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;
   9 } seqiterobject;
  10
  11 PyObject *
  12 PySeqIter_New(PyObject *seq)
  13 {
  14         seqiterobject *it;
  15         it = PyObject_NEW(seqiterobject, &PySeqIter_Type);
  16         if (it == NULL)
  17                 return NULL;
  18         it->it_index = 0;
  19         Py_INCREF(seq);
  20         it->it_seq = seq;
  21         PyObject_GC_Init(it);
  22         return (PyObject *)it;
  23 }
  24 static void
  25 iter_dealloc(seqiterobject *it)
  26 {
  27         PyObject_GC_Fini(it);
  28         Py_DECREF(it->it_seq);
  29         it = (seqiterobject *) PyObject_AS_GC(it);
  30         PyObject_DEL(it);
  31 }
  32
  33 static int
  34 iter_traverse(seqiterobject *it, visitproc visit, void *arg)
  35 {
  36         return visit(it->it_seq, arg);
  37 }
  38
  39 static PyObject *
  40 iter_next(seqiterobject *it)
  41 {
  42         PyObject *seq = it->it_seq;
  43         PyObject *result = PySequence_GetItem(seq, it->it_index++);
  44
  45         if (result == NULL && PyErr_ExceptionMatches(PyExc_IndexError))
  46                 PyErr_SetObject(PyExc_StopIteration, Py_None);
  47         return result;
  48 }
  49
  50 static PyObject *
  51 iter_getiter(PyObject *it)
  52 {
  53         Py_INCREF(it);
  54         return it;
  55 }
  56
  57 static PyObject *
  58 iter_iternext(PyObject *iterator)
  59 {
  60         seqiterobject *it;
  61         PyObject *seq;
  62
  63         assert(PySeqIter_Check(iterator));
  64         it = (seqiterobject *)iterator;
  65         seq = it->it_seq;
  66
  67         if (PyList_Check(seq)) {
  68                 PyObject *item;
  69                 if (it->it_index >= PyList_GET_SIZE(seq)) {
  70                         return NULL;
  71                 }
  72                 item = PyList_GET_ITEM(seq, it->it_index);
  73                 it->it_index++;
  74                 Py_INCREF(item);
  75                 return item;
  76         }
  77         else {
  78                 PyObject *result = PySequence_GetItem(seq, it->it_index++);
  79                 if (result != NULL) {
  80                         return result;
  81                 }
  82                 if (PyErr_ExceptionMatches(PyExc_IndexError) ||
  83                         PyErr_ExceptionMatches(PyExc_StopIteration)) {
  84                         PyErr_Clear();
  85                         return NULL;
  86                 }
  87                 else {
  88                         return NULL;
  89                 }
  90         }
  91 }
  92
  93 static PyMethodDef iter_methods[] = {
  94         {"next",        (PyCFunction)iter_next, METH_NOARGS,
  95          "it.next() -- get the next value, or raise StopIteration"},
  96         {NULL,          NULL}           /* sentinel */
  97 };
  98
  99 PyTypeObject PySeqIter_Type = {
 100         PyObject_HEAD_INIT(&PyType_Type)
 101         0,                                      /* ob_size */
 102         "iterator",                             /* tp_name */
 103         sizeof(seqiterobject) + PyGC_HEAD_SIZE, /* tp_basicsize */
 104         0,                                      /* tp_itemsize */
 105         /* methods */
 106         (destructor)iter_dealloc,               /* tp_dealloc */
 107         0,                                      /* tp_print */
 108         0,                                      /* tp_getattr */
 109         0,                                      /* tp_setattr */
 110         0,                                      /* tp_compare */
 111         0,                                      /* tp_repr */
 112         0,                                      /* tp_as_number */
 113         0,                                      /* tp_as_sequence */
 114         0,                                      /* tp_as_mapping */
 115         0,                                      /* tp_hash */
 116         0,                                      /* tp_call */
 117         0,                                      /* tp_str */
 118         PyObject_GenericGetAttr,                /* tp_getattro */
 119         0,                                      /* tp_setattro */
 120         0,                                      /* tp_as_buffer */
 121         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC,     /* tp_flags */
 122         0,                                      /* tp_doc */
 123         (traverseproc)iter_traverse,            /* tp_traverse */
 124         0,                                      /* tp_clear */
 125         0,                                      /* tp_richcompare */
 126         0,                                      /* tp_weaklistoffset */
 127         (getiterfunc)iter_getiter,              /* tp_iter */
 128         (iternextfunc)iter_iternext,            /* tp_iternext */
 129         iter_methods,                           /* tp_methods */
 130         0,                                      /* tp_members */
 131         0,                                      /* tp_getset */
 132         0,                                      /* tp_base */
 133         0,                                      /* tp_dict */
 134         0,                                      /* tp_descr_get */
 135         0,                                      /* tp_descr_set */
 136 };
 137
 138 /* -------------------------------------- */
 139
 140 typedef struct {
 141         PyObject_HEAD
 142         PyObject *it_callable;
 143         PyObject *it_sentinel;
 144 } calliterobject;
 145
 146 PyObject *
 147 PyCallIter_New(PyObject *callable, PyObject *sentinel)
 148 {
 149         calliterobject *it;
 150         it = PyObject_NEW(calliterobject, &PyCallIter_Type);
 151         if (it == NULL)
 152                 return NULL;
 153         Py_INCREF(callable);
 154         it->it_callable = callable;
 155         Py_INCREF(sentinel);
 156         it->it_sentinel = sentinel;
 157         PyObject_GC_Init(it);
 158         return (PyObject *)it;
 159 }
 160 static void
 161 calliter_dealloc(calliterobject *it)
 162 {
 163         PyObject_GC_Fini(it);
 164         Py_DECREF(it->it_callable);
 165         Py_DECREF(it->it_sentinel);
 166         it = (calliterobject *) PyObject_AS_GC(it);
 167         PyObject_DEL(it);
 168 }
 169
 170 static int
 171 calliter_traverse(calliterobject *it, visitproc visit, void *arg)
 172 {
 173         int err;
 174         if ((err = visit(it->it_callable, arg)))
 175                 return err;
 176         if ((err = visit(it->it_sentinel, arg)))
 177                 return err;
 178         return 0;
 179 }
 180
 181 static PyObject *
 182 calliter_next(calliterobject *it, PyObject *args)
 183 {
 184         PyObject *result = PyObject_CallObject(it->it_callable, NULL);
 185         if (result != NULL) {
 186                 if (PyObject_RichCompareBool(result, it->it_sentinel, Py_EQ)) {
 187                         PyErr_SetObject(PyExc_StopIteration, Py_None);
 188                         Py_DECREF(result);
 189                         result = NULL;
 190                 }
 191         }
 192         return result;
 193 }
 194
 195 static PyMethodDef calliter_methods[] = {
 196         {"next",        (PyCFunction)calliter_next,     METH_VARARGS,
 197          "it.next() -- get the next value, or raise StopIteration"},
 198         {NULL,          NULL}           /* sentinel */
 199 };
 200
 201 static PyObject *
 202 calliter_iternext(calliterobject *it)
 203 {
 204         PyObject *result = PyObject_CallObject(it->it_callable, NULL);
 205         if (result != NULL) {
 206                 if (PyObject_RichCompareBool(result, it->it_sentinel, Py_EQ)) {
 207                         Py_DECREF(result);
 208                         result = NULL;
 209                 }
 210         }
 211         else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
 212                 PyErr_Clear();
 213         }
 214         return result;
 215 }
 216
 217 PyTypeObject PyCallIter_Type = {
 218         PyObject_HEAD_INIT(&PyType_Type)
 219         0,                                      /* ob_size */
 220         "callable-iterator",                    /* tp_name */
 221         sizeof(calliterobject) + PyGC_HEAD_SIZE,/* tp_basicsize */
 222         0,                                      /* tp_itemsize */
 223         /* methods */
 224         (destructor)calliter_dealloc,           /* tp_dealloc */
 225         0,                                      /* tp_print */
 226         0,                                      /* tp_getattr */
 227         0,                                      /* tp_setattr */
 228         0,                                      /* tp_compare */
 229         0,                                      /* tp_repr */
 230         0,                                      /* tp_as_number */
 231         0,                                      /* tp_as_sequence */
 232         0,                                      /* tp_as_mapping */
 233         0,                                      /* tp_hash */
 234         0,                                      /* tp_call */
 235         0,                                      /* tp_str */
 236         PyObject_GenericGetAttr,                /* tp_getattro */
 237         0,                                      /* tp_setattro */
 238         0,                                      /* tp_as_buffer */
 239         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC,     /* tp_flags */
 240         0,                                      /* tp_doc */
 241         (traverseproc)calliter_traverse,        /* tp_traverse */
 242         0,                                      /* tp_clear */
 243         0,                                      /* tp_richcompare */
 244         0,                                      /* tp_weaklistoffset */
 245         (getiterfunc)iter_getiter,              /* tp_iter */
 246         (iternextfunc)calliter_iternext,        /* tp_iternext */
 247         calliter_methods,                       /* tp_methods */
 248         0,                                      /* tp_members */
 249         0,                                      /* tp_getset */
 250         0,                                      /* tp_base */
 251         0,                                      /* tp_dict */
 252         0,                                      /* tp_descr_get */
 253         0,                                      /* tp_descr_set */
 254 };