cpython/Objects/rangeobject.c

129 lines
2.4 KiB
C

/* Range object implementation */
#include "Python.h"
#include "structmember.h"
#include <string.h>
typedef struct {
PyObject_HEAD
long start;
long step;
long len;
} rangeobject;
PyObject *
PyRange_New(long start, long len, long step)
{
rangeobject *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;
return (PyObject *) obj;
}
static void
range_dealloc(rangeobject *r)
{
PyObject_DEL(r);
}
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)
{
/* buffers must be big enough to hold 3 longs + an int +
* a bit of "(xrange(...) * ...)" text.
*/
char buf1[250];
if (r->start == 0 && r->step == 1)
sprintf(buf1, "xrange(%ld)", r->start + r->len * r->step);
else if (r->step == 1)
sprintf(buf1, "xrange(%ld, %ld)",
r->start,
r->start + r->len * r->step);
else
sprintf(buf1, "xrange(%ld, %ld, %ld)",
r->start,
r->start + r->len * r->step,
r->step);
return PyString_FromString(buf1);
}
static PySequenceMethods range_as_sequence = {
(inquiry)range_length, /*sq_length*/
0, /*sq_concat*/
0, /*sq_repeat*/
(intargfunc)range_item, /*sq_item*/
0, /*sq_slice*/
0, /*sq_ass_item*/
0, /*sq_ass_slice*/
0, /*sq_contains*/
};
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)range_dealloc, /*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*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
};