#ifndef SCM_FLUIDS_INTERNAL_H
#define SCM_FLUIDS_INTERNAL_H

/* Copyright 1996,2000-2001,2006,2008-2013,2018,2025
     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/fluids.h>
#include <libguile/gc.h>
#include <libguile/cache-internal.h>

struct scm_fluid
{
  scm_t_bits tag_and_flags;
  SCM default_value;
};

struct scm_dynamic_state_snapshot
{
  scm_t_bits tag;
  SCM bindings;
};

static inline struct scm_fluid*
scm_to_fluid (SCM x)
{
  if (!scm_is_fluid (x))
    abort ();
  return (struct scm_fluid *) SCM_UNPACK_POINTER (x);
}

static inline SCM
scm_from_fluid (struct scm_fluid *fluid)
{
  return SCM_PACK_POINTER (fluid);
}

static inline struct scm_dynamic_state_snapshot*
scm_to_dynamic_state (SCM x)
{
  if (!scm_is_dynamic_state (x))
    abort ();
  return (struct scm_dynamic_state_snapshot *) SCM_UNPACK_POINTER (x);
}

static inline SCM
scm_from_dynamic_state (struct scm_dynamic_state_snapshot *dynstate)
{
  return SCM_PACK_POINTER (dynstate);
}



struct scm_ephemeron_table;
struct scm_dynamic_state
{
  SCM thread_local_values;
  struct scm_ephemeron_table *values;
  uint8_t has_aliased_values;
  struct scm_cache cache;
};

SCM_INTERNAL SCM scm_i_fluid_ref (scm_thread *thread, SCM fluid);

SCM_INTERNAL void scm_swap_fluid (SCM fluid, SCM value_box,
                                  scm_t_dynamic_state *dynamic_state);

SCM_INTERNAL SCM scm_dynamic_state_ref (SCM state, SCM fluid, SCM dflt);

SCM_INTERNAL SCM scm_i_make_initial_dynamic_state (void);

SCM_INTERNAL void scm_i_fluid_print (SCM exp, SCM port, scm_print_state *pstate);
SCM_INTERNAL void scm_i_dynamic_state_print (SCM exp, SCM port, scm_print_state *pstate);
SCM_INTERNAL void scm_init_fluids (void);

#endif  /* SCM_FLUIDS_INTERNAL_H */