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/* Range object implementation */
#include "Python.h"
typedef struct {
PyObject_HEAD
long start;
long step;
long len;
long index;
int used; /* Set to 1 if called by range_getiter */
} rangeobject;
PyObject *
PyRange_New(long start, long len, long step, int reps)
{
rangeobject *obj;
if (reps != 1) {
PyErr_SetString(PyExc_ValueError,
"PyRange_New's 'repetitions' argument must be 1");
return NULL;
}
obj = PyObject_New(rangeobject, &PyRange_Type);
if (obj == NULL)
return NULL;
if (len == 0) {
start = 0;
len = 0;
step = 1;
}
else {
long last = start + (len - 1) * step;
if ((step > 0) ?
(last > (PyInt_GetMax() - step)) :
(last < (-1 - PyInt_GetMax() - step))) {
PyErr_SetString(PyExc_OverflowError,
"integer addition");
return NULL;
}
}
obj->start = start;
obj->len = len;
obj->step = step;
obj->index = 0;
obj->used = 0;
return (PyObject *) obj;
}
static PyObject *
range_item(rangeobject *r, int i)
{
if (i < 0 || i >= r->len) {
PyErr_SetString(PyExc_IndexError,
"xrange object index out of range");
return NULL;
}
return PyInt_FromLong(r->start + (i % r->len) * r->step);
}
static int
range_length(rangeobject *r)
{
return r->len;
}
static PyObject *
range_repr(rangeobject *r)
{
PyObject *rtn;
if (r->start == 0 && r->step == 1)
rtn = PyString_FromFormat("xrange(%ld)",
r->start + r->len * r->step);
else if (r->step == 1)
rtn = PyString_FromFormat("xrange(%ld, %ld)",
r->start,
r->start + r->len * r->step);
else
rtn = PyString_FromFormat("xrange(%ld, %ld, %ld)",
r->start,
r->start + r->len * r->step,
r->step);
return rtn;
}
static PyObject *
range_getiter(rangeobject *r)
{
rangeobject *obj;
if (r->used == 0 || r->index >= r->len) {
Py_INCREF(r);
r->used = 1;
r->index = 0;
return (PyObject *)r;
}
obj = PyObject_NEW(rangeobject, &PyRange_Type);
if (obj == NULL)
return NULL;
obj->start = r->start;
obj->len = r->len;
obj->step = r->step;
obj->index = 0;
obj->used = 1;
return (PyObject *) obj;
}
static PyObject *
range_next(rangeobject *r)
{
if (r->index < r->len)
return PyInt_FromLong(r->start + (r->index++) * r->step);
PyErr_SetObject(PyExc_StopIteration, Py_None);
return NULL;
}
static PyMethodDef range_methods[] = {
{"next", (PyCFunction)range_next, METH_NOARGS,
"it.next() -- get the next value, or raise StopIteration"},
{NULL, NULL} /* sentinel */
};
static PySequenceMethods range_as_sequence = {
(inquiry)range_length, /* sq_length */
0, /* sq_concat */
0, /* sq_repeat */
(intargfunc)range_item, /* sq_item */
0, /* sq_slice */
};
PyTypeObject PyRange_Type = {
PyObject_HEAD_INIT(&PyType_Type)
0, /* Number of items for varobject */
"xrange", /* Name of this type */
sizeof(rangeobject), /* Basic object size */
0, /* Item size for varobject */
(destructor)PyObject_Del, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
(reprfunc)range_repr, /* tp_repr */
0, /* tp_as_number */
&range_as_sequence, /* 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, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
(getiterfunc)range_getiter, /* tp_iter */
(iternextfunc)range_next, /* tp_iternext */
range_methods, /* tp_methods */
};
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