#ifndef SCM_FOREIGN_H
#define SCM_FOREIGN_H

/* Copyright 2010-2013,2016,2018,2024
     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"
#include "libguile/snarf.h"

/* A "foreign pointer" is a wrapped C pointer.  It is represented by a
   cell whose second word is a pointer.  The first word has the
   `scm_tc7_pointer' type code.

   The basic idea is that we can help the programmer to avoid cutting herself,
   but we won't take away her knives.  */

enum scm_t_foreign_type
  {
    SCM_FOREIGN_TYPE_VOID,
    SCM_FOREIGN_TYPE_FLOAT,
    SCM_FOREIGN_TYPE_DOUBLE,
    SCM_FOREIGN_TYPE_UINT8,
    SCM_FOREIGN_TYPE_INT8,
    SCM_FOREIGN_TYPE_UINT16,
    SCM_FOREIGN_TYPE_INT16,
    SCM_FOREIGN_TYPE_UINT32,
    SCM_FOREIGN_TYPE_INT32,
    SCM_FOREIGN_TYPE_UINT64,
    SCM_FOREIGN_TYPE_INT64,
    SCM_FOREIGN_TYPE_COMPLEX_FLOAT,
    SCM_FOREIGN_TYPE_COMPLEX_DOUBLE,
    SCM_FOREIGN_TYPE_LAST = SCM_FOREIGN_TYPE_COMPLEX_DOUBLE
  };

typedef enum scm_t_foreign_type scm_t_foreign_type;

typedef void (*scm_t_pointer_finalizer) (void *);

#define SCM_POINTER_P(x) (SCM_HAS_TYP7 (x, scm_tc7_pointer))
#define SCM_VALIDATE_POINTER(pos, x)		\
  SCM_MAKE_VALIDATE (pos, x, POINTER_P)
#define SCM_POINTER_VALUE(x)			\
  ((void *) SCM_CELL_WORD_1 (x))

#define SCM_IMMUTABLE_POINTER(c_name, ptr)		\
  SCM_IMMUTABLE_CELL (c_name, scm_tc7_pointer, ptr)

SCM_API void *scm_to_pointer (SCM pointer);
SCM_API SCM scm_from_pointer (void *, scm_t_pointer_finalizer);

SCM_API SCM scm_alignof (SCM type);
SCM_API SCM scm_sizeof (SCM type);
SCM_API SCM scm_pointer_address (SCM pointer);
SCM_API SCM scm_pointer_to_scm (SCM pointer);
SCM_API SCM scm_scm_to_pointer (SCM scm);
SCM_API SCM scm_pointer_to_bytevector (SCM pointer, SCM type,
                                       SCM offset, SCM len);
SCM_API SCM scm_set_pointer_finalizer_x (SCM pointer, SCM finalizer);
SCM_API SCM scm_bytevector_to_pointer (SCM bv, SCM offset);

SCM_INTERNAL SCM scm_pointer_p (SCM obj);
SCM_INTERNAL SCM scm_make_pointer (SCM address, SCM finalizer);
SCM_INTERNAL void scm_i_pointer_print (SCM pointer, SCM port,
                                       scm_print_state *pstate);

SCM_INTERNAL SCM scm_dereference_pointer (SCM pointer);
SCM_INTERNAL SCM scm_string_to_pointer (SCM string, SCM encoding);
SCM_INTERNAL SCM scm_pointer_to_string (SCM pointer, SCM length, SCM encoding);