val 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 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
val 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 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
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
Steel.ST.Reference.ref Steel.Reference.ref Steel.ST.Coercions.coerce_steel Steel.Effect.Common.emp Steel.Reference.pts_to Steel.FractionalPermission.full_perm Steel.Effect.Common.vprop Prims.l_True Prims.b2t Prims.op_Negation Steel.Reference.is_null Prims.unit Steel.Reference.alloc_pt Steel.ST.Reference.pts_to Steel.ST.Reference.is_null
(*
   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)
val 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))
x: a -> Steel.ST.Effect.ST (Steel.ST.Reference.ref a)