hphp/hack/src/typing/typing_ops.ml

   1 (*
   2  * Copyright (c) 2015, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the MIT license found in the
   6  * LICENSE file in the "hack" directory of this source tree.
   7  *
   8  *)
   9
  10 open Core_kernel
  11 module Reason = Typing_reason
  12 module Env = Typing_env
  13 module MakeType = Typing_make_type
  14
  15 (*****************************************************************************)
  16 (* Exporting. *)
  17 (*****************************************************************************)
  18
  19 (* Tries to add constraint that ty_sub is subtype of ty_super in envs *)
  20 let sub_type p ur env ty_sub ty_super on_error =
  21   Typing_log.(
  22     log_with_level env "sub" 1 (fun () ->
  23         log_types
  24           p
  25           env
  26           [
  27             Log_head
  28               ( "Typing_ops.sub_type",
  29                 [Log_type ("ty_sub", ty_sub); Log_type ("ty_super", ty_super)]
  30               );
  31           ]));
  32   Errors.try_add_err
  33     p
  34     (Reason.string_of_ureason ur)
  35     (fun () -> Typing_subtype.sub_type env ty_sub ty_super on_error)
  36     (fun () -> env)
  37
  38 let sub_type_decl p ur env ty_sub ty_super =
  39   let (env, ty_super) = Typing_utils.localize_with_self env ty_super in
  40   let (env, ty_sub) = Typing_utils.localize_with_self env ty_sub in
  41   ignore (sub_type p ur env ty_sub ty_super Errors.unify_error)
  42
  43 (* Ensure that types are equivalent i.e. subtypes of each other *)
  44 let unify_decl p ur env ty1 ty2 =
  45   let (env, ty1) = Typing_utils.localize_with_self env ty1 in
  46   let (env, ty2) = Typing_utils.localize_with_self env ty2 in
  47   ignore (sub_type p ur env ty2 ty1 Errors.unify_error);
  48   ignore (sub_type p ur env ty1 ty2 Errors.unify_error)