diff options
| -rw-r--r-- | Modules/itertoolsmodule.c | 28 |
1 files changed, 12 insertions, 16 deletions
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c index c751184..4bc9192 100644 --- a/Modules/itertoolsmodule.c +++ b/Modules/itertoolsmodule.c @@ -2713,20 +2713,20 @@ cwr_next(cwrobject *co) PyObject *result = co->result; Py_ssize_t n = PyTuple_GET_SIZE(pool); Py_ssize_t r = co->r; - Py_ssize_t i, j, index; + Py_ssize_t i, index; if (co->stopped) return NULL; if (result == NULL) { - /* On the first pass, initialize result tuple using the indices */ + /* On the first pass, initialize result tuple with pool[0] */ result = PyTuple_New(r); if (result == NULL) goto empty; co->result = result; + elem = PyTuple_GET_ITEM(pool, 0); for (i=0; i<r ; i++) { - index = indices[i]; - elem = PyTuple_GET_ITEM(pool, index); + assert(indices[i] == 0); Py_INCREF(elem); PyTuple_SET_ITEM(result, i, elem); } @@ -2749,27 +2749,23 @@ cwr_next(cwrobject *co) empty tuple is a singleton and cached in PyTuple's freelist. */ assert(r == 0 || Py_REFCNT(result) == 1); - /* Scan indices right-to-left until finding one that is not - * at its maximum (n-1). */ + /* Scan indices right-to-left until finding one that is not + * at its maximum (n-1). */ for (i=r-1 ; i >= 0 && indices[i] == n-1; i--) ; /* If i is negative, then the indices are all at - their maximum value and we're done. */ + their maximum value and we're done. */ if (i < 0) goto empty; /* Increment the current index which we know is not at its - maximum. Then set all to the right to the same value. */ - indices[i]++; - for (j=i+1 ; j<r ; j++) - indices[j] = indices[j-1]; - - /* Update the result tuple for the new indices - starting with i, the leftmost index that changed */ + maximum. Then set all to the right to the same value. */ + index = indices[i] + 1; + assert(index < n); + elem = PyTuple_GET_ITEM(pool, index); for ( ; i<r ; i++) { - index = indices[i]; - elem = PyTuple_GET_ITEM(pool, index); + indices[i] = index; Py_INCREF(elem); oldelem = PyTuple_GET_ITEM(result, i); PyTuple_SET_ITEM(result, i, elem); |