#ifndef SCM_WEAKS_H
#define SCM_WEAKS_H
-/* Copyright (C) 1995,1996,2000,2001, 2003, 2006, 2008 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,2000,2001, 2003, 2006, 2008, 2009, 2011, 2014 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
#define SCM_WVECT_WEAK_KEY_P(x) (SCM_I_WVECT_EXTRA(x) & SCM_WVECTF_WEAK_KEY)
#define SCM_WVECT_WEAK_VALUE_P(x) (SCM_I_WVECT_EXTRA(x) & SCM_WVECTF_WEAK_VALUE)
-/* The DELTA field is used by the abstract hash tables. During GC,
- this field will be set to the number of items that have been
- dropped. The abstract hash table will then use it to update its
- item count. DELTA is unsigned.
-*/
-
-#define SCM_I_WVECT_DELTA(x) (SCM_I_WVECT_EXTRA(x) >> 3)
-#define SCM_I_SET_WVECT_DELTA(x,n) (SCM_I_SET_WVECT_EXTRA \
- ((x), ((SCM_I_WVECT_EXTRA (x) & 7) \
- | ((n) << 3))))
-
#define SCM_I_WVECT_TYPE(x) (SCM_I_WVECT_EXTRA(x) & 7)
#define SCM_I_SET_WVECT_TYPE(x,t) (SCM_I_SET_WVECT_EXTRA \
((x), (SCM_I_WVECT_EXTRA (x) & ~7) | (t)))
#define SCM_IS_WHVEC_ANY(X) (SCM_I_WVECT_TYPE (X) != 0)
\f
+/* Weak pairs. */
+
+SCM_INTERNAL SCM scm_weak_car_pair (SCM car, SCM cdr);
+SCM_INTERNAL SCM scm_weak_cdr_pair (SCM car, SCM cdr);
+SCM_INTERNAL SCM scm_doubly_weak_pair (SCM car, SCM cdr);
+
+/* Testing the weak component(s) of a cell for reachability. */
+#define SCM_WEAK_PAIR_WORD_DELETED_P(_cell, _word) \
+ (SCM_UNPACK (SCM_CELL_OBJECT ((_cell), (_word))) == 0)
+#define SCM_WEAK_PAIR_CAR_DELETED_P(_cell) \
+ (SCM_WEAK_PAIR_WORD_DELETED_P ((_cell), 0))
+#define SCM_WEAK_PAIR_CDR_DELETED_P(_cell) \
+ (SCM_WEAK_PAIR_WORD_DELETED_P ((_cell), 1))
+
+#define SCM_WEAK_PAIR_DELETED_P(_cell) \
+ ((SCM_WEAK_PAIR_CAR_DELETED_P (_cell)) \
+ || (SCM_WEAK_PAIR_CDR_DELETED_P (_cell)))
+
+/* Accessing the components of a weak cell. These return `SCM_UNDEFINED' if
+ the car/cdr has been collected. */
+#define SCM_WEAK_PAIR_WORD(_cell, _word) \
+ (SCM_WEAK_PAIR_WORD_DELETED_P ((_cell), (_word)) \
+ ? SCM_UNDEFINED \
+ : SCM_CELL_OBJECT ((_cell), (_word)))
+#define SCM_WEAK_PAIR_CAR(_cell) (SCM_WEAK_PAIR_WORD ((_cell), 0))
+#define SCM_WEAK_PAIR_CDR(_cell) (SCM_WEAK_PAIR_WORD ((_cell), 1))
+
+
+\f
+/* Weak vectors and weak hash tables. */
SCM_API SCM scm_make_weak_vector (SCM k, SCM fill);
SCM_API SCM scm_weak_vector (SCM l);
SCM_API SCM scm_weak_vector_p (SCM x);
+SCM_API SCM scm_weak_vector_length (SCM v);
+SCM_API SCM scm_weak_vector_ref (SCM v, SCM k);
+SCM_API SCM scm_weak_vector_set_x (SCM v, SCM k, SCM x);
+
+SCM_API SCM scm_c_make_weak_vector (size_t k, SCM fill);
+SCM_API int scm_is_weak_vector (SCM obj);
+SCM_API size_t scm_c_weak_vector_length (SCM vec);
+SCM_API SCM scm_c_weak_vector_ref (SCM v, size_t k);
+SCM_API void scm_c_weak_vector_set_x (SCM v, size_t k, SCM x);
+
SCM_API SCM scm_make_weak_key_alist_vector (SCM k);
SCM_API SCM scm_make_weak_value_alist_vector (SCM k);
SCM_API SCM scm_make_doubly_weak_alist_vector (SCM k);
SCM_API SCM scm_weak_value_alist_vector_p (SCM x);
SCM_API SCM scm_doubly_weak_alist_vector_p (SCM x);
SCM_INTERNAL SCM scm_init_weaks_builtins (void);
+SCM_INTERNAL void scm_weaks_prehistory (void);
SCM_INTERNAL void scm_init_weaks (void);
SCM_INTERNAL void scm_i_init_weak_vectors_for_gc (void);