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Re-add 'advanced' xrange features, adding DeprecationWarnings as discussed
on python-dev. The features will still vanish, however, just one release later.
1 parent 4ccf119 commit efafcea

3 files changed

Lines changed: 221 additions & 18 deletions

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‎Include/rangeobject.h‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -19,7 +19,7 @@ extern DL_IMPORT(PyTypeObject) PyRange_Type;
1919

2020
#define PyRange_Check(op) ((op)->ob_type == &PyRange_Type)
2121

22-
extern DL_IMPORT(PyObject *) PyRange_New(long, long, long);
22+
extern DL_IMPORT(PyObject *) PyRange_New(long, long, long, int);
2323

2424
#ifdef __cplusplus
2525
}

‎Objects/rangeobject.c‎

Lines changed: 219 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -5,40 +5,92 @@
55
#include "structmember.h"
66
#include <string.h>
77

8+
#define WARN(msg) if (PyErr_Warn(PyExc_DeprecationWarning, msg) < 0) \
9+
return NULL;
10+
811
typedef struct {
912
PyObject_HEAD
1013
long start;
1114
long step;
1215
long len;
16+
int reps;
17+
long totlen;
1318
} rangeobject;
1419

20+
static int
21+
long_mul(long i, long j, long *kk)
22+
{
23+
PyObject *a;
24+
PyObject *b;
25+
PyObject *c;
26+
27+
if ((a = PyInt_FromLong(i)) == NULL)
28+
return 0;
29+
30+
if ((b = PyInt_FromLong(j)) == NULL)
31+
return 0;
32+
33+
c = PyNumber_Multiply(a, b);
34+
35+
Py_DECREF(a);
36+
Py_DECREF(b);
37+
38+
if (c == NULL)
39+
return 0;
40+
41+
*kk = PyInt_AS_LONG(c);
42+
Py_DECREF(c);
43+
44+
if (*kk > INT_MAX) {
45+
PyErr_SetString(PyExc_OverflowError,
46+
"integer multiplication");
47+
return 0;
48+
}
49+
else
50+
return 1;
51+
}
52+
1553
PyObject *
16-
PyRange_New(long start, long len, long step)
54+
PyRange_New(long start, long len, long step, int reps)
1755
{
56+
long totlen = -1;
1857
rangeobject *obj = PyObject_NEW(rangeobject, &PyRange_Type);
1958

2059
if (obj == NULL)
2160
return NULL;
61+
62+
if (reps != 1)
63+
WARN("PyRange_New's 'repetitions' argument is deprecated");
2264

23-
if (len == 0) {
65+
if (len == 0 || reps <= 0) {
2466
start = 0;
2567
len = 0;
2668
step = 1;
69+
reps = 1;
70+
totlen = 0;
2771
}
2872
else {
2973
long last = start + (len - 1) * step;
3074
if ((step > 0) ?
31-
(last > (PyInt_GetMax() - step))
32-
:(last < (-1 - PyInt_GetMax() - step))) {
75+
(last > (PyInt_GetMax() - step)) :
76+
(last < (-1 - PyInt_GetMax() - step))) {
3377
PyErr_SetString(PyExc_OverflowError,
3478
"integer addition");
3579
return NULL;
80+
}
81+
if (! long_mul(len, (long) reps, &totlen)) {
82+
if(!PyErr_ExceptionMatches(PyExc_OverflowError))
83+
return NULL;
84+
PyErr_Clear();
85+
totlen = -1;
3686
}
3787
}
3888

3989
obj->start = start;
4090
obj->len = len;
4191
obj->step = step;
92+
obj->reps = reps;
93+
obj->totlen = totlen;
4294

4395
return (PyObject *) obj;
4496
}
@@ -52,19 +104,23 @@ range_dealloc(rangeobject *r)
52104
static PyObject *
53105
range_item(rangeobject *r, int i)
54106
{
55-
if (i < 0 || i >= r->len) {
56-
PyErr_SetString(PyExc_IndexError,
107+
if (i < 0 || i >= r->totlen)
108+
if (r->totlen!=-1) {
109+
PyErr_SetString(PyExc_IndexError,
57110
"xrange object index out of range");
58-
return NULL;
59-
}
111+
return NULL;
112+
}
60113

61114
return PyInt_FromLong(r->start + (i % r->len) * r->step);
62115
}
63116

64117
static int
65118
range_length(rangeobject *r)
66119
{
67-
return r->len;
120+
if (r->totlen == -1)
121+
PyErr_SetString(PyExc_OverflowError,
122+
"xrange object has too many items");
123+
return r->totlen;
68124
}
69125

70126
static PyObject *
@@ -74,6 +130,7 @@ range_repr(rangeobject *r)
74130
* a bit of "(xrange(...) * ...)" text.
75131
*/
76132
char buf1[250];
133+
char buf2[250];
77134

78135
if (r->start == 0 && r->step == 1)
79136
sprintf(buf1, "xrange(%ld)", r->start + r->len * r->step);
@@ -89,18 +146,162 @@ range_repr(rangeobject *r)
89146
r->start + r->len * r->step,
90147
r->step);
91148

92-
return PyString_FromString(buf1);
149+
if (r->reps != 1)
150+
sprintf(buf2, "(%s * %d)", buf1, r->reps);
151+
152+
return PyString_FromString(r->reps == 1 ? buf1 : buf2);
153+
}
154+
155+
static PyObject *
156+
range_repeat(rangeobject *r, int n)
157+
{
158+
long lreps = 0;
159+
160+
WARN("xrange object multiplication is deprecated; "
161+
"convert to list instead");
162+
163+
if (n <= 0)
164+
return (PyObject *) PyRange_New(0, 0, 1, 1);
165+
166+
else if (n == 1) {
167+
Py_INCREF(r);
168+
return (PyObject *) r;
169+
}
170+
171+
else if (! long_mul((long) r->reps, (long) n, &lreps))
172+
return NULL;
173+
174+
else
175+
return (PyObject *) PyRange_New(
176+
r->start,
177+
r->len,
178+
r->step,
179+
(int) lreps);
180+
}
181+
182+
static int
183+
range_compare(rangeobject *r1, rangeobject *r2)
184+
{
185+
186+
if (PyErr_Warn(PyExc_DeprecationWarning,
187+
"xrange object comparision is deprecated; "
188+
"convert to list instead") < 0)
189+
return -1;
190+
191+
if (r1->start != r2->start)
192+
return r1->start - r2->start;
193+
194+
else if (r1->step != r2->step)
195+
return r1->step - r2->step;
196+
197+
else if (r1->len != r2->len)
198+
return r1->len - r2->len;
199+
200+
else
201+
return r1->reps - r2->reps;
202+
}
203+
204+
static PyObject *
205+
range_slice(rangeobject *r, int low, int high)
206+
{
207+
WARN("xrange object slicing is deprecated; "
208+
"convert to list instead");
209+
210+
if (r->reps != 1) {
211+
PyErr_SetString(PyExc_TypeError,
212+
"cannot slice a replicated xrange");
213+
return NULL;
214+
}
215+
if (low < 0)
216+
low = 0;
217+
else if (low > r->len)
218+
low = r->len;
219+
if (high < 0)
220+
high = 0;
221+
if (high < low)
222+
high = low;
223+
else if (high > r->len)
224+
high = r->len;
225+
226+
if (low == 0 && high == r->len) {
227+
Py_INCREF(r);
228+
return (PyObject *) r;
229+
}
230+
231+
return (PyObject *) PyRange_New(
232+
low * r->step + r->start,
233+
high - low,
234+
r->step,
235+
1);
236+
}
237+
238+
static PyObject *
239+
range_tolist(rangeobject *self, PyObject *args)
240+
{
241+
PyObject *thelist;
242+
int j;
243+
244+
WARN("xrange.tolist() is deprecated; use list(xrange) instead");
245+
246+
if (! PyArg_ParseTuple(args, ":tolist"))
247+
return NULL;
248+
249+
if (self->totlen == -1)
250+
return PyErr_NoMemory();
251+
252+
if ((thelist = PyList_New(self->totlen)) == NULL)
253+
return NULL;
254+
255+
for (j = 0; j < self->totlen; ++j)
256+
if ((PyList_SetItem(thelist, j, (PyObject *) PyInt_FromLong(
257+
self->start + (j % self->len) * self->step))) < 0)
258+
return NULL;
259+
260+
return thelist;
261+
}
262+
263+
static PyObject *
264+
range_getattr(rangeobject *r, char *name)
265+
{
266+
PyObject *result;
267+
268+
static PyMethodDef range_methods[] = {
269+
{"tolist", (PyCFunction)range_tolist, METH_VARARGS,
270+
"tolist() -> list\n"
271+
"Return a list object with the same values.\n"
272+
"(This method is deprecated; use list() instead.)"},
273+
{NULL, NULL}
274+
};
275+
static struct memberlist range_members[] = {
276+
{"step", T_LONG, offsetof(rangeobject, step), RO},
277+
{"start", T_LONG, offsetof(rangeobject, start), RO},
278+
{"stop", T_LONG, 0, RO},
279+
{NULL, 0, 0, 0}
280+
};
281+
282+
result = Py_FindMethod(range_methods, (PyObject *) r, name);
283+
if (result == NULL) {
284+
PyErr_Clear();
285+
if (strcmp("stop", name) == 0)
286+
result = PyInt_FromLong(r->start + (r->len * r->step));
287+
else
288+
result = PyMember_Get((char *)r, range_members, name);
289+
if (result)
290+
WARN("xrange object's 'start', 'stop' and 'step' "
291+
"attributes are deprecated");
292+
}
293+
return result;
93294
}
94295

95296
static PySequenceMethods range_as_sequence = {
96297
(inquiry)range_length, /*sq_length*/
97298
0, /*sq_concat*/
98-
0, /*sq_repeat*/
99-
(intargfunc)range_item, /*sq_item*/
100-
0, /*sq_slice*/
299+
(intargfunc)range_repeat, /*sq_repeat*/
300+
(intargfunc)range_item, /*sq_item*/
301+
(intintargfunc)range_slice, /*sq_slice*/
101302
0, /*sq_ass_item*/
102303
0, /*sq_ass_slice*/
103-
0, /*sq_contains*/
304+
0, /*sq_contains*/
104305
};
105306

106307
PyTypeObject PyRange_Type = {
@@ -111,9 +312,9 @@ PyTypeObject PyRange_Type = {
111312
0, /* Item size for varobject */
112313
(destructor)range_dealloc, /*tp_dealloc*/
113314
0, /*tp_print*/
114-
0, /*tp_getattr*/
315+
(getattrfunc)range_getattr, /*tp_getattr*/
115316
0, /*tp_setattr*/
116-
0, /*tp_compare*/
317+
(cmpfunc)range_compare, /*tp_compare*/
117318
(reprfunc)range_repr, /*tp_repr*/
118319
0, /*tp_as_number*/
119320
&range_as_sequence, /*tp_as_sequence*/
@@ -126,3 +327,5 @@ PyTypeObject PyRange_Type = {
126327
0, /*tp_as_buffer*/
127328
Py_TPFLAGS_DEFAULT, /*tp_flags*/
128329
};
330+
331+
#undef WARN

‎Python/bltinmodule.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1763,7 +1763,7 @@ builtin_xrange(PyObject *self, PyObject *args)
17631763
"xrange() result has too many items");
17641764
return NULL;
17651765
}
1766-
return PyRange_New(ilow, n, istep);
1766+
return PyRange_New(ilow, n, istep, 1);
17671767
}
17681768

17691769
static char xrange_doc[] =

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