diff options
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/bltinmodule.c | 182 |
1 files changed, 173 insertions, 9 deletions
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c index 024729e..b3d8b16 100644 --- a/Python/bltinmodule.c +++ b/Python/bltinmodule.c @@ -1967,23 +1967,187 @@ When using a tuple as the second argument issubclass(X, (A, B, ...)),\n\ is a shortcut for issubclass(X, A) or issubclass(X, B) or ... (etc.)."); -static PyObject* -builtin_zip(PyObject *self, PyObject *args) +typedef struct { + PyObject_HEAD + Py_ssize_t tuplesize; + PyObject *ittuple; /* tuple of iterators */ + PyObject *result; +} zipobject; + +PyTypeObject PyZip_Type; + +static PyObject * +zip_new(PyTypeObject *type, PyObject *args, PyObject *kwds) { + zipobject *lz; + Py_ssize_t i; + PyObject *ittuple; /* tuple of iterators */ + PyObject *result; + Py_ssize_t tuplesize = PySequence_Length(args); + + if (type == &PyZip_Type && !_PyArg_NoKeywords("zip()", kwds)) + return NULL; + /* args must be a tuple */ assert(PyTuple_Check(args)); - return _PyZip_CreateIter(args); + /* obtain iterators */ + ittuple = PyTuple_New(tuplesize); + if (ittuple == NULL) + return NULL; + for (i=0; i < tuplesize; ++i) { + PyObject *item = PyTuple_GET_ITEM(args, i); + PyObject *it = PyObject_GetIter(item); + if (it == NULL) { + if (PyErr_ExceptionMatches(PyExc_TypeError)) + PyErr_Format(PyExc_TypeError, + "zip argument #%zd must support iteration", + i+1); + Py_DECREF(ittuple); + return NULL; + } + PyTuple_SET_ITEM(ittuple, i, it); + } + + /* create a result holder */ + result = PyTuple_New(tuplesize); + if (result == NULL) { + Py_DECREF(ittuple); + return NULL; + } + for (i=0 ; i < tuplesize ; i++) { + Py_INCREF(Py_None); + PyTuple_SET_ITEM(result, i, Py_None); + } + + /* create zipobject structure */ + lz = (zipobject *)type->tp_alloc(type, 0); + if (lz == NULL) { + Py_DECREF(ittuple); + Py_DECREF(result); + return NULL; + } + lz->ittuple = ittuple; + lz->tuplesize = tuplesize; + lz->result = result; + + return (PyObject *)lz; +} + +static void +zip_dealloc(zipobject *lz) +{ + PyObject_GC_UnTrack(lz); + Py_XDECREF(lz->ittuple); + Py_XDECREF(lz->result); + Py_TYPE(lz)->tp_free(lz); +} + +static int +zip_traverse(zipobject *lz, visitproc visit, void *arg) +{ + Py_VISIT(lz->ittuple); + Py_VISIT(lz->result); + return 0; } +static PyObject * +zip_next(zipobject *lz) +{ + Py_ssize_t i; + Py_ssize_t tuplesize = lz->tuplesize; + PyObject *result = lz->result; + PyObject *it; + PyObject *item; + PyObject *olditem; + + if (tuplesize == 0) + return NULL; + if (Py_REFCNT(result) == 1) { + Py_INCREF(result); + for (i=0 ; i < tuplesize ; i++) { + it = PyTuple_GET_ITEM(lz->ittuple, i); + assert(PyIter_Check(it)); + item = (*Py_TYPE(it)->tp_iternext)(it); + if (item == NULL) { + Py_DECREF(result); + return NULL; + } + olditem = PyTuple_GET_ITEM(result, i); + PyTuple_SET_ITEM(result, i, item); + Py_DECREF(olditem); + } + } else { + result = PyTuple_New(tuplesize); + if (result == NULL) + return NULL; + for (i=0 ; i < tuplesize ; i++) { + it = PyTuple_GET_ITEM(lz->ittuple, i); + assert(PyIter_Check(it)); + item = (*Py_TYPE(it)->tp_iternext)(it); + if (item == NULL) { + Py_DECREF(result); + return NULL; + } + PyTuple_SET_ITEM(result, i, item); + } + } + return result; +} PyDoc_STRVAR(zip_doc, -"zip(it1 [, it2 [...]]) -> iter([(it1[0], it2[0] ...), ...])\n\ +"zip(iter1 [,iter2 [...]]) --> zip object\n\ \n\ -Return an iterator yielding tuples, where each tuple contains the\n\ -corresponding element from each of the argument iterables.\n\ -The returned iterator ends when the shortest argument iterable is exhausted.\n\ -(This is identical to itertools.izip().)"); +Return a zip object whose .__next__() method returns a tuple where\n\ +the i-th element comes from the i-th iterable argument. The .__next__()\n\ +method continues until the shortest iterable in the argument sequence\n\ +is exhausted and then it raises StopIteration. Works like the zip()\n\ +function but consumes less memory by returning an iterator instead of\n\ +a list."); + +PyTypeObject PyZip_Type = { + PyVarObject_HEAD_INIT(&PyType_Type, 0) + "zip", /* tp_name */ + sizeof(zipobject), /* tp_basicsize */ + 0, /* tp_itemsize */ + /* methods */ + (destructor)zip_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 */ + zip_doc, /* tp_doc */ + (traverseproc)zip_traverse, /* tp_traverse */ + 0, /* tp_clear */ + 0, /* tp_richcompare */ + 0, /* tp_weaklistoffset */ + PyObject_SelfIter, /* tp_iter */ + (iternextfunc)zip_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 */ + zip_new, /* tp_new */ + PyObject_GC_Del, /* tp_free */ +}; static PyMethodDef builtin_methods[] = { @@ -2028,7 +2192,6 @@ static PyMethodDef builtin_methods[] = { {"sorted", (PyCFunction)builtin_sorted, METH_VARARGS | METH_KEYWORDS, sorted_doc}, {"sum", builtin_sum, METH_VARARGS, sum_doc}, {"vars", builtin_vars, METH_VARARGS, vars_doc}, - {"zip", builtin_zip, METH_VARARGS, zip_doc}, {NULL, NULL}, }; @@ -2097,6 +2260,7 @@ _PyBuiltin_Init(void) SETBUILTIN("super", &PySuper_Type); SETBUILTIN("tuple", &PyTuple_Type); SETBUILTIN("type", &PyType_Type); + SETBUILTIN("zip", &PyZip_Type); debug = PyBool_FromLong(Py_OptimizeFlag == 0); if (PyDict_SetItemString(dict, "__debug__", debug) < 0) { Py_XDECREF(debug); |