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authorGuido van Rossum <guido@python.org>2002-07-16 20:07:32 (GMT)
committerGuido van Rossum <guido@python.org>2002-07-16 20:07:32 (GMT)
commit86103ae53161a136a53d031190c2d0579dba2abf (patch)
treeab25d196fdfec182a131b3472b6559053c16c4f6 /Objects/listobject.c
parent9534e14033f26b32ed75c02a6a51bfe47c7f16a9 (diff)
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Make StopIteration a sink state. This is done by clearing out the
it_seq field when the end of the list is reached. Also remove the next() method -- one is supplied automatically by PyType_Ready() because the tp_iternext slot is set. That's a good thing, because the implementation given here was buggy (it never raised StopIteration).
Diffstat (limited to 'Objects/listobject.c')
-rw-r--r--Objects/listobject.c21
1 files changed, 10 insertions, 11 deletions
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 12a9272..b80e395 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -1,4 +1,3 @@
-
/* List object implementation */
#include "Python.h"
@@ -2016,7 +2015,7 @@ static PyTypeObject immutable_list_type = {
typedef struct {
PyObject_HEAD
long it_index;
- PyListObject *it_seq;
+ PyListObject *it_seq; /* Set to NULL when iterator is exhausted */
} listiterobject;
PyTypeObject PyListIter_Type;
@@ -2044,13 +2043,15 @@ static void
listiter_dealloc(listiterobject *it)
{
_PyObject_GC_UNTRACK(it);
- Py_DECREF(it->it_seq);
+ Py_XDECREF(it->it_seq);
PyObject_GC_Del(it);
}
static int
listiter_traverse(listiterobject *it, visitproc visit, void *arg)
{
+ if (it->it_seq == NULL)
+ return 0;
return visit((PyObject *)it->it_seq, arg);
}
@@ -2070,6 +2071,8 @@ listiter_next(listiterobject *it)
assert(it != NULL);
seq = it->it_seq;
+ if (seq == NULL)
+ return NULL;
assert(PyList_Check(seq));
if (it->it_index < PyList_GET_SIZE(seq)) {
@@ -2078,15 +2081,12 @@ listiter_next(listiterobject *it)
Py_INCREF(item);
return item;
}
+
+ Py_DECREF(seq);
+ it->it_seq = NULL;
return NULL;
}
-static PyMethodDef listiter_methods[] = {
- {"next", (PyCFunction)listiter_next, METH_NOARGS,
- "it.next() -- get the next value, or raise StopIteration"},
- {NULL, NULL} /* sentinel */
-};
-
PyTypeObject PyListIter_Type = {
PyObject_HEAD_INIT(&PyType_Type)
0, /* ob_size */
@@ -2117,7 +2117,7 @@ PyTypeObject PyListIter_Type = {
0, /* tp_weaklistoffset */
(getiterfunc)listiter_getiter, /* tp_iter */
(iternextfunc)listiter_next, /* tp_iternext */
- listiter_methods, /* tp_methods */
+ 0, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
0, /* tp_base */
@@ -2125,4 +2125,3 @@ PyTypeObject PyListIter_Type = {
0, /* tp_descr_get */
0, /* tp_descr_set */
};
-