/* Set object interface */

#ifndef Py_SETOBJECT_H

#define Py_SETOBJECT_H

#ifdef __cplusplus

extern "C" {

#endif

/*

There are three kinds of slots in the table:

1. Unused:  key == NULL

2. Active:  key != NULL and key != dummy

3. Dummy:   key == dummy

Note: .pop() abuses the hash field of an Unused or Dummy slot to

hold a search finger.  The hash field of Unused or Dummy slots has

no meaning otherwise.

*/

#define PySet_MINSIZE 8

typedef struct {

	long hash;      /* cached hash code for the entry key */

	PyObject *key;

} setentry;

/*

This data structure is shared by set and frozenset objects.

*/

typedef struct _setobject PySetObject;

struct _setobject {

	PyObject_HEAD

	Py_ssize_t fill;  /* # Active + # Dummy */

	Py_ssize_t used;  /* # Active */

	/* The table contains mask + 1 slots, and that's a power of 2.

	 * We store the mask instead of the size because the mask is more

	 * frequently needed.

	 */

	Py_ssize_t mask;

	/* table points to smalltable for small tables, else to

	 * additional malloc'ed memory.  table is never NULL!  This rule

	 * saves repeated runtime null-tests.

	 */

	setentry *table;

	setentry *(*lookup)(PySetObject *so, PyObject *key, long hash);

	setentry smalltable[PySet_MINSIZE];

	long hash;		/* only used by frozenset objects */

	PyObject *weakreflist;	/* List of weak references */

};

PyAPI_DATA(PyTypeObject) PySet_Type;

PyAPI_DATA(PyTypeObject) PyFrozenSet_Type;

/* Invariants for frozensets:

 *     data is immutable.

 *     hash is the hash of the frozenset or -1 if not computed yet.

 * Invariants for sets:

 *     hash is -1

 */

#define PyFrozenSet_CheckExact(ob) ((ob)->ob_type == &PyFrozenSet_Type)

#define PyAnySet_CheckExact(ob) \

	((ob)->ob_type == &PySet_Type || (ob)->ob_type == &PyFrozenSet_Type)

#define PyAnySet_Check(ob) \

	((ob)->ob_type == &PySet_Type || (ob)->ob_type == &PyFrozenSet_Type || \

	  PyType_IsSubtype((ob)->ob_type, &PySet_Type) || \

	  PyType_IsSubtype((ob)->ob_type, &PyFrozenSet_Type))

PyAPI_FUNC(PyObject *) PySet_New(PyObject *);

PyAPI_FUNC(PyObject *) PyFrozenSet_New(PyObject *);

PyAPI_FUNC(Py_ssize_t) PySet_Size(PyObject *anyset);

#define PySet_GET_SIZE(so) (((PySetObject *)(so))->used)

PyAPI_FUNC(int) PySet_Clear(PyObject *set);

PyAPI_FUNC(int) PySet_Contains(PyObject *anyset, PyObject *key);

PyAPI_FUNC(int) PySet_Discard(PyObject *set, PyObject *key);

PyAPI_FUNC(int) PySet_Add(PyObject *set, PyObject *key);

PyAPI_FUNC(int) _PySet_Next(PyObject *set, Py_ssize_t *pos, PyObject **key);

PyAPI_FUNC(int) _PySet_NextEntry(PyObject *set, Py_ssize_t *pos, PyObject **key, long *hash);

PyAPI_FUNC(PyObject *) PySet_Pop(PyObject *set);

PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);

#ifdef __cplusplus

}

#endif

#endif /* !Py_SETOBJECT_H */