hphp/hack/src/typing/typing_inference_env.mli

   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 Typing_defs
  10
  11 (** contains the inference env, containing all the information necessary to
  12 perform type inference, including global type variables. *)
  13 type t
  14
  15 (** contains only the information related to global type variables. This is returned
  16 after typechecking individual functions and all the global inference environments
  17 then get merged into a single one before being solved. *)
  18 type t_global
  19
  20 type t_global_with_pos = Pos.t * t_global
  21
  22 module Log : sig
  23   val inference_env_as_value : t -> Typing_log_value.value
  24
  25   val global_inference_env_as_value : t_global -> Typing_log_value.value
  26
  27   (** Convert a type variable from a global inference environment into json *)
  28   val tyvar_to_json_g :
  29     (locl_ty -> string) ->
  30     (internal_type -> string) ->
  31     t_global ->
  32     Ident.t ->
  33     Hh_json.json
  34 end
  35
  36 val pp : Format.formatter -> t -> unit
  37
  38 val empty_inference_env : t
  39
  40 val fresh_type : ?variance:Ast_defs.variance -> t -> Pos.t -> t * locl_ty
  41
  42 (** Same as fresh_type but takes a specific reason as parameter. *)
  43 val fresh_type_reason :
  44   ?variance:Ast_defs.variance -> t -> Reason.t -> t * locl_ty
  45
  46 val fresh_invariant_type_var : t -> Pos.t -> t * locl_ty
  47
  48 val open_tyvars : t -> Pos.t -> t
  49
  50 val get_current_tyvars : t -> Ident.t list
  51
  52 val close_tyvars : t -> t
  53
  54 val tyvar_is_solved : t -> Ident.t -> bool
  55
  56 val tyvar_occurs_in_tyvar : t -> Ident.t -> in_:Ident.t -> bool
  57
  58 val get_tyvar_occurrences : t -> Ident.t -> ISet.t
  59
  60 val get_tyvars_in_tyvar : t -> Ident.t -> ISet.t
  61
  62 val contains_unsolved_tyvars : t -> Ident.t -> bool
  63
  64 val make_tyvar_no_more_occur_in_tyvar : t -> int -> no_more_in:int -> t
  65
  66 val bind : t -> ?tyvar_pos:Pos.t -> Ident.t -> locl_ty -> t
  67
  68 val add : t -> ?tyvar_pos:Pos.t -> Ident.t -> locl_ty -> t
  69
  70 val get_direct_binding : t -> Ident.t -> locl_ty option
  71
  72 val get_type : t -> Reason.t -> Ident.t -> t * locl_ty
  73
  74 val expand_var : t -> Reason.t -> Ident.t -> t * locl_ty
  75
  76 val expand_type : t -> locl_ty -> t * locl_ty
  77
  78 val expand_internal_type : t -> internal_type -> t * internal_type
  79
  80 val get_tyvar_pos : t -> Ident.t -> Pos.t
  81
  82 (* Get or add to bounds on type variables *)
  83 val get_tyvar_lower_bounds : t -> Ident.t -> Internal_type_set.t
  84
  85 val get_tyvar_upper_bounds : t -> Ident.t -> Internal_type_set.t
  86
  87 val set_tyvar_lower_bounds : t -> Ident.t -> Internal_type_set.t -> t
  88
  89 val set_tyvar_upper_bounds : t -> Ident.t -> Internal_type_set.t -> t
  90
  91 (* Optionally supply intersection or union operations to simplify the bounds *)
  92 val add_tyvar_upper_bound :
  93   ?intersect:(internal_type -> internal_type list -> internal_type list) ->
  94   t ->
  95   Ident.t ->
  96   internal_type ->
  97   t
  98
  99 val add_tyvar_lower_bound :
 100   ?union:(internal_type -> internal_type list -> internal_type list) ->
 101   t ->
 102   Ident.t ->
 103   internal_type ->
 104   t
 105
 106 val remove_tyvar_upper_bound : t -> Ident.t -> Ident.t -> t
 107
 108 val remove_tyvar_lower_bound : t -> Ident.t -> Ident.t -> t
 109
 110 val set_tyvar_appears_covariantly : t -> Ident.t -> t
 111
 112 val set_tyvar_appears_contravariantly : t -> Ident.t -> t
 113
 114 val set_tyvar_eager_solve_fail : t -> Ident.t -> t
 115
 116 val get_tyvar_appears_covariantly : t -> Ident.t -> bool
 117
 118 val get_tyvar_appears_contravariantly : t -> Ident.t -> bool
 119
 120 val get_tyvar_appears_invariantly : t -> Ident.t -> bool
 121
 122 val is_global_tyvar : t -> Ident.t -> bool
 123
 124 val new_global_tyvar : t -> Ident.t -> Typing_reason.t -> t * locl_ty
 125
 126 val wrap_ty_in_var : t -> Typing_reason.t -> locl_ty -> t * locl_ty
 127
 128 val get_tyvar_eager_solve_fail : t -> Ident.t -> bool
 129
 130 val get_tyvar_type_const :
 131   t -> Ident.t -> Aast.sid -> (Aast.sid * locl_ty) option
 132
 133 val get_tyvar_pu_access :
 134   t -> Ident.t -> Aast.sid -> (locl_ty * Aast.sid * locl_ty * Aast.sid) option
 135
 136 val set_tyvar_type_const : t -> Ident.t -> Aast.sid -> locl_ty -> t
 137
 138 val set_tyvar_pu_access :
 139   t -> Ident.t -> locl_ty -> Aast.sid -> locl_ty -> Aast.sid -> t
 140
 141 val get_tyvar_type_consts : t -> Ident.t -> (Aast.sid * locl_ty) SMap.t
 142
 143 val add_subtype_prop : t -> Typing_logic.subtype_prop -> t
 144
 145 val get_current_pos_from_tyvar_stack : t -> Pos.t option
 146
 147 (** At the end of typechecking a function body, extract the remaining
 148 inference env, which should only contain global type variables. *)
 149 val extract_global_inference_env : t -> t * t_global
 150
 151 val get_vars : t -> Ident.t list
 152
 153 val get_vars_g : t_global -> Ident.t list
 154
 155 val copy_tyvar_from_genv_to_env :
 156   Ident.t -> to_:t -> from:t_global -> t * Ident.t
 157
 158 module Size : sig
 159   val ty_size : t -> locl_ty -> int
 160
 161   val inference_env_size : t -> int
 162 end
 163
 164 (** Only merge the tvenv parts. Resolve conflicts stupidly by taking the first mapping of the two. *)
 165 val simple_merge : t -> t -> t
 166
 167 (** Gets the part of the subtype proposition that should not be added to the
 168 constraint graph (e.g. because it contains disjunctions). *)
 169 val get_nongraph_subtype_prop : t -> Typing_logic.subtype_prop
 170
 171 val is_alias_for_another_var : t -> Ident.t -> bool
 172
 173 (** Remove variables containing no information. *)
 174 val compress : t -> t
 175
 176 (** Remove variables containing no information. *)
 177 val compress_g : t_global -> t_global
 178
 179 (** Split multiple global environments into (weakly) connected components. *)
 180 val connected_components_g :
 181   t_global_with_pos list -> t_global_with_pos list list