A few days ago, Guido said (in the thread "[Python-Dev] Python
version of PySlice_GetIndicesEx"):
> OK. Michael, if you want to check in indices(), go ahead.
Then I did what was needed, but didn't check it in. Here it is.
diff --git a/Objects/sliceobject.c b/Objects/sliceobject.c
index a43644d..f2d84da 100644
--- a/Objects/sliceobject.c
+++ b/Objects/sliceobject.c
@@ -221,6 +221,39 @@
{0}
};
+static PyObject*
+slice_indices(PySliceObject* self, PyObject* len)
+{
+ int ilen, start, stop, step, slicelength;
+
+ ilen = PyInt_AsLong(len);
+
+ if (ilen == -1 && PyErr_Occurred()) {
+ return NULL;
+ }
+
+ if (PySlice_GetIndicesEx(self, ilen, &start, &stop,
+ &step, &slicelength) < 0) {
+ return NULL;
+ }
+
+ return Py_BuildValue("(lll)", start, stop, step);
+}
+
+PyDoc_STRVAR(slice_indices_doc,
+"S.indices(len) -> (start, stop, stride)\n\
+\n\
+Assuming a sequence of length len, calculate the start and stop\n\
+indices, and the stride length of the extended slice described by\n\
+S. Out of bounds indices are clipped in a manner consistent with the\n\
+handling of normal slices.");
+
+static PyMethodDef slice_methods[] = {
+ {"indices", (PyCFuntion)slice_indices,
+ METH_O, slice_indices_doc},
+ {NULL, NULL}
+};
+
static int
slice_compare(PySliceObject *v, PySliceObject *w)
{
@@ -271,7 +304,7 @@
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
- 0, /* tp_methods */
+ slice_methods, /* tp_methods */
slice_members, /* tp_members */
0, /* tp_getset */
0, /* tp_base */