Issue 2186 and 2187. Move filter from itertools to builtins.
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 70237bf..7baaf14 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -277,29 +277,146 @@
Return the binary representation of an integer or long integer.");
+typedef struct {
+ PyObject_HEAD
+ PyObject *func;
+ PyObject *it;
+} filterobject;
+
+PyTypeObject PyFilter_Type;
+
static PyObject *
-builtin_filter(PyObject *self, PyObject *args)
+filter_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
- PyObject *itertools, *ifilter, *result;
- itertools = PyImport_ImportModuleNoBlock("itertools");
- if (itertools == NULL)
+ PyObject *func, *seq;
+ PyObject *it;
+ filterobject *lz;
+
+ if (type == &PyFilter_Type && !_PyArg_NoKeywords("filter()", kwds))
return NULL;
- ifilter = PyObject_GetAttrString(itertools, "ifilter");
- Py_DECREF(itertools);
- if (ifilter == NULL)
+
+ if (!PyArg_UnpackTuple(args, "filter", 2, 2, &func, &seq))
return NULL;
- result = PyObject_Call(ifilter, args, NULL);
- Py_DECREF(ifilter);
- return result;
+
+ /* Get iterator. */
+ it = PyObject_GetIter(seq);
+ if (it == NULL)
+ return NULL;
+
+ /* create filterobject structure */
+ lz = (filterobject *)type->tp_alloc(type, 0);
+ if (lz == NULL) {
+ Py_DECREF(it);
+ return NULL;
+ }
+ Py_INCREF(func);
+ lz->func = func;
+ lz->it = it;
+
+ return (PyObject *)lz;
+}
+
+static void
+filter_dealloc(filterobject *lz)
+{
+ PyObject_GC_UnTrack(lz);
+ Py_XDECREF(lz->func);
+ Py_XDECREF(lz->it);
+ Py_TYPE(lz)->tp_free(lz);
+}
+
+static int
+filter_traverse(filterobject *lz, visitproc visit, void *arg)
+{
+ Py_VISIT(lz->it);
+ Py_VISIT(lz->func);
+ return 0;
+}
+
+static PyObject *
+filter_next(filterobject *lz)
+{
+ PyObject *item;
+ PyObject *it = lz->it;
+ long ok;
+ PyObject *(*iternext)(PyObject *);
+
+ assert(PyIter_Check(it));
+ iternext = *Py_TYPE(it)->tp_iternext;
+ for (;;) {
+ item = iternext(it);
+ if (item == NULL)
+ return NULL;
+
+ if (lz->func == Py_None || lz->func == (PyObject *)&PyBool_Type) {
+ ok = PyObject_IsTrue(item);
+ } else {
+ PyObject *good;
+ good = PyObject_CallFunctionObjArgs(lz->func,
+ item, NULL);
+ if (good == NULL) {
+ Py_DECREF(item);
+ return NULL;
+ }
+ ok = PyObject_IsTrue(good);
+ Py_DECREF(good);
+ }
+ if (ok)
+ return item;
+ Py_DECREF(item);
+ }
}
PyDoc_STRVAR(filter_doc,
-"filter(predicate, iterable) -> iterator\n\
+"filter(function or None, sequence) --> filter object\n\
\n\
-Return an iterator yielding only those elements of the input iterable\n\
-for which the predicate (a Boolean function) returns true.\n\
-If the predicate is None, 'lambda x: bool(x)' is assumed.\n\
-(This is identical to itertools.ifilter().)");
+Return an iterator yielding those items of sequence for which function(item)\n\
+is true. If function is None, return the items that are true.");
+
+PyTypeObject PyFilter_Type = {
+ PyVarObject_HEAD_INIT(&PyType_Type, 0)
+ "filter", /* tp_name */
+ sizeof(filterobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)filter_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+ Py_TPFLAGS_BASETYPE, /* tp_flags */
+ filter_doc, /* tp_doc */
+ (traverseproc)filter_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ PyObject_SelfIter, /* tp_iter */
+ (iternextfunc)filter_next, /* tp_iternext */
+ 0, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ 0, /* tp_init */
+ PyType_GenericAlloc, /* tp_alloc */
+ filter_new, /* tp_new */
+ PyObject_GC_Del, /* tp_free */
+};
+
static PyObject *
builtin_format(PyObject *self, PyObject *args)
@@ -1763,7 +1880,6 @@
{"divmod", builtin_divmod, METH_VARARGS, divmod_doc},
{"eval", builtin_eval, METH_VARARGS, eval_doc},
{"exec", builtin_exec, METH_VARARGS, exec_doc},
- {"filter", builtin_filter, METH_VARARGS, filter_doc},
{"format", builtin_format, METH_VARARGS, format_doc},
{"getattr", builtin_getattr, METH_VARARGS, getattr_doc},
{"globals", (PyCFunction)builtin_globals, METH_NOARGS, globals_doc},
@@ -1843,6 +1959,7 @@
#endif
SETBUILTIN("dict", &PyDict_Type);
SETBUILTIN("enumerate", &PyEnum_Type);
+ SETBUILTIN("filter", &PyFilter_Type);
SETBUILTIN("float", &PyFloat_Type);
SETBUILTIN("frozenset", &PyFrozenSet_Type);
SETBUILTIN("property", &PyProperty_Type);