summaryrefslogtreecommitdiff
path: root/Objects/cellobject.c
blob: c206684dab14e445d100eabf94598c7a37dd665f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/* Cell object implementation */

#include "Python.h"

PyObject *
PyCell_New(PyObject *obj)
{
    PyCellObject *op;

    op = (PyCellObject *)PyObject_GC_New(PyCellObject, &PyCell_Type);
    if (op == NULL)
        return NULL;
    op->ob_ref = obj;
    Py_XINCREF(obj);

    _PyObject_GC_TRACK(op);
    return (PyObject *)op;
}

PyObject *
PyCell_Get(PyObject *op)
{
    if (!PyCell_Check(op)) {
        PyErr_BadInternalCall();
        return NULL;
    }
    Py_XINCREF(((PyCellObject*)op)->ob_ref);
    return PyCell_GET(op);
}

int
PyCell_Set(PyObject *op, PyObject *obj)
{
    PyObject* oldobj;
    if (!PyCell_Check(op)) {
        PyErr_BadInternalCall();
        return -1;
    }
    oldobj = PyCell_GET(op);
    Py_XINCREF(obj);
    PyCell_SET(op, obj);
    Py_XDECREF(oldobj);
    return 0;
}

static void
cell_dealloc(PyCellObject *op)
{
    _PyObject_GC_UNTRACK(op);
    Py_XDECREF(op->ob_ref);
    PyObject_GC_Del(op);
}

static int
cell_compare(PyCellObject *a, PyCellObject *b)
{
    /* Py3K warning for comparisons  */
    if (PyErr_WarnPy3k("cell comparisons not supported in 3.x",
                       1) < 0) {
        return -2;
    }

    if (a->ob_ref == NULL) {
        if (b->ob_ref == NULL)
            return 0;
        return -1;
    } else if (b->ob_ref == NULL)
        return 1;
    return PyObject_Compare(a->ob_ref, b->ob_ref);
}

static PyObject *
cell_repr(PyCellObject *op)
{
    if (op->ob_ref == NULL)
        return PyString_FromFormat("<cell at %p: empty>", op);

    return PyString_FromFormat("<cell at %p: %.80s object at %p>",
                               op, op->ob_ref->ob_type->tp_name,
                               op->ob_ref);
}

static int
cell_traverse(PyCellObject *op, visitproc visit, void *arg)
{
    Py_VISIT(op->ob_ref);
    return 0;
}

static int
cell_clear(PyCellObject *op)
{
    Py_CLEAR(op->ob_ref);
    return 0;
}

static PyObject *
cell_get_contents(PyCellObject *op, void *closure)
{
    if (op->ob_ref == NULL)
    {
        PyErr_SetString(PyExc_ValueError, "Cell is empty");
        return NULL;
    }
    Py_INCREF(op->ob_ref);
    return op->ob_ref;
}

static PyGetSetDef cell_getsetlist[] = {
    {"cell_contents", (getter)cell_get_contents, NULL},
    {NULL} /* sentinel */
};

PyTypeObject PyCell_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "cell",
    sizeof(PyCellObject),
    0,
    (destructor)cell_dealloc,                   /* tp_dealloc */
    0,                                          /* tp_print */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    (cmpfunc)cell_compare,                      /* tp_compare */
    (reprfunc)cell_repr,                        /* 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,    /* tp_flags */
    0,                                          /* tp_doc */
    (traverseproc)cell_traverse,                /* tp_traverse */
    (inquiry)cell_clear,                        /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    0,                                          /* tp_iter */
    0,                                          /* tp_iternext */
    0,                                          /* tp_methods */
    0,                                          /* tp_members */
    cell_getsetlist,                            /* tp_getset */
};