xref: /third_party/python/Doc/includes/sublist.c (revision 7db96d56)
1#define PY_SSIZE_T_CLEAN
2#include <Python.h>
3
4typedef struct {
5    PyListObject list;
6    int state;
7} SubListObject;
8
9static PyObject *
10SubList_increment(SubListObject *self, PyObject *unused)
11{
12    self->state++;
13    return PyLong_FromLong(self->state);
14}
15
16static PyMethodDef SubList_methods[] = {
17    {"increment", (PyCFunction) SubList_increment, METH_NOARGS,
18     PyDoc_STR("increment state counter")},
19    {NULL},
20};
21
22static int
23SubList_init(SubListObject *self, PyObject *args, PyObject *kwds)
24{
25    if (PyList_Type.tp_init((PyObject *) self, args, kwds) < 0)
26        return -1;
27    self->state = 0;
28    return 0;
29}
30
31static PyTypeObject SubListType = {
32    PyVarObject_HEAD_INIT(NULL, 0)
33    .tp_name = "sublist.SubList",
34    .tp_doc = PyDoc_STR("SubList objects"),
35    .tp_basicsize = sizeof(SubListObject),
36    .tp_itemsize = 0,
37    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
38    .tp_init = (initproc) SubList_init,
39    .tp_methods = SubList_methods,
40};
41
42static PyModuleDef sublistmodule = {
43    PyModuleDef_HEAD_INIT,
44    .m_name = "sublist",
45    .m_doc = "Example module that creates an extension type.",
46    .m_size = -1,
47};
48
49PyMODINIT_FUNC
50PyInit_sublist(void)
51{
52    PyObject *m;
53    SubListType.tp_base = &PyList_Type;
54    if (PyType_Ready(&SubListType) < 0)
55        return NULL;
56
57    m = PyModule_Create(&sublistmodule);
58    if (m == NULL)
59        return NULL;
60
61    Py_INCREF(&SubListType);
62    if (PyModule_AddObject(m, "SubList", (PyObject *) &SubListType) < 0) {
63        Py_DECREF(&SubListType);
64        Py_DECREF(m);
65        return NULL;
66    }
67
68    return m;
69}
70