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-rw-r--r--Objects/rangeobject.c216
1 files changed, 15 insertions, 201 deletions
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index f2030c3..c4ba715 100644
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -139,7 +139,11 @@ PyDoc_STRVAR(range_doc,
"range(stop) -> range object\n\
range(start, stop[, step]) -> range object\n\
\n\
-Return a virtual sequence of numbers from start to stop by step.");
+Return an object that produces a sequence of integers from start (inclusive)\n\
+to stop (exclusive) by step. range(i, j) produces i, i+1, i+2, ..., j-1.\n\
+start defaults to 0, and stop is omitted! range(4) produces 0, 1, 2, 3.\n\
+These are exactly the valid indices for a list of 4 elements.\n\
+When step is given, it specifies the increment (or decrement).");
static void
range_dealloc(rangeobject *r)
@@ -190,8 +194,11 @@ compute_range_length(PyObject *start, PyObject *stop, PyObject *step)
}
/* if (lo >= hi), return length of 0. */
- if (PyObject_RichCompareBool(lo, hi, Py_GE) == 1) {
+ cmp_result = PyObject_RichCompareBool(lo, hi, Py_GE);
+ if (cmp_result != 0) {
Py_XDECREF(step);
+ if (cmp_result < 0)
+ return NULL;
return PyLong_FromLong(0);
}
@@ -318,195 +325,6 @@ range_item(rangeobject *r, Py_ssize_t i)
return res;
}
-/* Additional helpers, since the standard slice helpers
- * all clip to PY_SSIZE_T_MAX
- */
-
-/* Replace _PyEval_SliceIndex */
-static PyObject *
-compute_slice_element(PyObject *obj)
-{
- PyObject *result = NULL;
- if (obj != NULL) {
- if (PyIndex_Check(obj)) {
- result = PyNumber_Index(obj);
- }
- else {
- PyErr_SetString(PyExc_TypeError,
- "slice indices must be integers or "
- "None or have an __index__ method");
- }
- }
- return result;
-}
-
-/* Replace PySlice_GetIndicesEx
- * Result indicates whether or not the slice is empty
- * (-1 = error, 0 = empty slice, 1 = slice contains elements)
- */
-static int
-compute_slice_indices(rangeobject *r, PySliceObject *slice,
- PyObject **start, PyObject **stop, PyObject **step)
-{
- int cmp_result, has_elements;
- Py_ssize_t clamped_step = 0;
- PyObject *zero = NULL, *one = NULL, *neg_one = NULL, *candidate = NULL;
- PyObject *tmp_start = NULL, *tmp_stop = NULL, *tmp_step = NULL;
- zero = PyLong_FromLong(0);
- if (zero == NULL) goto Fail;
- one = PyLong_FromLong(1);
- if (one == NULL) goto Fail;
- neg_one = PyLong_FromLong(-1);
- if (neg_one == NULL) goto Fail;
-
- /* Calculate step value */
- if (slice->step == Py_None) {
- clamped_step = 1;
- tmp_step = one;
- Py_INCREF(tmp_step);
- } else {
- if (!_PyEval_SliceIndex(slice->step, &clamped_step)) goto Fail;
- if (clamped_step == 0) {
- PyErr_SetString(PyExc_ValueError,
- "slice step cannot be zero");
- goto Fail;
- }
- tmp_step = compute_slice_element(slice->step);
- if (tmp_step == NULL) goto Fail;
- }
-
- /* Calculate start value */
- if (slice->start == Py_None) {
- if (clamped_step < 0) {
- tmp_start = PyNumber_Subtract(r->length, one);
- if (tmp_start == NULL) goto Fail;
- } else {
- tmp_start = zero;
- Py_INCREF(tmp_start);
- }
- } else {
- candidate = compute_slice_element(slice->start);
- if (candidate == NULL) goto Fail;
- cmp_result = PyObject_RichCompareBool(candidate, zero, Py_LT);
- if (cmp_result == -1) goto Fail;
- if (cmp_result) {
- /* candidate < 0 */
- tmp_start = PyNumber_Add(r->length, candidate);
- if (tmp_start == NULL) goto Fail;
- Py_CLEAR(candidate);
- } else {
- /* candidate >= 0 */
- tmp_start = candidate;
- candidate = NULL;
- }
- cmp_result = PyObject_RichCompareBool(tmp_start, zero, Py_LT);
- if (cmp_result == -1) goto Fail;
- if (cmp_result) {
- /* tmp_start < 0 */
- Py_CLEAR(tmp_start);
- if (clamped_step < 0) {
- tmp_start = neg_one;
- } else {
- tmp_start = zero;
- }
- Py_INCREF(tmp_start);
- } else {
- /* tmp_start >= 0 */
- cmp_result = PyObject_RichCompareBool(tmp_start, r->length, Py_GE);
- if (cmp_result == -1) goto Fail;
- if (cmp_result) {
- /* tmp_start >= r->length */
- Py_CLEAR(tmp_start);
- if (clamped_step < 0) {
- tmp_start = PyNumber_Subtract(r->length, one);
- if (tmp_start == NULL) goto Fail;
- } else {
- tmp_start = r->length;
- Py_INCREF(tmp_start);
- }
- }
- }
- }
-
- /* Calculate stop value */
- if (slice->stop == Py_None) {
- if (clamped_step < 0) {
- tmp_stop = neg_one;
- } else {
- tmp_stop = r->length;
- }
- Py_INCREF(tmp_stop);
- } else {
- candidate = compute_slice_element(slice->stop);
- if (candidate == NULL) goto Fail;
- cmp_result = PyObject_RichCompareBool(candidate, zero, Py_LT);
- if (cmp_result == -1) goto Fail;
- if (cmp_result) {
- /* candidate < 0 */
- tmp_stop = PyNumber_Add(r->length, candidate);
- if (tmp_stop == NULL) goto Fail;
- Py_CLEAR(candidate);
- } else {
- /* candidate >= 0 */
- tmp_stop = candidate;
- candidate = NULL;
- }
- cmp_result = PyObject_RichCompareBool(tmp_stop, zero, Py_LT);
- if (cmp_result == -1) goto Fail;
- if (cmp_result) {
- /* tmp_stop < 0 */
- Py_CLEAR(tmp_stop);
- if (clamped_step < 0) {
- tmp_stop = neg_one;
- } else {
- tmp_stop = zero;
- }
- Py_INCREF(tmp_stop);
- } else {
- /* tmp_stop >= 0 */
- cmp_result = PyObject_RichCompareBool(tmp_stop, r->length, Py_GE);
- if (cmp_result == -1) goto Fail;
- if (cmp_result) {
- /* tmp_stop >= r->length */
- Py_CLEAR(tmp_stop);
- if (clamped_step < 0) {
- tmp_stop = PyNumber_Subtract(r->length, one);
- if (tmp_stop == NULL) goto Fail;
- } else {
- tmp_stop = r->length;
- Py_INCREF(tmp_stop);
- }
- }
- }
- }
-
- /* Check if the slice is empty or not */
- if (clamped_step < 0) {
- has_elements = PyObject_RichCompareBool(tmp_start, tmp_stop, Py_GT);
- } else {
- has_elements = PyObject_RichCompareBool(tmp_start, tmp_stop, Py_LT);
- }
- if (has_elements == -1) goto Fail;
-
- *start = tmp_start;
- *stop = tmp_stop;
- *step = tmp_step;
- Py_DECREF(neg_one);
- Py_DECREF(one);
- Py_DECREF(zero);
- return has_elements;
-
- Fail:
- Py_XDECREF(tmp_start);
- Py_XDECREF(tmp_stop);
- Py_XDECREF(tmp_step);
- Py_XDECREF(candidate);
- Py_XDECREF(neg_one);
- Py_XDECREF(one);
- Py_XDECREF(zero);
- return -1;
-}
-
static PyObject *
compute_slice(rangeobject *r, PyObject *_slice)
{
@@ -514,10 +332,11 @@ compute_slice(rangeobject *r, PyObject *_slice)
rangeobject *result;
PyObject *start = NULL, *stop = NULL, *step = NULL;
PyObject *substart = NULL, *substop = NULL, *substep = NULL;
- int has_elements;
+ int error;
- has_elements = compute_slice_indices(r, slice, &start, &stop, &step);
- if (has_elements == -1) return NULL;
+ error = _PySlice_GetLongIndices(slice, r->length, &start, &stop, &step);
+ if (error == -1)
+ return NULL;
substep = PyNumber_Multiply(r->step, step);
if (substep == NULL) goto fail;
@@ -527,13 +346,8 @@ compute_slice(rangeobject *r, PyObject *_slice)
if (substart == NULL) goto fail;
Py_CLEAR(start);
- if (has_elements) {
- substop = compute_item(r, stop);
- if (substop == NULL) goto fail;
- } else {
- substop = substart;
- Py_INCREF(substop);
- }
+ substop = compute_item(r, stop);
+ if (substop == NULL) goto fail;
Py_CLEAR(stop);
result = make_range_object(Py_TYPE(r), substart, substop, substep);
generated by cgit v0.12 at 2025-11-18 21:29:13 (GMT)