Skip to content
This repository
tag: v1502
Fetching contributors…

Cannot retrieve contributors at this time

file 920 lines (809 sloc) 33.993 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
(*
Copyright © 2011, 2012 MLstate

This file is part of OPA.

OPA is free software: you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License, version 3, as published by
the Free Software Foundation.

OPA is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for
more details.

You should have received a copy of the GNU Affero General Public License
along with OPA. If not, see <http://www.gnu.org/licenses/>.
*)

(* cf mli *)
(* depends *)
module List = BaseList

(* shorthands *)
module Q = QmlAst
module QTV = QmlTypeVars
module I = Ident

(* aliases *)
module TypeIdent = QmlAst.TypeIdent
module TypeIdentMap = QmlAst.TypeIdentMap

module FreeVars = QmlTypeVars.FreeVars
module TypeVar = QmlTypeVars.TypeVar
module RowVar = QmlTypeVars.RowVar
module ColVar = QmlTypeVars.ColVar

module TypeVarSet = QmlTypeVars.TypeVarSet
module RowVarSet = QmlTypeVars.RowVarSet
module ColVarSet = QmlTypeVars.ColVarSet

module RowVarMap = QmlTypeVars.RowVarMap
module ColVarMap = QmlTypeVars.ColVarMap
module TypeVarMap = QmlTypeVars.TypeVarMap

let (@*) = InfixOperator.(@*)
(* -- *)

type error = TyperError of Q.code_elt * (exn * exn list) (** guard for a non empty list *)
exception Exception of error

let warning fmt = OManager.warning ~wclass:QmlTyperWarnings.typer fmt

let type_err_raise t exn =
  let loc =
    QmlTyperException.loc_make (`Ty_loc t) QmlTyperException.loc_set_empty
  in
  raise (QmlTyperException.Exception (loc, exn))

let invalidTypeDefinition (tvars, tname, ty) =
  let typedef = Q.TypeName (List.map (fun t -> Q.TypeVar t) tvars, tname) in
  QmlTyperException.InvalidTypeDefinition (typedef, ty)

type bypass_typer = BslKey.t -> Q.ty option
type typescheme = (Q.ty, unit) QmlGenericScheme.tsc (* no constraints in public env *)

module ImplFieldMap = SetMap.Make(String)(TypeIdent)
module ImplFieldMapQuick = SetMap.Make(StringSet)(TypeIdent)

type abbrev_height = int

type gamma = {
  ident : typescheme IdentMap.t ;
  type_ident :
    (typescheme * abbrev_height * QmlAst.type_def_visibility) TypeIdentMap.t ;
}


type options =
    {
      explicit_instantiation : bool;
      value_restriction : [`disabled|`normal|`strict];
    }

let default_options =
    {
      explicit_instantiation = true; (* in case Explicit Instantiation used *)
      value_restriction = `disabled; (* in case value restriction used *)
    }

module type QML_LOW_LEVEL_TYPER =
sig
  val type_of_expr :
    ?options : options ->
    ?annotmap : Q.annotmap ->
    bypass_typer : bypass_typer ->
    gamma: gamma ->
    Q.expr ->
    (gamma * gamma) * Q.annotmap * Q.ty

  (* Voir mli *)
end
(** empty *)
let gamma_empty = {
  ident = IdentMap.empty ;
  type_ident = TypeIdentMap.empty ;
}

let rec ty_ty ~with_forall ~free = function
  | Q.TypeAbstract
  | Q.TypeConst _ -> free
  | Q.TypeVar typevar -> FreeVars.add_ty typevar free
  | Q.TypeArrow (le1, e2) ->
      let free = ty_ty_list ~with_forall ~free le1 in
      ty_ty ~with_forall ~free e2
  | Q.TypeRecord _ty_row -> ty_row ~with_forall ~free _ty_row
  | Q.TypeName (params, _) -> ty_ty_list ~with_forall ~free params
  | Q.TypeSum sum -> ty_sums ~with_forall ~free sum
  | Q.TypeSumSugar sum -> ty_sums_sugar ~with_forall ~free sum
  | Q.TypeForall (vars, rvars, cvars, t) ->
      if with_forall
      then ty_ty ~with_forall ~free t
      else
        let ts = TypeVarSet.from_list vars in
        let rs = RowVarSet.from_list rvars in
        let cs = ColVarSet.from_list cvars in
        let vars = FreeVars.import_from_sets ts rs cs in
        FreeVars.diff (ty_ty ~with_forall ~free t) vars

and ty_ty_list ~with_forall ~free tyl =
  List.fold_left (fun free -> ty_ty ~with_forall ~free) free tyl

and ty_row ~with_forall ~free (Q.TyRow (fields, rv)) =
  let free = List.fold_left (fun free (_, tau) -> ty_ty ~with_forall ~free tau) free fields in
  let free = Option.default_map free (fun v -> FreeVars.add_row v free) rv
  in free

and ty_sums ~with_forall ~free sum =
  let Q.TyCol (_, cv) = sum in
  let free = Option.default_map free (fun v -> FreeVars.add_col v free) cv in
  let lt = Q.column_to_records sum in
  List.fold_left (fun free _ty -> ty_ty ~with_forall ~free _ty) free lt

and ty_sums_sugar ~with_forall ~free sum =
  List.fold_left (fun free _ty -> ty_ty ~with_forall ~free _ty) free sum

let freevars_of_ty ?(with_forall=false) ?(free=FreeVars.empty) t =
  ty_ty ~with_forall ~free t
let freevars_of_row ?(with_forall=false) ?(free=FreeVars.empty) t =
  ty_row ~with_forall ~free t
let freevars_of_col ?(with_forall=false) ?(free=FreeVars.empty) t =
  ty_sums ~with_forall ~free t

  let freevars_of_typescheme =
    let f body () = freevars_of_ty body in
    QmlGenericScheme.freevars_with_cache f

  let freevars_of_gamma g =
    let free = FreeVars.empty in
    let free = IdentMap.fold (fun _ sh acc -> let free = freevars_of_typescheme sh in FreeVars.union acc free) g.ident free in
    free

(** a function to specialize types from 3 functions of maping for typevars *)
(** for rows and cols, it DOES NOT perform the merge (merge in map_row and map_col if you want) *)
let map_vars_of_ty map_ty map_row map_col =
  let ty_row ((Q.TyRow (_, rv)) as row) =
    Option.default_map row (map_row row) rv
  and ty_sums ((Q.TyCol (_, cv)) as col) =
    Option.default_map col (map_col col) cv
  in
  QmlAstWalk.Type.map_up
    (function
      | (Q.TypeVar v) as ty -> map_ty ty v
      | Q.TypeRecord row -> Q.TypeRecord (ty_row row)
      | Q.TypeSum sum -> Q.TypeSum (ty_sums sum)
      | ty -> ty)

module Scheme =
struct
  type t = typescheme
  type renaming = TypeVar.t TypeVarMap.t * RowVar.t RowVarMap.t * ColVar.t ColVarMap.t

  let empty_renaming = (TypeVarMap.empty,RowVarMap.empty,ColVarMap.empty)
  let next v = QmlGenericScheme.import FreeVars.empty (Q.TypeVar v) ()

  (* TODO: we will also need a version which keeps track between runs
which variable is changed to which, e.g. to rename user-written
vars consistently in a freshly parsed code. It may be good
to write the general function and then instantiate it for
typesheme refresh below
*)
  let refresh_quantifier_and_renaming s =
    let ordered_quantif = QmlGenericScheme.export_ordered_quantif s in
    (** BEWARE : refreshing set and ordered quantification with coherence *)
    let typevarmap, new_typevar =
      (* we fold over ordered_quantif, to reflect the order of vars
by the order in which we generate them (and so the order in the set);
to keep it correct, refresh has to be performed in the order given
and generate variables which are stricly greater than any
variables generated before (e.g. using a global counter) *)
      List.fold_left (fun (map, set) elt ->
        let index = TypeVar.refresh elt in
        let map = TypeVarMap.add elt index map in
        let set = TypeVarSet.add index set in
        (map, set))
        (TypeVarMap.empty, TypeVarSet.empty)
        ordered_quantif.QTV.typevar
    in
    let rowvarmap, new_rowvar =
      List.fold_left (fun (map, set) elt ->
        let index = RowVar.refresh elt in
        let map = RowVarMap.add elt index map in
        let set = RowVarSet.add index set in
        (map, set))
        (RowVarMap.empty, RowVarSet.empty)
        ordered_quantif.QTV.rowvar
    in
    let colvarmap, new_colvar =
      List.fold_left (fun (map, set) elt ->
        let index = ColVar.refresh elt in
        let map = ColVarMap.add elt index map in
        let set = ColVarSet.add index set in
        (map, set))
        (ColVarMap.empty, ColVarSet.empty)
        ordered_quantif.QTV.colvar
    in
    let new_quantif =
      { QTV.
        typevar = new_typevar;
        rowvar = new_rowvar;
        colvar = new_colvar
      } in
    new_quantif, (typevarmap, rowvarmap, colvarmap)

  let apply_renaming (((typevarmap, rowvarmap, colvarmap) as renaming) : renaming) ty =
    if renaming = empty_renaming then ty else (
      (** /!\ Beware here, use the refresh substitution to refresh all variable
according to the new quantification *)
      let map_ty ty v =
        match TypeVarMap.find_opt v typevarmap with
        | Some t -> Q.TypeVar t
        | None -> ty
      in
      let map_row ((Q.TyRow (r, _)) as row) v =
        match RowVarMap.find_opt v rowvarmap with
        | Some t -> Q.TyRow (r, Some t)
        | None -> row
      in
      let map_col ((Q.TyCol (l, _)) as col) v =
        match ColVarMap.find_opt v colvarmap with
        | Some t -> Q.TyCol (l, Some t)
        | None -> col
      in
      map_vars_of_ty map_ty map_row map_col ty
    )

  let refresh_and_renaming s =
    let new_quantif, renaming = refresh_quantifier_and_renaming s in
    let (_, body, ()) = QmlGenericScheme.export_unsafe s in
    let new_body = apply_renaming renaming body in
    let new_s = QmlGenericScheme.import new_quantif new_body () in
    new_s, renaming

  let refresh s =
    fst (refresh_and_renaming s)

  let instantiate t =
    let s = refresh t in
    let (_, body, ()) = QmlGenericScheme.export_unsafe s in
    body

  let export t =
    let t = refresh t in
    let ordered_quantif = QmlGenericScheme.export_ordered_quantif t in
    (ordered_quantif.QTV.typevar,
     ordered_quantif.QTV.rowvar,
     ordered_quantif.QTV.colvar),
    let (_, body, ()) = QmlGenericScheme.export_unsafe t in
    body

  let generalize gamma ty =
    let free_ty = freevars_of_ty ty in
    let free_gamma = freevars_of_gamma gamma in
    let quantif = FreeVars.diff free_ty free_gamma in
    QmlGenericScheme.import quantif ty ()

  let quantify ty =
    let quantif = freevars_of_ty ty in
    QmlGenericScheme.import quantif ty ()



  (* ************************************************************************ *)
  (** We check that for recursive type definitions the recursive reference
uses the same type parameters, i.e.:
type 'a t = ... 'b t ..., if a <> b raises InvalidTypeUsage
We check that the type definition is not trivially cyclic, i.e we forbid
type t('a) = t('a).
We check that sum types do not have cases containing the same labels,
i.e. we forbid
type t = { A } / { B } / { A }
type t = { A; B } / { A; B }
type t = { A : int } / { A : char }
but we do not forbid
type t = { A; B } / { A; C }
type t = { A; B } / { A } *)
  (* ************************************************************************ *)
  (* TODO: This will have to be extended to mutually recursive types, once those are
handled properly *)
  let check_definition tname tvars ty =
    let rec check_row (Q.TyRow (fields, _)) =
      List.iter (check ~top:false @* snd) fields

    and check_col (Q.TyCol (l, _)) =
      let seen_sum_cases = ref [] in
      List.iter
        (fun a_case_fields ->
           (* For the current case of the sum, check the fields making this case
and by the way, recover all the labels presents in the record
forming this case. *)
           let the_case_labels =
             List.map
               (fun (label, field_ty) ->
                  (* Recursively check the type of the label. *)
                  check ~top: false field_ty ;
                  (* Return the label found for this field of the row. *)
                  label)
               a_case_fields in
           (* Now, sort the labels of this case of the sum to compare them with
those already found for the other cases of the sum type. *)
           let the_case_labels_sorted = List.sort compare the_case_labels in
           if not (List.mem the_case_labels_sorted !seen_sum_cases) then
             seen_sum_cases := the_case_labels_sorted :: !seen_sum_cases
           else
             let exc = invalidTypeDefinition (tvars, tname, ty) in
             type_err_raise ty exc)
        l


    and check ?(top=false) t =
      match t with
      | Q.TypeConst _ | Q.TypeVar _ -> ()
      | Q.TypeArrow (lt, u) ->
          List.iter check lt;
          check u
      | Q.TypeSumSugar s -> List.iter check s
      | Q.TypeSum col -> check_col col
      | Q.TypeRecord r -> check_row r
      | Q.TypeName (vars, name) ->
          List.iter check vars ;
          if TypeIdent.equal name tname then
            let ok =
              if ty == t then (
                (* We want to reject definitions trivially cyclic like
type t = t. This is the case when the initial type expression
is the same than the current one. *)
                false
               )
              else (
                try
                  let c = List.combine tvars vars in
                  let pos_ok (v, t) =
                    match t with
                    | Q.TypeVar v' -> TypeVar.equal v v'
                    | _ -> false in
                  List.for_all pos_ok c
                with Invalid_argument "List.combine" -> false) in
            if not ok then
              let exc = invalidTypeDefinition (tvars, tname, ty) in
              type_err_raise t exc
      | Q.TypeAbstract ->
          if (not top) then
            let exc =
              QmlTyperException.InvalidType (ty, `abstract_in_ty_annotation) in
            type_err_raise t exc (* "abstract" nested inside a type def *)
      | Q.TypeForall (_, _, _, t) -> check t
    in
    let rec repeated_var = function
      | [] -> false
      | x::xs -> List.exists (fun y -> TypeVar.equal x y) xs || repeated_var xs
    in
    if repeated_var tvars then
      let exc = invalidTypeDefinition (tvars, tname, ty) in
      type_err_raise ty exc
    else
      check ~top:true ty

  let definition_no_check ?(typevar=[]) ?(ty_row=[]) tname typ =
    let error () =
      let exn = invalidTypeDefinition (typevar, tname, typ) in
      type_err_raise typ exn
    in
    let build_typevar = List.fold_left
      (fun free v ->
         if TypeVarSet.mem v free then error ()
         else TypeVarSet.add v free
      ) TypeVarSet.empty
    in
    let build_rowvar = List.fold_left
      (fun free v ->
         if RowVarSet.mem v free then error ()
         else RowVarSet.add v free
      ) RowVarSet.empty
    in
    let ty_params = build_typevar typevar in
    let row_params = build_rowvar ty_row in

    let free = freevars_of_ty typ in
    let new_free =
      { QTV.
        typevar = ty_params;
        rowvar = row_params;
        colvar = ColVarSet.empty
      }
    in

    if
      TypeVarSet.subset free.QTV.typevar ty_params
        (* for now other kinds of variables are forbidden in type defs: *)
      && RowVarSet.is_empty free.QTV.rowvar
    then
      (* TODO: why do we refresh here? isn't it enough to refresh at each access *)
      refresh (QmlGenericScheme.import new_free typ ())

    else error ()

  let definition ?(typevar=[]) ?(ty_row=[]) tname typ =
    check_definition tname typevar typ;
    definition_no_check ~typevar ~ty_row tname typ

  (* we could also specialize column variables if needed *)
  let specialize ~typeident ?(ty=[]) ?(ty_row=[]) s =
    let error () =
      let exn = QmlTyperException.InvalidTypeUsage (typeident, (QmlGenericScheme.export_ordered_quantif s).QTV.typevar, ty) in
    let (_, body, ()) = QmlGenericScheme.export_unsafe s in
    type_err_raise body exn
    in
    (* The different maps are built from a fold_left2 between parameters provided and the
ordered representation of the quantification
Any problem by doing the fold_left2 means that the arity of type constructors are not respected
We raise error when instantiating type with too many or too few parameters,
but not with no parameters, since it is a nice abbreviation (e.g., [] : list, means [] : 'a list) *)
    let typevarmap, rowvarmap =
      try
        let build cons add empty refresh a b =
          let a, b =
            match a, b with
            | _::_, [] ->
                (** this is the case we want to allow *)
                a, List.map (fun var -> cons (refresh var)) a
            | _, _ -> a, b in

          List.fold_left2 (fun map index ty -> add index ty map) empty a b in

        let typevar_refresh = TypeVar.refresh in
        let rowvar_refresh = RowVar.refresh in
        build (fun s -> Q.TypeVar s) TypeVarMap.add TypeVarMap.empty typevar_refresh (QmlGenericScheme.export_ordered_quantif s).QTV.typevar ty,
        build (fun s -> Q.TyRow ([], Some s)) RowVarMap.add RowVarMap.empty rowvar_refresh (QmlGenericScheme.export_ordered_quantif s).QTV.rowvar ty_row
      with
      | Invalid_argument _ -> error ()
    in
    let map_ty ty v = Option.default ty (TypeVarMap.find_opt v typevarmap) in
    let map_row row v =
      match RowVarMap.find_opt v rowvarmap with
      | Some t ->
          let cmp_fields (f1, _) (f2, _) = String.compare f1 f2 in
          let Q.TyRow (fields1, _) = row in
          let Q.TyRow (fields2, rv) = t in
          let fields = List.uniq_unsorted ~cmp:cmp_fields
            (fields1 @ fields2) in (* so we prefer duplicates from fields1 rather than from fields2 *)
          Q.TyRow (fields, rv)
      | None -> row in
    let (_, body, ()) = QmlGenericScheme.export_unsafe s in
    map_vars_of_ty map_ty map_row (fun col _ -> col) body

  let id ty = QmlGenericScheme.import FreeVars.empty ty ()

  let explicit_forall tsc =
    let (tv,rv,cv),ty = export tsc in
      match tv,rv,cv with
        | [],[],[] -> ty
        | _ -> Q.TypeForall(tv,rv,cv,ty)

end

module Env =
struct
  type t = gamma
  let empty = gamma_empty
  module Ident =
  struct
    let find_opt id g = IdentMap.find_opt id g.ident
    let find id g = match find_opt id g with
      | Some t -> t
      | None ->
          raise (QmlTyperException.Exception
                   (QmlTyperException.loc_empty,
                    QmlTyperException.IdentifierNotFound
                      (id, IdentMap.keys g.ident)))
    let add id s g = { g with ident = IdentMap.add id s g.ident }
    let remove id g = { g with ident = IdentMap.remove id g.ident }
    let mem id g = IdentMap.mem id g.ident
    let iter f g = IdentMap.iter f g.ident
    let fold f g = IdentMap.fold f g.ident
    let map f g = {g with ident = IdentMap.map f g.ident}
    let fold_map f gamma acc =
      let acc, ident = IdentMap.fold_map f gamma.ident acc in
      acc, {gamma with ident = ident}
    let from_map map gamma =
      {gamma with ident = map}
    let to_map gamma = gamma.ident
    let pp f gamma =
      iter (fun ident tsc ->
              Format.fprintf f "@[<2> %s -> %a@]@\n" (try Ident.to_uniq_string ident with _ -> "erro") QmlPrint.pp#tsc tsc
           ) gamma
  end

  module TypeIdent =
  struct
    module T = TypeIdent

    (** [TODO] Documentation. *)
    let apply_visibility scheme abbrev_height = function
      | QmlAst.TDV_public -> Some (scheme, abbrev_height)
      | QmlAst.TDV_private package ->
          (* Since types private to a package are not visible at all from
other packages, this type must be considered as non-existant
if we are not in its definition package. *)
          if package <> (ObjectFiles.get_current_package_name ()) then None
          else Some (scheme, abbrev_height)
      | QmlAst.TDV_abstract package ->
          (* If we are not in the type's definition package, then it
must be considered as abstract. *)
          if package <> (ObjectFiles.get_current_package_name ()) then (
            (* Turn the body of the scheme into a [TypeAbstract]. *)
            let (quantif, _, constraints) =
              QmlGenericScheme.export_unsafe scheme in
            Some
              ((QmlGenericScheme.import quantif
                  QmlAst.TypeAbstract constraints),
               0)
          )
          else Some (scheme, abbrev_height)

    (** [TODO] Documentation of [~visibility_applies] for passes that anyway
need to see types' structure once the typechecker ensured these types,
even not visible are used in a consistent way. *)
    let find_opt ~visibility_applies id g =
      let opt_found = TypeIdentMap.find_opt id g.type_ident in
      match opt_found with
      | None -> None
      | Some (sch, abbrev_height, visibility) ->
          if visibility_applies then
            apply_visibility sch abbrev_height visibility
          else Some (sch, abbrev_height)

    let findi_opt ~visibility_applies id g =
      let opt_found = TypeIdentMap.findi_opt id g.type_ident in
      match opt_found with
      | None -> None
      | Some (i, (sch, abbrev_height, visibility)) -> (
          if not visibility_applies then Some (i, (sch, abbrev_height))
          else
            match apply_visibility sch abbrev_height visibility with
            | None -> None
            | Some sch' -> Some (i, sch')
        )

    let find ~visibility_applies id g =
      Option.get_exn
        (QmlTyperException.Exception
           (QmlTyperException.loc_empty,
            QmlTyperException.TypeIdentNotFound id))
        (find_opt ~visibility_applies id g)
    let findi ~visibility_applies id g =
      Option.get_exn
        (QmlTyperException.Exception
           (QmlTyperException.loc_empty,
            QmlTyperException.TypeIdentNotFound id))
        (findi_opt ~visibility_applies id g)


    (* ********************************************************************** *)
    (** {b Descr}: See .mli file.
{b Visibility}: Exported outside this module. *)
    (* ********************************************************************** *)
    let raw_find id g =
      (* Since we return both the bound scheme and its visibility information,
fetch in the environment is done ignoring visibility. *)
      let opt_found = TypeIdentMap.find_opt id g.type_ident in
      Option.get_exn
        (QmlTyperException.Exception
           (QmlTyperException.loc_empty,
            QmlTyperException.TypeIdentNotFound id))
        opt_found


    let records_field_names t =
      let handle_ty_row acc (Q.TyRow (fields, _)) =
        let handle_field_t acc (name, _) = name :: acc in
        List.fold_left handle_field_t acc fields
      in
      let rec handle_ty acc = function
        | Q.TypeSum (Q.TyCol (l, _)) ->
            List.flatten (List.map (List.map fst) l) @ acc
        | Q.TypeSumSugar sum ->
            List.fold_left handle_ty acc sum
        | Q.TypeRecord r -> handle_ty_row acc r
        | _ -> acc (* record cannot have any other unnamed type *)
      in handle_ty [] t

    let records_field_names_quick t =
      let handle_ty_row (Q.TyRow (fields, _)) = List.map fst fields in
      let rec handle_ty acc = function
        | Q.TypeSum (Q.TyCol (l, _)) ->
            List.map (List.map fst) l @ acc
        | Q.TypeSumSugar sum ->
            List.fold_left handle_ty acc sum
        | Q.TypeRecord r -> handle_ty_row r :: acc
        | _ -> acc (* record cannot have any other unnamed type *)
      in handle_ty [] t

    let add id (s, abbrev_height, visibility) g =
      let type_ident =
        TypeIdentMap.add id (s, abbrev_height, visibility) g.type_ident in
      { g with type_ident = type_ident ; }

    let mem id g = TypeIdentMap.mem id g.type_ident

    let iter f g = TypeIdentMap.iter f g.type_ident

    let fold f g = TypeIdentMap.fold f g.type_ident

    let to_list gamma = TypeIdentMap.to_list gamma.type_ident

    let fold_map f gamma acc =
      let acc, type_ident = TypeIdentMap.fold_map f gamma.type_ident acc in
      (acc, {gamma with type_ident = type_ident })

    let map f gamma =
      let type_ident = TypeIdentMap.map f gamma.type_ident in
      { gamma with type_ident = type_ident }

    let pp f gamma =
      iter
        (fun typeident (tsc, _, _) ->
           Format.fprintf f "@[<2>%s -> %a@]@\n"
             (TypeIdent.to_debug_string typeident) QmlPrint.pp#tsc tsc)
        gamma
  end


  let pp f gamma =
    Format.fprintf f "@[<v>@[<v2>ident:@ %a@]@ @[<v2>types:@ %a@]@]" Ident.pp gamma TypeIdent.pp gamma

  (* Appends the definition in g2 to those of g1 *)
  let append g1 g2 =
    let ident = IdentMap.merge_i
      (fun i _ _ -> OManager.i_error
         "Duplicate ident %s (CheckDuplication should catch it before)"
         (I.to_string i)
      )
      g1.ident g2.ident in
    let type_ident = TypeIdentMap.merge_i
      (fun i _ x ->
         assert (BaseString.is_prefix "tuple_" (I.original_name i));
         x
      ) g1.type_ident g2.type_ident in
    { ident = ident ; type_ident = type_ident ;}

  let unsafe_append g1 g2 =
    let ident = IdentMap.merge_i
      (fun _ _ x -> x)
      g1.ident g2.ident in
    let type_ident = TypeIdentMap.merge_i
      (fun _ _ x -> x)
      g1.type_ident g2.type_ident in
    { ident = ident ; type_ident = type_ident ;}


end

(** More Common Types, needed in order that differents HighTyper could share the type env *)
type typed_code_elt = (Q.ty, Scheme.t) Q.maped_code_elt
type 'schema public_env =
    {
      exported_values_idents : IdentSet.t ;
      gamma : gamma ;
      schema : 'schema ;
      annotmap : Q.annotmap ;
      bypass_typer : bypass_typer ;
      had_error : bool ;
      exception_handler : 'schema public_env -> exn -> unit ;
      display : bool ; (** false by default *)
      options : options ;
    }

(** Helper functions to normalize types wrt a gamma (process typenames, remove
sugared sums, etc.) *)
let unsugar_type gamma ty =
  let error kind =
    type_err_raise ty (QmlTyperException.InvalidType (ty, kind)) in

  (** {b Descr}: Local function to unwind named type expression, i.e. to
replace them by the efective structure that are bound to, with their
effective arguments used to instantiate parameters of the definition the
name is bound to. *)
  let unwind_type gamma = function
    | Q.TypeName (params, ti) ->
        let (ti, (tsc, _)) =
          Env.TypeIdent.findi ~visibility_applies: true ti gamma in
        if (Scheme.instantiate tsc) = Q.TypeAbstract then (
          (* The type name is bound to a definition that is said "abstract" or
"extern", so return a type that is a named type with the same
name than the initial one. This way, since the type has no
representation, i.e. the name is not bound to a definition
providing an explicit structure for this name, it will be
considered as being structured as itself, hence it will be
compatible only with itself. And that, this is really the meaning
of an abstract type. *)
          Q.TypeName (params, ti)
        )
        else (
          (* Ok, the name of this type is bound to a type definition. So we
instantiate this definition's scheme by the effective arguments
aplied to the type name. Hence, we get a new type that is an
instance of the name's definition in which parameters are replaced
by the effective types applied to the type name. *)
          Scheme.specialize ~typeident: ti ~ty: params tsc
        )
    | t ->
        (* The type is not a named type, hence it has its own structure and
doesn't unwind. So return it unchanged. *)
        t in

  let deal_with_duplicates l =
    let module SpecialMapForDuplicates = BaseMap.Make ( StringSet ) in
    let safe_add f s =
      if StringSet.mem f s then (
        (* There is a duplicate field inside a same record. *)
        error `duplicate_field
      )
      else StringSet.add f s in
    let undup acc fields =
      let (s, m) =
        List.fold_left
          (fun (s, m) (f, (t : QmlAst.ty)) ->
             (safe_add f s, StringMap.add f t m))
          (StringSet.empty, StringMap.empty)
          fields in
      match SpecialMapForDuplicates.find_opt s acc with
      | None -> ((SpecialMapForDuplicates.add s m acc), (Some fields))
      | Some m' when StringMap.compare (Pervasives.compare) m m' = 0 ->
          (* We are in the case where several cases of the sum have exactly
the same fields with the same types. Hence, we have duplicate
sum cases. Just drop this redundant case. *)
          (acc, None)
      | _ ->
          (* There is a duplicate field in different cases of the sum with
different types. *)
          error `duplicate_field_with_diff_ty_in_sum_cases in
    snd (List.fold_left_filter_map undup SpecialMapForDuplicates.empty l) in

  let make_typesum = function
    | [r] -> Q.TypeRecord (Q.TyRow (r, None))
    | l -> Q.TypeSum (Q.TyCol (l, None)) in

  let get_fields = function
    | Q.TypeRecord (Q.TyRow (fields, None)) -> [fields]
    | Q.TypeSum (Q.TyCol (fields, None)) -> fields
    | Q.TypeRecord (Q.TyRow (_, Some _)) -> error `record_not_closed
    | _ -> error `not_a_record in

  let aux = function
    | Q.TypeSumSugar l ->
        (make_typesum @* deal_with_duplicates)
          (List.concat_map (get_fields @* unwind_type gamma) l)
    | Q.TypeRecord (Q.TyRow (fields, _)) as t ->
        ignore (deal_with_duplicates [fields]) ;
        t
    | Q.TypeSum (Q.TyCol (cases, _)) as t ->
        (* For each case of the sum, check that the record representing this
case doesn't have duplicate fields and that is a field appears in
different sum cases, then it doesn't have different types. *)
        ignore (deal_with_duplicates cases) ;
        t
    | t -> t in
  QmlAstWalk.Type.map_up aux ty



(* FPE says: after so many refactoring, it seems tat now this function only
checks that names of types are used with the right arity... *)
let process_typenames ?(typedef=false) gamma ty =
  let aux ty =
    match ty with
    | Q.TypeName (tl, ti) ->
        let (ti, (ts, _)) =
          Env.TypeIdent.findi ~visibility_applies: true ti gamma in
        if (typedef || tl <> []) &&
           (List.length tl <> QmlGenericScheme.arity ts) then (
          let exn =
            QmlTyperException.InvalidTypeUsage
              (ti, (QmlGenericScheme.export_ordered_quantif ts).QTV.typevar,
               tl) in
          let (_, body, ()) = QmlGenericScheme.export_unsafe ts in
          type_err_raise body exn
         )
        else Q.TypeName (tl, ti)
    | _ -> ty in
  QmlAstWalk.Type.map_up aux ty



(** {b Visibility}: Not exported outside this module. *)
(* FPE says: test cases like type 'at = 'a type 'a u = 'a t to see. *)
let get_abbreviation_height gamma ty =
  match ty with
  | Q.TypeName (_, ti) ->
      let (_, (_, abb_height)) =
        Env.TypeIdent.findi ~visibility_applies: true ti gamma in
      abb_height
  | Q.TypeVar _ -> -1
  | _ -> 0



let type_of_type ?(typedef = false) ?(tirec = []) gamma ty =
  let gamma =
    List.fold_left
      (fun gamma (ti,vars) ->
         let fake_rec_def =
           Scheme.definition_no_check ~typevar: vars ti Q.TypeAbstract in
         Env.TypeIdent.add
           ti
           (fake_rec_def,
            (* Abbreviations height is 0 since the definition is considered as
binding an abstract type. *)
            0,
            QmlAst.TDV_private (ObjectFiles.get_current_package_name ()))
           gamma)
      gamma tirec in
  let ty = process_typenames ~typedef gamma ty in
  let ty = unsugar_type gamma ty in
  let abb_height = get_abbreviation_height gamma ty in
  (ty, abb_height)

let process_scheme gamma tsc =
  QmlGenericScheme.map_body_unsafe2 (type_of_type gamma) tsc
    (* safe as long as type_of_type doesn't touch type variables, etc. *)

let process_gamma ~gamma target_gamma =
  let new_gamma = Env.empty in
  let new_gamma =
    Env.Ident.fold
      (fun id tsc new_gamma ->
         let (tsc', _) = process_scheme gamma tsc in
         Env.Ident.add id tsc' new_gamma)
      target_gamma new_gamma in
  let new_gamma =
    Env.TypeIdent.fold
      (fun id (tsc, height, visibility) new_gamma ->
         let (tsc', height') = process_scheme gamma tsc in
         (* FPE says: I think this should be the case... *)
         assert (height = height') ;
         Env.TypeIdent.add id (tsc', height, visibility) new_gamma)
      target_gamma new_gamma in
  new_gamma

let process_typenames_annotmap ~gamma annotmap =
  QmlAnnotMap.map (process_typenames ~typedef:false gamma) annotmap

let process_annotmap ~gamma annotmap =
  QmlAnnotMap.map (fun ty -> fst (type_of_type gamma ty)) annotmap



let check_no_duplicate_type_defs =
  let cmp x y =
    let c = TypeIdent.compare x y in
    if c = 0 then
      raise
        (QmlTyperException.Exception
           (QmlTyperException.loc_empty,
            QmlTyperException.DuplicateTypeDefinitions
              (TypeIdent.to_string x))) ;
    c in
  ignore @* (List.sort cmp) @*
    (List.concat_map
       (function Q.NewType (_, l) ->
          List.map (fun ty_def -> ty_def.QmlAst.ty_def_name) l | _ -> []))


class pp_with_gamma gamma =
  let to_flush = ref IdentMap.empty in
  let flushed = ref IdentMap.empty in
object(self)
  inherit QmlPrint.opa_printer as super
  method typeident f t =
    if Env.TypeIdent.mem t gamma
      && not (IdentMap.mem t !flushed ) then
        to_flush := IdentMap.add t (Env.TypeIdent.find ~visibility_applies:false t gamma) !to_flush;
    super#typeident f t

  method flush f () =
    Format.fprintf f "@[<v>";
    let rec aux s =
      if IdentMap.is_empty !to_flush then ()
      else
        let (t, (sch,_)) = IdentMap.min !to_flush in
        to_flush := IdentMap.remove t !to_flush;
        flushed := IdentMap.add t sch !flushed ;
        let ty = Scheme.instantiate sch in
        Format.fprintf f "@[%s %a = %a @]" s self#typeident t self#ty ty;
        if IdentMap.is_empty !to_flush then ()
        else aux "and"
    in aux "type";
    to_flush := IdentMap.empty;
    flushed := IdentMap.empty;
    Format.fprintf f "@]"
end
Something went wrong with that request. Please try again.