diff options
Diffstat (limited to 'Python/bltinmodule.c')
| -rw-r--r-- | Python/bltinmodule.c | 154 |
1 files changed, 138 insertions, 16 deletions
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 @@ Return the identity of an object. This is guaranteed to be unique among\n\ 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; + } + + 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; - result = PyObject_Call(imap, args, NULL); - Py_DECREF(imap); + + 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 @@ static PyMethodDef builtin_methods[] = { {"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 @@ _PyBuiltin_Init(void) 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); |