cpython/Include/tupleobject.h
Armin Rigo 89a39461bf Wrote down the invariants of some common objects whose structure is
exposed in header files.  Fixed a few comments in these headers.

As we might have expected, writing down invariants systematically exposed a
(minor) bug.  In this case, function objects have a writeable func_code
attribute, which could be set to code objects with the wrong number of
free variables.  Calling the resulting function segfaulted the interpreter.
Added a corresponding test.
2004-10-28 16:32:00 +00:00

58 lines
2.0 KiB
C

/* Tuple object interface */
#ifndef Py_TUPLEOBJECT_H
#define Py_TUPLEOBJECT_H
#ifdef __cplusplus
extern "C" {
#endif
/*
Another generally useful object type is a tuple of object pointers.
For Python, this is an immutable type. C code can change the tuple items
(but not their number), and even use tuples are general-purpose arrays of
object references, but in general only brand new tuples should be mutated,
not ones that might already have been exposed to Python code.
*** WARNING *** PyTuple_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 tuple. Similarly, PyTuple_GetItem does not increment the
returned item's reference count.
*/
typedef struct {
PyObject_VAR_HEAD
PyObject *ob_item[1];
/* ob_item contains space for 'ob_size' elements.
* Items must normally not be NULL, except during construction when
* the tuple is not yet visible outside the function that builds it.
*/
} PyTupleObject;
PyAPI_DATA(PyTypeObject) PyTuple_Type;
#define PyTuple_Check(op) PyObject_TypeCheck(op, &PyTuple_Type)
#define PyTuple_CheckExact(op) ((op)->ob_type == &PyTuple_Type)
PyAPI_FUNC(PyObject *) PyTuple_New(int size);
PyAPI_FUNC(int) PyTuple_Size(PyObject *);
PyAPI_FUNC(PyObject *) PyTuple_GetItem(PyObject *, int);
PyAPI_FUNC(int) PyTuple_SetItem(PyObject *, int, PyObject *);
PyAPI_FUNC(PyObject *) PyTuple_GetSlice(PyObject *, int, int);
PyAPI_FUNC(int) _PyTuple_Resize(PyObject **, int);
PyAPI_FUNC(PyObject *) PyTuple_Pack(int, ...);
/* Macro, trading safety for speed */
#define PyTuple_GET_ITEM(op, i) (((PyTupleObject *)(op))->ob_item[i])
#define PyTuple_GET_SIZE(op) (((PyTupleObject *)(op))->ob_size)
/* Macro, *only* to be used to fill in brand new tuples */
#define PyTuple_SET_ITEM(op, i, v) (((PyTupleObject *)(op))->ob_item[i] = v)
#ifdef __cplusplus
}
#endif
#endif /* !Py_TUPLEOBJECT_H */