hphp/hack/src/typing/typing_solver.mli

   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 module Env = Typing_env
  11 open Typing_defs
  12 open Typing_env_types
  13
  14 (* Non-side-effecting test for subtypes.
  15     result = true implies ty1 <: ty2
  16     result = false implies NOT ty1 <: ty2 OR we don't know
  17 *)
  18 val is_sub_type : env -> locl_ty -> locl_ty -> bool * Typing_error.t option
  19
  20 val non_null : env -> Pos_or_decl.t -> locl_ty -> env * locl_ty
  21
  22 (* Force solve all remaining unsolved type variables *)
  23 val solve_all_unsolved_tyvars : env -> env * Typing_error.t option
  24
  25 val expand_type_and_solve :
  26   env ->
  27   ?default:locl_ty ->
  28   ?freshen:bool ->
  29   description_of_expected:string ->
  30   Pos.t ->
  31   locl_ty ->
  32   (env * Typing_error.t option) * locl_ty
  33
  34 val expand_type_and_solve_eq :
  35   env -> locl_ty -> (env * Typing_error.t option) * locl_ty
  36
  37 (** Expand an already-solved type variable to its solution.
  38     If the type variable is not yet solved, but one of its lower bounds is dynamic,
  39     i.e. dynamic, t1, ..., tn <: #0 <: u1, ..., um,
  40     then solve the type variable to #0 := ~#1 for fresh type variable #1, where
  41     t1, ..., tn <: #1 <: u1, ..., um.
  42     This is used in the strip_dynamic functions in Typing_dynamic_utils before matching the type on ~t
  43   *)
  44 val expand_type_for_strip_dynamic : env -> locl_ty -> env * locl_ty
  45
  46 val expand_type_and_narrow :
  47   env ->
  48   ?default:locl_ty ->
  49   ?allow_nothing:bool ->
  50   ?force_solve:bool ->
  51   description_of_expected:string ->
  52   (env -> locl_ty -> (env * Typing_error.t option) * locl_ty option) ->
  53   Pos.t ->
  54   locl_ty ->
  55   (env * Typing_error.t option) * locl_ty
  56
  57 val solve_to_equal_bound_or_wrt_variance :
  58   env -> Reason.t -> Tvid.t -> env * Typing_error.t option
  59
  60 val close_tyvars_and_solve : env -> env * Typing_error.t option
  61
  62 val bind : env -> Tvid.t -> locl_ty -> env * Typing_error.t option
  63
  64 val try_bind_to_equal_bound : env -> Tvid.t -> env * Typing_error.t option