Make int, long and float subclassable.
This uses a slightly wimpy and wasteful approach, but it works. :-)
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 69aede4..295f47e 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -626,13 +626,17 @@
}
+staticforward PyObject *
+float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
+
static PyObject *
float_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
PyObject *x = Py_False; /* Integer zero */
static char *kwlist[] = {"x", 0};
- assert(type == &PyFloat_Type);
+ if (type != &PyFloat_Type)
+ return float_subtype_new(type, args, kwds); /* Wimp out */
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:float", kwlist, &x))
return NULL;
if (PyString_Check(x))
@@ -640,6 +644,29 @@
return PyNumber_Float(x);
}
+/* Wimpy, slow approach to tp_new calls for subtypes of float:
+ first create a regular float from whatever arguments we got,
+ then allocate a subtype instance and initialize its ob_fval
+ from the regular float. The regular float is then thrown away.
+*/
+static PyObject *
+float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+ PyObject *tmp, *new;
+
+ assert(PyType_IsSubtype(type, &PyFloat_Type));
+ tmp = float_new(&PyFloat_Type, args, kwds);
+ if (tmp == NULL)
+ return NULL;
+ assert(PyFloat_Check(tmp));
+ new = type->tp_alloc(type, 0);;
+ if (new == NULL)
+ return NULL;
+ ((PyFloatObject *)new)->ob_fval = ((PyFloatObject *)tmp)->ob_fval;
+ Py_DECREF(tmp);
+ return new;
+}
+
static char float_doc[] =
"float(x) -> floating point number\n\
\n\
@@ -708,7 +735,8 @@
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
+ Py_TPFLAGS_BASETYPE, /* tp_flags */
float_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
@@ -750,7 +778,7 @@
for (i = 0, p = &list->objects[0];
i < N_FLOATOBJECTS;
i++, p++) {
- if (PyFloat_Check(p) && p->ob_refcnt != 0)
+ if (p->ob_type == &PyFloat_Type && p->ob_refcnt != 0)
frem++;
}
next = list->next;
@@ -760,7 +788,8 @@
for (i = 0, p = &list->objects[0];
i < N_FLOATOBJECTS;
i++, p++) {
- if (!PyFloat_Check(p) || p->ob_refcnt == 0) {
+ if (p->ob_type != &PyFloat_Type ||
+ p->ob_refcnt == 0) {
p->ob_type = (struct _typeobject *)
free_list;
free_list = p;
@@ -792,7 +821,8 @@
for (i = 0, p = &list->objects[0];
i < N_FLOATOBJECTS;
i++, p++) {
- if (PyFloat_Check(p) && p->ob_refcnt != 0) {
+ if (p->ob_type == &PyFloat_Type &&
+ p->ob_refcnt != 0) {
char buf[100];
PyFloat_AsString(buf, p);
fprintf(stderr,