

return NULL;

else if (rcmp == 0)

break;

}

if (groupby_step(gbo) < 0)

return NULL;

}

Py_INCREF(gbo->currkey);

Py_XSETREF(gbo->tgtkey, gbo->currkey);

grouper = _grouper_create(gbo, gbo->tgtkey);

if (grouper == NULL)

return NULL;

r = PyTuple_Pack(2, gbo->currkey, grouper);

Py_DECREF(grouper);

return r;

}

static PyObject *

groupby_reduce(groupbyobject *lz, PyObject *Py_UNUSED(ignored))

{

/* reduce as a 'new' call with an optional 'setstate' if groupby

* has started

*/

PyObject *value;

if (lz->tgtkey && lz->currkey && lz->currvalue)

value = Py_BuildValue("O(OO)(OOO)", Py_TYPE(lz),

lz->it, lz->keyfunc, lz->currkey, lz->currvalue, lz->tgtkey);

else

value = Py_BuildValue("O(OO)", Py_TYPE(lz),

lz->it, lz->keyfunc);

return value;

}

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

static PyObject *

groupby_setstate(groupbyobject *lz, PyObject *state)

{

PyObject *currkey, *currvalue, *tgtkey;

if (!PyTuple_Check(state)) {

PyErr_SetString(PyExc_TypeError, "state is not a tuple");

return NULL;

}

if (!PyArg_ParseTuple(state, "OOO", &currkey, &currvalue, &tgtkey)) {

return NULL;

}

Py_INCREF(currkey);

Py_XSETREF(lz->currkey, currkey);

Py_INCREF(currvalue);

Py_XSETREF(lz->currvalue, currvalue);

Py_INCREF(tgtkey);

Py_XSETREF(lz->tgtkey, tgtkey);

Py_RETURN_NONE;

}

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

static PyMethodDef groupby_methods[] = {

{"__reduce__", (PyCFunction)groupby_reduce, METH_NOARGS,

reduce_doc},

{"__setstate__", (PyCFunction)groupby_setstate, METH_O,

setstate_doc},

{NULL, NULL} /* sentinel */

};

static PyTypeObject groupby_type = {

PyVarObject_HEAD_INIT(NULL, 0)

"itertools.groupby", /* tp_name */

sizeof(groupbyobject), /* tp_basicsize */

0, /* tp_itemsize */

/* methods */

(destructor)groupby_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 */

itertools_groupby__doc__, /* tp_doc */

(traverseproc)groupby_traverse, /* tp_traverse */

0, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

PyObject_SelfIter, /* tp_iter */

(iternextfunc)groupby_next, /* tp_iternext */

groupby_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 */

0, /* tp_alloc */

itertools_groupby, /* tp_new */

PyObject_GC_Del, /* tp_free */

};

/* _grouper object (internal) ************************************************/

typedef struct {

PyObject_HEAD

PyObject *parent;

PyObject *tgtkey;

} _grouperobject;

/*[clinic input]

@classmethod

itertools._grouper.__new__

parent: object(subclass_of='&groupby_type')

tgtkey: object

/

[clinic start generated code]*/

static PyObject *

itertools__grouper_impl(PyTypeObject *type, PyObject *parent,

PyObject *tgtkey)

/*[clinic end generated code: output=462efb1cdebb5914 input=dc180d7771fc8c59]*/

{

return _grouper_create((groupbyobject*) parent, tgtkey);

}

static PyObject *

_grouper_create(groupbyobject *parent, PyObject *tgtkey)

{

_grouperobject *igo;

igo = PyObject_GC_New(_grouperobject, &_grouper_type);

if (igo == NULL)

return NULL;

igo->parent = (PyObject *)parent;

Py_INCREF(parent);

igo->tgtkey = tgtkey;

Py_INCREF(tgtkey);

parent->currgrouper = igo; /* borrowed reference */

PyObject_GC_Track(igo);

return (PyObject *)igo;

}

static void

_grouper_dealloc(_grouperobject *igo)

{

PyObject_GC_UnTrack(igo);

Py_DECREF(igo->parent);

Py_DECREF(igo->tgtkey);

PyObject_GC_Del(igo);

}

static int

_grouper_traverse(_grouperobject *igo, visitproc visit, void *arg)

{

Py_VISIT(igo->parent);

Py_VISIT(igo->tgtkey);

return 0;

}

static PyObject *

_grouper_next(_grouperobject *igo)

{

groupbyobject *gbo = (groupbyobject *)igo->parent;

PyObject *r;

int rcmp;

if (gbo->currgrouper != igo)

return NULL;

if (gbo->currvalue == NULL) {

if (groupby_step(gbo) < 0)

return NULL;

}

assert(gbo->currkey != NULL);

rcmp = PyObject_RichCompareBool(igo->tgtkey, gbo->currkey, Py_EQ);

if (rcmp <= 0)

/* got any error or current group is end */

return NULL;

r = gbo->currvalue;

gbo->currvalue = NULL;

Py_CLEAR(gbo->currkey);

return r;

}

static PyObject *

_grouper_reduce(_grouperobject *lz, PyObject *Py_UNUSED(ignored))

{

if (((groupbyobject *)lz->parent)->currgrouper != lz) {

return Py_BuildValue("N(())", _PyEval_GetBuiltin(&_Py_ID(iter)));

}

return Py_BuildValue("O(OO)", Py_TYPE(lz), lz->parent, lz->tgtkey);

}

static PyMethodDef _grouper_methods[] = {

{"__reduce__", (PyCFunction)_grouper_reduce, METH_NOARGS,

reduce_doc},

{NULL, NULL} /* sentinel */

};

static PyTypeObject _grouper_type = {

PyVarObject_HEAD_INIT(NULL, 0)

"itertools._grouper", /* tp_name */

sizeof(_grouperobject), /* tp_basicsize */

0, /* tp_itemsize */

/* methods */

(destructor)_grouper_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 */

(traverseproc)_grouper_traverse, /* tp_traverse */

0, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

PyObject_SelfIter, /* tp_iter */

(iternextfunc)_grouper_next, /* tp_iternext */

_grouper_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 */

0, /* tp_alloc */

itertools__grouper, /* tp_new */

PyObject_GC_Del, /* tp_free */

};

/* tee object and with supporting function and objects ***********************/

/* The teedataobject pre-allocates space for LINKCELLS number of objects.

To help the object fit neatly inside cache lines (space for 16 to 32

pointers), the value should be a multiple of 16 minus space for

the other structure members including PyHEAD overhead. The larger the

value, the less memory overhead per object and the less time spent

allocating/deallocating new links. The smaller the number, the less

wasted space and the more rapid freeing of older data.

*/

#define LINKCELLS 57

typedef struct {

PyObject_HEAD

PyObject *it;

int numread; /* 0 <= numread <= LINKCELLS */

int running;

PyObject *nextlink;

PyObject *(values[LINKCELLS]);

} teedataobject;

typedef struct {

PyObject_HEAD

teedataobject *dataobj;

int index; /* 0 <= index <= LINKCELLS */

PyObject *weakreflist;

} teeobject;

static PyObject *

teedataobject_newinternal(PyObject *it)

{

teedataobject *tdo;

tdo = PyObject_GC_New(teedataobject, &teedataobject_type);

if (tdo == NULL)

return NULL;

tdo->running = 0;

tdo->numread = 0;

tdo->nextlink = NULL;

Py_INCREF(it);

tdo->it = it;

PyObject_GC_Track(tdo);

return (PyObject *)tdo;

}

static PyObject *

teedataobject_jumplink(teedataobject *tdo)

{

if (tdo->nextlink == NULL)

tdo->nextlink = teedataobject_newinternal(tdo->it);

Py_XINCREF(tdo->nextlink);

return tdo->nextlink;

}

static PyObject *

teedataobject_getitem(teedataobject *tdo, int i)

{

PyObject *value;

assert(i < LINKCELLS);

if (i < tdo->numread)

value = tdo->values[i];

else {

/* this is the lead iterator, so fetch more data */

assert(i == tdo->numread);

if (tdo->running) {

PyErr_SetString(PyExc_RuntimeError,

"cannot re-enter the tee iterator");

return NULL;

}

tdo->running = 1;

value = PyIter_Next(tdo->it);

tdo->running = 0;

if (value == NULL)

return NULL;

tdo->numread++;

tdo->values[i] = value;

}

Py_INCREF(value);

return value;

}

static int

teedataobject_traverse(teedataobject *tdo, visitproc visit, void * arg)

{

int i;

Py_VISIT(tdo->it);

for (i = 0; i < tdo->numread; i++)

Py_VISIT(tdo->values[i]);

Py_VISIT(tdo->nextlink);

return 0;

}

static void

teedataobject_safe_decref(PyObject *obj)

{

while (obj && Py_IS_TYPE(obj, &teedataobject_type) &&

Py_REFCNT(obj) == 1) {

PyObject *nextlink = ((teedataobject *)obj)->nextlink;

((teedataobject *)obj)->nextlink = NULL;

Py_DECREF(obj);

obj = nextlink;

}

Py_XDECREF(obj);

}

static int

teedataobject_clear(teedataobject *tdo)

{

int i;

PyObject *tmp;

Py_CLEAR(tdo->it);

for (i=0 ; i<tdo->numread ; i++)

Py_CLEAR(tdo->values[i]);

tmp = tdo->nextlink;

tdo->nextlink = NULL;

teedataobject_safe_decref(tmp);

return 0;

}

static void

teedataobject_dealloc(teedataobject *tdo)

{

PyObject_GC_UnTrack(tdo);

teedataobject_clear(tdo);

PyObject_GC_Del(tdo);

}

static PyObject *

teedataobject_reduce(teedataobject *tdo, PyObject *Py_UNUSED(ignored))

{

int i;

/* create a temporary list of already iterated values */

PyObject *values = PyList_New(tdo->numread);

if (!values)

return NULL;

for (i=0 ; i<tdo->numread ; i++) {

Py_INCREF(tdo->values[i]);

PyList_SET_ITEM(values, i, tdo->values[i]);

}

return Py_BuildValue("O(ONO)", Py_TYPE(tdo), tdo->it,

values,

tdo->nextlink ? tdo->nextlink : Py_None);

}

/*[clinic input]

@classmethod

itertools.teedataobject.__new__

iterable as it: object

values: object(subclass_of='&PyList_Type')

next: object

/

Data container common to multiple tee objects.

[clinic start generated code]*/

static PyObject *

itertools_teedataobject_impl(PyTypeObject *type, PyObject *it,

PyObject *values, PyObject *next)

/*[clinic end generated code: output=3343ceb07e08df5e input=be60f2fabd2b72ba]*/

{

teedataobject *tdo;

Py_ssize_t i, len;

assert(type == &teedataobject_type);

tdo = (teedataobject *)teedataobject_newinternal(it);

if (!tdo)

return NULL;

len = PyList_GET_SIZE(values);

if (len > LINKCELLS)

goto err;

for (i=0; i<len; i++) {

tdo->values[i] = PyList_GET_ITEM(values, i);

Py_INCREF(tdo->values[i]);

}

/* len <= LINKCELLS < INT_MAX */

tdo->numread = Py_SAFE_DOWNCAST(len, Py_ssize_t, int);

if (len == LINKCELLS) {

if (next != Py_None) {

if (!Py_IS_TYPE(next, &teedataobject_type))

goto err;

assert(tdo->nextlink == NULL);

Py_INCREF(next);

tdo->nextlink = next;

}

} else {

if (next != Py_None)

goto err; /* shouldn't have a next if we are not full */

}

return (PyObject*)tdo;

err:

Py_XDECREF(tdo);

PyErr_SetString(PyExc_ValueError, "Invalid arguments");

return NULL;

}

static PyMethodDef teedataobject_methods[] = {

{"__reduce__", (PyCFunction)teedataobject_reduce, METH_NOARGS,

reduce_doc},

{NULL, NULL} /* sentinel */

};

static PyTypeObject teedataobject_type = {

PyVarObject_HEAD_INIT(0, 0) /* Must fill in type value later */

"itertools._tee_dataobject", /* tp_name */

sizeof(teedataobject), /* tp_basicsize */

0, /* tp_itemsize */

/* methods */

(destructor)teedataobject_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 */

itertools_teedataobject__doc__, /* tp_doc */

(traverseproc)teedataobject_traverse, /* tp_traverse */

(inquiry)teedataobject_clear, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

0, /* tp_iter */

0, /* tp_iternext */

teedataobject_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 */

0, /* tp_alloc */

itertools_teedataobject, /* tp_new */

PyObject_GC_Del, /* tp_free */

};

static PyObject *

tee_next(teeobject *to)

{

PyObject *value, *link;

if (to->index >= LINKCELLS) {

link = teedataobject_jumplink(to->dataobj);

if (link == NULL)

return NULL;

Py_SETREF(to->dataobj, (teedataobject *)link);

to->index = 0;

}

value = teedataobject_getitem(to->dataobj, to->index);

if (value == NULL)

return NULL;

to->index++;

return value;

}

static int

tee_traverse(teeobject *to, visitproc visit, void *arg)

{

Py_VISIT((PyObject *)to->dataobj);

return 0;

}

static PyObject *

tee_copy(teeobject *to, PyObject *Py_UNUSED(ignored))

{

teeobject *newto;

newto = PyObject_GC_New(teeobject, &tee_type);

if (newto == NULL)

return NULL;

Py_INCREF(to->dataobj);

newto->dataobj = to->dataobj;

newto->index = to->index;

newto->weakreflist = NULL;

PyObject_GC_Track(newto);

return (PyObject *)newto;

}

PyDoc_STRVAR(teecopy_doc, "Returns an independent iterator.");

static PyObject *

tee_fromiterable(PyObject *iterable)

{

teeobject *to;

PyObject *it;

it = PyObject_GetIter(iterable);

if (it == NULL)

return NULL;

if (PyObject_TypeCheck(it, &tee_type)) {

to = (teeobject *)tee_copy((teeobject *)it, NULL);

goto done;

}

PyObject *dataobj = teedataobject_newinternal(it);

if (!dataobj) {

to = NULL;

goto done;

}

to = PyObject_GC_New(teeobject, &tee_type);

if (to == NULL) {

Py_DECREF(dataobj);

goto done;

}

to->dataobj = (teedataobject *)dataobj;

to->index = 0;

to->weakreflist = NULL;

PyObject_GC_Track(to);

done:

Py_DECREF(it);

return (PyObject *)to;

}

/*[clinic input]

@classmethod

itertools._tee.__new__

iterable: object

/

Iterator wrapped to make it copyable.

[clinic start generated code]*/

static PyObject *

itertools__tee_impl(PyTypeObject *type, PyObject *iterable)

/*[clinic end generated code: output=b02d3fd26c810c3f input=adc0779d2afe37a2]*/

{

return tee_fromiterable(iterable);

}

static int

tee_clear(teeobject *to)

{

if (to->weakreflist != NULL)

PyObject_ClearWeakRefs((PyObject *) to);

Py_CLEAR(to->dataobj);

return 0;

}

static void

tee_dealloc(teeobject *to)

{

PyObject_GC_UnTrack(to);

tee_clear(to);

PyObject_GC_Del(to);

}

static PyObject *

tee_reduce(teeobject *to, PyObject *Py_UNUSED(ignored))

{

return Py_BuildValue("O(())(Oi)", Py_TYPE(to), to->dataobj, to->index);

}

static PyObject *

tee_setstate(teeobject *to, PyObject *state)

{

teedataobject *tdo;

int index;

if (!PyTuple_Check(state)) {

PyErr_SetString(PyExc_TypeError, "state is not a tuple");

return NULL;

}

if (!PyArg_ParseTuple(state, "O!i", &teedataobject_type, &tdo, &index)) {

return NULL;

}

if (index < 0 || index > LINKCELLS) {

PyErr_SetString(PyExc_ValueError, "Index out of range");

return NULL;

}

Py_INCREF(tdo);

Py_XSETREF(to->dataobj, tdo);

to->index = index;

Py_RETURN_NONE;

}

static PyMethodDef tee_methods[] = {

{"__copy__", (PyCFunction)tee_copy, METH_NOARGS, teecopy_doc},

{"__reduce__", (PyCFunction)tee_reduce, METH_NOARGS, reduce_doc},

{"__setstate__", (PyCFunction)tee_setstate, METH_O, setstate_doc},

{NULL, NULL} /* sentinel */

};

static PyTypeObject tee_type = {

PyVarObject_HEAD_INIT(NULL, 0)

"itertools._tee", /* tp_name */

sizeof(teeobject), /* tp_basicsize */

0, /* tp_itemsize */

/* methods */

(destructor)tee_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 */

0, /* tp_getattro */

0, /* tp_setattro */

0, /* tp_as_buffer */

Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */

itertools__tee__doc__, /* tp_doc */

(traverseproc)tee_traverse, /* tp_traverse */

(inquiry)tee_clear, /* tp_clear */

0, /* tp_richcompare */

offsetof(teeobject, weakreflist), /* tp_weaklistoffset */

PyObject_SelfIter, /* tp_iter */

(iternextfunc)tee_next, /* tp_iternext */

tee_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 */

0, /* tp_alloc */

itertools__tee, /* tp_new */

PyObject_GC_Del, /* tp_free */