Merged revisions 55545-55587 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/p3yk
........
r55587 | guido.van.rossum | 2007-05-25 10:37:01 -0700 (Fri, 25 May 2007) | 2 lines
Implement isinstance and issubclass overriding, a la PEP 3119.
........
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 645fd95..dc66893 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2130,7 +2130,25 @@
int
PyObject_IsInstance(PyObject *inst, PyObject *cls)
{
- return recursive_isinstance(inst, cls, Py_GetRecursionLimit());
+ PyObject *t, *v, *tb;
+ PyErr_Fetch(&t, &v, &tb);
+ PyObject *checker = PyObject_GetAttrString(cls, "__instancecheck__");
+ PyErr_Restore(t, v, tb);
+ if (checker != NULL) {
+ PyObject *res;
+ int ok = -1;
+ if (Py_EnterRecursiveCall(" in __instancecheck__"))
+ return ok;
+ res = PyObject_CallFunctionObjArgs(checker, inst, NULL);
+ Py_LeaveRecursiveCall();
+ Py_DECREF(checker);
+ if (res != NULL) {
+ ok = PyObject_IsTrue(res);
+ Py_DECREF(res);
+ }
+ return ok;
+ }
+ return recursive_isinstance(inst, cls, Py_GetRecursionLimit());
}
static int
@@ -2180,7 +2198,25 @@
int
PyObject_IsSubclass(PyObject *derived, PyObject *cls)
{
- return recursive_issubclass(derived, cls, Py_GetRecursionLimit());
+ PyObject *t, *v, *tb;
+ PyErr_Fetch(&t, &v, &tb);
+ PyObject *checker = PyObject_GetAttrString(cls, "__subclasscheck__");
+ PyErr_Restore(t, v, tb);
+ if (checker != NULL) {
+ PyObject *res;
+ int ok = -1;
+ if (Py_EnterRecursiveCall(" in __subclasscheck__"))
+ return ok;
+ res = PyObject_CallFunctionObjArgs(checker, derived, NULL);
+ Py_LeaveRecursiveCall();
+ Py_DECREF(checker);
+ if (res != NULL) {
+ ok = PyObject_IsTrue(res);
+ Py_DECREF(res);
+ }
+ return ok;
+ }
+ return recursive_issubclass(derived, cls, Py_GetRecursionLimit());
}