source: trunk/essentials/dev-lang/python/Objects/iterobject.c@ 3314

/* 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;

        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();
                Py_DECREF(seq);