Issues 2186 and 2187. Move map() from itertools to builtins.
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 7baaf14..024729e 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -864,31 +864,153 @@
simultaneously existing objects. (Hint: it's the object's memory address.)");
+/* map object ************************************************************/
+
+typedef struct {
+ PyObject_HEAD
+ PyObject *iters;
+ PyObject *func;
+} mapobject;
+
+PyTypeObject PyMap_Type;
+
static PyObject *
-builtin_map(PyObject *self, PyObject *args)
+map_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
- PyObject *itertools, *imap, *result;
- itertools = PyImport_ImportModuleNoBlock("itertools");
- if (itertools == NULL)
+ PyObject *it, *iters, *func;
+ mapobject *lz;
+ Py_ssize_t numargs, i;
+
+ if (type == &PyMap_Type && !_PyArg_NoKeywords("map()", kwds))
return NULL;
- imap = PyObject_GetAttrString(itertools, "imap");
- Py_DECREF(itertools);
- if (imap == NULL)
+
+ numargs = PyTuple_Size(args);
+ if (numargs < 2) {
+ PyErr_SetString(PyExc_TypeError,
+ "map() must have at least two arguments.");
return NULL;
- result = PyObject_Call(imap, args, NULL);
- Py_DECREF(imap);
+ }
+
+ iters = PyTuple_New(numargs-1);
+ if (iters == NULL)
+ return NULL;
+
+ for (i=1 ; i<numargs ; i++) {
+ /* Get iterator. */
+ it = PyObject_GetIter(PyTuple_GET_ITEM(args, i));
+ if (it == NULL) {
+ Py_DECREF(iters);
+ return NULL;
+ }
+ PyTuple_SET_ITEM(iters, i-1, it);
+ }
+
+ /* create mapobject structure */
+ lz = (mapobject *)type->tp_alloc(type, 0);
+ if (lz == NULL) {
+ Py_DECREF(iters);
+ return NULL;
+ }
+ lz->iters = iters;
+ func = PyTuple_GET_ITEM(args, 0);
+ Py_INCREF(func);
+ lz->func = func;
+
+ return (PyObject *)lz;
+}
+
+static void
+map_dealloc(mapobject *lz)
+{
+ PyObject_GC_UnTrack(lz);
+ Py_XDECREF(lz->iters);
+ Py_XDECREF(lz->func);
+ Py_TYPE(lz)->tp_free(lz);
+}
+
+static int
+map_traverse(mapobject *lz, visitproc visit, void *arg)
+{
+ Py_VISIT(lz->iters);
+ Py_VISIT(lz->func);
+ return 0;
+}
+
+static PyObject *
+map_next(mapobject *lz)
+{
+ PyObject *val;
+ PyObject *argtuple;
+ PyObject *result;
+ Py_ssize_t numargs, i;
+
+ numargs = PyTuple_Size(lz->iters);
+ argtuple = PyTuple_New(numargs);
+ if (argtuple == NULL)
+ return NULL;
+
+ for (i=0 ; i<numargs ; i++) {
+ val = PyIter_Next(PyTuple_GET_ITEM(lz->iters, i));
+ if (val == NULL) {
+ Py_DECREF(argtuple);
+ return NULL;
+ }
+ PyTuple_SET_ITEM(argtuple, i, val);
+ }
+ result = PyObject_Call(lz->func, argtuple, NULL);
+ Py_DECREF(argtuple);
return result;
}
PyDoc_STRVAR(map_doc,
-"map(function, iterable[, iterable, ...]) -> iterator\n\
+"map(func, *iterables) --> map object\n\
\n\
-Return an iterator yielding the results of applying the function to the\n\
-items of the argument iterables(s). If more than one iterable is given,\n\
-the function is called with an argument list consisting of the\n\
-corresponding item of each iterable, until an iterable is exhausted.\n\
-(This is identical to itertools.imap().)");
+Make an iterator that computes the function using arguments from\n\
+each of the iterables. Stops when the shortest iterable is exhausted.");
+PyTypeObject PyMap_Type = {
+ PyVarObject_HEAD_INIT(&PyType_Type, 0)
+ "map", /* tp_name */
+ sizeof(mapobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)map_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 */
+ map_doc, /* tp_doc */
+ (traverseproc)map_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ PyObject_SelfIter, /* tp_iter */
+ (iternextfunc)map_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 */
+ map_new, /* tp_new */
+ PyObject_GC_Del, /* tp_free */
+};
static PyObject *
builtin_next(PyObject *self, PyObject *args)
@@ -1893,7 +2015,6 @@
{"iter", builtin_iter, METH_VARARGS, iter_doc},
{"len", builtin_len, METH_O, len_doc},
{"locals", (PyCFunction)builtin_locals, METH_NOARGS, locals_doc},
- {"map", builtin_map, METH_VARARGS, map_doc},
{"max", (PyCFunction)builtin_max, METH_VARARGS | METH_KEYWORDS, max_doc},
{"min", (PyCFunction)builtin_min, METH_VARARGS | METH_KEYWORDS, min_doc},
{"next", (PyCFunction)builtin_next, METH_VARARGS, next_doc},
@@ -1965,6 +2086,7 @@
SETBUILTIN("property", &PyProperty_Type);
SETBUILTIN("int", &PyLong_Type);
SETBUILTIN("list", &PyList_Type);
+ SETBUILTIN("map", &PyMap_Type);
SETBUILTIN("object", &PyBaseObject_Type);
SETBUILTIN("range", &PyRange_Type);
SETBUILTIN("reversed", &PyReversed_Type);