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cpython/Include/listobject.h
Armin Rigo 93677f075d * drop the unreasonable list invariant that ob_item should never come back
to NULL during the lifetime of the object.

* listobject.c nevertheless did not conform to the other invariants,
  either; fixed.

* listobject.c now uses list_clear() as the obvious internal way to clear
  a list, instead of abusing list_ass_slice() for that.  It makes it easier
  to enforce the invariant about ob_item == NULL.

* listsort() sets allocated to -1 during sort; any mutation will set it
  to a value >= 0, so it is a safe way to detect mutation.  A negative
  value for allocated does not cause a problem elsewhere currently.
  test_sort.py has a new test for this fix.

* listsort() leak: if items were added to the list during the sort, AND if
  these items had a __del__ that puts still more stuff into the list,
  then this more stuff (and the PyObject** array to hold them) were
  overridden at the end of listsort() and never released.
2004-07-29 12:40:23 +00:00

65 lines
2.2 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
* list.sort() temporarily sets allocated to -1 to detect mutations.
*/
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 */