Issue #9213: Add index and count methods to range objects, needed to
meet the API of the collections.Sequence ABC.
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index e36469c..9650386 100644
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -273,60 +273,135 @@
r->start, r->stop, r->step);
}
+/* Assumes (PyLong_CheckExact(ob) || PyBool_Check(ob)) */
+static int
+range_contains_long(rangeobject *r, PyObject *ob)
+{
+ int cmp1, cmp2, cmp3;
+ PyObject *tmp1 = NULL;
+ PyObject *tmp2 = NULL;
+ PyObject *zero = NULL;
+ int result = -1;
+
+ zero = PyLong_FromLong(0);
+ if (zero == NULL) /* MemoryError in int(0) */
+ goto end;
+
+ /* Check if the value can possibly be in the range. */
+
+ cmp1 = PyObject_RichCompareBool(r->step, zero, Py_GT);
+ if (cmp1 == -1)
+ goto end;
+ if (cmp1 == 1) { /* positive steps: start <= ob < stop */
+ cmp2 = PyObject_RichCompareBool(r->start, ob, Py_LE);
+ cmp3 = PyObject_RichCompareBool(ob, r->stop, Py_LT);
+ }
+ else { /* negative steps: stop < ob <= start */
+ cmp2 = PyObject_RichCompareBool(ob, r->start, Py_LE);
+ cmp3 = PyObject_RichCompareBool(r->stop, ob, Py_LT);
+ }
+
+ if (cmp2 == -1 || cmp3 == -1) /* TypeError */
+ goto end;
+ if (cmp2 == 0 || cmp3 == 0) { /* ob outside of range */
+ result = 0;
+ goto end;
+ }
+
+ /* Check that the stride does not invalidate ob's membership. */
+ tmp1 = PyNumber_Subtract(ob, r->start);
+ if (tmp1 == NULL)
+ goto end;
+ tmp2 = PyNumber_Remainder(tmp1, r->step);
+ if (tmp2 == NULL)
+ goto end;
+ /* result = (int(ob) - start % step) == 0 */
+ result = PyObject_RichCompareBool(tmp2, zero, Py_EQ);
+ end:
+ Py_XDECREF(tmp1);
+ Py_XDECREF(tmp2);
+ Py_XDECREF(zero);
+ return result;
+}
+
static int
range_contains(rangeobject *r, PyObject *ob) {
- if (PyLong_CheckExact(ob) || PyBool_Check(ob)) {
- int cmp1, cmp2, cmp3;
- PyObject *tmp1 = NULL;
- PyObject *tmp2 = NULL;
- PyObject *zero = NULL;
- int result = -1;
+ if (PyLong_CheckExact(ob) || PyBool_Check(ob))
+ return range_contains_long(r, ob);
- zero = PyLong_FromLong(0);
- if (zero == NULL) /* MemoryError in int(0) */
- goto end;
-
- /* Check if the value can possibly be in the range. */
-
- cmp1 = PyObject_RichCompareBool(r->step, zero, Py_GT);
- if (cmp1 == -1)
- goto end;
- if (cmp1 == 1) { /* positive steps: start <= ob < stop */
- cmp2 = PyObject_RichCompareBool(r->start, ob, Py_LE);
- cmp3 = PyObject_RichCompareBool(ob, r->stop, Py_LT);
- }
- else { /* negative steps: stop < ob <= start */
- cmp2 = PyObject_RichCompareBool(ob, r->start, Py_LE);
- cmp3 = PyObject_RichCompareBool(r->stop, ob, Py_LT);
- }
-
- if (cmp2 == -1 || cmp3 == -1) /* TypeError */
- goto end;
- if (cmp2 == 0 || cmp3 == 0) { /* ob outside of range */
- result = 0;
- goto end;
- }
-
- /* Check that the stride does not invalidate ob's membership. */
- tmp1 = PyNumber_Subtract(ob, r->start);
- if (tmp1 == NULL)
- goto end;
- tmp2 = PyNumber_Remainder(tmp1, r->step);
- if (tmp2 == NULL)
- goto end;
- /* result = (int(ob) - start % step) == 0 */
- result = PyObject_RichCompareBool(tmp2, zero, Py_EQ);
- end:
- Py_XDECREF(tmp1);
- Py_XDECREF(tmp2);
- Py_XDECREF(zero);
- return result;
- }
- /* Fall back to iterative search. */
return (int)_PySequence_IterSearch((PyObject*)r, ob,
PY_ITERSEARCH_CONTAINS);
}
+static PyObject *
+range_count(rangeobject *r, PyObject *ob)
+{
+ if (PyLong_CheckExact(ob) || PyBool_Check(ob)) {
+ if (range_contains_long(r, ob))
+ Py_RETURN_TRUE;
+ else
+ Py_RETURN_FALSE;
+ } else {
+ Py_ssize_t count;
+ count = _PySequence_IterSearch((PyObject*)r, ob, PY_ITERSEARCH_COUNT);
+ if (count == -1)
+ return NULL;
+ return PyLong_FromSsize_t(count);
+ }
+}
+
+static PyObject *
+range_index(rangeobject *r, PyObject *ob)
+{
+ PyObject *idx, *tmp;
+ int contains;
+ PyObject *format_tuple, *err_string;
+ static PyObject *err_format = NULL;
+
+ if (!PyLong_CheckExact(ob) && !PyBool_Check(ob)) {
+ Py_ssize_t index;
+ index = _PySequence_IterSearch((PyObject*)r, ob, PY_ITERSEARCH_INDEX);
+ if (index == -1)
+ return NULL;
+ return PyLong_FromSsize_t(index);
+ }
+
+ contains = range_contains_long(r, ob);
+ if (contains == -1)
+ return NULL;
+
+ if (!contains)
+ goto value_error;
+
+ tmp = PyNumber_Subtract(ob, r->start);
+ if (tmp == NULL)
+ return NULL;
+
+ /* idx = (ob - r.start) // r.step */
+ idx = PyNumber_FloorDivide(tmp, r->step);
+ Py_DECREF(tmp);
+ return idx;
+
+value_error:
+
+ /* object is not in the range */
+ if (err_format == NULL) {
+ err_format = PyUnicode_FromString("%r is not in range");
+ if (err_format == NULL)
+ return NULL;
+ }
+ format_tuple = PyTuple_Pack(1, ob);
+ if (format_tuple == NULL)
+ return NULL;
+ err_string = PyUnicode_Format(err_format, format_tuple);
+ Py_DECREF(format_tuple);
+ if (err_string == NULL)
+ return NULL;
+ PyErr_SetObject(PyExc_ValueError, err_string);
+ Py_DECREF(err_string);
+ return NULL;
+}
+
static PySequenceMethods range_as_sequence = {
(lenfunc)range_length, /* sq_length */
0, /* sq_concat */
@@ -344,10 +419,18 @@
PyDoc_STRVAR(reverse_doc,
"Returns a reverse iterator.");
+PyDoc_STRVAR(count_doc,
+"rangeobject.count(value) -> integer -- return number of occurrences of value");
+
+PyDoc_STRVAR(index_doc,
+"rangeobject.index(value, [start, [stop]]) -> integer -- return index of value.\n"
+"Raises ValueError if the value is not present.");
+
static PyMethodDef range_methods[] = {
- {"__reversed__", (PyCFunction)range_reverse, METH_NOARGS,
- reverse_doc},
- {"__reduce__", (PyCFunction)range_reduce, METH_VARARGS},
+ {"__reversed__", (PyCFunction)range_reverse, METH_NOARGS, reverse_doc},
+ {"__reduce__", (PyCFunction)range_reduce, METH_VARARGS},
+ {"count", (PyCFunction)range_count, METH_O, count_doc},
+ {"index", (PyCFunction)range_index, METH_O, index_doc},
{NULL, NULL} /* sentinel */
};