mirror of https://github.com/python/cpython
Add 'super', another new object type with magical properties.
super(type) -> unbound super object
super(type, obj) -> bound super object; requires isinstance(obj, type)
Typical use to call a cooperative superclass method:
class C(B):
def meth(self, arg):
super(C, self).meth(arg);
This commit is contained in:
Guido van Rossum
parent
76f0cb85c2
commit
705f0f5a91
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@ -2998,3 +2998,158 @@ override_slots(PyTypeObject *type, PyObject *dict)
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TPSLOT("__init__", tp_init, slot_tp_init);
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TPSLOT("__new__", tp_new, slot_tp_new);
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}
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/* Cooperative 'super' */
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typedef struct {
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PyObject_HEAD
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PyObject *type;
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PyObject *obj;
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} superobject;
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static void
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super_dealloc(PyObject *self)
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{
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superobject *su = (superobject *)self;
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Py_XDECREF(su->obj);
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Py_XDECREF(su->type);
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self->ob_type->tp_free(self);
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}
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static PyObject *
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super_getattro(PyObject *self, PyObject *name)
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{
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superobject *su = (superobject *)self;
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if (su->obj != NULL) {
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PyObject *mro, *res, *tmp;
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descrgetfunc f;
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int i, n;
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mro = ((PyTypeObject *)(su->obj->ob_type))->tp_mro;
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assert(mro != NULL && PyTuple_Check(mro));
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n = PyTuple_GET_SIZE(mro);
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for (i = 0; i < n; i++) {
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if (su->type == PyTuple_GET_ITEM(mro, i))
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break;
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}
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assert(i < n);
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i++;
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res = NULL;
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for (; i < n; i++) {
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tmp = PyTuple_GET_ITEM(mro, i);
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assert(PyType_Check(tmp));
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res = PyDict_GetItem(
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((PyTypeObject *)tmp)->tp_defined, name);
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if (res != NULL) {
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Py_INCREF(res);
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f = res->ob_type->tp_descr_get;
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if (f != NULL) {
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tmp = f(res, su->obj, res);
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Py_DECREF(res);
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res = tmp;
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}
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return res;
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}
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}
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}
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return PyObject_GenericGetAttr(self, name);
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}
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static PyObject *
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super_descr_get(PyObject *self, PyObject *obj, PyObject *type)
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{
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superobject *su = (superobject *)self;
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superobject *new;
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if (obj == NULL || obj == Py_None || su->obj != NULL) {
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/* Not binding to an object, or already bound */
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Py_INCREF(self);
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return self;
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}
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new = (superobject *)PySuper_Type.tp_new(&PySuper_Type, NULL, NULL);
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if (new == NULL)
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return NULL;
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Py_INCREF(su->type);
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Py_INCREF(obj);
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new->type = su->type;
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new->obj = obj;
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return (PyObject *)new;
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}
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static int
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super_init(PyObject *self, PyObject *args, PyObject *kwds)
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{
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superobject *su = (superobject *)self;
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PyObject *type, *obj = NULL;
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if (!PyArg_ParseTuple(args, "O!|O:super", &PyType_Type, &type, &obj))
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return -1;
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if (obj == Py_None)
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obj = NULL;
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if (obj != NULL && !PyType_IsSubtype(obj->ob_type,
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(PyTypeObject *)type)) {
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PyErr_SetString(PyExc_TypeError,
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"super(type, obj) requires isinstance(obj, type)");
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return -1;
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}
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Py_INCREF(type);
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Py_XINCREF(obj);
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su->type = type;
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su->obj = obj;
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return 0;
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}
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static char super_doc[] =
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"super(type) -> unbound super object\n"
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"super(type, obj) -> bound super object; requires isinstance(obj, type)\n"
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"Typical use to call a cooperative superclass method:\n"
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"class C(B):\n"
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" def meth(self, arg):\n"
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" super(C, self).meth(arg)";
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PyTypeObject PySuper_Type = {
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PyObject_HEAD_INIT(&PyType_Type)
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0, /* ob_size */
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"super", /* tp_name */
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sizeof(superobject), /* tp_basicsize */
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0, /* tp_itemsize */
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/* methods */
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super_dealloc, /* tp_dealloc */
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0, /* tp_print */
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0, /* tp_getattr */
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0, /* tp_setattr */
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0, /* tp_compare */
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0, /* tp_repr */
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0, /* tp_as_number */
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0, /* tp_as_sequence */
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0, /* tp_as_mapping */
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0, /* tp_hash */
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0, /* tp_call */
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0, /* tp_str */
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super_getattro, /* tp_getattro */
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0, /* tp_setattro */
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0, /* tp_as_buffer */
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Py_TPFLAGS_DEFAULT, /* tp_flags */
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super_doc, /* tp_doc */
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0, /* tp_traverse */
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0, /* tp_clear */
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0, /* tp_richcompare */
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0, /* tp_weaklistoffset */
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0, /* tp_iter */
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0, /* tp_iternext */
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0, /* tp_methods */
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0, /* tp_members */
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0, /* tp_getset */
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0, /* tp_base */
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0, /* tp_dict */
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super_descr_get, /* tp_descr_get */
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0, /* tp_descr_set */
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0, /* tp_dictoffset */
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super_init, /* tp_init */
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PyType_GenericAlloc, /* tp_alloc */
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PyType_GenericNew, /* tp_new */
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_PyObject_Del, /* tp_free */
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};
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