Merge pull request #123 from AeneasVerif/son/clean

Cleanup the code in preparation of the nested loops

2 files changed, 44 insertions, 48 deletions

diff --git a/tests/fstar/demo/Demo.fst b/tests/fstar/demo/Demo.fst
index 9c59ab9b..b210662f 100644
--- a/tests/fstar/demo/Demo.fst
+++ b/tests/fstar/demo/Demo.fst
@@ -10,8 +10,8 @@ open Primitives
 let choose
   (t : Type0) (b : bool) (x : t) (y : t) : result (t & (t -> result (t & t))) =
   if b
-  then let back = fun ret -> Return (ret, y) in Return (x, back)
-  else let back = fun ret -> Return (x, ret) in Return (y, back)
+  then let back = fun ret -> Ok (ret, y) in Ok (x, back)
+  else let back = fun ret -> Ok (x, ret) in Ok (y, back)
 
 (** [demo::mul2_add1]:
     Source: 'src/demo.rs', lines 13:0-13:31 *)
@@ -31,7 +31,7 @@ let incr (x : u32) : result u32 =
 (** [demo::use_incr]:
     Source: 'src/demo.rs', lines 25:0-25:17 *)
 let use_incr : result unit =
-  let* x = incr 0 in let* x1 = incr x in let* _ = incr x1 in Return ()
+  let* x = incr 0 in let* x1 = incr x in let* _ = incr x1 in Ok ()
 
 (** [demo::CList]
     Source: 'src/demo.rs', lines 34:0-34:17 *)
@@ -48,7 +48,7 @@ let rec list_nth (t : Type0) (n : nat) (l : cList_t t) (i : u32) : result t =
     let n1 = decrease n in
     begin match l with
     | CList_CCons x tl ->
-      if i = 0 then Return x else let* i1 = u32_sub i 1 in list_nth t n1 tl i1
+      if i = 0 then Ok x else let* i1 = u32_sub i 1 in list_nth t n1 tl i1
     | CList_CNil -> Fail Failure
     end
 
@@ -65,15 +65,14 @@ let rec list_nth_mut
     begin match l with
     | CList_CCons x tl ->
       if i = 0
-      then
-        let back = fun ret -> Return (CList_CCons ret tl) in Return (x, back)
+      then let back = fun ret -> Ok (CList_CCons ret tl) in Ok (x, back)
       else
         let* i1 = u32_sub i 1 in
         let* (x1, list_nth_mut_back) = list_nth_mut t n1 tl i1 in
         let back =
-          fun ret ->
-            let* tl1 = list_nth_mut_back ret in Return (CList_CCons x tl1) in
-        Return (x1, back)
+          fun ret -> let* tl1 = list_nth_mut_back ret in Ok (CList_CCons x tl1)
+          in
+        Ok (x1, back)
     | CList_CNil -> Fail Failure
     end
 
@@ -90,14 +89,12 @@ let rec list_nth_mut1_loop
     begin match l with
     | CList_CCons x tl ->
       if i = 0
-      then
-        let back = fun ret -> Return (CList_CCons ret tl) in Return (x, back)
+      then let back = fun ret -> Ok (CList_CCons ret tl) in Ok (x, back)
       else
         let* i1 = u32_sub i 1 in
         let* (x1, back) = list_nth_mut1_loop t n1 tl i1 in
-        let back1 =
-          fun ret -> let* tl1 = back ret in Return (CList_CCons x tl1) in
-        Return (x1, back1)
+        let back1 = fun ret -> let* tl1 = back ret in Ok (CList_CCons x tl1) in
+        Ok (x1, back1)
     | CList_CNil -> Fail Failure
     end
 
@@ -117,7 +114,7 @@ let rec i32_id (n : nat) (i : i32) : result i32 =
   else
     let n1 = decrease n in
     if i = 0
-    then Return 0
+    then Ok 0
     else let* i1 = i32_sub i 1 in let* i2 = i32_id n1 i1 in i32_add i2 1
 
 (** [demo::list_tail]:
@@ -134,10 +131,9 @@ let rec list_tail
     | CList_CCons x tl ->
       let* (c, list_tail_back) = list_tail t n1 tl in
       let back =
-        fun ret -> let* tl1 = list_tail_back ret in Return (CList_CCons x tl1)
-        in
-      Return (c, back)
-    | CList_CNil -> Return (CList_CNil, Return)
+        fun ret -> let* tl1 = list_tail_back ret in Ok (CList_CCons x tl1) in
+      Ok (c, back)
+    | CList_CNil -> Ok (CList_CNil, Ok)
     end
 
 (** Trait declaration: [demo::Counter]
@@ -147,7 +143,7 @@ noeq type counter_t (self : Type0) = { incr : self -> result (usize & self); }
 (** [demo::{(demo::Counter for usize)}::incr]:
     Source: 'src/demo.rs', lines 102:4-102:31 *)
 let counterUsize_incr (self : usize) : result (usize & usize) =
-  let* self1 = usize_add self 1 in Return (self, self1)
+  let* self1 = usize_add self 1 in Ok (self, self1)
 
 (** Trait implementation: [demo::{(demo::Counter for usize)}]
     Source: 'src/demo.rs', lines 101:0-101:22 *)
diff --git a/tests/fstar/demo/Primitives.fst b/tests/fstar/demo/Primitives.fst
index fca80829..acdb09dc 100644
--- a/tests/fstar/demo/Primitives.fst
+++ b/tests/fstar/demo/Primitives.fst
@@ -23,11 +23,11 @@ type error : Type0 =
 | OutOfFuel
 
 type result (a : Type0) : Type0 =
-| Return : v:a -> result a
+| Ok : v:a -> result a
 | Fail : e:error -> result a
 
 // Monadic return operator
-unfold let return (#a : Type0) (x : a) : result a = Return x
+unfold let return (#a : Type0) (x : a) : result a = Ok x
 
 // Monadic bind operator.
 // Allows to use the notation:
@@ -36,17 +36,17 @@ unfold let return (#a : Type0) (x : a) : result a = Return x
 // ...
 // ```
 unfold let (let*) (#a #b : Type0) (m: result a)
-  (f: (x:a) -> Pure (result b) (requires (m == Return x)) (ensures fun _ -> True)) :
+  (f: (x:a) -> Pure (result b) (requires (m == Ok x)) (ensures fun _ -> True)) :
   result b =
   match m with
-  | Return x -> f x
+  | Ok x -> f x
   | Fail e   -> Fail e
 
 // Monadic assert(...)
-let massert (b:bool) : result unit = if b then Return () else Fail Failure
+let massert (b:bool) : result unit = if b then Ok () else Fail Failure
 
 // Normalize and unwrap a successful result (used for globals).
-let eval_global (#a : Type0) (x : result a{Return? (normalize_term x)}) : a = Return?.v x
+let eval_global (#a : Type0) (x : result a{Ok? (normalize_term x)}) : a = Ok?.v x
 
 (*** Misc *)
 type char = FStar.Char.char
@@ -144,7 +144,7 @@ let scalar_max (ty : scalar_ty) : int =
 type scalar (ty : scalar_ty) : eqtype = x:int{scalar_min ty <= x && x <= scalar_max ty}
 
 let mk_scalar (ty : scalar_ty) (x : int) : result (scalar ty) =
-  if scalar_min ty <= x && scalar_max ty >= x then Return x else Fail Failure
+  if scalar_min ty <= x && scalar_max ty >= x then Ok x else Fail Failure
 
 let scalar_neg (#ty : scalar_ty) (x : scalar ty) : result (scalar ty) = mk_scalar ty (-x)
 
@@ -498,9 +498,9 @@ type core_ops_range_Range (a : Type0) = {
 
 (*** [alloc] *)
 
-let alloc_boxed_Box_deref (t : Type0) (x : t) : result t = Return x
+let alloc_boxed_Box_deref (t : Type0) (x : t) : result t = Ok x
 let alloc_boxed_Box_deref_mut (t : Type0) (x : t) : result (t & (t -> result t)) =
-  Return (x, (fun x -> Return x))
+  Ok (x, (fun x -> Ok x))
 
 // Trait instance
 let alloc_boxed_Box_coreopsDerefInst (self : Type0) : core_ops_deref_Deref self = {
@@ -528,20 +528,20 @@ let mk_array (a : Type0) (n : usize)
   l
 
 let array_index_usize (a : Type0) (n : usize) (x : array a n) (i : usize) : result a =
-  if i < length x then Return (index x i)
+  if i < length x then Ok (index x i)
   else Fail Failure
 
 let array_update_usize (a : Type0) (n : usize) (x : array a n) (i : usize) (nx : a) :
   result (array a n) =
-  if i < length x then Return (list_update x i nx)
+  if i < length x then Ok (list_update x i nx)
   else Fail Failure
 
 let array_index_mut_usize (a : Type0) (n : usize) (x : array a n) (i : usize) :
   result (a & (a -> result (array a n))) =
   match array_index_usize a n x i with
   | Fail e -> Fail e
-  | Return v ->
-    Return (v, array_update_usize a n x i)
+  | Ok v ->
+    Ok (v, array_update_usize a n x i)
 
 (*** Slice *)
 type slice (a : Type0) = s:list a{length s <= usize_max}
@@ -549,30 +549,30 @@ type slice (a : Type0) = s:list a{length s <= usize_max}
 let slice_len (a : Type0) (s : slice a) : usize = length s
 
 let slice_index_usize (a : Type0) (x : slice a) (i : usize) : result a =
-  if i < length x then Return (index x i)
+  if i < length x then Ok (index x i)
   else Fail Failure
 
 let slice_update_usize (a : Type0) (x : slice a) (i : usize) (nx : a) : result (slice a) =
-  if i < length x then Return (list_update x i nx)
+  if i < length x then Ok (list_update x i nx)
   else Fail Failure
 
 let slice_index_mut_usize (a : Type0) (s : slice a) (i : usize) :
   result (a & (a -> result (slice a))) =
   match slice_index_usize a s i with
   | Fail e -> Fail e
-  | Return x ->
-    Return (x, slice_update_usize a s i)
+  | Ok x ->
+    Ok (x, slice_update_usize a s i)
 
 (*** Subslices *)
 
-let array_to_slice (a : Type0) (n : usize) (x : array a n) : result (slice a) = Return x
+let array_to_slice (a : Type0) (n : usize) (x : array a n) : result (slice a) = Ok x
 let array_from_slice (a : Type0) (n : usize) (x : array a n) (s : slice a) : result (array a n) =
-  if length s = n then Return s
+  if length s = n then Ok s
   else Fail Failure
 
 let array_to_slice_mut (a : Type0) (n : usize) (x : array a n) :
   result (slice a & (slice a -> result (array a n))) =
-  Return (x, array_from_slice a n x)
+  Ok (x, array_from_slice a n x)
 
 // TODO: finish the definitions below (there lacks [List.drop] and [List.take] in the standard library *)
 let array_subslice (a : Type0) (n : usize) (x : array a n) (r : core_ops_range_Range usize) : result (slice a) =
@@ -598,16 +598,16 @@ let alloc_vec_Vec_len (a : Type0) (v : alloc_vec_Vec a) : usize = length v
 
 // Helper
 let alloc_vec_Vec_index_usize (#a : Type0) (v : alloc_vec_Vec a) (i : usize) : result a =
-  if i < length v then Return (index v i) else Fail Failure
+  if i < length v then Ok (index v i) else Fail Failure
 // Helper
 let alloc_vec_Vec_update_usize (#a : Type0) (v : alloc_vec_Vec a) (i : usize) (x : a) : result (alloc_vec_Vec a) =
-  if i < length v then Return (list_update v i x) else Fail Failure
+  if i < length v then Ok (list_update v i x) else Fail Failure
 
 let alloc_vec_Vec_index_mut_usize (#a : Type0) (v: alloc_vec_Vec a) (i: usize) :
   result (a & (a → result (alloc_vec_Vec a))) =
   match alloc_vec_Vec_index_usize v i with
-  | Return x ->
-    Return (x, alloc_vec_Vec_update_usize v i)
+  | Ok x ->
+    Ok (x, alloc_vec_Vec_update_usize v i)
   | Fail e -> Fail e
 
 let alloc_vec_Vec_push (a  : Type0) (v : alloc_vec_Vec a) (x : a) :
@@ -616,17 +616,17 @@ let alloc_vec_Vec_push (a  : Type0) (v : alloc_vec_Vec a) (x : a) :
   (ensures (fun res ->
     match res with
     | Fail e -> e == Failure
-    | Return v' -> length v' = length v + 1)) =
+    | Ok v' -> length v' = length v + 1)) =
   if length v < usize_max then begin
     (**) assert_norm(length [x] == 1);
     (**) append_length v [x];
     (**) assert(length (append v [x]) = length v + 1);
-    Return (append v [x])
+    Ok (append v [x])
     end
   else Fail Failure
 
 let alloc_vec_Vec_insert (a : Type0) (v : alloc_vec_Vec a) (i : usize) (x : a) : result (alloc_vec_Vec a) =
-  if i < length v then Return (list_update v i x) else Fail Failure
+  if i < length v then Ok (list_update v i x) else Fail Failure
 
 // Trait declaration: [core::slice::index::private_slice_index::Sealed]
 type core_slice_index_private_slice_index_Sealed (self : Type0) = unit
@@ -650,7 +650,7 @@ let core_slice_index_Slice_index
   let* x = inst.get i s in
   match x with
   | None -> Fail Failure
-  | Some x -> Return x
+  | Some x -> Ok x
 
 // [core::slice::index::Range:::get]: forward function
 let core_slice_index_RangeUsize_get (t : Type0) (i : core_ops_range_Range usize) (s : slice t) :