cpython/Include/listobject.h
Tim Peters 51b4ade306 Fix obscure breakage (relative to 2.3) in listsort: the test for list
mutation during list.sort() used to rely on that listobject.c always
NULL'ed ob_item when ob_size fell to 0.  That's no longer true, so the
test for list mutation during a sort is no longer reliable.  Changed the
test to rely instead on that listobject.c now never NULLs-out ob_item
after (if ever) ob_item gets a non-NULL value.  This new assumption is
also documented now, as a required invariant in listobject.h.

The new assumption allowed some real simplification to some of the
hairier code in listsort(), so is a Good Thing on that count.
2004-07-29 04:07:15 +00:00

66 lines
2.4 KiB
C

/* List object interface */
/*
Another generally useful object type is an list of object pointers.
This is a mutable type: the list items can be changed, and items can be
added or removed. Out-of-range indices or non-list objects are ignored.
*** WARNING *** PyList_SetItem does not increment the new item's reference
count, but does decrement the reference count of the item it replaces,
if not nil. It does *decrement* the reference count if it is *not*
inserted in the list. Similarly, PyList_GetItem does not increment the
returned item's reference count.
*/
#ifndef Py_LISTOBJECT_H
#define Py_LISTOBJECT_H
#ifdef __cplusplus
extern "C" {
#endif
typedef struct {
PyObject_VAR_HEAD
/* Vector of pointers to list elements. list[0] is ob_item{0], etc. */
PyObject **ob_item;
/* ob_item contains space for 'allocated' elements. The number
* currently in use is ob_size.
* Invariants:
* 0 <= ob_size <= allocated
* len(list) == ob_size
* ob_item == NULL implies ob_size == allocated == 0
* If ob_item ever becomes non-NULL, it remains non-NULL for the
* life of the list object. The check for mutation in list.sort()
* relies on this odd detail.
*/
int allocated;
} PyListObject;
PyAPI_DATA(PyTypeObject) PyList_Type;
#define PyList_Check(op) PyObject_TypeCheck(op, &PyList_Type)
#define PyList_CheckExact(op) ((op)->ob_type == &PyList_Type)
PyAPI_FUNC(PyObject *) PyList_New(int size);
PyAPI_FUNC(int) PyList_Size(PyObject *);
PyAPI_FUNC(PyObject *) PyList_GetItem(PyObject *, int);
PyAPI_FUNC(int) PyList_SetItem(PyObject *, int, PyObject *);
PyAPI_FUNC(int) PyList_Insert(PyObject *, int, PyObject *);
PyAPI_FUNC(int) PyList_Append(PyObject *, PyObject *);
PyAPI_FUNC(PyObject *) PyList_GetSlice(PyObject *, int, int);
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])
#define PyList_SET_ITEM(op, i, v) (((PyListObject *)(op))->ob_item[i] = (v))
#define PyList_GET_SIZE(op) (((PyListObject *)(op))->ob_size)
#ifdef __cplusplus
}
#endif
#endif /* !Py_LISTOBJECT_H */