Guido van Rossum | 12d12c5 | 1993-10-26 17:58:25 +0000 | [diff] [blame] | 1 | /* Range object implementation */ |
| 2 | |
Guido van Rossum | c0b618a | 1997-05-02 03:12:38 +0000 | [diff] [blame] | 3 | #include "Python.h" |
Benjamin Peterson | 878ce38 | 2011-11-05 15:17:52 -0400 | [diff] [blame] | 4 | #include "structmember.h" |
Thomas Wouters | efafcea | 2001-07-09 12:30:54 +0000 | [diff] [blame] | 5 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 6 | /* Support objects whose length is > PY_SSIZE_T_MAX. |
| 7 | |
| 8 | This could be sped up for small PyLongs if they fit in an Py_ssize_t. |
| 9 | This only matters on Win64. Though we could use PY_LONG_LONG which |
| 10 | would presumably help perf. |
| 11 | */ |
| 12 | |
Guido van Rossum | 12d12c5 | 1993-10-26 17:58:25 +0000 | [diff] [blame] | 13 | typedef struct { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 14 | PyObject_HEAD |
| 15 | PyObject *start; |
| 16 | PyObject *stop; |
| 17 | PyObject *step; |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 18 | PyObject *length; |
Guido van Rossum | 12d12c5 | 1993-10-26 17:58:25 +0000 | [diff] [blame] | 19 | } rangeobject; |
| 20 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 21 | /* Helper function for validating step. Always returns a new reference or |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 22 | NULL on error. |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 23 | */ |
| 24 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 25 | validate_step(PyObject *step) |
| 26 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 27 | /* No step specified, use a step of 1. */ |
| 28 | if (!step) |
Christian Heimes | 217cfd1 | 2007-12-02 14:31:20 +0000 | [diff] [blame] | 29 | return PyLong_FromLong(1); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 30 | |
| 31 | step = PyNumber_Index(step); |
| 32 | if (step) { |
| 33 | Py_ssize_t istep = PyNumber_AsSsize_t(step, NULL); |
| 34 | if (istep == -1 && PyErr_Occurred()) { |
| 35 | /* Ignore OverflowError, we know the value isn't 0. */ |
| 36 | PyErr_Clear(); |
| 37 | } |
| 38 | else if (istep == 0) { |
| 39 | PyErr_SetString(PyExc_ValueError, |
| 40 | "range() arg 3 must not be zero"); |
| 41 | Py_CLEAR(step); |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | return step; |
Raymond Hettinger | c4c453f | 2002-06-05 23:12:45 +0000 | [diff] [blame] | 46 | } |
| 47 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 48 | static PyObject * |
| 49 | compute_range_length(PyObject *start, PyObject *stop, PyObject *step); |
| 50 | |
| 51 | static rangeobject * |
| 52 | make_range_object(PyTypeObject *type, PyObject *start, |
| 53 | PyObject *stop, PyObject *step) |
| 54 | { |
| 55 | rangeobject *obj = NULL; |
| 56 | PyObject *length; |
| 57 | length = compute_range_length(start, stop, step); |
| 58 | if (length == NULL) { |
| 59 | return NULL; |
| 60 | } |
| 61 | obj = PyObject_New(rangeobject, type); |
| 62 | if (obj == NULL) { |
| 63 | Py_DECREF(length); |
| 64 | return NULL; |
| 65 | } |
| 66 | obj->start = start; |
| 67 | obj->stop = stop; |
| 68 | obj->step = step; |
| 69 | obj->length = length; |
| 70 | return obj; |
| 71 | } |
| 72 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 73 | /* XXX(nnorwitz): should we error check if the user passes any empty ranges? |
| 74 | range(-10) |
| 75 | range(0, -5) |
| 76 | range(0, 5, -1) |
| 77 | */ |
Raymond Hettinger | c4c453f | 2002-06-05 23:12:45 +0000 | [diff] [blame] | 78 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 79 | range_new(PyTypeObject *type, PyObject *args, PyObject *kw) |
| 80 | { |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 81 | rangeobject *obj; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 82 | PyObject *start = NULL, *stop = NULL, *step = NULL; |
Raymond Hettinger | c4c453f | 2002-06-05 23:12:45 +0000 | [diff] [blame] | 83 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 84 | if (!_PyArg_NoKeywords("range()", kw)) |
| 85 | return NULL; |
Georg Brandl | 02c4287 | 2005-08-26 06:42:30 +0000 | [diff] [blame] | 86 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 87 | if (PyTuple_Size(args) <= 1) { |
| 88 | if (!PyArg_UnpackTuple(args, "range", 1, 1, &stop)) |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 89 | return NULL; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 90 | stop = PyNumber_Index(stop); |
| 91 | if (!stop) |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 92 | return NULL; |
Christian Heimes | 217cfd1 | 2007-12-02 14:31:20 +0000 | [diff] [blame] | 93 | start = PyLong_FromLong(0); |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 94 | if (!start) { |
| 95 | Py_DECREF(stop); |
| 96 | return NULL; |
| 97 | } |
Christian Heimes | 217cfd1 | 2007-12-02 14:31:20 +0000 | [diff] [blame] | 98 | step = PyLong_FromLong(1); |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 99 | if (!step) { |
| 100 | Py_DECREF(stop); |
| 101 | Py_DECREF(start); |
| 102 | return NULL; |
| 103 | } |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 104 | } |
| 105 | else { |
| 106 | if (!PyArg_UnpackTuple(args, "range", 2, 3, |
| 107 | &start, &stop, &step)) |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 108 | return NULL; |
Tim Peters | feec453 | 2004-08-08 07:17:39 +0000 | [diff] [blame] | 109 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 110 | /* Convert borrowed refs to owned refs */ |
| 111 | start = PyNumber_Index(start); |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 112 | if (!start) |
| 113 | return NULL; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 114 | stop = PyNumber_Index(stop); |
Raymond Hettinger | 94f5583 | 2009-06-12 18:40:16 +0000 | [diff] [blame] | 115 | if (!stop) { |
| 116 | Py_DECREF(start); |
| 117 | return NULL; |
| 118 | } |
| 119 | step = validate_step(step); /* Caution, this can clear exceptions */ |
| 120 | if (!step) { |
| 121 | Py_DECREF(start); |
| 122 | Py_DECREF(stop); |
| 123 | return NULL; |
| 124 | } |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 125 | } |
| 126 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 127 | obj = make_range_object(type, start, stop, step); |
| 128 | if (obj != NULL) |
| 129 | return (PyObject *) obj; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 130 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 131 | /* Failed to create object, release attributes */ |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 132 | Py_XDECREF(start); |
| 133 | Py_XDECREF(stop); |
| 134 | Py_XDECREF(step); |
| 135 | return NULL; |
Raymond Hettinger | c4c453f | 2002-06-05 23:12:45 +0000 | [diff] [blame] | 136 | } |
| 137 | |
Martin v. Löwis | 14f8b4c | 2002-06-13 20:33:02 +0000 | [diff] [blame] | 138 | PyDoc_STRVAR(range_doc, |
Chris Jerdonek | 83fe2e1 | 2012-10-07 14:48:36 -0700 | [diff] [blame] | 139 | "range(stop) -> range object\n\ |
| 140 | range(start, stop[, step]) -> range object\n\ |
Raymond Hettinger | c4c453f | 2002-06-05 23:12:45 +0000 | [diff] [blame] | 141 | \n\ |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 142 | Returns a virtual sequence of numbers from start to stop by step."); |
Raymond Hettinger | c4c453f | 2002-06-05 23:12:45 +0000 | [diff] [blame] | 143 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 144 | static void |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 145 | range_dealloc(rangeobject *r) |
| 146 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 147 | Py_DECREF(r->start); |
| 148 | Py_DECREF(r->stop); |
| 149 | Py_DECREF(r->step); |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 150 | Py_DECREF(r->length); |
Amaury Forgeot d'Arc | b7f17e4 | 2007-11-15 20:52:21 +0000 | [diff] [blame] | 151 | PyObject_Del(r); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 152 | } |
| 153 | |
Mark Dickinson | 732166d | 2009-06-28 22:08:40 +0000 | [diff] [blame] | 154 | /* Return number of items in range (lo, hi, step) as a PyLong object, |
| 155 | * when arguments are PyLong objects. Arguments MUST return 1 with |
| 156 | * PyLong_Check(). Return NULL when there is an error. |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 157 | */ |
| 158 | static PyObject* |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 159 | compute_range_length(PyObject *start, PyObject *stop, PyObject *step) |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 160 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 161 | /* ------------------------------------------------------------- |
| 162 | Algorithm is equal to that of get_len_of_range(), but it operates |
Benjamin Peterson | a47af9c | 2009-06-24 21:14:38 +0000 | [diff] [blame] | 163 | on PyObjects (which are assumed to be PyLong objects). |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 164 | ---------------------------------------------------------------*/ |
Mark Dickinson | 211c625 | 2009-02-01 10:28:51 +0000 | [diff] [blame] | 165 | int cmp_result; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 166 | PyObject *lo, *hi; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 167 | PyObject *diff = NULL; |
| 168 | PyObject *one = NULL; |
| 169 | PyObject *tmp1 = NULL, *tmp2 = NULL, *result; |
| 170 | /* holds sub-expression evaluations */ |
| 171 | |
| 172 | PyObject *zero = PyLong_FromLong(0); |
| 173 | if (zero == NULL) |
| 174 | return NULL; |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 175 | cmp_result = PyObject_RichCompareBool(step, zero, Py_GT); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 176 | Py_DECREF(zero); |
Mark Dickinson | 211c625 | 2009-02-01 10:28:51 +0000 | [diff] [blame] | 177 | if (cmp_result == -1) |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 178 | return NULL; |
| 179 | |
Mark Dickinson | 211c625 | 2009-02-01 10:28:51 +0000 | [diff] [blame] | 180 | if (cmp_result == 1) { |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 181 | lo = start; |
| 182 | hi = stop; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 183 | Py_INCREF(step); |
| 184 | } else { |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 185 | lo = stop; |
| 186 | hi = start; |
| 187 | step = PyNumber_Negative(step); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 188 | if (!step) |
| 189 | return NULL; |
| 190 | } |
| 191 | |
| 192 | /* if (lo >= hi), return length of 0. */ |
Mark Dickinson | 211c625 | 2009-02-01 10:28:51 +0000 | [diff] [blame] | 193 | if (PyObject_RichCompareBool(lo, hi, Py_GE) == 1) { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 194 | Py_XDECREF(step); |
| 195 | return PyLong_FromLong(0); |
| 196 | } |
| 197 | |
| 198 | if ((one = PyLong_FromLong(1L)) == NULL) |
| 199 | goto Fail; |
| 200 | |
| 201 | if ((tmp1 = PyNumber_Subtract(hi, lo)) == NULL) |
| 202 | goto Fail; |
| 203 | |
| 204 | if ((diff = PyNumber_Subtract(tmp1, one)) == NULL) |
| 205 | goto Fail; |
| 206 | |
| 207 | if ((tmp2 = PyNumber_FloorDivide(diff, step)) == NULL) |
| 208 | goto Fail; |
| 209 | |
| 210 | if ((result = PyNumber_Add(tmp2, one)) == NULL) |
| 211 | goto Fail; |
| 212 | |
| 213 | Py_DECREF(tmp2); |
| 214 | Py_DECREF(diff); |
| 215 | Py_DECREF(step); |
| 216 | Py_DECREF(tmp1); |
| 217 | Py_DECREF(one); |
| 218 | return result; |
| 219 | |
| 220 | Fail: |
| 221 | Py_XDECREF(tmp2); |
| 222 | Py_XDECREF(diff); |
| 223 | Py_XDECREF(step); |
| 224 | Py_XDECREF(tmp1); |
| 225 | Py_XDECREF(one); |
| 226 | return NULL; |
Guido van Rossum | 12d12c5 | 1993-10-26 17:58:25 +0000 | [diff] [blame] | 227 | } |
| 228 | |
Martin v. Löwis | 18e1655 | 2006-02-15 17:27:45 +0000 | [diff] [blame] | 229 | static Py_ssize_t |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 230 | range_length(rangeobject *r) |
| 231 | { |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 232 | return PyLong_AsSsize_t(r->length); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 233 | } |
| 234 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 235 | static PyObject * |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 236 | compute_item(rangeobject *r, PyObject *i) |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 237 | { |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 238 | PyObject *incr, *result; |
| 239 | /* PyLong equivalent to: |
| 240 | * return r->start + (i * r->step) |
| 241 | */ |
| 242 | incr = PyNumber_Multiply(i, r->step); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 243 | if (!incr) |
| 244 | return NULL; |
| 245 | result = PyNumber_Add(r->start, incr); |
| 246 | Py_DECREF(incr); |
| 247 | return result; |
Guido van Rossum | 7d6aa51 | 1993-12-21 22:50:31 +0000 | [diff] [blame] | 248 | } |
| 249 | |
Guido van Rossum | c0b618a | 1997-05-02 03:12:38 +0000 | [diff] [blame] | 250 | static PyObject * |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 251 | compute_range_item(rangeobject *r, PyObject *arg) |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 252 | { |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 253 | int cmp_result; |
| 254 | PyObject *i, *result; |
Tim Peters | d976ab7 | 2004-08-08 06:29:10 +0000 | [diff] [blame] | 255 | |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 256 | PyObject *zero = PyLong_FromLong(0); |
| 257 | if (zero == NULL) |
| 258 | return NULL; |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 259 | |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 260 | /* PyLong equivalent to: |
| 261 | * if (arg < 0) { |
| 262 | * i = r->length + arg |
| 263 | * } else { |
| 264 | * i = arg |
| 265 | * } |
| 266 | */ |
| 267 | cmp_result = PyObject_RichCompareBool(arg, zero, Py_LT); |
| 268 | if (cmp_result == -1) { |
| 269 | Py_DECREF(zero); |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 270 | return NULL; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 271 | } |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 272 | if (cmp_result == 1) { |
| 273 | i = PyNumber_Add(r->length, arg); |
| 274 | if (!i) { |
| 275 | Py_DECREF(zero); |
| 276 | return NULL; |
| 277 | } |
| 278 | } else { |
| 279 | i = arg; |
| 280 | Py_INCREF(i); |
| 281 | } |
| 282 | |
| 283 | /* PyLong equivalent to: |
| 284 | * if (i < 0 || i >= r->length) { |
| 285 | * <report index out of bounds> |
| 286 | * } |
| 287 | */ |
| 288 | cmp_result = PyObject_RichCompareBool(i, zero, Py_LT); |
| 289 | Py_DECREF(zero); |
| 290 | if (cmp_result == 0) { |
| 291 | cmp_result = PyObject_RichCompareBool(i, r->length, Py_GE); |
| 292 | } |
| 293 | if (cmp_result == -1) { |
| 294 | Py_DECREF(i); |
| 295 | return NULL; |
| 296 | } |
| 297 | if (cmp_result == 1) { |
| 298 | Py_DECREF(i); |
| 299 | PyErr_SetString(PyExc_IndexError, |
| 300 | "range object index out of range"); |
| 301 | return NULL; |
| 302 | } |
| 303 | |
| 304 | result = compute_item(r, i); |
| 305 | Py_DECREF(i); |
| 306 | return result; |
| 307 | } |
| 308 | |
| 309 | static PyObject * |
| 310 | range_item(rangeobject *r, Py_ssize_t i) |
| 311 | { |
Antoine Pitrou | a103b96 | 2012-05-16 14:37:54 +0200 | [diff] [blame] | 312 | PyObject *res, *arg = PyLong_FromSsize_t(i); |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 313 | if (!arg) { |
| 314 | return NULL; |
| 315 | } |
Benjamin Peterson | 547d485 | 2011-01-13 04:22:54 +0000 | [diff] [blame] | 316 | res = compute_range_item(r, arg); |
| 317 | Py_DECREF(arg); |
| 318 | return res; |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 319 | } |
| 320 | |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 321 | static PyObject * |
| 322 | compute_slice(rangeobject *r, PyObject *_slice) |
| 323 | { |
| 324 | PySliceObject *slice = (PySliceObject *) _slice; |
| 325 | rangeobject *result; |
| 326 | PyObject *start = NULL, *stop = NULL, *step = NULL; |
| 327 | PyObject *substart = NULL, *substop = NULL, *substep = NULL; |
Mark Dickinson | ffdb2c2 | 2012-11-17 19:18:10 +0000 | [diff] [blame] | 328 | int error; |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 329 | |
Mark Dickinson | ffdb2c2 | 2012-11-17 19:18:10 +0000 | [diff] [blame] | 330 | error = _PySlice_GetLongIndices(slice, r->length, &start, &stop, &step); |
| 331 | if (error == -1) |
| 332 | return NULL; |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 333 | |
| 334 | substep = PyNumber_Multiply(r->step, step); |
| 335 | if (substep == NULL) goto fail; |
| 336 | Py_CLEAR(step); |
| 337 | |
| 338 | substart = compute_item(r, start); |
| 339 | if (substart == NULL) goto fail; |
| 340 | Py_CLEAR(start); |
| 341 | |
Mark Dickinson | ffdb2c2 | 2012-11-17 19:18:10 +0000 | [diff] [blame] | 342 | substop = compute_item(r, stop); |
| 343 | if (substop == NULL) goto fail; |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 344 | Py_CLEAR(stop); |
| 345 | |
| 346 | result = make_range_object(Py_TYPE(r), substart, substop, substep); |
| 347 | if (result != NULL) { |
| 348 | return (PyObject *) result; |
| 349 | } |
| 350 | fail: |
| 351 | Py_XDECREF(start); |
| 352 | Py_XDECREF(stop); |
| 353 | Py_XDECREF(step); |
| 354 | Py_XDECREF(substart); |
| 355 | Py_XDECREF(substop); |
| 356 | Py_XDECREF(substep); |
| 357 | return NULL; |
Alexandre Vassalotti | 7505607 | 2008-06-10 04:03:04 +0000 | [diff] [blame] | 358 | } |
| 359 | |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 360 | /* Assumes (PyLong_CheckExact(ob) || PyBool_Check(ob)) */ |
| 361 | static int |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 362 | range_contains_long(rangeobject *r, PyObject *ob) |
| 363 | { |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 364 | int cmp1, cmp2, cmp3; |
| 365 | PyObject *tmp1 = NULL; |
| 366 | PyObject *tmp2 = NULL; |
| 367 | PyObject *zero = NULL; |
| 368 | int result = -1; |
| 369 | |
| 370 | zero = PyLong_FromLong(0); |
| 371 | if (zero == NULL) /* MemoryError in int(0) */ |
| 372 | goto end; |
| 373 | |
| 374 | /* Check if the value can possibly be in the range. */ |
| 375 | |
| 376 | cmp1 = PyObject_RichCompareBool(r->step, zero, Py_GT); |
| 377 | if (cmp1 == -1) |
| 378 | goto end; |
| 379 | if (cmp1 == 1) { /* positive steps: start <= ob < stop */ |
| 380 | cmp2 = PyObject_RichCompareBool(r->start, ob, Py_LE); |
| 381 | cmp3 = PyObject_RichCompareBool(ob, r->stop, Py_LT); |
| 382 | } |
| 383 | else { /* negative steps: stop < ob <= start */ |
| 384 | cmp2 = PyObject_RichCompareBool(ob, r->start, Py_LE); |
| 385 | cmp3 = PyObject_RichCompareBool(r->stop, ob, Py_LT); |
| 386 | } |
| 387 | |
| 388 | if (cmp2 == -1 || cmp3 == -1) /* TypeError */ |
| 389 | goto end; |
| 390 | if (cmp2 == 0 || cmp3 == 0) { /* ob outside of range */ |
| 391 | result = 0; |
| 392 | goto end; |
| 393 | } |
| 394 | |
| 395 | /* Check that the stride does not invalidate ob's membership. */ |
| 396 | tmp1 = PyNumber_Subtract(ob, r->start); |
| 397 | if (tmp1 == NULL) |
| 398 | goto end; |
| 399 | tmp2 = PyNumber_Remainder(tmp1, r->step); |
| 400 | if (tmp2 == NULL) |
| 401 | goto end; |
| 402 | /* result = (int(ob) - start % step) == 0 */ |
| 403 | result = PyObject_RichCompareBool(tmp2, zero, Py_EQ); |
| 404 | end: |
| 405 | Py_XDECREF(tmp1); |
| 406 | Py_XDECREF(tmp2); |
| 407 | Py_XDECREF(zero); |
| 408 | return result; |
| 409 | } |
| 410 | |
Mark Dickinson | 3e124ae | 2009-09-22 21:47:24 +0000 | [diff] [blame] | 411 | static int |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 412 | range_contains(rangeobject *r, PyObject *ob) |
| 413 | { |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 414 | if (PyLong_CheckExact(ob) || PyBool_Check(ob)) |
| 415 | return range_contains_long(r, ob); |
Mark Dickinson | 3e124ae | 2009-09-22 21:47:24 +0000 | [diff] [blame] | 416 | |
Mark Dickinson | 3e124ae | 2009-09-22 21:47:24 +0000 | [diff] [blame] | 417 | return (int)_PySequence_IterSearch((PyObject*)r, ob, |
| 418 | PY_ITERSEARCH_CONTAINS); |
| 419 | } |
| 420 | |
Mark Dickinson | 3664568 | 2011-10-23 19:53:01 +0100 | [diff] [blame] | 421 | /* Compare two range objects. Return 1 for equal, 0 for not equal |
| 422 | and -1 on error. The algorithm is roughly the C equivalent of |
| 423 | |
| 424 | if r0 is r1: |
| 425 | return True |
| 426 | if len(r0) != len(r1): |
| 427 | return False |
| 428 | if not len(r0): |
| 429 | return True |
| 430 | if r0.start != r1.start: |
| 431 | return False |
| 432 | if len(r0) == 1: |
| 433 | return True |
| 434 | return r0.step == r1.step |
| 435 | */ |
| 436 | static int |
| 437 | range_equals(rangeobject *r0, rangeobject *r1) |
| 438 | { |
| 439 | int cmp_result; |
| 440 | PyObject *one; |
| 441 | |
| 442 | if (r0 == r1) |
| 443 | return 1; |
| 444 | cmp_result = PyObject_RichCompareBool(r0->length, r1->length, Py_EQ); |
| 445 | /* Return False or error to the caller. */ |
| 446 | if (cmp_result != 1) |
| 447 | return cmp_result; |
| 448 | cmp_result = PyObject_Not(r0->length); |
| 449 | /* Return True or error to the caller. */ |
| 450 | if (cmp_result != 0) |
| 451 | return cmp_result; |
| 452 | cmp_result = PyObject_RichCompareBool(r0->start, r1->start, Py_EQ); |
| 453 | /* Return False or error to the caller. */ |
| 454 | if (cmp_result != 1) |
| 455 | return cmp_result; |
| 456 | one = PyLong_FromLong(1); |
| 457 | if (!one) |
| 458 | return -1; |
| 459 | cmp_result = PyObject_RichCompareBool(r0->length, one, Py_EQ); |
| 460 | Py_DECREF(one); |
| 461 | /* Return True or error to the caller. */ |
| 462 | if (cmp_result != 0) |
| 463 | return cmp_result; |
| 464 | return PyObject_RichCompareBool(r0->step, r1->step, Py_EQ); |
| 465 | } |
| 466 | |
| 467 | static PyObject * |
| 468 | range_richcompare(PyObject *self, PyObject *other, int op) |
| 469 | { |
| 470 | int result; |
| 471 | |
| 472 | if (!PyRange_Check(other)) |
| 473 | Py_RETURN_NOTIMPLEMENTED; |
| 474 | switch (op) { |
| 475 | case Py_NE: |
| 476 | case Py_EQ: |
| 477 | result = range_equals((rangeobject*)self, (rangeobject*)other); |
| 478 | if (result == -1) |
| 479 | return NULL; |
| 480 | if (op == Py_NE) |
| 481 | result = !result; |
| 482 | if (result) |
| 483 | Py_RETURN_TRUE; |
| 484 | else |
| 485 | Py_RETURN_FALSE; |
| 486 | case Py_LE: |
| 487 | case Py_GE: |
| 488 | case Py_LT: |
| 489 | case Py_GT: |
| 490 | Py_RETURN_NOTIMPLEMENTED; |
| 491 | default: |
| 492 | PyErr_BadArgument(); |
| 493 | return NULL; |
| 494 | } |
| 495 | } |
| 496 | |
| 497 | /* Hash function for range objects. Rough C equivalent of |
| 498 | |
| 499 | if not len(r): |
| 500 | return hash((len(r), None, None)) |
| 501 | if len(r) == 1: |
| 502 | return hash((len(r), r.start, None)) |
| 503 | return hash((len(r), r.start, r.step)) |
| 504 | */ |
| 505 | static Py_hash_t |
| 506 | range_hash(rangeobject *r) |
| 507 | { |
| 508 | PyObject *t; |
| 509 | Py_hash_t result = -1; |
| 510 | int cmp_result; |
| 511 | |
| 512 | t = PyTuple_New(3); |
| 513 | if (!t) |
| 514 | return -1; |
| 515 | Py_INCREF(r->length); |
| 516 | PyTuple_SET_ITEM(t, 0, r->length); |
| 517 | cmp_result = PyObject_Not(r->length); |
| 518 | if (cmp_result == -1) |
| 519 | goto end; |
| 520 | if (cmp_result == 1) { |
| 521 | Py_INCREF(Py_None); |
| 522 | Py_INCREF(Py_None); |
| 523 | PyTuple_SET_ITEM(t, 1, Py_None); |
| 524 | PyTuple_SET_ITEM(t, 2, Py_None); |
| 525 | } |
| 526 | else { |
| 527 | PyObject *one; |
| 528 | Py_INCREF(r->start); |
| 529 | PyTuple_SET_ITEM(t, 1, r->start); |
| 530 | one = PyLong_FromLong(1); |
| 531 | if (!one) |
| 532 | goto end; |
| 533 | cmp_result = PyObject_RichCompareBool(r->length, one, Py_EQ); |
| 534 | Py_DECREF(one); |
| 535 | if (cmp_result == -1) |
| 536 | goto end; |
| 537 | if (cmp_result == 1) { |
| 538 | Py_INCREF(Py_None); |
| 539 | PyTuple_SET_ITEM(t, 2, Py_None); |
| 540 | } |
| 541 | else { |
| 542 | Py_INCREF(r->step); |
| 543 | PyTuple_SET_ITEM(t, 2, r->step); |
| 544 | } |
| 545 | } |
| 546 | result = PyObject_Hash(t); |
| 547 | end: |
| 548 | Py_DECREF(t); |
| 549 | return result; |
| 550 | } |
| 551 | |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 552 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 553 | range_count(rangeobject *r, PyObject *ob) |
| 554 | { |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 555 | if (PyLong_CheckExact(ob) || PyBool_Check(ob)) { |
Georg Brandl | 7e5343b | 2010-11-20 22:40:10 +0000 | [diff] [blame] | 556 | int result = range_contains_long(r, ob); |
| 557 | if (result == -1) |
| 558 | return NULL; |
| 559 | else if (result) |
Benjamin Peterson | 0b458d5 | 2010-11-20 22:35:41 +0000 | [diff] [blame] | 560 | return PyLong_FromLong(1); |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 561 | else |
Benjamin Peterson | 0b458d5 | 2010-11-20 22:35:41 +0000 | [diff] [blame] | 562 | return PyLong_FromLong(0); |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 563 | } else { |
| 564 | Py_ssize_t count; |
| 565 | count = _PySequence_IterSearch((PyObject*)r, ob, PY_ITERSEARCH_COUNT); |
| 566 | if (count == -1) |
| 567 | return NULL; |
| 568 | return PyLong_FromSsize_t(count); |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 573 | range_index(rangeobject *r, PyObject *ob) |
| 574 | { |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 575 | int contains; |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 576 | |
| 577 | if (!PyLong_CheckExact(ob) && !PyBool_Check(ob)) { |
| 578 | Py_ssize_t index; |
| 579 | index = _PySequence_IterSearch((PyObject*)r, ob, PY_ITERSEARCH_INDEX); |
| 580 | if (index == -1) |
| 581 | return NULL; |
| 582 | return PyLong_FromSsize_t(index); |
| 583 | } |
| 584 | |
| 585 | contains = range_contains_long(r, ob); |
| 586 | if (contains == -1) |
| 587 | return NULL; |
| 588 | |
Benjamin Peterson | 155614b | 2010-11-20 22:44:32 +0000 | [diff] [blame] | 589 | if (contains) { |
| 590 | PyObject *idx, *tmp = PyNumber_Subtract(ob, r->start); |
| 591 | if (tmp == NULL) |
| 592 | return NULL; |
| 593 | /* idx = (ob - r.start) // r.step */ |
| 594 | idx = PyNumber_FloorDivide(tmp, r->step); |
| 595 | Py_DECREF(tmp); |
| 596 | return idx; |
| 597 | } |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 598 | |
| 599 | /* object is not in the range */ |
Benjamin Peterson | 155614b | 2010-11-20 22:44:32 +0000 | [diff] [blame] | 600 | PyErr_Format(PyExc_ValueError, "%R is not in range", ob); |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 601 | return NULL; |
| 602 | } |
| 603 | |
Guido van Rossum | c0b618a | 1997-05-02 03:12:38 +0000 | [diff] [blame] | 604 | static PySequenceMethods range_as_sequence = { |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 605 | (lenfunc)range_length, /* sq_length */ |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 606 | 0, /* sq_concat */ |
| 607 | 0, /* sq_repeat */ |
| 608 | (ssizeargfunc)range_item, /* sq_item */ |
| 609 | 0, /* sq_slice */ |
| 610 | 0, /* sq_ass_item */ |
| 611 | 0, /* sq_ass_slice */ |
Mark Dickinson | 3e124ae | 2009-09-22 21:47:24 +0000 | [diff] [blame] | 612 | (objobjproc)range_contains, /* sq_contains */ |
Guido van Rossum | 12d12c5 | 1993-10-26 17:58:25 +0000 | [diff] [blame] | 613 | }; |
| 614 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 615 | static PyObject * |
| 616 | range_repr(rangeobject *r) |
| 617 | { |
| 618 | Py_ssize_t istep; |
| 619 | |
| 620 | /* Check for special case values for printing. We don't always |
| 621 | need the step value. We don't care about errors |
| 622 | (it means overflow), so clear the errors. */ |
| 623 | istep = PyNumber_AsSsize_t(r->step, NULL); |
| 624 | if (istep != 1 || (istep == -1 && PyErr_Occurred())) { |
| 625 | PyErr_Clear(); |
| 626 | } |
| 627 | |
| 628 | if (istep == 1) |
| 629 | return PyUnicode_FromFormat("range(%R, %R)", r->start, r->stop); |
| 630 | else |
| 631 | return PyUnicode_FromFormat("range(%R, %R, %R)", |
| 632 | r->start, r->stop, r->step); |
| 633 | } |
| 634 | |
| 635 | /* Pickling support */ |
| 636 | static PyObject * |
| 637 | range_reduce(rangeobject *r, PyObject *args) |
| 638 | { |
| 639 | return Py_BuildValue("(O(OOO))", Py_TYPE(r), |
| 640 | r->start, r->stop, r->step); |
| 641 | } |
| 642 | |
| 643 | static PyObject * |
| 644 | range_subscript(rangeobject* self, PyObject* item) |
| 645 | { |
| 646 | if (PyIndex_Check(item)) { |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 647 | PyObject *i, *result; |
| 648 | i = PyNumber_Index(item); |
| 649 | if (!i) |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 650 | return NULL; |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 651 | result = compute_range_item(self, i); |
| 652 | Py_DECREF(i); |
| 653 | return result; |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 654 | } |
| 655 | if (PySlice_Check(item)) { |
Nick Coghlan | e993b10 | 2011-01-12 03:15:52 +0000 | [diff] [blame] | 656 | return compute_slice(self, item); |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 657 | } |
| 658 | PyErr_Format(PyExc_TypeError, |
| 659 | "range indices must be integers or slices, not %.200s", |
| 660 | item->ob_type->tp_name); |
| 661 | return NULL; |
| 662 | } |
| 663 | |
| 664 | |
| 665 | static PyMappingMethods range_as_mapping = { |
| 666 | (lenfunc)range_length, /* mp_length */ |
| 667 | (binaryfunc)range_subscript, /* mp_subscript */ |
| 668 | (objobjargproc)0, /* mp_ass_subscript */ |
| 669 | }; |
| 670 | |
Jeremy Hylton | 938ace6 | 2002-07-17 16:30:39 +0000 | [diff] [blame] | 671 | static PyObject * range_iter(PyObject *seq); |
Raymond Hettinger | 85c20a4 | 2003-11-06 14:06:48 +0000 | [diff] [blame] | 672 | static PyObject * range_reverse(PyObject *seq); |
| 673 | |
| 674 | PyDoc_STRVAR(reverse_doc, |
| 675 | "Returns a reverse iterator."); |
| 676 | |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 677 | PyDoc_STRVAR(count_doc, |
| 678 | "rangeobject.count(value) -> integer -- return number of occurrences of value"); |
| 679 | |
| 680 | PyDoc_STRVAR(index_doc, |
| 681 | "rangeobject.index(value, [start, [stop]]) -> integer -- return index of value.\n" |
| 682 | "Raises ValueError if the value is not present."); |
| 683 | |
Raymond Hettinger | 85c20a4 | 2003-11-06 14:06:48 +0000 | [diff] [blame] | 684 | static PyMethodDef range_methods[] = { |
Daniel Stutzbach | 9f0cbf1 | 2010-09-13 21:16:29 +0000 | [diff] [blame] | 685 | {"__reversed__", (PyCFunction)range_reverse, METH_NOARGS, reverse_doc}, |
| 686 | {"__reduce__", (PyCFunction)range_reduce, METH_VARARGS}, |
| 687 | {"count", (PyCFunction)range_count, METH_O, count_doc}, |
| 688 | {"index", (PyCFunction)range_index, METH_O, index_doc}, |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 689 | {NULL, NULL} /* sentinel */ |
Raymond Hettinger | 85c20a4 | 2003-11-06 14:06:48 +0000 | [diff] [blame] | 690 | }; |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 691 | |
Benjamin Peterson | 878ce38 | 2011-11-05 15:17:52 -0400 | [diff] [blame] | 692 | static PyMemberDef range_members[] = { |
| 693 | {"start", T_OBJECT_EX, offsetof(rangeobject, start), READONLY}, |
| 694 | {"stop", T_OBJECT_EX, offsetof(rangeobject, stop), READONLY}, |
| 695 | {"step", T_OBJECT_EX, offsetof(rangeobject, step), READONLY}, |
| 696 | {0} |
| 697 | }; |
| 698 | |
Guido van Rossum | c0b618a | 1997-05-02 03:12:38 +0000 | [diff] [blame] | 699 | PyTypeObject PyRange_Type = { |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 700 | PyVarObject_HEAD_INIT(&PyType_Type, 0) |
| 701 | "range", /* Name of this type */ |
| 702 | sizeof(rangeobject), /* Basic object size */ |
| 703 | 0, /* Item size for varobject */ |
| 704 | (destructor)range_dealloc, /* tp_dealloc */ |
| 705 | 0, /* tp_print */ |
| 706 | 0, /* tp_getattr */ |
| 707 | 0, /* tp_setattr */ |
| 708 | 0, /* tp_reserved */ |
| 709 | (reprfunc)range_repr, /* tp_repr */ |
| 710 | 0, /* tp_as_number */ |
| 711 | &range_as_sequence, /* tp_as_sequence */ |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 712 | &range_as_mapping, /* tp_as_mapping */ |
Mark Dickinson | 3664568 | 2011-10-23 19:53:01 +0100 | [diff] [blame] | 713 | (hashfunc)range_hash, /* tp_hash */ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 714 | 0, /* tp_call */ |
| 715 | 0, /* tp_str */ |
| 716 | PyObject_GenericGetAttr, /* tp_getattro */ |
| 717 | 0, /* tp_setattro */ |
| 718 | 0, /* tp_as_buffer */ |
| 719 | Py_TPFLAGS_DEFAULT, /* tp_flags */ |
| 720 | range_doc, /* tp_doc */ |
| 721 | 0, /* tp_traverse */ |
| 722 | 0, /* tp_clear */ |
Mark Dickinson | 3664568 | 2011-10-23 19:53:01 +0100 | [diff] [blame] | 723 | range_richcompare, /* tp_richcompare */ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 724 | 0, /* tp_weaklistoffset */ |
| 725 | range_iter, /* tp_iter */ |
| 726 | 0, /* tp_iternext */ |
| 727 | range_methods, /* tp_methods */ |
Benjamin Peterson | 878ce38 | 2011-11-05 15:17:52 -0400 | [diff] [blame] | 728 | range_members, /* tp_members */ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 729 | 0, /* tp_getset */ |
| 730 | 0, /* tp_base */ |
| 731 | 0, /* tp_dict */ |
| 732 | 0, /* tp_descr_get */ |
| 733 | 0, /* tp_descr_set */ |
| 734 | 0, /* tp_dictoffset */ |
| 735 | 0, /* tp_init */ |
| 736 | 0, /* tp_alloc */ |
| 737 | range_new, /* tp_new */ |
Guido van Rossum | 12d12c5 | 1993-10-26 17:58:25 +0000 | [diff] [blame] | 738 | }; |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 739 | |
Walter Dörwald | 4ad9421 | 2007-05-21 18:01:17 +0000 | [diff] [blame] | 740 | /*********************** range Iterator **************************/ |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 741 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 742 | /* There are 2 types of iterators, one for C longs, the other for |
Serhiy Storchaka | 9594942 | 2013-08-27 19:40:23 +0300 | [diff] [blame] | 743 | Python ints (ie, PyObjects). This should make iteration fast |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 744 | in the normal case, but possible for any numeric value. |
| 745 | */ |
| 746 | |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 747 | typedef struct { |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 748 | PyObject_HEAD |
| 749 | long index; |
| 750 | long start; |
| 751 | long step; |
| 752 | long len; |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 753 | } rangeiterobject; |
| 754 | |
Raymond Hettinger | 85c20a4 | 2003-11-06 14:06:48 +0000 | [diff] [blame] | 755 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 756 | rangeiter_next(rangeiterobject *r) |
| 757 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 758 | if (r->index < r->len) |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 759 | /* cast to unsigned to avoid possible signed overflow |
Mark Dickinson | b43dbc2 | 2009-11-15 12:56:08 +0000 | [diff] [blame] | 760 | in intermediate calculations. */ |
| 761 | return PyLong_FromLong((long)(r->start + |
| 762 | (unsigned long)(r->index++) * r->step)); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 763 | return NULL; |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 764 | } |
| 765 | |
Raymond Hettinger | 6b27cda | 2005-09-24 21:23:05 +0000 | [diff] [blame] | 766 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 767 | rangeiter_len(rangeiterobject *r) |
| 768 | { |
Christian Heimes | 217cfd1 | 2007-12-02 14:31:20 +0000 | [diff] [blame] | 769 | return PyLong_FromLong(r->len - r->index); |
Raymond Hettinger | ef9bf40 | 2004-03-10 10:10:42 +0000 | [diff] [blame] | 770 | } |
| 771 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 772 | PyDoc_STRVAR(length_hint_doc, |
| 773 | "Private method returning an estimate of len(list(it))."); |
Raymond Hettinger | ef9bf40 | 2004-03-10 10:10:42 +0000 | [diff] [blame] | 774 | |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 775 | static PyObject * |
| 776 | rangeiter_reduce(rangeiterobject *r) |
| 777 | { |
| 778 | PyObject *start=NULL, *stop=NULL, *step=NULL; |
| 779 | PyObject *range; |
Chris Jerdonek | 042fa65 | 2012-10-07 14:56:27 -0700 | [diff] [blame] | 780 | |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 781 | /* create a range object for pickling */ |
| 782 | start = PyLong_FromLong(r->start); |
| 783 | if (start == NULL) |
| 784 | goto err; |
| 785 | stop = PyLong_FromLong(r->start + r->len * r->step); |
| 786 | if (stop == NULL) |
| 787 | goto err; |
| 788 | step = PyLong_FromLong(r->step); |
| 789 | if (step == NULL) |
| 790 | goto err; |
| 791 | range = (PyObject*)make_range_object(&PyRange_Type, |
| 792 | start, stop, step); |
| 793 | if (range == NULL) |
| 794 | goto err; |
| 795 | /* return the result */ |
Antoine Pitrou | a701388 | 2012-04-05 00:04:20 +0200 | [diff] [blame] | 796 | return Py_BuildValue("N(N)i", _PyObject_GetBuiltin("iter"), range, r->index); |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 797 | err: |
| 798 | Py_XDECREF(start); |
| 799 | Py_XDECREF(stop); |
| 800 | Py_XDECREF(step); |
| 801 | return NULL; |
| 802 | } |
| 803 | |
| 804 | static PyObject * |
| 805 | rangeiter_setstate(rangeiterobject *r, PyObject *state) |
| 806 | { |
| 807 | long index = PyLong_AsLong(state); |
| 808 | if (index == -1 && PyErr_Occurred()) |
| 809 | return NULL; |
| 810 | if (index < 0 || index >= r->len) { |
| 811 | PyErr_SetString(PyExc_ValueError, "index out of range"); |
| 812 | return NULL; |
| 813 | } |
| 814 | r->index = index; |
| 815 | Py_RETURN_NONE; |
| 816 | } |
| 817 | |
| 818 | PyDoc_STRVAR(reduce_doc, "Return state information for pickling."); |
| 819 | PyDoc_STRVAR(setstate_doc, "Set state information for unpickling."); |
| 820 | |
Raymond Hettinger | 6b27cda | 2005-09-24 21:23:05 +0000 | [diff] [blame] | 821 | static PyMethodDef rangeiter_methods[] = { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 822 | {"__length_hint__", (PyCFunction)rangeiter_len, METH_NOARGS, |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 823 | length_hint_doc}, |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 824 | {"__reduce__", (PyCFunction)rangeiter_reduce, METH_NOARGS, |
| 825 | reduce_doc}, |
| 826 | {"__setstate__", (PyCFunction)rangeiter_setstate, METH_O, |
| 827 | setstate_doc}, |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 828 | {NULL, NULL} /* sentinel */ |
Raymond Hettinger | 6b27cda | 2005-09-24 21:23:05 +0000 | [diff] [blame] | 829 | }; |
Raymond Hettinger | ef9bf40 | 2004-03-10 10:10:42 +0000 | [diff] [blame] | 830 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 831 | static PyObject *rangeiter_new(PyTypeObject *, PyObject *args, PyObject *kw); |
| 832 | |
Christian Heimes | a22e8bd | 2007-11-29 22:35:39 +0000 | [diff] [blame] | 833 | PyTypeObject PyRangeIter_Type = { |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 834 | PyVarObject_HEAD_INIT(&PyType_Type, 0) |
| 835 | "range_iterator", /* tp_name */ |
| 836 | sizeof(rangeiterobject), /* tp_basicsize */ |
| 837 | 0, /* tp_itemsize */ |
| 838 | /* methods */ |
| 839 | (destructor)PyObject_Del, /* tp_dealloc */ |
| 840 | 0, /* tp_print */ |
| 841 | 0, /* tp_getattr */ |
| 842 | 0, /* tp_setattr */ |
| 843 | 0, /* tp_reserved */ |
| 844 | 0, /* tp_repr */ |
| 845 | 0, /* tp_as_number */ |
| 846 | 0, /* tp_as_sequence */ |
| 847 | 0, /* tp_as_mapping */ |
| 848 | 0, /* tp_hash */ |
| 849 | 0, /* tp_call */ |
| 850 | 0, /* tp_str */ |
| 851 | PyObject_GenericGetAttr, /* tp_getattro */ |
| 852 | 0, /* tp_setattro */ |
| 853 | 0, /* tp_as_buffer */ |
| 854 | Py_TPFLAGS_DEFAULT, /* tp_flags */ |
| 855 | 0, /* tp_doc */ |
| 856 | 0, /* tp_traverse */ |
| 857 | 0, /* tp_clear */ |
| 858 | 0, /* tp_richcompare */ |
| 859 | 0, /* tp_weaklistoffset */ |
| 860 | PyObject_SelfIter, /* tp_iter */ |
| 861 | (iternextfunc)rangeiter_next, /* tp_iternext */ |
| 862 | rangeiter_methods, /* tp_methods */ |
| 863 | 0, /* tp_members */ |
| 864 | 0, /* tp_getset */ |
| 865 | 0, /* tp_base */ |
| 866 | 0, /* tp_dict */ |
| 867 | 0, /* tp_descr_get */ |
| 868 | 0, /* tp_descr_set */ |
| 869 | 0, /* tp_dictoffset */ |
| 870 | 0, /* tp_init */ |
| 871 | 0, /* tp_alloc */ |
| 872 | rangeiter_new, /* tp_new */ |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 873 | }; |
| 874 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 875 | /* Return number of items in range (lo, hi, step). step != 0 |
| 876 | * required. The result always fits in an unsigned long. |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 877 | */ |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 878 | static unsigned long |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 879 | get_len_of_range(long lo, long hi, long step) |
| 880 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 881 | /* ------------------------------------------------------------- |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 882 | If step > 0 and lo >= hi, or step < 0 and lo <= hi, the range is empty. |
| 883 | Else for step > 0, if n values are in the range, the last one is |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 884 | lo + (n-1)*step, which must be <= hi-1. Rearranging, |
| 885 | n <= (hi - lo - 1)/step + 1, so taking the floor of the RHS gives |
| 886 | the proper value. Since lo < hi in this case, hi-lo-1 >= 0, so |
| 887 | the RHS is non-negative and so truncation is the same as the |
| 888 | floor. Letting M be the largest positive long, the worst case |
| 889 | for the RHS numerator is hi=M, lo=-M-1, and then |
| 890 | hi-lo-1 = M-(-M-1)-1 = 2*M. Therefore unsigned long has enough |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 891 | precision to compute the RHS exactly. The analysis for step < 0 |
| 892 | is similar. |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 893 | ---------------------------------------------------------------*/ |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 894 | assert(step != 0); |
| 895 | if (step > 0 && lo < hi) |
| 896 | return 1UL + (hi - 1UL - lo) / step; |
| 897 | else if (step < 0 && lo > hi) |
| 898 | return 1UL + (lo - 1UL - hi) / (0UL - step); |
| 899 | else |
| 900 | return 0UL; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 901 | } |
| 902 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 903 | /* Initialize a rangeiter object. If the length of the rangeiter object |
| 904 | is not representable as a C long, OverflowError is raised. */ |
| 905 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 906 | static PyObject * |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 907 | fast_range_iter(long start, long stop, long step) |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 908 | { |
Christian Heimes | a22e8bd | 2007-11-29 22:35:39 +0000 | [diff] [blame] | 909 | rangeiterobject *it = PyObject_New(rangeiterobject, &PyRangeIter_Type); |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 910 | unsigned long ulen; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 911 | if (it == NULL) |
| 912 | return NULL; |
| 913 | it->start = start; |
| 914 | it->step = step; |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 915 | ulen = get_len_of_range(start, stop, step); |
| 916 | if (ulen > (unsigned long)LONG_MAX) { |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 917 | Py_DECREF(it); |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 918 | PyErr_SetString(PyExc_OverflowError, |
| 919 | "range too large to represent as a range_iterator"); |
| 920 | return NULL; |
| 921 | } |
| 922 | it->len = (long)ulen; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 923 | it->index = 0; |
| 924 | return (PyObject *)it; |
| 925 | } |
| 926 | |
| 927 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 928 | rangeiter_new(PyTypeObject *type, PyObject *args, PyObject *kw) |
| 929 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 930 | long start, stop, step; |
| 931 | |
| 932 | if (!_PyArg_NoKeywords("rangeiter()", kw)) |
| 933 | return NULL; |
| 934 | |
| 935 | if (!PyArg_ParseTuple(args, "lll;rangeiter() requires 3 int arguments", |
| 936 | &start, &stop, &step)) |
| 937 | return NULL; |
| 938 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 939 | return fast_range_iter(start, stop, step); |
| 940 | } |
| 941 | |
| 942 | typedef struct { |
| 943 | PyObject_HEAD |
| 944 | PyObject *index; |
| 945 | PyObject *start; |
| 946 | PyObject *step; |
| 947 | PyObject *len; |
| 948 | } longrangeiterobject; |
| 949 | |
| 950 | static PyObject * |
| 951 | longrangeiter_len(longrangeiterobject *r, PyObject *no_args) |
| 952 | { |
| 953 | return PyNumber_Subtract(r->len, r->index); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 954 | } |
| 955 | |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 956 | static PyObject * |
| 957 | longrangeiter_reduce(longrangeiterobject *r) |
| 958 | { |
| 959 | PyObject *product, *stop=NULL; |
| 960 | PyObject *range; |
| 961 | |
| 962 | /* create a range object for pickling. Must calculate the "stop" value */ |
| 963 | product = PyNumber_Multiply(r->len, r->step); |
| 964 | if (product == NULL) |
| 965 | return NULL; |
| 966 | stop = PyNumber_Add(r->start, product); |
| 967 | Py_DECREF(product); |
| 968 | if (stop == NULL) |
| 969 | return NULL; |
| 970 | Py_INCREF(r->start); |
| 971 | Py_INCREF(r->step); |
| 972 | range = (PyObject*)make_range_object(&PyRange_Type, |
| 973 | r->start, stop, r->step); |
| 974 | if (range == NULL) { |
| 975 | Py_DECREF(r->start); |
| 976 | Py_DECREF(stop); |
| 977 | Py_DECREF(r->step); |
| 978 | return NULL; |
| 979 | } |
| 980 | |
| 981 | /* return the result */ |
Antoine Pitrou | a701388 | 2012-04-05 00:04:20 +0200 | [diff] [blame] | 982 | return Py_BuildValue("N(N)O", _PyObject_GetBuiltin("iter"), range, r->index); |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 983 | } |
| 984 | |
| 985 | static PyObject * |
| 986 | longrangeiter_setstate(longrangeiterobject *r, PyObject *state) |
| 987 | { |
| 988 | Py_CLEAR(r->index); |
| 989 | r->index = state; |
| 990 | Py_INCREF(r->index); |
| 991 | Py_RETURN_NONE; |
| 992 | } |
| 993 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 994 | static PyMethodDef longrangeiter_methods[] = { |
| 995 | {"__length_hint__", (PyCFunction)longrangeiter_len, METH_NOARGS, |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 996 | length_hint_doc}, |
Kristján Valur Jónsson | 31668b8 | 2012-04-03 10:49:41 +0000 | [diff] [blame] | 997 | {"__reduce__", (PyCFunction)longrangeiter_reduce, METH_NOARGS, |
| 998 | reduce_doc}, |
| 999 | {"__setstate__", (PyCFunction)longrangeiter_setstate, METH_O, |
| 1000 | setstate_doc}, |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 1001 | {NULL, NULL} /* sentinel */ |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1002 | }; |
| 1003 | |
| 1004 | static void |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 1005 | longrangeiter_dealloc(longrangeiterobject *r) |
| 1006 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1007 | Py_XDECREF(r->index); |
Guido van Rossum | 317e774 | 2007-05-08 15:18:31 +0000 | [diff] [blame] | 1008 | Py_XDECREF(r->start); |
| 1009 | Py_XDECREF(r->step); |
| 1010 | Py_XDECREF(r->len); |
Amaury Forgeot d'Arc | b7f17e4 | 2007-11-15 20:52:21 +0000 | [diff] [blame] | 1011 | PyObject_Del(r); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1012 | } |
| 1013 | |
| 1014 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 1015 | longrangeiter_next(longrangeiterobject *r) |
| 1016 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1017 | PyObject *one, *product, *new_index, *result; |
| 1018 | if (PyObject_RichCompareBool(r->index, r->len, Py_LT) != 1) |
| 1019 | return NULL; |
| 1020 | |
| 1021 | one = PyLong_FromLong(1); |
| 1022 | if (!one) |
| 1023 | return NULL; |
| 1024 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1025 | new_index = PyNumber_Add(r->index, one); |
| 1026 | Py_DECREF(one); |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 1027 | if (!new_index) |
| 1028 | return NULL; |
| 1029 | |
| 1030 | product = PyNumber_Multiply(r->index, r->step); |
| 1031 | if (!product) { |
| 1032 | Py_DECREF(new_index); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1033 | return NULL; |
| 1034 | } |
| 1035 | |
| 1036 | result = PyNumber_Add(r->start, product); |
| 1037 | Py_DECREF(product); |
| 1038 | if (result) { |
| 1039 | Py_DECREF(r->index); |
| 1040 | r->index = new_index; |
| 1041 | } |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 1042 | else { |
| 1043 | Py_DECREF(new_index); |
| 1044 | } |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1045 | |
| 1046 | return result; |
| 1047 | } |
| 1048 | |
Christian Heimes | a22e8bd | 2007-11-29 22:35:39 +0000 | [diff] [blame] | 1049 | PyTypeObject PyLongRangeIter_Type = { |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 1050 | PyVarObject_HEAD_INIT(&PyType_Type, 0) |
| 1051 | "longrange_iterator", /* tp_name */ |
| 1052 | sizeof(longrangeiterobject), /* tp_basicsize */ |
| 1053 | 0, /* tp_itemsize */ |
| 1054 | /* methods */ |
| 1055 | (destructor)longrangeiter_dealloc, /* tp_dealloc */ |
| 1056 | 0, /* tp_print */ |
| 1057 | 0, /* tp_getattr */ |
| 1058 | 0, /* tp_setattr */ |
| 1059 | 0, /* tp_reserved */ |
| 1060 | 0, /* tp_repr */ |
| 1061 | 0, /* tp_as_number */ |
| 1062 | 0, /* tp_as_sequence */ |
| 1063 | 0, /* tp_as_mapping */ |
| 1064 | 0, /* tp_hash */ |
| 1065 | 0, /* tp_call */ |
| 1066 | 0, /* tp_str */ |
| 1067 | PyObject_GenericGetAttr, /* tp_getattro */ |
| 1068 | 0, /* tp_setattro */ |
| 1069 | 0, /* tp_as_buffer */ |
| 1070 | Py_TPFLAGS_DEFAULT, /* tp_flags */ |
| 1071 | 0, /* tp_doc */ |
| 1072 | 0, /* tp_traverse */ |
| 1073 | 0, /* tp_clear */ |
| 1074 | 0, /* tp_richcompare */ |
| 1075 | 0, /* tp_weaklistoffset */ |
| 1076 | PyObject_SelfIter, /* tp_iter */ |
| 1077 | (iternextfunc)longrangeiter_next, /* tp_iternext */ |
| 1078 | longrangeiter_methods, /* tp_methods */ |
| 1079 | 0, |
Raymond Hettinger | 48165d4 | 2002-06-05 20:08:48 +0000 | [diff] [blame] | 1080 | }; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1081 | |
| 1082 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 1083 | range_iter(PyObject *seq) |
| 1084 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1085 | rangeobject *r = (rangeobject *)seq; |
| 1086 | longrangeiterobject *it; |
Martin v. Löwis | 8445104 | 2007-12-20 22:57:23 +0000 | [diff] [blame] | 1087 | long lstart, lstop, lstep; |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1088 | PyObject *int_it; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1089 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1090 | assert(PyRange_Check(seq)); |
Martin v. Löwis | 8445104 | 2007-12-20 22:57:23 +0000 | [diff] [blame] | 1091 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1092 | /* If all three fields and the length convert to long, use the int |
| 1093 | * version */ |
Martin v. Löwis | 8445104 | 2007-12-20 22:57:23 +0000 | [diff] [blame] | 1094 | lstart = PyLong_AsLong(r->start); |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1095 | if (lstart == -1 && PyErr_Occurred()) { |
| 1096 | PyErr_Clear(); |
| 1097 | goto long_range; |
Martin v. Löwis | 8445104 | 2007-12-20 22:57:23 +0000 | [diff] [blame] | 1098 | } |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1099 | lstop = PyLong_AsLong(r->stop); |
| 1100 | if (lstop == -1 && PyErr_Occurred()) { |
| 1101 | PyErr_Clear(); |
| 1102 | goto long_range; |
| 1103 | } |
| 1104 | lstep = PyLong_AsLong(r->step); |
| 1105 | if (lstep == -1 && PyErr_Occurred()) { |
| 1106 | PyErr_Clear(); |
| 1107 | goto long_range; |
| 1108 | } |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1109 | int_it = fast_range_iter(lstart, lstop, lstep); |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1110 | if (int_it == NULL && PyErr_ExceptionMatches(PyExc_OverflowError)) { |
| 1111 | PyErr_Clear(); |
| 1112 | goto long_range; |
| 1113 | } |
| 1114 | return (PyObject *)int_it; |
| 1115 | |
| 1116 | long_range: |
Christian Heimes | a22e8bd | 2007-11-29 22:35:39 +0000 | [diff] [blame] | 1117 | it = PyObject_New(longrangeiterobject, &PyLongRangeIter_Type); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1118 | if (it == NULL) |
| 1119 | return NULL; |
Guido van Rossum | 317e774 | 2007-05-08 15:18:31 +0000 | [diff] [blame] | 1120 | |
| 1121 | /* Do all initialization here, so we can DECREF on failure. */ |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1122 | it->start = r->start; |
Guido van Rossum | 317e774 | 2007-05-08 15:18:31 +0000 | [diff] [blame] | 1123 | it->step = r->step; |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1124 | it->len = r->length; |
Guido van Rossum | 317e774 | 2007-05-08 15:18:31 +0000 | [diff] [blame] | 1125 | Py_INCREF(it->start); |
| 1126 | Py_INCREF(it->step); |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1127 | Py_INCREF(it->len); |
Guido van Rossum | 317e774 | 2007-05-08 15:18:31 +0000 | [diff] [blame] | 1128 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1129 | it->index = PyLong_FromLong(0); |
| 1130 | if (!it->index) |
| 1131 | goto create_failure; |
| 1132 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1133 | return (PyObject *)it; |
| 1134 | |
| 1135 | create_failure: |
Guido van Rossum | 317e774 | 2007-05-08 15:18:31 +0000 | [diff] [blame] | 1136 | Py_DECREF(it); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1137 | return NULL; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1138 | } |
| 1139 | |
| 1140 | static PyObject * |
Benjamin Peterson | a1864f3 | 2010-11-20 23:05:39 +0000 | [diff] [blame] | 1141 | range_reverse(PyObject *seq) |
| 1142 | { |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1143 | rangeobject *range = (rangeobject*) seq; |
| 1144 | longrangeiterobject *it; |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1145 | PyObject *one, *sum, *diff, *product; |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1146 | long lstart, lstop, lstep, new_start, new_stop; |
| 1147 | unsigned long ulen; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1148 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1149 | assert(PyRange_Check(seq)); |
Martin v. Löwis | 8445104 | 2007-12-20 22:57:23 +0000 | [diff] [blame] | 1150 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1151 | /* reversed(range(start, stop, step)) can be expressed as |
| 1152 | range(start+(n-1)*step, start-step, -step), where n is the number of |
| 1153 | integers in the range. |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1154 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1155 | If each of start, stop, step, -step, start-step, and the length |
| 1156 | of the iterator is representable as a C long, use the int |
| 1157 | version. This excludes some cases where the reversed range is |
| 1158 | representable as a range_iterator, but it's good enough for |
| 1159 | common cases and it makes the checks simple. */ |
| 1160 | |
| 1161 | lstart = PyLong_AsLong(range->start); |
| 1162 | if (lstart == -1 && PyErr_Occurred()) { |
| 1163 | PyErr_Clear(); |
| 1164 | goto long_range; |
| 1165 | } |
| 1166 | lstop = PyLong_AsLong(range->stop); |
| 1167 | if (lstop == -1 && PyErr_Occurred()) { |
| 1168 | PyErr_Clear(); |
| 1169 | goto long_range; |
| 1170 | } |
| 1171 | lstep = PyLong_AsLong(range->step); |
| 1172 | if (lstep == -1 && PyErr_Occurred()) { |
| 1173 | PyErr_Clear(); |
| 1174 | goto long_range; |
| 1175 | } |
| 1176 | /* check for possible overflow of -lstep */ |
| 1177 | if (lstep == LONG_MIN) |
| 1178 | goto long_range; |
| 1179 | |
| 1180 | /* check for overflow of lstart - lstep: |
| 1181 | |
| 1182 | for lstep > 0, need only check whether lstart - lstep < LONG_MIN. |
| 1183 | for lstep < 0, need only check whether lstart - lstep > LONG_MAX |
| 1184 | |
| 1185 | Rearrange these inequalities as: |
| 1186 | |
| 1187 | lstart - LONG_MIN < lstep (lstep > 0) |
| 1188 | LONG_MAX - lstart < -lstep (lstep < 0) |
| 1189 | |
| 1190 | and compute both sides as unsigned longs, to avoid the |
| 1191 | possibility of undefined behaviour due to signed overflow. */ |
| 1192 | |
| 1193 | if (lstep > 0) { |
| 1194 | if ((unsigned long)lstart - LONG_MIN < (unsigned long)lstep) |
| 1195 | goto long_range; |
| 1196 | } |
| 1197 | else { |
| 1198 | if (LONG_MAX - (unsigned long)lstart < 0UL - lstep) |
| 1199 | goto long_range; |
| 1200 | } |
| 1201 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1202 | ulen = get_len_of_range(lstart, lstop, lstep); |
| 1203 | if (ulen > (unsigned long)LONG_MAX) |
| 1204 | goto long_range; |
| 1205 | |
| 1206 | new_stop = lstart - lstep; |
| 1207 | new_start = (long)(new_stop + ulen * lstep); |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1208 | return fast_range_iter(new_start, new_stop, -lstep); |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1209 | |
| 1210 | long_range: |
Christian Heimes | a22e8bd | 2007-11-29 22:35:39 +0000 | [diff] [blame] | 1211 | it = PyObject_New(longrangeiterobject, &PyLongRangeIter_Type); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1212 | if (it == NULL) |
| 1213 | return NULL; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1214 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1215 | /* start + (len - 1) * step */ |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1216 | it->len = range->length; |
| 1217 | Py_INCREF(it->len); |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 1218 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1219 | one = PyLong_FromLong(1); |
| 1220 | if (!one) |
| 1221 | goto create_failure; |
| 1222 | |
Nick Coghlan | 37ee850 | 2010-12-03 14:26:13 +0000 | [diff] [blame] | 1223 | diff = PyNumber_Subtract(it->len, one); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1224 | Py_DECREF(one); |
| 1225 | if (!diff) |
| 1226 | goto create_failure; |
| 1227 | |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1228 | product = PyNumber_Multiply(diff, range->step); |
| 1229 | Py_DECREF(diff); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1230 | if (!product) |
| 1231 | goto create_failure; |
| 1232 | |
| 1233 | sum = PyNumber_Add(range->start, product); |
| 1234 | Py_DECREF(product); |
| 1235 | it->start = sum; |
| 1236 | if (!it->start) |
| 1237 | goto create_failure; |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1238 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1239 | it->step = PyNumber_Negative(range->step); |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 1240 | if (!it->step) |
Mark Dickinson | d550c9a | 2009-11-15 09:57:26 +0000 | [diff] [blame] | 1241 | goto create_failure; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1242 | |
| 1243 | it->index = PyLong_FromLong(0); |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 1244 | if (!it->index) |
| 1245 | goto create_failure; |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1246 | |
| 1247 | return (PyObject *)it; |
| 1248 | |
| 1249 | create_failure: |
Benjamin Peterson | 36fbb73 | 2009-11-16 00:34:25 +0000 | [diff] [blame] | 1250 | Py_DECREF(it); |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 1251 | return NULL; |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 1252 | } |