(***********************************************************************)
(*                                                                     *)
(*                         Applied Type System                         *)
(*                                                                     *)
(*                              Hongwei Xi                             *)
(*                                                                     *)
(***********************************************************************)

(*
 * ATS - Unleashing the Power of Types!
 *
 * Copyright (C) 2002-2007 Hongwei Xi, Boston University
 *
 * All rights reserved
 *
 * ATS 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 2.1, or (at your option)  any
 * later version.
 * 
 * ATS 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 General Public License
 * for more details.
 * 
 * You  should  have  received  a  copy of the GNU General Public License
 * along  with  ATS;  see the  file COPYING.  If not, please write to the
 * Free Software Foundation,  51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *)

(* ****** ****** *)

(* author: Hongwei Xi (hwxi AT cs DOT bu DOT edu) *)

(* ****** ****** *)

// some common functions on references

#if VERBOSE_PRELUDE #then

#print "Loading [reference.sats] starts!\n"

#endif

(* ****** ****** *)

// implemented in [prelude/CATS/reference.cats]
fun ref_make_elt_tsz
  {a:viewt@ype} (x: &a >> a?, tsz: sizeof_t a):<> ref a
  = "atspre_ref_make_elt_tsz"

// implemented in [prelude/DATS/reference.dats]
fun{a:viewt@ype} ref_make_elt (x: a):<> ref a

// this is really an identity function; it is
// implemented in [prelude/CATS/reference.cats]
fun ref_make_view_ptr
  {a:viewt@ype} {l:addr} (pf: vbox (a @ l) | p: ptr l):<> ref a
  = "atspre_ref_make_view_ptr"

// implemented in [prelude/CATS/reference.cats]
fun ref_void_make ():<> ref void = "atspre_ref_void_make"

(* ****** ****** *)

// Operationally, it is the same as [ref_make_view_ptr]
fun refconst_make_view_ptr
  {a:t@ype} {l:addr} (pf: a @ l | p: ptr l):<> refconst a
  = "atspre_ref_make_view_ptr"

(* ****** ****** *)

// implemented in [prelude/DATS/reference.dats]
fun{a:t@ype} ref_get_elt (r: ref a):<!ref> a
  = "atspre_ref_get_elt"

// implemented in [prelude/DATS/reference.dats]
fun{a:t@ype} ref_set_elt (r: ref a, x: a):<!ref> void

(* ****** ****** *)

// Operationally, it is the same as [ref_get_elt]
fun{a:t@ype} refconst_get_elt (r: refconst a):<> a

(* ****** ****** *)

// implemented in [prelude/CATS/reference.cats]
fun ref_get_view_ptr
  {a:viewt@ype} (r: ref a):<> [l:addr] (vbox (a @ l) | ptr l)
  = "atspre_ref_get_view_ptr"

// implemented in [prelude/DATS/reference.dats]
fun{a:viewt@ype} ref_swap (r: ref a, x: &a):<!ref> void

// implemented in [prelude/DATS/reference.dats]
fun ref_map {a:viewt@ype} {f:eff}
  (r: ref a, f: !(&a) -<> void):<!ref> void

(*

macdef ++r = let val x = !r + 1 in r := x; x end
macdef r++ = let val x = !r in r := x + 1; x end

macdef --r = let val x = !r - 1 in r := x; x end
macdef r-- = let val x = !r in r := x - 1; x end

*)

(* ****** ****** *)

#if VERBOSE_PRELUDE #then

#print "Loading [reference.sats] finishes!\n"

#endif

(* end of [reference.sats] *)