#include "Python.h"

#include "pycore_object.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;

}

PyDoc_STRVAR(cell_new_doc,

" raise a ValueError.");

static PyObject *

cell_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)

{

PyObject *return_value = NULL;

PyObject *obj = NULL;

if (!_PyArg_NoKeywords("cell", kwargs)) {

goto exit;

}

/* min = 0: we allow the cell to be empty */

if (!PyArg_UnpackTuple(args, "cell", 0, 1, &obj)) {

goto exit;

}

return_value = PyCell_New(obj);

exit:

return return_value;

}

PyObject *

PyCell_Get(PyObject *op)

{

if (!PyCell_Check(op)) {

PyErr_BadInternalCall();

return NULL;

}

PyObject *value = PyCell_GET(op);

return Py_XNewRef(value);

}

PyCell_Set(PyObject *op, PyObject *value)

{

if (!PyCell_Check(op)) {

PyErr_BadInternalCall();

return -1;

}

PyObject *old_value = PyCell_GET(op);

Py_XINCREF(value);

PyCell_SET(op, value);

Py_XDECREF(old_value);

return 0;

}

static void

cell_dealloc(PyCellObject *op)

{

_PyObject_GC_UNTRACK(op);

Py_XDECREF(op->ob_ref);

PyObject_GC_Del(op);

}

static PyObject *

cell_richcompare(PyObject *a, PyObject *b, int op)

{

/* neither argument should be NULL, unless something's gone wrong */

assert(a != NULL && b != NULL);

/* both arguments should be instances of PyCellObject */

if (!PyCell_Check(a) || !PyCell_Check(b)) {

Py_RETURN_NOTIMPLEMENTED;

}

/* compare cells by contents; empty cells come before anything else */

a = ((PyCellObject *)a)->ob_ref;

b = ((PyCellObject *)b)->ob_ref;

if (a != NULL && b != NULL)

return PyObject_RichCompare(a, b, op);

Py_RETURN_RICHCOMPARE(b == NULL, a == NULL, op);

}

static PyObject *

cell_repr(PyCellObject *op)

{

if (op->ob_ref == NULL)

return PyUnicode_FromFormat("<cell at %p: empty>", op);

return PyUnicode_FromFormat("<cell at %p: %.80s object at %p>",

op, Py_TYPE(op->ob_ref)->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 int

cell_set_contents(PyCellObject *op, PyObject *obj, void *Py_UNUSED(ignored))

{

Py_XINCREF(obj);

Py_XSETREF(op->ob_ref, obj);

return 0;

}

static PyGetSetDef cell_getsetlist[] = {

{"cell_contents", (getter)cell_get_contents,

(setter)cell_set_contents, NULL},

{NULL} /* sentinel */

};

PyTypeObject PyCell_Type = {

PyVarObject_HEAD_INIT(&PyType_Type, 0)

"cell",

sizeof(PyCellObject),

0,

(destructor)cell_dealloc, /* tp_dealloc */

0, /* tp_vectorcall_offset */

0, /* tp_getattr */

0, /* tp_setattr */

0, /* tp_as_async */

(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 */

cell_new_doc, /* tp_doc */

(traverseproc)cell_traverse, /* tp_traverse */

(inquiry)cell_clear, /* tp_clear */

cell_richcompare, /* tp_richcompare */

0, /* tp_weaklistoffset */

0, /* tp_iter */

0, /* tp_iternext */

0, /* tp_methods */

0, /* tp_members */

cell_getsetlist, /* tp_getset */

0, /* tp_base */

0, /* tp_dict */

0, /* tp_descr_get */

0, /* tp_descr_set */

0, /* tp_dictoffset */

0, /* tp_init */

0, /* tp_alloc */

(newfunc)cell_new, /* tp_new */

0, /* tp_free */

};