val free (#a:Type0)
         (#v:erased a)
         (r:ref a)
  : STT unit
    (pts_to r full_perm v) (fun _ -> emp)
let free (#a:Type0)
         (#v:erased a)
         (r:ref a)
  : STT unit
        (pts_to r full_perm v)
        (fun _ -> emp)
  = coerce_steel(fun _ -> R.free_pt r);
    return ()
val free (#a:Type0)
         (#v:erased a)
         (r:ref a)
  : STT unit
    (pts_to r full_perm v) (fun _ -> emp)
let free (#a: Type0) (#v: erased a) (r: ref a) : STT unit (pts_to r full_perm v) (fun _ -> emp) =
coerce_steel (fun _ -> R.free_pt r);
return ()
Steel.ST.Reference.fst.checked
Steel.ST.Util.fsti.checked Steel.ST.Coercions.fsti.checked Steel.Reference.fsti.checked prims.fst.checked FStar.Pervasives.fsti.checked FStar.Ghost.fsti.checked
Steel.ST.Reference.fst
FStar.Ghost.erased Steel.ST.Reference.ref Steel.ST.Util.return Prims.unit FStar.Ghost.hide FStar.Set.set Steel.Memory.iname FStar.Set.empty FStar.Algebra.CommMonoid.Equiv.__proj__CM__item__unit Steel.Effect.Common.vprop Steel.Effect.Common.req Steel.Effect.Common.rm Steel.ST.Coercions.coerce_steel Steel.Reference.pts_to Steel.FractionalPermission.full_perm FStar.Ghost.reveal Steel.Effect.Common.emp Prims.l_True Steel.Reference.free_pt Steel.ST.Reference.pts_to
(*
   Copyright 2020 Microsoft Research

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*)

module Steel.ST.Reference
open FStar.Ghost
open Steel.ST.Util
open Steel.ST.Coercions
module R = Steel.Reference

let ref (a:Type0)
  : Type0
  = R.ref a

let null (#a:Type0)
  : ref a
  = R.null #a

let is_null (#a:Type0) (r:ref a)
  : b:bool{b <==> r == null}
  = R.is_null r

let pts_to (#a:Type0)
           (r:ref a)
           ([@@@smt_fallback] p:perm)
           ([@@@smt_fallback] v:a)
  : vprop
  = R.pts_to r p v

let pts_to_injective_eq
      (#a: Type)
      (#opened:inames)
      (#p0 #p1:perm)
      (#v0 #v1:a)
      (r: ref a)
  : STGhost unit opened
      (pts_to r p0 v0 `star` pts_to r p1 v1)
      (fun _ -> pts_to r p0 v0 `star` pts_to r p1 v0)
      (requires True)
      (ensures fun _ -> v0 == v1)
  = coerce_ghost
    (fun _ -> R.pts_to_injective_eq #a #opened #p0 #p1 #(hide v0) #(hide v1) r)

let pts_to_not_null #a #opened #p #v r
  = extract_fact #opened (pts_to r p v) (r =!= null) (R.pts_to_not_null r p v);
    ()

let alloc (#a:Type) (x:a)
  : ST (ref a)
      emp
      (fun r -> pts_to r full_perm x)
      (requires True)
      (ensures fun r -> not (is_null r))
  = let r = coerce_steel (fun _ -> R.alloc_pt x) in
    r

let read (#a:Type)
         (#p:perm)
         (#v:erased a)
         (r:ref a)
  : ST a
      (pts_to r p v)
      (fun _ -> pts_to r p v)
      (requires True)
      (ensures fun x -> x == Ghost.reveal v)
  = let u = coerce_steel (fun _ -> R.read_pt r) in
    return u

let write (#a:Type0)
          (#v:erased a)
          (r:ref a)
          (x:a)
  : STT unit
      (pts_to r full_perm v)
      (fun _ -> pts_to r full_perm x)
  = coerce_steel (fun _ -> R.write_pt r x);
    return ()

let free (#a:Type0)
         (#v:erased a)
         (r:ref a)
  : STT unit
        (pts_to r full_perm v)
val free (#a:Type0)
         (#v:erased a)
         (r:ref a)
  : STT unit
    (pts_to r full_perm v) (fun _ -> emp)
r: Steel.ST.Reference.ref a -> Steel.ST.Effect.STT Prims.unit