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Make int, long and float subclassable.

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This uses a slightly wimpy and wasteful approach, but it works. :-)
This commit is contained in:
Guido van Rossum 2001-08-29 15:47:46 +00:00
parent e705ef1bce
commit bef1417f9f
3 changed files with 111 additions and 14 deletions
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38
Objects/longobject.c
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@ -2038,6 +2038,8 @@ long_hex(PyObject *v)
{
return long_format(v, 16, 1);
}
staticforward PyObject *
long_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
static PyObject *
long_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
@ -2046,7 +2048,8 @@ long_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
int base = -909; /* unlikely! */
static char *kwlist[] = {"x", "base", 0};
assert(type == &PyLong_Type);
if (type != &PyLong_Type)
return long_subtype_new(type, args, kwds); /* Wimp out */
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oi:long", kwlist,
&x, &base))
return NULL;
@ -2069,6 +2072,36 @@ long_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
}
}
/* Wimpy, slow approach to tp_new calls for subtypes of long:
first create a regular long from whatever arguments we got,
then allocate a subtype instance and initialize it from
the regular long. The regular long is then thrown away.
*/
static PyObject *
long_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
PyLongObject *tmp, *new;
int i, n;
assert(PyType_IsSubtype(type, &PyLong_Type));
tmp = (PyLongObject *)long_new(&PyLong_Type, args, kwds);
if (tmp == NULL)
return NULL;
assert(PyLong_Check(tmp));
n = tmp->ob_size;
if (n < 0)
n = -n;
new = (PyLongObject *)type->tp_alloc(type, n);
if (new == NULL)
return NULL;
assert(PyLong_Check(new));
new->ob_size = type->ob_size;
for (i = 0; i < n; i++)
new->ob_digit[i] = tmp->ob_digit[i];
Py_DECREF(tmp);
return (PyObject *)new;
}
static char long_doc[] =
"long(x[, base]) -> integer\n\
\n\
@ -2140,7 +2173,8 @@ PyTypeObject PyLong_Type = {
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 */
long_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */