Patch #552433: Special-case tuples. Avoid sub-type checking for lists.
Avoid checks for negative indices and duplicate checks for support of
the sequence protocol.
diff --git a/Doc/api/abstract.tex b/Doc/api/abstract.tex
index 0e25afa..e4f299d 100644
--- a/Doc/api/abstract.tex
+++ b/Doc/api/abstract.tex
@@ -765,6 +765,13 @@
and that \var{i} is within bounds.
\end{cfuncdesc}
+\begin{cfuncdesc}{PyObject*}{PySequence_ITEM}{PyObject *o, int i}
+ Return the \var{i}th element of \var{o} or \NULL on failure.
+ Macro form of \cfunction{PySequence_GetItem()} but without checking
+ that \cfunction{PySequence_Check(\var{o})} is true and without
+ adjustment for negative indices.
+\end{cfuncdesc}
+
\begin{cfuncdesc}{int}{PySequence_Fast_GET_SIZE}{PyObject *o}
Returns the length of \var{o}, assuming that \var{o} was
returned by \cfunction{PySequence_Fast()} and that \var{o} is
diff --git a/Include/abstract.h b/Include/abstract.h
index 226e5e8..459bd56 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -1015,6 +1015,12 @@
PySequence_Fast, and that i is within bounds.
*/
+#define PySequence_ITEM(o, i)\
+ ( o->ob_type->tp_as_sequence->sq_item(o, i) )
+ /* Assume tp_as_sequence and sq_item exist and that i does not
+ need to be corrected for a negative index
+ */
+
DL_IMPORT(int) PySequence_Count(PyObject *o, PyObject *value);
/*
diff --git a/Misc/NEWS b/Misc/NEWS
index 34befe8..d31e09d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -192,6 +192,10 @@
C API
+- Added new macro PySequence_ITEM(o, i) that directly calls
+ sq_item without rechecking that o is a sequence and without
+ adjusting for negative indices.
+
- PyRange_New() now raises ValueError if the fourth argument is not 1.
This is part of the removal of deprecated features of the xrange
object.
diff --git a/Objects/iterobject.c b/Objects/iterobject.c
index 789eb6c..de9f2f9 100644
--- a/Objects/iterobject.c
+++ b/Objects/iterobject.c
@@ -12,6 +12,11 @@
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;
@@ -63,7 +68,7 @@
it = (seqiterobject *)iterator;
seq = it->it_seq;
- if (PyList_Check(seq)) {
+ if (PyList_CheckExact(seq)) {
PyObject *item;
if (it->it_index >= PyList_GET_SIZE(seq)) {
return NULL;
@@ -73,8 +78,19 @@
Py_INCREF(item);
return item;
}
+ if (PyTuple_CheckExact(seq)) {
+ PyObject *item;
+ if (it->it_index >= PyTuple_GET_SIZE(seq)) {
+ return NULL;
+ }
+ item = PyTuple_GET_ITEM(seq, it->it_index);
+ it->it_index++;
+ Py_INCREF(item);
+ return item;
+ }
else {
- PyObject *result = PySequence_GetItem(seq, it->it_index++);
+ PyObject *result = PySequence_ITEM(seq, it->it_index);
+ it->it_index++;
if (result != NULL) {
return result;
}