boolobject.c

/* Boolean type, a subtype of int */

#include"Python.h"

/* We need to define bool_print to override int_print */

staticint
bool_print(PyBoolObject*self, FILE*fp, intflags)
{
Py_BEGIN_ALLOW_THREADS
fputs(self->ob_ival==0 ? "False" : "True", fp);
Py_END_ALLOW_THREADS
return0;
}

/* We define bool_repr to return "False" or "True" */

staticPyObject*false_str=NULL;
staticPyObject*true_str=NULL;

staticPyObject*
bool_repr(PyBoolObject*self)
{
PyObject*s;

if (self->ob_ival)
s=true_str ? true_str :
 (true_str=PyString_InternFromString("True"));
else
s=false_str ? false_str :
 (false_str=PyString_InternFromString("False"));
Py_XINCREF(s);
returns;
}

/* Function to return a bool from a C long */

PyObject*PyBool_FromLong(longok)
{
PyObject*result;

if (ok)
result=Py_True;
else
result=Py_False;
Py_INCREF(result);
returnresult;
}

/* We define bool_new to always return either Py_True or Py_False */

staticPyObject*
bool_new(PyTypeObject*type, PyObject*args, PyObject*kwds)
{
staticchar*kwlist[] = {"x", 0};
PyObject*x=Py_False;
longok;

if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:bool", kwlist, &x))
returnNULL;
ok=PyObject_IsTrue(x);
if (ok<0)
returnNULL;
returnPyBool_FromLong(ok);
}

/* Arithmetic operations redefined to return bool if both args are bool. */

staticPyObject*
bool_and(PyObject*a, PyObject*b)
{
if (!PyBool_Check(a) || !PyBool_Check(b))
returnPyInt_Type.tp_as_number->nb_and(a, b);
returnPyBool_FromLong(
 ((PyBoolObject*)a)->ob_ival& ((PyBoolObject*)b)->ob_ival);
}

staticPyObject*
bool_or(PyObject*a, PyObject*b)
{
if (!PyBool_Check(a) || !PyBool_Check(b))
returnPyInt_Type.tp_as_number->nb_or(a, b);
returnPyBool_FromLong(
 ((PyBoolObject*)a)->ob_ival | ((PyBoolObject*)b)->ob_ival);
}

staticPyObject*
bool_xor(PyObject*a, PyObject*b)
{
if (!PyBool_Check(a) || !PyBool_Check(b))
returnPyInt_Type.tp_as_number->nb_xor(a, b);
returnPyBool_FromLong(
 ((PyBoolObject*)a)->ob_ival ^ ((PyBoolObject*)b)->ob_ival);
}

/* Doc string */

PyDoc_STRVAR(bool_doc,
"bool(x) -> bool\n\
\n\
Returns True when the argument x is true, False otherwise.\n\
The builtins True and False are the only two instances of the class bool.\n\
The class bool is a subclass of the class int, and cannot be subclassed.");

/* Arithmetic methods -- only so we can override &, |, ^. */

staticPyNumberMethodsbool_as_number= {
0, /* nb_add */
0, /* nb_subtract */
0, /* nb_multiply */
0, /* nb_divide */
0, /* nb_remainder */
0, /* nb_divmod */
0, /* nb_power */
0, /* nb_negative */
0, /* nb_positive */
0, /* nb_absolute */
0, /* nb_nonzero */
0, /* nb_invert */
0, /* nb_lshift */
0, /* nb_rshift */
bool_and, /* nb_and */
bool_xor, /* nb_xor */
bool_or, /* nb_or */
0, /* nb_coerce */
0, /* nb_int */
0, /* nb_long */
0, /* nb_float */
0, /* nb_oct */
0, /* nb_hex */
0, /* nb_inplace_add */
0, /* nb_inplace_subtract */
0, /* nb_inplace_multiply */
0, /* nb_inplace_divide */
0, /* nb_inplace_remainder */
0, /* nb_inplace_power */
0, /* nb_inplace_lshift */
0, /* nb_inplace_rshift */
0, /* nb_inplace_and */
0, /* nb_inplace_xor */
0, /* nb_inplace_or */
0, /* nb_floor_divide */
0, /* nb_true_divide */
0, /* nb_inplace_floor_divide */
0, /* nb_inplace_true_divide */
};

/* The type object for bool. Note that this cannot be subclassed! */

PyTypeObjectPyBool_Type= {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"bool",
sizeof(PyIntObject),
0,
0, /* tp_dealloc */
 (printfunc)bool_print, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
 (reprfunc)bool_repr, /* tp_repr */
&bool_as_number, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
 (reprfunc)bool_repr, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES, /* tp_flags */
bool_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
&PyInt_Type, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
bool_new, /* tp_new */
};

/* The objects representing bool values False and True */

/* Named Zero for link-level compatibility */
PyIntObject_Py_ZeroStruct= {
PyObject_HEAD_INIT(&PyBool_Type)
0
};

PyIntObject_Py_TrueStruct= {
PyObject_HEAD_INIT(&PyBool_Type)
1
};