Make progress on ExtractToFStar

2 files changed, 184 insertions, 48 deletions

diff --git a/src/ExtractToFStar.ml b/src/ExtractToFStar.ml
index 56a8c338..35d15607 100644
--- a/src/ExtractToFStar.ml
+++ b/src/ExtractToFStar.ml
@@ -37,11 +37,11 @@ let rec extract_ty (ctx : extraction_ctx) (fmt : F.formatter) (inside : bool)
           F.pp_print_string fmt ")"
       | AdtId _ | Assumed _ ->
           if inside then F.pp_print_string fmt "(";
-          F.pp_print_string fmt (ctx_find_type type_id ctx);
+          F.pp_print_string fmt (ctx_get_type type_id ctx);
           if tys <> [] then F.pp_print_space fmt ();
           list_iterb (F.pp_print_space fmt) (extract_ty ctx fmt true) tys;
           if inside then F.pp_print_string fmt ")")
-  | TypeVar vid -> F.pp_print_string fmt (ctx_find_type_var vid ctx)
+  | TypeVar vid -> F.pp_print_string fmt (ctx_get_type_var vid ctx)
   | Bool -> F.pp_print_string fmt ctx.fmt.bool_name
   | Char -> F.pp_print_string fmt ctx.fmt.char_name
   | Integer int_ty -> F.pp_print_string fmt (ctx.fmt.int_name int_ty)
@@ -49,21 +49,20 @@ let rec extract_ty (ctx : extraction_ctx) (fmt : F.formatter) (inside : bool)
   | Array _ | Slice _ -> raise Unimplemented
 
 let extract_type_def_struct_body (ctx : extraction_ctx) (fmt : F.formatter)
-    (type_name : string) (type_params : string list) (fields : field list) :
-    unit =
+    (def : type_def) (fields : field list) : unit =
   (* We want to generate a definition which looks like this:
    * ```
-   * type s = { x : int; y : bool; }
+   * type t = { x : int; y : bool; }
    * ```
    *
    * Or if there isn't enough space on one line:
    * ```
-   * type s = {
+   * type t = {
    *   x : int;
    *   y : bool;
    * }
    * ```
-   * Note that we already printed: `type s =`
+   * Note that we already printed: `type t =`
    *)
   F.pp_print_space fmt ();
   F.pp_print_string fmt "{";
@@ -72,8 +71,8 @@ let extract_type_def_struct_body (ctx : extraction_ctx) (fmt : F.formatter)
   F.pp_open_hvbox fmt ctx.indent_incr;
   F.pp_print_space fmt ();
   (* Print the fields *)
-  let print_field (f : field) : unit =
-    let field_name = ctx.fmt.field_name type_name f.field_name in
+  let print_field (field_id : FieldId.id) (f : field) : unit =
+    let field_name = ctx_get_field def.def_id field_id ctx in
     F.pp_open_box fmt ctx.indent_incr;
     F.pp_print_string fmt field_name;
     F.pp_print_space fmt ();
@@ -82,27 +81,131 @@ let extract_type_def_struct_body (ctx : extraction_ctx) (fmt : F.formatter)
     extract_ty ctx fmt false f.field_ty;
     F.pp_close_box fmt ()
   in
-  List.iter print_field fields;
+  let fields = FieldId.mapi (fun fid f -> (fid, f)) fields in
+  List.iter (fun (fid, f) -> print_field fid f) fields;
   (* Close *)
   F.pp_close_box fmt ();
   F.pp_print_string fmt "}";
   F.pp_close_box fmt ()
 
 let extract_type_def_enum_body (ctx : extraction_ctx) (fmt : F.formatter)
-    (type_name : string) (type_params : string list) (variants : variant list) :
-    unit =
-  raise Unimplemented
+    (def : type_def) (type_name : string) (type_params : string list)
+    (variants : variant list) : unit =
+  (* We want to generate a definition which looks like this:
+   * ```
+   * type list a = | Cons : a -> list a -> list a | Nil : list a
+   * ```
+   *
+   * If there isn't enough space on one line:
+   * ```
+   * type s =
+   * | Cons : a -> list a -> list a
+   * | Nil : list a
+   * ```
+   *
+   * And if we need to write the type of a variant on several lines:
+   * ```
+   * type s =
+   * | Cons :
+   *   a ->
+   *   list a ->
+   *   list a
+   * | Nil : list a
+   * ```
+   *
+   * Finally, it is possible to give names to the variant fields in Rust.
+   * In this situation, we generate a definition like this:
+   * ```
+   * type s =
+   * | Cons : hd:a -> tl:list a -> list a
+   * | Nil : list a
+   * ```
+   *
+   * Note that we already printed: `type s =`
+   *)
+  (* Open the body box *)
+  F.pp_open_hvbox fmt 0;
+  (* Print the variants *)
+  let print_variant (variant_id : VariantId.id) (variant : variant) : unit =
+    let variant_name = ctx_get_variant def.def_id variant_id ctx in
+    F.pp_print_space fmt ();
+    F.pp_open_hvbox fmt ctx.indent_incr;
+    (* variant box *)
+    (* `| Cons :`
+     * Note that we really don't want any break above so we print everything
+     * at once. *)
+    F.pp_print_string fmt ("| " ^ variant_name ^ " :");
+    F.pp_print_space fmt ();
+    let print_field (fid : FieldId.id) (f : field) (ctx : extraction_ctx) :
+        extraction_ctx =
+      (* Open the field box *)
+      F.pp_open_box fmt ctx.indent_incr;
+      (* Print the field names
+       * `  x :`
+       * Note that when printing fields, we register the field names as
+       * *variables*: they don't need to be unique at the top level. *)
+      let ctx =
+        match f.field_name with
+        | None -> ctx
+        | Some field_name ->
+            let var_id = VarId.of_int (FieldId.to_int fid) in
+            let ctx, field_name = ctx_add_var field_name var_id ctx in
+            F.pp_print_string fmt (field_name ^ " :");
+            F.pp_space fmt ();
+            ctx
+      in
+      (* Print the field type *)
+      extract_ty ctx fmt false f.field_ty;
+      (* Print the arrow `->`*)
+      F.pp_space fmt ();
+      F.pp_print_string "->";
+      (* Close the field box *)
+      F.pp_close_box fmt ();
+      F.pp_space fmt ();
+      (* Return *)
+      ctx
+    in
+    (* Print the fields *)
+    let fields = FieldId.mapi (fun fid f -> (fid, f)) variant.fields in
+    let ctx =
+      List.fold_left (fun ctx (fid, f) -> print_field fid f ctx) ctx fields
+    in
+    (* Print the final type *)
+    F.pp_open_hovbox fmt ();
+    F.pp_string fmt def_name;
+    List.iter
+      (fun type_param ->
+        F.pp_space fmt ();
+        F.pp_string fmt type_param)
+      type_params;
+    F.pp_close_hovbox fmt ();
+    (* Close the variant box *)
+    F.pp_close_box fmt ()
+  in
+  (* Print the variants *)
+  let variants = VariantId.mapi (fun vid v -> (vid, v)) variants in
+  List.iter (fun (vid, v) -> print_variant vid v) variants;
+  (* Close the body box *)
+  F.pp_close_box fmt ()
 
 let rec extract_type_def (ctx : extraction_ctx) (fmt : F.formatter)
     (def : type_def) : extraction_ctx =
   (* Compute and register the type def name *)
   let ctx, def_name = ctx_add_type_def def ctx in
-  (* Compute and register the variant names, if this is an enumeration *)
-  let ctx, variant_names =
+  (* Compute and register:
+   * - the variant names, if this is an enumeration
+   * - the field names, if this is a structure
+   * We do this because in F*, they have to be unique at the top-level.
+   *)
+  let ctx =
     match def.kind with
-    | Struct _ -> (ctx, [])
+    | Struct fields ->
+        fst (ctx_add_fields def (FieldId.mapi (fun id f -> (id, f)) fields) ctx)
     | Enum variants ->
-        ctx_add_variants def (VariantId.mapi (fun id v -> (id, v)) variants) ctx
+        fst
+          (ctx_add_variants def
+             (VariantId.mapi (fun id v -> (id, v)) variants)
+             ctx)
   in
   (* Add the type params - note that we remember those bindings only for the
    * body translation: the updated ctx we return at the end of the function
@@ -113,8 +216,7 @@ let rec extract_type_def (ctx : extraction_ctx) (fmt : F.formatter)
   F.pp_print_space fmt ();
   F.pp_print_string fmt def_name;
   (match def.kind with
-  | Struct fields ->
-      extract_type_def_struct_body ctx_body fmt def_name type_params fields
+  | Struct fields -> extract_type_def_struct_body ctx_body fmt fields
   | Enum variants ->
-      extract_type_def_enum_body ctx_body fmt def_name type_params variants);
+      extract_type_def_enum_body ctx_body fmt def def_name type_params variants);
   ctx
diff --git a/src/PureToExtract.ml b/src/PureToExtract.ml
index f9c021fb..f2c03b90 100644
--- a/src/PureToExtract.ml
+++ b/src/PureToExtract.ml
@@ -35,7 +35,7 @@ type name_formatter = {
   char_name : string;
   int_name : integer_type -> string;
   str_name : string;
-  field_name : string -> string -> string;
+  field_name : name -> string -> string;
       (** Inputs:
           - type name
           - field name
@@ -160,6 +160,11 @@ type id =
       (** If often happens that variant names must be unique (it is the case in
           F* ) which is why we register them here.
        *)
+  | FieldId of TypeDefId.id * FieldId.id
+      (** If often happens that in the case of structures, the field names
+          must be unique (it is the case in F* ) which is why we register
+          them here.
+       *)
   | TypeVarId of TypeVarId.id
   | VarId of VarId.id
   | UnknownId
@@ -207,29 +212,29 @@ let names_map_add (id : id) (name : string) (nm : names_map) : names_map =
   { id_to_name; name_to_id; names_set }
 
 (* TODO: remove those functions? We use the ones of extraction_ctx *)
-let names_map_find (id : id) (nm : names_map) : string =
+let names_map_get (id : id) (nm : names_map) : string =
   IdMap.find id nm.id_to_name
 
-let names_map_find_function (id : A.fun_id) (rg : RegionGroupId.id option)
+let names_map_get_function (id : A.fun_id) (rg : RegionGroupId.id option)
     (nm : names_map) : string =
-  names_map_find (FunId (id, rg)) nm
+  names_map_get (FunId (id, rg)) nm
 
-let names_map_find_local_function (id : FunDefId.id)
+let names_map_get_local_function (id : FunDefId.id)
     (rg : RegionGroupId.id option) (nm : names_map) : string =
-  names_map_find_function (A.Local id) rg nm
+  names_map_get_function (A.Local id) rg nm
 
-let names_map_find_type (id : type_id) (nm : names_map) : string =
+let names_map_get_type (id : type_id) (nm : names_map) : string =
   assert (id <> Tuple);
-  names_map_find (TypeId id) nm
+  names_map_get (TypeId id) nm
 
-let names_map_find_local_type (id : TypeDefId.id) (nm : names_map) : string =
-  names_map_find_type (AdtId id) nm
+let names_map_get_local_type (id : TypeDefId.id) (nm : names_map) : string =
+  names_map_get_type (AdtId id) nm
 
-let names_map_find_var (id : VarId.id) (nm : names_map) : string =
-  names_map_find (VarId id) nm
+let names_map_get_var (id : VarId.id) (nm : names_map) : string =
+  names_map_get (VarId id) nm
 
-let names_map_find_type_var (id : TypeVarId.id) (nm : names_map) : string =
-  names_map_find (TypeVarId id) nm
+let names_map_get_type_var (id : TypeVarId.id) (nm : names_map) : string =
+  names_map_get (TypeVarId id) nm
 
 (** Make a (variable) basename unique (by adding an index).
 
@@ -266,31 +271,39 @@ let ctx_add (id : id) (name : string) (ctx : extraction_ctx) : extraction_ctx =
   let names_map = names_map_add id name ctx.names_map in
   { ctx with names_map }
 
-let ctx_find (id : id) (ctx : extraction_ctx) : string =
+let ctx_get (id : id) (ctx : extraction_ctx) : string =
   IdMap.find id ctx.names_map.id_to_name
 
-let ctx_find_function (id : A.fun_id) (rg : RegionGroupId.id option)
+let ctx_get_function (id : A.fun_id) (rg : RegionGroupId.id option)
     (ctx : extraction_ctx) : string =
-  ctx_find (FunId (id, rg)) ctx
+  ctx_get (FunId (id, rg)) ctx
 
-let ctx_find_local_function (id : FunDefId.id) (rg : RegionGroupId.id option)
+let ctx_get_local_function (id : FunDefId.id) (rg : RegionGroupId.id option)
     (ctx : extraction_ctx) : string =
-  ctx_find_function (A.Local id) rg ctx
+  ctx_get_function (A.Local id) rg ctx
 
-let ctx_find_type (id : type_id) (ctx : extraction_ctx) : string =
+let ctx_get_type (id : type_id) (ctx : extraction_ctx) : string =
   assert (id <> Tuple);
-  ctx_find (TypeId id) ctx
+  ctx_get (TypeId id) ctx
+
+let ctx_get_local_type (id : TypeDefId.id) (ctx : extraction_ctx) : string =
+  ctx_get_type (AdtId id) ctx
 
-let ctx_find_local_type (id : TypeDefId.id) (ctx : extraction_ctx) : string =
-  ctx_find_type (AdtId id) ctx
+let ctx_get_var (id : VarId.id) (ctx : extraction_ctx) : string =
+  ctx_get (VarId id) ctx
 
-let ctx_find_var (id : VarId.id) (ctx : extraction_ctx) : string =
-  ctx_find (VarId id) ctx
+let ctx_get_type_var (id : TypeVarId.id) (ctx : extraction_ctx) : string =
+  ctx_get (TypeVarId id) ctx
 
-let ctx_find_type_var (id : TypeVarId.id) (ctx : extraction_ctx) : string =
-  ctx_find (TypeVarId id) ctx
+let ctx_get_field (def_id : TypeDefId.id) (field_id : FieldId.id)
+    (ctx : extraction_ctx) : string =
+  ctx_get (FieldId (def_id, field_id)) ctx
+
+let ctx_get_variant (def_id : TypeDefId.id) (variant_id : VariantId.id)
+    (ctx : extraction_ctx) : string =
+  ctx_get (VariantId (def_id, variant_id)) ctx
 
-(** Generate a unique type variable name and add to the context *)
+(** Generate a unique type variable name and add it to the context *)
 let ctx_add_type_var (basename : string) (id : TypeVarId.id)
     (ctx : extraction_ctx) : extraction_ctx * string =
   let name =
@@ -299,6 +312,15 @@ let ctx_add_type_var (basename : string) (id : TypeVarId.id)
   let ctx = ctx_add (TypeVarId id) name ctx in
   (ctx, name)
 
+(** Generate a unique variable name and add it to the context *)
+let ctx_add_var (basename : string) (id : VarId.id) (ctx : extraction_ctx) :
+    extraction_ctx * string =
+  let name =
+    basename_to_unique ctx.names_map.names_set ctx.fmt.append_index basename
+  in
+  let ctx = ctx_add (VarId id) name ctx in
+  (ctx, name)
+
 (** See [ctx_add_type_var] *)
 let ctx_add_type_vars (vars : (string * TypeVarId.id) list)
     (ctx : extraction_ctx) : extraction_ctx * string list =
@@ -318,6 +340,18 @@ let ctx_add_type_def (def : type_def) (ctx : extraction_ctx) :
   let ctx = ctx_add (TypeId (AdtId def.def_id)) def_name ctx in
   (ctx, def_name)
 
+let ctx_add_field (def : type_def) (field_id : FieldId.id) (field : field)
+    (ctx : extraction_ctx) : extraction_ctx * string =
+  let name = ctx.fmt.field_name def.name field.field_name in
+  let ctx = ctx_add (FieldId (def.def_id, field_id)) name ctx in
+  (ctx, name)
+
+let ctx_add_fields (def : type_def) (fields : (FieldId.id * field) list)
+    (ctx : extraction_ctx) : extraction_ctx * string list =
+  List.fold_left_map
+    (fun ctx (vid, v) -> ctx_add_field def vid v ctx)
+    ctx fields
+
 let ctx_add_variant (def : type_def) (variant_id : VariantId.id)
     (variant : variant) (ctx : extraction_ctx) : extraction_ctx * string =
   let name = ctx.fmt.variant_name def.name variant.variant_name in