val _push_frame: Prims.unit -> STT unit emp (fun _ -> _stack_frame)
let _push_frame () : STT unit emp (fun _ -> _stack_frame) =
  rewrite (pure True) _stack_frame
val _push_frame: Prims.unit -> STT unit emp (fun _ -> _stack_frame)
let _push_frame () : STT unit emp (fun _ -> _stack_frame) =
rewrite (pure True) _stack_frame
Steel.ST.HigherReference.fst.checked
Steel.ST.Util.fsti.checked Steel.ST.Coercions.fsti.checked Steel.HigherReference.fsti.checked prims.fst.checked FStar.Pervasives.fsti.checked FStar.Ghost.fsti.checked
Steel.ST.HigherReference.fst
Prims.unit Steel.ST.Util.rewrite FStar.Ghost.hide FStar.Set.set Steel.Memory.iname FStar.Set.empty Steel.ST.Util.pure Prims.l_True Steel.ST.HigherReference._stack_frame Steel.Effect.Common.emp Steel.Effect.Common.vprop
(*
   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.HigherReference
open FStar.Ghost
open Steel.ST.Util
open Steel.ST.Coercions
module R = Steel.HigherReference

let ref (a:Type u#1)
  : Type0
  = R.ref a

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

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

let pts_to (#a:Type)
           (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.higher_ref_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 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 r) in
    return u

let write (#a:Type)
          (#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 r x);
    return ()

let free (#a:Type)
         (#v:erased a)
         (r:ref a)
  : STT unit
        (pts_to r full_perm v)
        (fun _ -> emp)
  = coerce_steel(fun _ -> R.free r);
    return ()

/// Local primitive, to be extracted to Low* EPushFrame.  To remember
/// that we need to call some pop_frame later, we insert some dummy
/// vprop into the context.
let _stack_frame : vprop = pure True
val _push_frame: Prims.unit -> STT unit emp (fun _ -> _stack_frame)
_: Prims.unit -> Steel.ST.Effect.STT Prims.unit