#ifndef SCM_HASHTAB_H
#define SCM_HASHTAB_H

/* Copyright 1995-1996,1999-2001,2003-2004,2006,2008-2009,2011,2018,2025
     Free Software Foundation, Inc.

   This file is part of Guile.

   Guile is free software: you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Guile is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with Guile.  If not, see
   <https://www.gnu.org/licenses/>.  */



#include "libguile/gc.h"



/* Function that computes a hash of OBJ modulo MAX.  */
typedef unsigned long (*scm_t_hash_fn) (SCM obj, unsigned long max,
					void *closure);

/* Function that returns the value associated with OBJ in ALIST according to
   some equality predicate.  */
typedef SCM (*scm_t_assoc_fn) (SCM obj, SCM alist, void *closure);

/* Function to fold over the entries of a hash table.  */
typedef SCM (*scm_t_hash_fold_fn) (void *closure, SCM key, SCM value,
				   SCM result);

/* Function to iterate over the handles (key-value pairs) of a hash
   table.  */
typedef SCM (*scm_t_hash_handle_fn) (void *closure, SCM handle);

typedef struct scm_t_hashtable {
  scm_t_bits tag;
  SCM buckets;
  unsigned long n_items;	/* number of items in table */
  unsigned long lower;		/* when to shrink */
  unsigned long upper;		/* when to grow */
  int size_index;		/* index into hashtable_size */
  int min_size_index;		/* minimum size_index */
  scm_t_hash_fn hash_fn;  /* for rehashing after a GC. */
} scm_t_hashtable;

static inline int
scm_is_hashtable (SCM x)
{
  return SCM_HAS_TYP7 (x, scm_tc7_hashtable);
}

static inline struct scm_t_hashtable*
scm_to_hashtable (SCM x)
{
  if (!scm_is_hashtable (x))
    abort ();
  return (struct scm_t_hashtable *) SCM_UNPACK_POINTER (x);
}

static inline SCM
scm_from_hashtable (struct scm_t_hashtable *x)
{
  return SCM_PACK_POINTER (x);
}

#define SCM_HASHTABLE_P(x) scm_is_hashtable (x)
#define SCM_VALIDATE_HASHTABLE(pos, arg) \
  SCM_MAKE_VALIDATE_MSG (pos, arg, HASHTABLE_P, "hash-table")



SCM_API SCM scm_vector_to_hash_table (SCM vector);
SCM_API SCM scm_c_make_hash_table (unsigned long k);
SCM_API SCM scm_make_hash_table (SCM n);

SCM_API SCM scm_hash_table_p (SCM h);

SCM_API SCM scm_hash_fn_get_handle (SCM table, SCM obj,
				    scm_t_hash_fn hash_fn,
				    scm_t_assoc_fn assoc_fn,
				    void *closure);
SCM_API SCM scm_hash_fn_create_handle_x (SCM table, SCM obj, SCM init,
					 scm_t_hash_fn hash_fn,
					 scm_t_assoc_fn assoc_fn,
					 void *closure);
SCM_API SCM scm_hash_fn_ref (SCM table, SCM obj, SCM dflt,
			     scm_t_hash_fn hash_fn,
			     scm_t_assoc_fn assoc_fn,
			     void *closure);
SCM_API SCM scm_hash_fn_set_x (SCM table, SCM obj, SCM val,
			       scm_t_hash_fn hash_fn,
			       scm_t_assoc_fn assoc_fn,
			       void *closure);
SCM_API SCM scm_hash_fn_remove_x (SCM table, SCM obj,
				  scm_t_hash_fn hash_fn,
				  scm_t_assoc_fn assoc_fn,
				  void *closure);
SCM_API SCM scm_internal_hash_fold (scm_t_hash_fold_fn fn, void *closure,
				    SCM init, SCM table);
SCM_API void scm_internal_hash_for_each_handle (scm_t_hash_handle_fn fn,
						void *closure, SCM table);
SCM_API SCM scm_hash_clear_x (SCM table);

SCM_API SCM scm_hashq_get_handle (SCM table, SCM obj);
SCM_API SCM scm_hashq_create_handle_x (SCM table, SCM obj, SCM init);
SCM_API SCM scm_hashq_ref (SCM table, SCM obj, SCM dflt);
SCM_API SCM scm_hashq_set_x (SCM table, SCM obj, SCM val);
SCM_API SCM scm_hashq_remove_x (SCM table, SCM obj);
SCM_API SCM scm_hashv_get_handle (SCM table, SCM obj);
SCM_API SCM scm_hashv_create_handle_x (SCM table, SCM obj, SCM init);
SCM_API SCM scm_hashv_ref (SCM table, SCM obj, SCM dflt);
SCM_API SCM scm_hashv_set_x (SCM table, SCM obj, SCM val);
SCM_API SCM scm_hashv_remove_x (SCM table, SCM obj);
SCM_API SCM scm_hash_get_handle (SCM table, SCM obj);
SCM_API SCM scm_hash_create_handle_x (SCM table, SCM obj, SCM init);
SCM_API SCM scm_hash_ref (SCM table, SCM obj, SCM dflt);
SCM_API SCM scm_hash_set_x (SCM table, SCM obj, SCM val);
SCM_API SCM scm_hash_remove_x (SCM table, SCM obj);
SCM_API SCM scm_hashx_get_handle (SCM hash, SCM assoc, SCM table, SCM obj);
SCM_API SCM scm_hashx_create_handle_x (SCM hash, SCM assoc, SCM table, SCM obj, SCM init);
SCM_API SCM scm_hashx_ref (SCM hash, SCM assoc, SCM table, SCM obj, SCM dflt);
SCM_API SCM scm_hashx_set_x (SCM hash, SCM assoc, SCM table, SCM obj, SCM val);
SCM_API SCM scm_hashx_remove_x (SCM hash, SCM assoc, SCM table, SCM obj);
SCM_API SCM scm_hash_fold (SCM proc, SCM init, SCM hash);
SCM_API SCM scm_hash_for_each (SCM proc, SCM hash);
SCM_API SCM scm_hash_for_each_handle (SCM proc, SCM hash);
SCM_API SCM scm_hash_map_to_list (SCM proc, SCM hash);
SCM_API SCM scm_hash_count (SCM hash, SCM pred);
SCM_INTERNAL void scm_i_hashtable_print (SCM exp, SCM port, scm_print_state *pstate);
SCM_INTERNAL void scm_init_hashtab (void);

#if (SCM_ENABLE_DEPRECATED == 1)
SCM_DEPRECATED SCM scm_make_weak_key_hash_table (SCM k);
SCM_DEPRECATED SCM scm_make_weak_value_hash_table (SCM k);
SCM_DEPRECATED SCM scm_make_doubly_weak_hash_table (SCM k);
SCM_DEPRECATED SCM scm_weak_key_hash_table_p (SCM h);
SCM_DEPRECATED SCM scm_weak_value_hash_table_p (SCM h);
SCM_DEPRECATED SCM scm_doubly_weak_hash_table_p (SCM h);
#endif

#endif  /* SCM_HASHTAB_H */