AppPkg/Applications/Python/Python-2.7.10/Objects/iterobject.c

   1 /* Iterator objects */
   2
   3 #include "Python.h"
   4
   5 typedef struct {
   6     PyObject_HEAD
   7     long      it_index;
   8     PyObject *it_seq; /* Set to NULL when iterator is exhausted */
   9 } seqiterobject;
  10
  11 PyObject *
  12 PySeqIter_New(PyObject *seq)
  13 {
  14     seqiterobject *it;
  15
  16     if (!PySequence_Check(seq)) {
  17         PyErr_BadInternalCall();
  18         return NULL;
  19     }
  20     it = PyObject_GC_New(seqiterobject, &PySeqIter_Type);
  21     if (it == NULL)
  22         return NULL;
  23     it->it_index = 0;
  24     Py_INCREF(seq);
  25     it->it_seq = seq;
  26     _PyObject_GC_TRACK(it);
  27     return (PyObject *)it;
  28 }
  29
  30 static void
  31 iter_dealloc(seqiterobject *it)
  32 {
  33     _PyObject_GC_UNTRACK(it);
  34     Py_XDECREF(it->it_seq);
  35     PyObject_GC_Del(it);
  36 }
  37
  38 static int
  39 iter_traverse(seqiterobject *it, visitproc visit, void *arg)
  40 {
  41     Py_VISIT(it->it_seq);
  42     return 0;
  43 }
  44
  45 static PyObject *
  46 iter_iternext(PyObject *iterator)
  47 {
  48     seqiterobject *it;
  49     PyObject *seq;
  50     PyObject *result;
  51
  52     assert(PySeqIter_Check(iterator));
  53     it = (seqiterobject *)iterator;
  54     seq = it->it_seq;
  55     if (seq == NULL)
  56         return NULL;
  57
  58     result = PySequence_GetItem(seq, it->it_index);
  59     if (result != NULL) {
  60         it->it_index++;
  61         return result;
  62     }
  63     if (PyErr_ExceptionMatches(PyExc_IndexError) ||
  64         PyErr_ExceptionMatches(PyExc_StopIteration))
  65     {
  66         PyErr_Clear();
  67         Py_DECREF(seq);
  68         it->it_seq = NULL;
  69     }
  70     return NULL;
  71 }
  72
  73 static PyObject *
  74 iter_len(seqiterobject *it)
  75 {
  76     Py_ssize_t seqsize, len;
  77
  78     if (it->it_seq) {
  79         seqsize = PySequence_Size(it->it_seq);
  80         if (seqsize == -1)
  81             return NULL;
  82         len = seqsize - it->it_index;
  83         if (len >= 0)
  84             return PyInt_FromSsize_t(len);
  85     }
  86     return PyInt_FromLong(0);
  87 }
  88
  89 PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
  90
  91 static PyMethodDef seqiter_methods[] = {
  92     {"__length_hint__", (PyCFunction)iter_len, METH_NOARGS, length_hint_doc},
  93     {NULL,              NULL}           /* sentinel */
  94 };
  95
  96 PyTypeObject PySeqIter_Type = {
  97     PyVarObject_HEAD_INIT(&PyType_Type, 0)
  98     "iterator",                                 /* tp_name */
  99     sizeof(seqiterobject),                      /* tp_basicsize */
 100     0,                                          /* tp_itemsize */
 101     /* methods */
 102     (destructor)iter_dealloc,                   /* tp_dealloc */
 103     0,                                          /* tp_print */
 104     0,                                          /* tp_getattr */
 105     0,                                          /* tp_setattr */
 106     0,                                          /* tp_compare */
 107     0,                                          /* tp_repr */
 108     0,                                          /* tp_as_number */
 109     0,                                          /* tp_as_sequence */
 110     0,                                          /* tp_as_mapping */
 111     0,                                          /* tp_hash */
 112     0,                                          /* tp_call */
 113     0,                                          /* tp_str */
 114     PyObject_GenericGetAttr,                    /* tp_getattro */
 115     0,                                          /* tp_setattro */
 116     0,                                          /* tp_as_buffer */
 117     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
 118     0,                                          /* tp_doc */
 119     (traverseproc)iter_traverse,                /* tp_traverse */
 120     0,                                          /* tp_clear */
 121     0,                                          /* tp_richcompare */
 122     0,                                          /* tp_weaklistoffset */
 123     PyObject_SelfIter,                          /* tp_iter */
 124     iter_iternext,                              /* tp_iternext */
 125     seqiter_methods,                            /* tp_methods */
 126     0,                                          /* tp_members */
 127 };
 128
 129 /* -------------------------------------- */
 130
 131 typedef struct {
 132     PyObject_HEAD
 133     PyObject *it_callable; /* Set to NULL when iterator is exhausted */
 134     PyObject *it_sentinel; /* Set to NULL when iterator is exhausted */
 135 } calliterobject;
 136
 137 PyObject *
 138 PyCallIter_New(PyObject *callable, PyObject *sentinel)
 139 {
 140     calliterobject *it;
 141     it = PyObject_GC_New(calliterobject, &PyCallIter_Type);
 142     if (it == NULL)
 143         return NULL;
 144     Py_INCREF(callable);
 145     it->it_callable = callable;
 146     Py_INCREF(sentinel);
 147     it->it_sentinel = sentinel;
 148     _PyObject_GC_TRACK(it);
 149     return (PyObject *)it;
 150 }
 151 static void
 152 calliter_dealloc(calliterobject *it)
 153 {
 154     _PyObject_GC_UNTRACK(it);
 155     Py_XDECREF(it->it_callable);
 156     Py_XDECREF(it->it_sentinel);
 157     PyObject_GC_Del(it);
 158 }
 159
 160 static int
 161 calliter_traverse(calliterobject *it, visitproc visit, void *arg)
 162 {
 163     Py_VISIT(it->it_callable);
 164     Py_VISIT(it->it_sentinel);
 165     return 0;
 166 }
 167
 168 static PyObject *
 169 calliter_iternext(calliterobject *it)
 170 {
 171     if (it->it_callable != NULL) {
 172         PyObject *args = PyTuple_New(0);
 173         PyObject *result;
 174         if (args == NULL)
 175             return NULL;
 176         result = PyObject_Call(it->it_callable, args, NULL);
 177         Py_DECREF(args);
 178         if (result != NULL) {
 179             int ok;
 180             ok = PyObject_RichCompareBool(result,
 181                                           it->it_sentinel,
 182                                           Py_EQ);
 183             if (ok == 0)
 184                 return result; /* Common case, fast path */
 185             Py_DECREF(result);
 186             if (ok > 0) {
 187                 Py_CLEAR(it->it_callable);
 188                 Py_CLEAR(it->it_sentinel);
 189             }
 190         }
 191         else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
 192             PyErr_Clear();
 193             Py_CLEAR(it->it_callable);
 194             Py_CLEAR(it->it_sentinel);
 195         }
 196     }
 197     return NULL;
 198 }
 199
 200 PyTypeObject PyCallIter_Type = {
 201     PyVarObject_HEAD_INIT(&PyType_Type, 0)
 202     "callable-iterator",                        /* tp_name */
 203     sizeof(calliterobject),                     /* tp_basicsize */
 204     0,                                          /* tp_itemsize */
 205     /* methods */
 206     (destructor)calliter_dealloc,               /* tp_dealloc */
 207     0,                                          /* tp_print */
 208     0,                                          /* tp_getattr */
 209     0,                                          /* tp_setattr */
 210     0,                                          /* tp_compare */
 211     0,                                          /* tp_repr */
 212     0,                                          /* tp_as_number */
 213     0,                                          /* tp_as_sequence */
 214     0,                                          /* tp_as_mapping */
 215     0,                                          /* tp_hash */
 216     0,                                          /* tp_call */
 217     0,                                          /* tp_str */
 218     PyObject_GenericGetAttr,                    /* tp_getattro */
 219     0,                                          /* tp_setattro */
 220     0,                                          /* tp_as_buffer */
 221     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
 222     0,                                          /* tp_doc */
 223     (traverseproc)calliter_traverse,            /* tp_traverse */
 224     0,                                          /* tp_clear */
 225     0,                                          /* tp_richcompare */
 226     0,                                          /* tp_weaklistoffset */
 227     PyObject_SelfIter,                          /* tp_iter */
 228     (iternextfunc)calliter_iternext,            /* tp_iternext */
 229     0,                                          /* tp_methods */
 230 };