diff options
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/enumobject.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/Objects/enumobject.c b/Objects/enumobject.c new file mode 100644 index 0000000..1964956 --- /dev/null +++ b/Objects/enumobject.c @@ -0,0 +1,139 @@ +/* enumerate object */ + +#include "Python.h" + +typedef struct { + PyObject_HEAD + long en_index; /* current index of enumeration */ + PyObject* en_sit; /* secondary iterator of enumeration */ +} enumobject; + +PyTypeObject PyEnum_Type; + +static PyObject * +enum_new(PyTypeObject *type, PyObject *args, PyObject *kwds) +{ + enumobject *en; + PyObject *seq = NULL; + static char *kwlist[] = {"sequence", 0}; + + if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:enumerate", kwlist, + &seq)) + return NULL; + + en = (enumobject *)type->tp_alloc(type, 0); + if (en == NULL) + return NULL; + en->en_index = 0; + en->en_sit = PyObject_GetIter(seq); + if (en->en_sit == NULL) { + Py_DECREF(en); + return NULL; + } + return (PyObject *)en; +} + +static void +enum_dealloc(enumobject *en) +{ + PyObject_GC_UnTrack(en); + Py_XDECREF(en->en_sit); + en->ob_type->tp_free(en); +} + +static int +enum_traverse(enumobject *en, visitproc visit, void *arg) +{ + if (en->en_sit) + return visit(en->en_sit, arg); + return 0; +} + +static PyObject * +enum_next(enumobject *en) +{ + PyObject *result; + PyObject *next_index; + + PyObject *next_item = PyIter_Next(en->en_sit); + if (next_item == NULL) + return NULL; + + result = PyTuple_New(2); + if (result == NULL) { + Py_DECREF(next_item); + return NULL; + } + + next_index = PyInt_FromLong(en->en_index++); + if (next_index == NULL) { + Py_DECREF(next_item); + Py_DECREF(result); + return NULL; + } + + PyTuple_SET_ITEM(result, 0, next_index); + PyTuple_SET_ITEM(result, 1, next_item); + return result; +} + +static PyObject * +enum_getiter(PyObject *en) +{ + Py_INCREF(en); + return en; +} + +static PyMethodDef enum_methods[] = { + {"next", (PyCFunction)enum_next, METH_NOARGS, + "return the next (index, value) pair, or raise StopIteration"}, + {NULL, NULL} /* sentinel */ +}; + +static char enum_doc[] = + "enumerate(iterable) -> create an enumerating-iterator"; + +PyTypeObject PyEnum_Type = { + PyObject_HEAD_INIT(&PyType_Type) + 0, /* ob_size */ + "enumerate", /* tp_name */ + sizeof(enumobject), /* tp_basicsize */ + 0, /* tp_itemsize */ + /* methods */ + (destructor)enum_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 */ + enum_doc, /* tp_doc */ + (traverseproc)enum_traverse, /* tp_traverse */ + 0, /* tp_clear */ + 0, /* tp_richcompare */ + 0, /* tp_weaklistoffset */ + (getiterfunc)enum_getiter, /* tp_iter */ + (iternextfunc)enum_next, /* tp_iternext */ + enum_methods, /* 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 */ + enum_new, /* tp_new */ + PyObject_GC_Del, /* tp_free */ +}; |