cpython/Objects/iterobject.c

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/* Iterator objects */
#include "Python.h"
typedef struct {
PyObject_HEAD
long 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;
Py_INCREF(seq);
it->it_seq = seq;
_PyObject_GC_TRACK(it);
return (PyObject *)it;
}
static void
iter_dealloc(seqiterobject *it)
{
_PyObject_GC_UNTRACK(it);
Py_XDECREF(it->it_seq);
PyObject_GC_Del(it);
}
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static int
iter_traverse(seqiterobject *it, visitproc visit, void *arg)
{
Py_VISIT(it->it_seq);
return 0;
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}
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;
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();
Py_DECREF(seq);
it->it_seq = NULL;
}
return NULL;
}
static PyObject *
iter_len(seqiterobject *it)
{
Py_ssize_t seqsize, len;
if (it->it_seq) {
seqsize = PySequence_Size(it->it_seq);
if (seqsize == -1)
return NULL;
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 PyMethodDef seqiter_methods[] = {
{"__length_hint__", (PyCFunction)iter_len, METH_NOARGS, length_hint_doc},
{NULL, NULL} /* sentinel */
};
PyTypeObject PySeqIter_Type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"iterator", /* tp_name */
sizeof(seqiterobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)iter_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
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)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;
Py_INCREF(callable);
it->it_callable = callable;
Py_INCREF(sentinel);
it->it_sentinel = sentinel;
_PyObject_GC_TRACK(it);
return (PyObject *)it;
}
static void
calliter_dealloc(calliterobject *it)
{
_PyObject_GC_UNTRACK(it);
Py_XDECREF(it->it_callable);
Py_XDECREF(it->it_sentinel);
PyObject_GC_Del(it);
}
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static int
calliter_traverse(calliterobject *it, visitproc visit, void *arg)
{
Py_VISIT(it->it_callable);
Py_VISIT(it->it_sentinel);
return 0;
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}
static PyObject *
calliter_iternext(calliterobject *it)
{
if (it->it_callable != NULL) {
PyObject *args = PyTuple_New(0);
PyObject *result;
if (args == NULL)
return NULL;
result = PyObject_Call(it->it_callable, args, NULL);
Py_DECREF(args);
if (result != NULL) {
int ok;
ok = PyObject_RichCompareBool(result,
it->it_sentinel,
Py_EQ);
if (ok == 0)
return result; /* Common case, fast path */
Py_DECREF(result);
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);
}
}
return NULL;
}
PyTypeObject PyCallIter_Type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"callable_iterator", /* tp_name */
sizeof(calliterobject), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
(destructor)calliter_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
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)calliter_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
PyObject_SelfIter, /* tp_iter */
(iternextfunc)calliter_iternext, /* tp_iternext */
0, /* tp_methods */
};