* Eliminated tuple re-use in imap(). Doing it correctly made the code

  too hard to read.
* Simplified previous changes to izip() to make it easier to read.

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 69ee3d4eae36f5d3ddd26204401e9079bdb58f41..453b4a2eb34a72e33307dd4767e4d88210504216 100644 (file)
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -637,7 +637,6 @@ PyTypeObject starmap_type = {
 typedef struct {
        PyObject_HEAD
        PyObject *iters;
-       PyObject *argtuple;
        PyObject *func;
 } imapobject;
 
@@ -646,7 +645,7 @@ PyTypeObject imap_type;
 static PyObject *
 imap_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
-       PyObject *it, *iters, *argtuple, *func;
+       PyObject *it, *iters, *func;
        imapobject *lz;
        int numargs, i;
 
@@ -661,34 +660,23 @@ imap_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
        if (iters == NULL)
                return NULL;
 
-       argtuple = PyTuple_New(numargs-1);
-       if (argtuple == NULL) {
-               Py_DECREF(iters);
-               return NULL;
-       }
-
        for (i=1 ; i<numargs ; i++) {
                /* Get iterator. */
                it = PyObject_GetIter(PyTuple_GET_ITEM(args, i));
                if (it == NULL) {
-                       Py_DECREF(argtuple);
                        Py_DECREF(iters);
                        return NULL;
                }
                PyTuple_SET_ITEM(iters, i-1, it);
-               Py_INCREF(Py_None);
-               PyTuple_SET_ITEM(argtuple, i-1, Py_None);
        }
 
        /* create imapobject structure */
        lz = (imapobject *)type->tp_alloc(type, 0);
        if (lz == NULL) {
-               Py_DECREF(argtuple);
                Py_DECREF(iters);
                return NULL;
        }
        lz->iters = iters;
-       lz->argtuple = argtuple;
        func = PyTuple_GET_ITEM(args, 0);
        Py_INCREF(func);
        lz->func = func;
@@ -700,7 +688,6 @@ static void
 imap_dealloc(imapobject *lz)
 {
        PyObject_GC_UnTrack(lz);
-       Py_XDECREF(lz->argtuple);
        Py_XDECREF(lz->iters);
        Py_XDECREF(lz->func);
        lz->ob_type->tp_free(lz);
@@ -716,11 +703,6 @@ imap_traverse(imapobject *lz, visitproc visit, void *arg)
                if (err)
                        return err;
        }
-       if (lz->argtuple) {
-               err = visit(lz->argtuple, arg);
-               if (err)
-                       return err;
-       }
        if (lz->func) {
                err = visit(lz->func, arg);
                if (err)
@@ -758,39 +740,28 @@ static PyObject *
 imap_next(imapobject *lz)
 {
        PyObject *val;
-       PyObject *argtuple=lz->argtuple;
+       PyObject *argtuple;
+       PyObject *result;
        int numargs, i;
 
        numargs = PyTuple_Size(lz->iters);
-       if (lz->func == Py_None) {
-               argtuple = PyTuple_New(numargs);
-               if (argtuple == NULL)
-                       return NULL;
+       argtuple = PyTuple_New(numargs);
+       if (argtuple == NULL)
+               return NULL;
 
-               for (i=0 ; i<numargs ; i++) {
-                       val = PyIter_Next(PyTuple_GET_ITEM(lz->iters, i));
-                       if (val == NULL) {
-                               Py_DECREF(argtuple);
-                               return NULL;
-                       }
-                       PyTuple_SET_ITEM(argtuple, i, val);
-               }
-               return argtuple;
-       } else {
-               if (argtuple->ob_refcnt > 1) {
-                       argtuple = PyTuple_New(numargs);
-                       if (argtuple == NULL)
-                               return NULL;
-               }
-               for (i=0 ; i<numargs ; i++) {
-                       val = PyIter_Next(PyTuple_GET_ITEM(lz->iters, i));
-                       if (val == NULL)
-                               return NULL;
-                       Py_DECREF(PyTuple_GET_ITEM(argtuple, i));
-                       PyTuple_SET_ITEM(argtuple, i, val);
+       for (i=0 ; i<numargs ; i++) {
+               val = PyIter_Next(PyTuple_GET_ITEM(lz->iters, i));
+               if (val == NULL) {
+                       Py_DECREF(argtuple);
+                       return NULL;
                }
-               return PyObject_Call(lz->func, argtuple, NULL);
+               PyTuple_SET_ITEM(argtuple, i, val);
        }
+       if (lz->func == Py_None) 
+               return argtuple;
+       result = PyObject_Call(lz->func, argtuple, NULL);
+       Py_DECREF(argtuple);
+       return result;
 }
 
 static PyObject *
@@ -1331,32 +1302,29 @@ izip_next(izipobject *lz)
        PyObject *it;
        PyObject *item;
 
-       assert(result->ob_refcnt >= 1);
        if (result->ob_refcnt == 1) {
                for (i=0 ; i < tuplesize ; i++) {
+                       it = PyTuple_GET_ITEM(lz->ittuple, i);
+                       item = PyIter_Next(it);
+                       if (item == NULL)
+                               return NULL;
                        Py_DECREF(PyTuple_GET_ITEM(result, i));
-                       PyTuple_SET_ITEM(result, i, NULL);
+                       PyTuple_SET_ITEM(result, i, item);
                }
                Py_INCREF(result);
        } else {
-               Py_DECREF(result);
                result = PyTuple_New(tuplesize);
                if (result == NULL)
                        return NULL;
-               Py_INCREF(result);
-               lz->result = result;
-       }
-       assert(lz->result == result);
-       assert(result->ob_refcnt == 2);
-
-       for (i=0 ; i < tuplesize ; i++) {
-               it = PyTuple_GET_ITEM(lz->ittuple, i);
-               item = PyIter_Next(it);
-               if (item == NULL) {
-                       Py_DECREF(result);
-                       return NULL;
+               for (i=0 ; i < tuplesize ; i++) {
+                       it = PyTuple_GET_ITEM(lz->ittuple, i);
+                       item = PyIter_Next(it);
+                       if (item == NULL) {
+                               Py_DECREF(result);
+                               return NULL;
+                       }
+                       PyTuple_SET_ITEM(result, i, item);
                }
-               PyTuple_SET_ITEM(result, i, item);
        }
        return result;
 }