Staging
v0.8.1
v0.8.1
https://github.com/python/cpython
Tip revision: 74f4bd53e03ded8408bcc2de67cf0f5a4ac5b1a1 authored by Barry Warsaw on 23 February 2012, 15:59:38 UTC
Bump some more copyright years (as per PEP 101), since this is the first
Bump some more copyright years (as per PEP 101), since this is the first
Tip revision: 74f4bd5
enumobject.c
/* enumerate object */
#include "Python.h"
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;
static PyObject *
enum_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
enumobject *en;
PyObject *seq = NULL;
PyObject *start = NULL;
static char *kwlist[] = {"sequence", "start", 0};
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:enumerate", kwlist,
&seq, &start))
return NULL;
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(PyInt_Check(start) || PyLong_Check(start));
en->en_index = PyInt_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(seq);
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)
{
static PyObject *one = NULL;
PyObject *result = en->en_result;
PyObject *next_index;
PyObject *stepped_up;
if (en->en_longindex == NULL) {
en->en_longindex = PyInt_FromSsize_t(PY_SSIZE_T_MAX);
if (en->en_longindex == NULL)
return NULL;
}
if (one == NULL) {
one = PyInt_FromLong(1);
if (one == NULL)
return NULL;
}
next_index = en->en_longindex;
assert(next_index != NULL);
stepped_up = PyNumber_Add(next_index, one);
if (stepped_up == NULL)
return NULL;
en->en_longindex = stepped_up;
if (result->ob_refcnt == 1) {
Py_INCREF(result);
Py_DECREF(PyTuple_GET_ITEM(result, 0));
Py_DECREF(PyTuple_GET_ITEM(result, 1));
} else {
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;
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 = PyInt_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);
Py_DECREF(PyTuple_GET_ITEM(result, 0));
Py_DECREF(PyTuple_GET_ITEM(result, 1));
} else {
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;
}
PyDoc_STRVAR(enum_doc,
"enumerate(iterable[, start]) -> iterator for index, value of iterable\n"
"\n"
"Return an enumerate object. iterable must be another object that supports\n"
"iteration. The enumerate object yields pairs containing a count (from\n"
"start, which defaults to zero) and a value yielded by the iterable argument.\n"
"enumerate is useful for obtaining an indexed list:\n"
" (0, seq[0]), (1, seq[1]), (2, seq[2]), ...");
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_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
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_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 */
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 */
enum_new, /* tp_new */
PyObject_GC_Del, /* tp_free */
};
/* Reversed Object ***************************************************************/
typedef struct {
PyObject_HEAD
Py_ssize_t index;
PyObject* seq;
} reversedobject;
static PyObject *
reversed_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
Py_ssize_t n;
PyObject *seq;
reversedobject *ro;
if (type == &PyReversed_Type && !_PyArg_NoKeywords("reversed()", kwds))
return NULL;
if (!PyArg_UnpackTuple(args, "reversed", 1, 1, &seq) )
return NULL;
if (PyObject_HasAttrString(seq, "__reversed__"))
return PyObject_CallMethod(seq, "__reversed__", NULL);
if (!PySequence_Check(seq)) {
PyErr_SetString(PyExc_TypeError,
"argument to reversed() must be a sequence");
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;
}
PyDoc_STRVAR(reversed_doc,
"reversed(sequence) -> reverse iterator over values of the sequence\n"
"\n"
"Return a reverse iterator");
static PyObject *
reversed_len(reversedobject *ro)
{
Py_ssize_t position, seqsize;
if (ro->seq == NULL)
return PyInt_FromLong(0);
seqsize = PySequence_Size(ro->seq);
if (seqsize == -1)
return NULL;
position = ro->index + 1;
return PyInt_FromSsize_t((seqsize < position) ? 0 : position);
}
PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
static PyMethodDef reversediter_methods[] = {
{"__length_hint__", (PyCFunction)reversed_len, METH_NOARGS, length_hint_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_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
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_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 */
};