Eliminate a big block of duplicate code in PySequence_List() by

exposing _PyList_Extend().

diff --git a/Include/listobject.h b/Include/listobject.h
index 6221b80d1f9262d7033aaec0740b4379c89cbc80..b4935ae89469e14c28a51066b1bdfb0dec7665c9 100644 (file)
--- a/Include/listobject.h
+++ b/Include/listobject.h
@@ -41,6 +41,7 @@ PyAPI_FUNC(int) PyList_SetSlice(PyObject *, int, int, PyObject *);
 PyAPI_FUNC(int) PyList_Sort(PyObject *);
 PyAPI_FUNC(int) PyList_Reverse(PyObject *);
 PyAPI_FUNC(PyObject *) PyList_AsTuple(PyObject *);
+PyAPI_FUNC(PyObject *) _PyList_Extend(PyListObject *, PyObject *);
 
 /* Macro, trading safety for speed */
 #define PyList_GET_ITEM(op, i) (((PyListObject *)(op))->ob_item[i])

diff --git a/Objects/abstract.c b/Objects/abstract.c
index 4ac92608ab91a128c3b8be97a9123178d54a1f14..90efd9010f25982342589146ba0a87ced18b66aa 100644 (file)
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1427,69 +1427,21 @@ Fail:
 PyObject *
 PySequence_List(PyObject *v)
 {
-       PyObject *it;      /* iter(v) */
        PyObject *result;  /* result list */
-       int n;             /* guess for result list size */
-       int i;
+       PyObject *rv;      /* return value from PyList_Extend */
 
        if (v == NULL)
                return null_error();
 
-       /* Special-case list(a_list), for speed. */
-       if (PyList_Check(v))
-               return PyList_GetSlice(v, 0, PyList_GET_SIZE(v));
-
-       /* Get iterator.  There may be some low-level efficiency to be gained
-        * by caching the tp_iternext slot instead of using PyIter_Next()
-        * later, but premature optimization is the root etc.
-        */
-       it = PyObject_GetIter(v);
-       if (it == NULL)
+       result = PyList_New(0);
+       if (result == NULL)
                return NULL;
 
-       /* Guess a result list size. */
-       n = PyObject_Size(v);
-       if (n < 0) {
-               PyErr_Clear();
-               n = 8;  /* arbitrary */
-       }
-       result = PyList_New(n);
-       if (result == NULL) {
-               Py_DECREF(it);
+       rv = _PyList_Extend((PyListObject *)result, v);
+       if (rv == NULL) {
+               Py_DECREF(result);
                return NULL;
        }
-
-       /* Run iterator to exhaustion. */
-       for (i = 0; ; i++) {
-               PyObject *item = PyIter_Next(it);
-               if (item == NULL) {
-                       if (PyErr_Occurred()) {
-                               Py_DECREF(result);
-                               result = NULL;
-                       }
-                       break;
-               }
-               if (i < n)
-                       PyList_SET_ITEM(result, i, item); /* steals ref */
-               else {
-                       int status = PyList_Append(result, item);
-                       Py_DECREF(item);  /* append creates a new ref */
-                       if (status < 0) {
-                               Py_DECREF(result);
-                               result = NULL;
-                               break;
-                       }
-               }
-       }
-
-       /* Cut back result list if initial guess was too large. */
-       if (i < n && result != NULL) {
-               if (PyList_SetSlice(result, i, n, (PyObject *)NULL) != 0) {
-                       Py_DECREF(result);
-                       result = NULL;
-               }
-       }
-       Py_DECREF(it);
        return result;
 }
 

diff --git a/Objects/listobject.c b/Objects/listobject.c
index 6bb6d8c797351ab6f82d01423bd6654bbc1563d8..ed6ed3e56108f8f2903f01ee56813e95b9a7e1e6 100644 (file)
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -776,6 +776,12 @@ listextend(PyListObject *self, PyObject *b)
        return NULL;
 }
 
+PyObject *
+_PyList_Extend(PyListObject *self, PyObject *b)
+{
+       return listextend(self, b);
+}
+
 static PyObject *
 list_inplace_concat(PyListObject *self, PyObject *other)
 {