hphp/hack/src/shape_analysis/shape_analysis_logic.ml

   1 (*
   2  * Copyright (c) Facebook, Inc. and its affiliates.
   3  *
   4  * This source code is licensed under the MIT license found in the
   5  * LICENSE file in the "hack" directory of this source tree.
   6  *
   7  *)
   8
   9 open Shape_analysis_types
  10
  11 let result_id_counter = ref 0
  12
  13 let fresh_result_id () =
  14   let result_id = !result_id_counter in
  15   result_id_counter := result_id + 1;
  16   ResultID.singleton result_id
  17
  18 let singleton result_id key ty = (result_id, ShapeKeyMap.singleton key ty)
  19
  20 let ( <> ) ~env (id1, sk1) (id2, sk2) =
  21   let merge_shape_key_map _key ty_opt ty_opt' =
  22     match (ty_opt, ty_opt') with
  23     | (Some ty, Some ty') ->
  24       let (_env, ty) = Typing_union.union env ty ty' in
  25       Some ty
  26     | (None, (Some _ as ty_opt))
  27     | ((Some _ as ty_opt), None) ->
  28       ty_opt
  29     | (None, None) -> None
  30   in
  31   let result_id = ResultID.union id1 id2 in
  32   let map = ShapeKeyMap.merge merge_shape_key_map sk1 sk2 in
  33   (result_id, map)