aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/tools/python/src/Objects/iterobject.c
blob: 346d2d97a99b223f181cb2abb35571ec31e201df (plain) (blame)
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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/* Iterator objects */

#include "Python.h"

typedef struct {
    PyObject_HEAD
    long      it_index;
    PyObject *it_seq; /* Set to NULL when iterator is exhausted */
} seqiterobject;

PyObject *
PySeqIter_New(PyObject *seq)
{
    seqiterobject *it;

    if (!PySequence_Check(seq)) {
        PyErr_BadInternalCall();
        return NULL;
    }
    it = PyObject_GC_New(seqiterobject, &PySeqIter_Type);
    if (it == NULL)
        return NULL;
    it->it_index = 0;
    Py_INCREF(seq);
    it->it_seq = seq;
    _PyObject_GC_TRACK(it);
    return (PyObject *)it;
}

static void
iter_dealloc(seqiterobject *it)
{
    _PyObject_GC_UNTRACK(it);
    Py_XDECREF(it->it_seq);
    PyObject_GC_Del(it);
}

static int
iter_traverse(seqiterobject *it, visitproc visit, void *arg)
{
    Py_VISIT(it->it_seq);
    return 0;
}

static PyObject *
iter_iternext(PyObject *iterator)
{
    seqiterobject *it;
    PyObject *seq;
    PyObject *result;

    assert(PySeqIter_Check(iterator));
    it = (seqiterobject *)iterator;
    seq = it->it_seq;
    if (seq == NULL)
        return NULL;
    if (it->it_index == LONG_MAX) {
        PyErr_SetString(PyExc_OverflowError,
                        "iter index too large");
        return NULL;
    }

    result = PySequence_GetItem(seq, it->it_index);
    if (result != NULL) {
        it->it_index++;
        return result;
    }
    if (PyErr_ExceptionMatches(PyExc_IndexError) ||
        PyErr_ExceptionMatches(PyExc_StopIteration))
    {
        PyErr_Clear();
        it->it_seq = NULL;
        Py_DECREF(seq);
    }
    return NULL;
}

static PyObject *
iter_len(seqiterobject *it)
{
    Py_ssize_t seqsize, len;

    if (it->it_seq) {
        seqsize = PySequence_Size(it->it_seq);
        if (seqsize == -1)
            return NULL;
        len = seqsize - it->it_index;
        if (len >= 0)
            return PyInt_FromSsize_t(len);
    }
    return PyInt_FromLong(0);
}

PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");

static PyMethodDef seqiter_methods[] = {
    {"__length_hint__", (PyCFunction)iter_len, METH_NOARGS, length_hint_doc},
    {NULL,              NULL}           /* sentinel */
};

PyTypeObject PySeqIter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "iterator",                                 /* tp_name */
    sizeof(seqiterobject),                      /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    (destructor)iter_dealloc,                   /* tp_dealloc */
    0,                                          /* tp_print */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* tp_compare */
    0,                                          /* 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)iter_traverse,                /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    iter_iternext,                              /* tp_iternext */
    seqiter_methods,                            /* tp_methods */
    0,                                          /* tp_members */
};

/* -------------------------------------- */

typedef struct {
    PyObject_HEAD
    PyObject *it_callable; /* Set to NULL when iterator is exhausted */
    PyObject *it_sentinel; /* Set to NULL when iterator is exhausted */
} calliterobject;

PyObject *
PyCallIter_New(PyObject *callable, PyObject *sentinel)
{
    calliterobject *it;
    it = PyObject_GC_New(calliterobject, &PyCallIter_Type);
    if (it == NULL)
        return NULL;
    Py_INCREF(callable);
    it->it_callable = callable;
    Py_INCREF(sentinel);
    it->it_sentinel = sentinel;
    _PyObject_GC_TRACK(it);
    return (PyObject *)it;
}
static void
calliter_dealloc(calliterobject *it)
{
    _PyObject_GC_UNTRACK(it);
    Py_XDECREF(it->it_callable);
    Py_XDECREF(it->it_sentinel);
    PyObject_GC_Del(it);
}

static int
calliter_traverse(calliterobject *it, visitproc visit, void *arg)
{
    Py_VISIT(it->it_callable);
    Py_VISIT(it->it_sentinel);
    return 0;
}

static PyObject *
calliter_iternext(calliterobject *it)
{
    if (it->it_callable != NULL) {
        PyObject *args = PyTuple_New(0);
        PyObject *result;
        if (args == NULL)
            return NULL;
        result = PyObject_Call(it->it_callable, args, NULL);
        Py_DECREF(args);
        if (result != NULL) {
            int ok;
            ok = PyObject_RichCompareBool(result,
                                          it->it_sentinel,
                                          Py_EQ);
            if (ok == 0)
                return result; /* Common case, fast path */
            Py_DECREF(result);
            if (ok > 0) {
                Py_CLEAR(it->it_callable);
                Py_CLEAR(it->it_sentinel);
            }
        }
        else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
            PyErr_Clear();
            Py_CLEAR(it->it_callable);
            Py_CLEAR(it->it_sentinel);
        }
    }
    return NULL;
}

PyTypeObject PyCallIter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "callable-iterator",                        /* tp_name */
    sizeof(calliterobject),                     /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    (destructor)calliter_dealloc,               /* tp_dealloc */
    0,                                          /* tp_print */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* tp_compare */
    0,                                          /* 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)calliter_traverse,            /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    PyObject_SelfIter,                          /* tp_iter */
    (iternextfunc)calliter_iternext,            /* tp_iternext */
    0,                                          /* tp_methods */
};