summaryrefslogtreecommitdiffstats
path: root/Objects/boolobject.c
blob: 677a98ba2e0766b06f62d94fb5e111070de2a427 (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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/* Boolean type, a subtype of int */

#include "Python.h"

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

static int
bool_print(PyBoolObject *self, FILE *fp, int flags)
{
	fputs(self->ob_ival == 0 ? "False" : "True", fp);
	return 0;
}

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

static PyObject *false_str = NULL;
static PyObject *true_str = NULL;

static PyObject *
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);
	return s;
}

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

PyObject *PyBool_FromLong(long ok)
{
	PyObject *result;

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

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

static PyObject *
bool_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	static const char *kwlist[] = {"x", 0};
	PyObject *x = Py_False;
	long ok;

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

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

static PyObject *
bool_and(PyObject *a, PyObject *b)
{
	if (!PyBool_Check(a) || !PyBool_Check(b))
		return PyInt_Type.tp_as_number->nb_and(a, b);
	return PyBool_FromLong(
		((PyBoolObject *)a)->ob_ival & ((PyBoolObject *)b)->ob_ival);
}

static PyObject *
bool_or(PyObject *a, PyObject *b)
{
	if (!PyBool_Check(a) || !PyBool_Check(b))
		return PyInt_Type.tp_as_number->nb_or(a, b);
	return PyBool_FromLong(
		((PyBoolObject *)a)->ob_ival | ((PyBoolObject *)b)->ob_ival);
}

static PyObject *
bool_xor(PyObject *a, PyObject *b)
{
	if (!PyBool_Check(a) || !PyBool_Check(b))
		return PyInt_Type.tp_as_number->nb_xor(a, b);
	return PyBool_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 &, |, ^. */

static PyNumberMethods bool_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 */
	(binaryfunc)bool_and,			/* nb_and */
	(binaryfunc)bool_xor,			/* nb_xor */
	(binaryfunc)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! */

PyTypeObject PyBool_Type = {
	PyObject_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
};