remove parameters field from kind definition

Summary:
This diff is part of a series that removes the implementation of higher-kinded types from the type-checker.

This diff removes the `parameters` field from `Typing_kinding_defs.kind`, our main representation of kinds. This means that higher-kinded type parameters cannot exist in the typing environment anymore.

Reviewed By: mheiber

Differential Revision: D74463076

fbshipit-source-id: 731fbccfcbbbc4405581c519bd62f91e824af16f

Author: frank-emrich

hphp/hack/src/annotated_ast/aast_defs.ml

@@ -927,6 +927,7 @@ and ('ex, 'en) file_attribute = {
 and ('ex, 'en) tparam = {
   tp_variance: Ast_defs.variance; [@transform.opaque]
   tp_name: sid;
+  (* TODO(T222659258) Can remove tp_parameters, now that HKTs are removed *)
   tp_parameters: ('ex, 'en) tparam list;
   tp_constraints: ((Ast_defs.constraint_kind[@transform.opaque]) * hint) list;
   tp_reified: reify_kind; [@transform.opaque]

hphp/hack/src/oxidized/gen/typing_kinding_defs.rs

@@ -3,7 +3,7 @@
 // This source code is licensed under the MIT license found in the
 // LICENSE file in the "hack" directory of this source tree.
 //
-// @generated SignedSource<<8be733e9b0946dd30f0ee749ba761a48>>
+// @generated SignedSource<<47660976ed4933977f98d2fd9c51a99d>>
 //
 // To regenerate this file, run:
 //   hphp/hack/src/oxidized_regen.sh
@@ -44,7 +44,6 @@ pub struct Kind {
     pub enforceable: bool,
     pub newable: bool,
     pub require_dynamic: bool,
-    pub parameters: Vec<NamedKind>,
     pub rank: isize,
 }
 

hphp/hack/src/typing/env/typing_env.ml

@@ -511,7 +511,6 @@ let add_fresh_generic_parameter env pos prefix ~reified ~enforceable ~newable =
         enforceable;
         newable;
         require_dynamic = true;
-        parameters = [];
         rank = 0;
       }
   in
@@ -536,8 +535,6 @@ let get_tpenv_tparams env =
               enforceable = _;
               newable = _;
               require_dynamic = _;
-              (* FIXME what to do here? it seems dangerous to just traverse *)
-              parameters = _;
               rank = _;
             }
           acc ->

hphp/hack/src/typing/type_parameter_env.ml

@@ -95,10 +95,9 @@ let get_upper_bounds tpenv name =
   | None -> empty_bounds
   | Some { upper_bounds; _ } -> upper_bounds
 
-let get_arity tpenv name =
-  match get name tpenv with
-  | None -> 0
-  | Some { parameters; _ } -> List.length parameters
+let get_arity _tpenv _name =
+  (* TODO(T222659258) Always 0 now that higher-kinded types are being removed *)
+  0
 
 let get_reified tpenv name =
   match get name tpenv with
@@ -160,7 +159,6 @@ let add_upper_bound_ tpenv name ty =
             enforceable = false;
             newable = false;
             require_dynamic = false;
-            parameters = [];
             rank = 0;
           } )
       | Some (pos, tp) ->
@@ -185,7 +183,6 @@ let add_lower_bound_ tpenv name ty =
             enforceable = false;
             newable = false;
             require_dynamic = false;
-            parameters = [];
             rank = 0;
           } )
       | Some (pos, tp) ->
@@ -226,7 +223,6 @@ let add_upper_bound ?intersect env_tpenv name ty =
     let enforceable = get_enforceable env_tpenv name in
     let newable = get_newable env_tpenv name in
     let require_dynamic = get_require_dynamic env_tpenv name in
-    let parameters = [] in
     let rank = get_rank env_tpenv name in
     add
       ~def_pos
@@ -238,7 +234,6 @@ let add_upper_bound ?intersect env_tpenv name ty =
         enforceable;
         newable;
         require_dynamic;
-        parameters;
         rank;
       }
       tpenv
@@ -269,7 +264,6 @@ let add_lower_bound ?union env_tpenv name ty =
     let enforceable = get_enforceable env_tpenv name in
     let newable = get_newable env_tpenv name in
     let require_dynamic = get_require_dynamic env_tpenv name in
-    let parameters = [] in
     let rank = get_rank env_tpenv name in
     add
       ~def_pos
@@ -281,7 +275,6 @@ let add_lower_bound ?union env_tpenv name ty =
         enforceable;
         newable;
         require_dynamic;
-        parameters;
         rank;
       }
       tpenv
@@ -325,8 +318,8 @@ let remove tpenv name =
 (* Add type parameters to environment, initially with no bounds.
  * Existing type parameters with the same name will be overridden. *)
 let add_generic_parameters tpenv tparaml =
-  let rec make_param_info ast_tparam =
-    let { tp_user_attributes; tp_tparams; _ } = ast_tparam in
+  let make_param_info ast_tparam =
+    let { tp_user_attributes; _ } = ast_tparam in
     let enforceable =
       Attributes.mem SN.UserAttributes.uaEnforceable tp_user_attributes
     in
@@ -336,9 +329,6 @@ let add_generic_parameters tpenv tparaml =
     let require_dynamic =
       Attributes.mem SN.UserAttributes.uaRequireDynamic tp_user_attributes
     in
-    let nested_params =
-      List.map tp_tparams ~f:(fun tp -> (tp.tp_name, make_param_info tp))
-    in
 
     {
       lower_bounds = empty_bounds;
@@ -347,7 +337,6 @@ let add_generic_parameters tpenv tparaml =
       enforceable;
       newable;
       require_dynamic;
-      parameters = nested_params;
       rank = 0;
     }
   in
@@ -358,8 +347,10 @@ let add_generic_parameters tpenv tparaml =
   in
   List.fold_left tparaml ~f:add_top ~init:tpenv
 
-let get_parameter_names tpi =
-  List.map tpi.parameters ~f:(fun (name, _) -> snd name)
+let get_parameter_names _tpi =
+  (* TODO(T222659258) Always empty now that higher-kinded types are
+     being removed *)
+  []
 
 let force_lazy_values_tparam_info (info : tparam_info) =
   Typing_kinding_defs.force_lazy_values info

hphp/hack/src/typing/typing_kinding_defs.ml

@@ -6,15 +6,13 @@ module SN = Naming_special_names
 
 type tparam_bounds = TySet.t [@@deriving hash, show]
 
-(* TODO(T222659258) remove parameters field here *)
 type kind = {
   lower_bounds: tparam_bounds;
   upper_bounds: tparam_bounds;
   reified: Aast.reify_kind;
   enforceable: bool;
   newable: bool;
   require_dynamic: bool;
-  parameters: named_kind list;
   rank: int;
 }
 
@@ -24,47 +22,18 @@ let dummy_name = (Pos_or_decl.none, "")
 
 let with_dummy_name k = (dummy_name, k)
 
-let get_arity k = List.length k.parameters
-
-let string_of_kind (kind : kind) =
-  let rec stringify toplevel k =
-    match k.parameters with
-    | [] -> "Type"
-    | params ->
-      let parts = List.map params ~f:(fun (_, pk) -> stringify false pk) in
-      let res = String.concat ~sep:" -> " parts ^ " -> Type" in
-      if toplevel then
-        res
-      else
-        "(" ^ res ^ ")"
-  in
-  stringify true kind
-
-let description_of_kind kind =
-  match kind.parameters with
-  | [] -> "a fully-applied type"
-  | params
-    when List.for_all params ~f:(fun (_, param) ->
-             Int.( = ) 0 (get_arity param)) ->
-    (* no higher-order arguments *)
-    let param_count = List.length params in
-    let args_desc =
-      if Int.( = ) 1 param_count then
-        "a single (fully-applied) type argument"
-      else
-        string_of_int param_count ^ "(fully-applied) type arguments"
-    in
-    "a type constructor expecting " ^ args_desc
-  | _ -> "a type constructor of kind " ^ string_of_kind kind
+let get_arity _k =
+  (* TODO(T222659258) Always 0 now that higher-kinded types are being removed *)
+  0
 
-let rec remove_bounds kind =
-  {
-    kind with
-    lower_bounds = TySet.empty;
-    upper_bounds = TySet.empty;
-    parameters =
-      List.map kind.parameters ~f:(fun (n, k) -> (n, remove_bounds k));
-  }
+let string_of_kind (_kind : kind) =
+  (* TODO(T222659258) Find and remove users of this  *) "Type"
+
+let description_of_kind _kind =
+  (* TODO(T222659258) Find and remove users of this  *) "a fully-applied type"
+
+let remove_bounds kind =
+  { kind with lower_bounds = TySet.empty; upper_bounds = TySet.empty }
 
 module Simple = struct
   type bounds_for_wildcard =
@@ -101,7 +70,6 @@ module Simple = struct
         enforceable;
         newable;
         require_dynamic = false;
-        parameters = [];
         rank = 0;
       },
       NonLocalized [] )
@@ -122,16 +90,7 @@ module Simple = struct
       Attributes.mem SN.UserAttributes.uaNewable tp_user_attributes
     in
     let (st, _) = fully_applied_type ~reified ~enforceable ~newable () in
-    ( tp_name,
-      {
-        st with
-        parameters = named_internal_kinds_of_decl_tparams decl_tparam.tp_tparams;
-      } )
-
-  (* not public *)
-  and named_internal_kinds_of_decl_tparams (tparams : decl_tparam list) :
-      named_full_kind list =
-    List.map tparams ~f:named_internal_kind_of_decl_tparam
+    (tp_name, st)
 
   (* public *)
   and named_kind_of_decl_tparam decl_tparam : named_kind =
@@ -144,14 +103,12 @@ module Simple = struct
   let named_kinds_of_decl_tparams decl_tparams : named_kind list =
     List.map decl_tparams ~f:named_kind_of_decl_tparam
 
-  let type_with_params_to_simple_kind ?reified ?enforceable ?newable tparams =
+  let type_with_params_to_simple_kind ?reified ?enforceable ?newable _tparams =
     let (st, _) = fully_applied_type ?reified ?enforceable ?newable () in
-    ( { st with parameters = named_internal_kinds_of_decl_tparams tparams },
-      NonLocalized [] )
+    (st, NonLocalized [])
 
   (** Returns the type parameters of the kind, more or less. *)
-  let get_named_parameter_kinds (kind, _) : named_kind list =
-    List.map kind.parameters ~f:(fun (n, fk) -> (n, (fk, NonLocalized [])))
+  let get_named_parameter_kinds (_kind, _) : named_kind list = []
 
   let from_full_kind fk =
     let wildcard_bounds =
@@ -165,15 +122,14 @@ module Simple = struct
   let with_dummy_name = with_dummy_name
 end
 
-let rec force_lazy_values (kind : kind) =
+let force_lazy_values (kind : kind) =
   let {
     lower_bounds;
     upper_bounds;
     reified;
     enforceable;
     newable;
     require_dynamic;
-    parameters;
     rank;
   } =
     kind
@@ -185,9 +141,5 @@ let rec force_lazy_values (kind : kind) =
     enforceable;
     newable;
     require_dynamic;
-    parameters = List.map parameters ~f:force_lazy_values_named_kind;
     rank;
   }
-
-and force_lazy_values_named_kind ((p, kind) : named_kind) =
-  (p, force_lazy_values kind)

hphp/hack/src/typing/typing_kinding_defs.mli

@@ -25,7 +25,6 @@ type kind = {
   require_dynamic: bool;
       (** Set if class is marked <<__SupportDynamicType>> and
           generic parameter does *not* have attribute <<__NoRequireDynamic>> *)
-  parameters: named_kind list;
   rank: int;
 }
 

hphp/hack/src/typing/typing_log.ml

@@ -321,7 +321,7 @@ let reify_kind_as_value k =
 let tyset_as_value env tys =
   Set (TySet.fold (fun t s -> SSet.add (Pr.debug env t) s) tys SSet.empty)
 
-let rec tparam_info_as_value env tpinfo =
+let tparam_info_as_value env tpinfo =
   let Typing_kinding_defs.
         {
           lower_bounds;
@@ -330,7 +330,6 @@ let rec tparam_info_as_value env tpinfo =
           enforceable;
           newable;
           require_dynamic;
-          parameters;
           rank;
         } =
     tpinfo
@@ -343,18 +342,9 @@ let rec tparam_info_as_value env tpinfo =
       ("enforceable", bool_as_value enforceable);
       ("newable", bool_as_value newable);
       ("require_dynamic", bool_as_value require_dynamic);
-      ("parameters", named_tparam_info_list_as_value env parameters);
       ("rank", string_as_value (Int.to_string rank));
     ]
 
-and named_tparam_info_list_as_value env parameters =
-  let param_values =
-    List.map parameters ~f:(fun (name, param) ->
-        list_as_value
-          [string_as_value (snd name); tparam_info_as_value env param])
-  in
-  list_as_value param_values
-
 let tpenv_as_value env tpenv =
   make_map
     [

hphp/hack/src/typing/typing_subtype.ml

@@ -8985,7 +8985,6 @@ end = struct
               enforceable;
               newable;
               require_dynamic;
-              parameters = [];
               rank;
             }
         in

hphp/hack/test/map_reduce/tast_hashes/tast_hashes_test.php.exp

@@ -2,7 +2,7 @@
   "tast_hashes": {
     "tast_hashes_test.php": {
       "tast_hashes": {
-        "class_tast_hashes": { "\\A": 190846743, "\\B": 556599326 },
+        "class_tast_hashes": { "\\A": 399326371, "\\B": 902123085 },
         "gconst_tast_hashes": { "\\B": 561084034 }
       },
       "error_hashes": []