Make functional.partial() more closely match the spec by emulating
some useful features of regular functions:
* Made weak referencable.
* Allow attribute access so a user can set __name__, __doc__, etc.
diff --git a/Lib/test/test_functional.py b/Lib/test/test_functional.py
index db3a289..8f19d6b 100644
--- a/Lib/test/test_functional.py
+++ b/Lib/test/test_functional.py
@@ -1,6 +1,7 @@
import functional
import unittest
from test import test_support
+from weakref import proxy
@staticmethod
def PythonPartial(func, *args, **keywords):
@@ -116,6 +117,22 @@
self.assertRaises(ZeroDivisionError, self.thetype(f), 1, 0)
self.assertRaises(ZeroDivisionError, self.thetype(f, y=0), 1)
+ def test_attributes(self):
+ p = self.thetype(hex)
+ try:
+ del p.__dict__
+ except TypeError:
+ pass
+ else:
+ self.fail('partial object allowed __dict__ to be deleted')
+
+ def test_weakref(self):
+ f = self.thetype(int, base=16)
+ p = proxy(f)
+ self.assertEqual(f.func, p.func)
+ f = None
+ self.assertRaises(ReferenceError, getattr, p, 'func')
+
class PartialSubclass(functional.partial):
pass
diff --git a/Modules/functionalmodule.c b/Modules/functionalmodule.c
index 18efab2..95ffd5d 100644
--- a/Modules/functionalmodule.c
+++ b/Modules/functionalmodule.c
@@ -16,6 +16,8 @@
PyObject *fn;
PyObject *args;
PyObject *kw;
+ PyObject *dict;
+ PyObject *weakreflist; /* List of weak references */
} partialobject;
static PyTypeObject partial_type;
@@ -63,6 +65,9 @@
Py_INCREF(Py_None);
}
+ pto->weakreflist = NULL;
+ pto->dict = NULL;
+
return (PyObject *)pto;
}
@@ -70,9 +75,12 @@
partial_dealloc(partialobject *pto)
{
PyObject_GC_UnTrack(pto);
+ if (pto->weakreflist != NULL)
+ PyObject_ClearWeakRefs((PyObject *) pto);
Py_XDECREF(pto->fn);
Py_XDECREF(pto->args);
Py_XDECREF(pto->kw);
+ Py_XDECREF(pto->dict);
pto->ob_type->tp_free(pto);
}
@@ -128,6 +136,7 @@
Py_VISIT(pto->fn);
Py_VISIT(pto->args);
Py_VISIT(pto->kw);
+ Py_VISIT(pto->dict);
return 0;
}
@@ -146,6 +155,47 @@
{NULL} /* Sentinel */
};
+static PyObject *
+partial_get_dict(partialobject *pto)
+{
+ if (pto->dict == NULL) {
+ pto->dict = PyDict_New();
+ if (pto->dict == NULL)
+ return NULL;
+ }
+ Py_INCREF(pto->dict);
+ return pto->dict;
+}
+
+static int
+partial_set_dict(partialobject *pto, PyObject *value)
+{
+ PyObject *tmp;
+
+ /* It is illegal to del p.__dict__ */
+ if (value == NULL) {
+ PyErr_SetString(PyExc_TypeError,
+ "a partial object's dictionary may not be deleted");
+ return -1;
+ }
+ /* Can only set __dict__ to a dictionary */
+ if (!PyDict_Check(value)) {
+ PyErr_SetString(PyExc_TypeError,
+ "setting partial object's dictionary to a non-dict");
+ return -1;
+ }
+ tmp = pto->dict;
+ Py_INCREF(value);
+ pto->dict = value;
+ Py_XDECREF(tmp);
+ return 0;
+}
+
+static PyGetSetDef partail_getsetlist[] = {
+ {"__dict__", (getter)partial_get_dict, (setter)partial_set_dict},
+ {NULL} /* Sentinel */
+};
+
static PyTypeObject partial_type = {
PyObject_HEAD_INIT(NULL)
0, /* ob_size */
@@ -166,25 +216,25 @@
(ternaryfunc)partial_call, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
- 0, /* tp_setattro */
+ PyObject_GenericSetAttr, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
- Py_TPFLAGS_BASETYPE, /* tp_flags */
+ Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_WEAKREFS, /* tp_flags */
partial_doc, /* tp_doc */
(traverseproc)partial_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
- 0, /* tp_weaklistoffset */
+ offsetof(partialobject, weakreflist), /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
partial_memberlist, /* tp_members */
- 0, /* tp_getset */
+ partail_getsetlist, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
- 0, /* tp_dictoffset */
+ offsetof(partialobject, dict), /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
partial_new, /* tp_new */