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-rw-r--r--Python/bltinmodule.c134
1 files changed, 68 insertions, 66 deletions
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 9e8a227..0c20d10 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -936,9 +936,8 @@ static PyObject *
builtin_map(PyObject *self, PyObject *args)
{
typedef struct {
- PyObject *seq;
- PySequenceMethods *sqf;
- int saw_IndexError;
+ PyObject *it; /* the iterator object */
+ int saw_StopIteration; /* bool: did the iterator end? */
} sequence;
PyObject *func, *result;
@@ -961,104 +960,105 @@ builtin_map(PyObject *self, PyObject *args)
return PySequence_List(PyTuple_GetItem(args, 1));
}
+ /* Get space for sequence descriptors. Must NULL out the iterator
+ * pointers so that jumping to Fail_2 later doesn't see trash.
+ */
if ((seqs = PyMem_NEW(sequence, n)) == NULL) {
PyErr_NoMemory();
- goto Fail_2;
+ return NULL;
+ }
+ for (i = 0; i < n; ++i) {
+ seqs[i].it = (PyObject*)NULL;
+ seqs[i].saw_StopIteration = 0;
}
- /* Do a first pass to (a) verify the args are sequences; (b) set
- * len to the largest of their lengths; (c) initialize the seqs
- * descriptor vector.
+ /* Do a first pass to obtain iterators for the arguments, and set len
+ * to the largest of their lengths.
*/
- for (len = 0, i = 0, sqp = seqs; i < n; ++i, ++sqp) {
+ len = 0;
+ for (i = 0, sqp = seqs; i < n; ++i, ++sqp) {
+ PyObject *curseq;
int curlen;
- PySequenceMethods *sqf;
- if ((sqp->seq = PyTuple_GetItem(args, i + 1)) == NULL)
- goto Fail_2;
-
- sqp->saw_IndexError = 0;
-
- sqp->sqf = sqf = sqp->seq->ob_type->tp_as_sequence;
- if (sqf == NULL ||
- sqf->sq_item == NULL)
- {
+ /* Get iterator. */
+ curseq = PyTuple_GetItem(args, i+1);
+ sqp->it = PyObject_GetIter(curseq);
+ if (sqp->it == NULL) {
static char errmsg[] =
- "argument %d to map() must be a sequence object";
+ "argument %d to map() must support iteration";
char errbuf[sizeof(errmsg) + 25];
-
sprintf(errbuf, errmsg, i+2);
PyErr_SetString(PyExc_TypeError, errbuf);
goto Fail_2;
}
- if (sqf->sq_length == NULL)
- /* doesn't matter -- make something up */
- curlen = 8;
- else
- curlen = (*sqf->sq_length)(sqp->seq);
+ /* Update len. */
+ curlen = -1; /* unknown */
+ if (PySequence_Check(curseq) &&
+ curseq->ob_type->tp_as_sequence->sq_length) {
+ curlen = PySequence_Size(curseq);
+ if (curlen < 0)
+ PyErr_Clear();
+ }
if (curlen < 0)
- goto Fail_2;
+ curlen = 8; /* arbitrary */
if (curlen > len)
len = curlen;
}
+ /* Get space for the result list. */
if ((result = (PyObject *) PyList_New(len)) == NULL)
goto Fail_2;
- /* Iterate over the sequences until all have raised IndexError. */
+ /* Iterate over the sequences until all have stopped. */
for (i = 0; ; ++i) {
PyObject *alist, *item=NULL, *value;
- int any = 0;
+ int numactive = 0;
if (func == Py_None && n == 1)
alist = NULL;
- else {
- if ((alist = PyTuple_New(n)) == NULL)
- goto Fail_1;
- }
+ else if ((alist = PyTuple_New(n)) == NULL)
+ goto Fail_1;
for (j = 0, sqp = seqs; j < n; ++j, ++sqp) {
- if (sqp->saw_IndexError) {
+ if (sqp->saw_StopIteration) {
Py_INCREF(Py_None);
item = Py_None;
}
else {
- item = (*sqp->sqf->sq_item)(sqp->seq, i);
- if (item == NULL) {
- if (PyErr_ExceptionMatches(
- PyExc_IndexError))
- {
- PyErr_Clear();
- Py_INCREF(Py_None);
- item = Py_None;
- sqp->saw_IndexError = 1;
- }
- else {
- goto Fail_0;
+ item = PyIter_Next(sqp->it);
+ if (item)
+ ++numactive;
+ else {
+ /* StopIteration is *implied* by a
+ * NULL return from PyIter_Next() if
+ * PyErr_Occurred() is false.
+ */
+ if (PyErr_Occurred()) {
+ if (PyErr_ExceptionMatches(
+ PyExc_StopIteration))
+ PyErr_Clear();
+ else {
+ Py_XDECREF(alist);
+ goto Fail_1;
+ }
}
+ Py_INCREF(Py_None);
+ item = Py_None;
+ sqp->saw_StopIteration = 1;
}
- else
- any = 1;
}
- if (!alist)
+ if (alist)
+ PyTuple_SET_ITEM(alist, j, item);
+ else
break;
- if (PyTuple_SetItem(alist, j, item) < 0) {
- Py_DECREF(item);
- goto Fail_0;
- }
- continue;
-
- Fail_0:
- Py_XDECREF(alist);
- goto Fail_1;
}
if (!alist)
alist = item;
- if (!any) {
+ if (numactive == 0) {
Py_DECREF(alist);
break;
}
@@ -1077,23 +1077,25 @@ builtin_map(PyObject *self, PyObject *args)
if (status < 0)
goto Fail_1;
}
- else {
- if (PyList_SetItem(result, i, value) < 0)
- goto Fail_1;
- }
+ else if (PyList_SetItem(result, i, value) < 0)
+ goto Fail_1;
}
if (i < len && PyList_SetSlice(result, i, len, NULL) < 0)
goto Fail_1;
- PyMem_DEL(seqs);
- return result;
+ goto Succeed;
Fail_1:
Py_DECREF(result);
Fail_2:
- if (seqs) PyMem_DEL(seqs);
- return NULL;
+ result = NULL;
+Succeed:
+ assert(seqs);
+ for (i = 0; i < n; ++i)
+ Py_XDECREF(seqs[i].it);
+ PyMem_DEL(seqs);
+ return result;
}
static char map_doc[] =