1711 lines
59 KiB
OCaml
1711 lines
59 KiB
OCaml
(***********************************************************************)
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(* *)
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(* OCaml *)
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(* *)
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(* Xavier Leroy and Jerome Vouillon, projet Cristal, INRIA Rocquencourt*)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the Q Public License version 1.0. *)
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(* *)
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(***********************************************************************)
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(**** Typing of type definitions ****)
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open Misc
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open Asttypes
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open Parsetree
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open Primitive
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open Types
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open Typetexp
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type error =
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Repeated_parameter
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| Duplicate_constructor of string
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| Too_many_constructors
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| Duplicate_label of string
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| Recursive_abbrev of string
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| Cycle_in_def of string * type_expr
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| Definition_mismatch of type_expr * Includecore.type_mismatch list
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| Constraint_failed of type_expr * type_expr
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| Inconsistent_constraint of Env.t * (type_expr * type_expr) list
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| Type_clash of Env.t * (type_expr * type_expr) list
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| Parameters_differ of Path.t * type_expr * type_expr
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| Null_arity_external
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| Missing_native_external
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| Unbound_type_var of type_expr * type_declaration
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| Not_open_type of Path.t
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| Not_extensible_type of Path.t
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| Extension_mismatch of Path.t * Includecore.type_mismatch list
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| Rebind_wrong_type of Longident.t * Env.t * (type_expr * type_expr) list
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| Rebind_mismatch of Longident.t * Path.t * Path.t
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| Rebind_private of Longident.t
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| Bad_variance of int * (bool * bool * bool) * (bool * bool * bool)
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| Unavailable_type_constructor of Path.t
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| Bad_fixed_type of string
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| Unbound_type_var_ext of type_expr * extension_constructor
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| Varying_anonymous
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open Typedtree
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exception Error of Location.t * error
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(* Enter all declared types in the environment as abstract types *)
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let enter_type env sdecl id =
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let decl =
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{ type_params =
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List.map (fun _ -> Btype.newgenvar ()) sdecl.ptype_params;
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type_arity = List.length sdecl.ptype_params;
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type_kind = Type_abstract;
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type_private = sdecl.ptype_private;
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type_manifest =
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begin match sdecl.ptype_manifest with None -> None
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| Some _ -> Some(Ctype.newvar ()) end;
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type_variance = List.map (fun _ -> Variance.full) sdecl.ptype_params;
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type_newtype_level = None;
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type_loc = sdecl.ptype_loc;
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type_attributes = sdecl.ptype_attributes;
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}
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in
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Env.add_type ~check:true id decl env
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let update_type temp_env env id loc =
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let path = Path.Pident id in
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let decl = Env.find_type path temp_env in
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match decl.type_manifest with None -> ()
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| Some ty ->
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let params = List.map (fun _ -> Ctype.newvar ()) decl.type_params in
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try Ctype.unify env (Ctype.newconstr path params) ty
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with Ctype.Unify trace ->
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raise (Error(loc, Type_clash (env, trace)))
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(* Determine if a type is (an abbreviation for) the type "float" *)
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(* We use the Ctype.expand_head_opt version of expand_head to get access
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to the manifest type of private abbreviations. *)
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let is_float env ty =
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match Ctype.repr (Ctype.expand_head_opt env ty) with
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{desc = Tconstr(p, _, _)} -> Path.same p Predef.path_float
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| _ -> false
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(* Determine if a type definition defines a fixed type. (PW) *)
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let is_fixed_type sd =
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let rec has_row_var sty =
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match sty.ptyp_desc with
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Ptyp_alias (sty, _) -> has_row_var sty
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| Ptyp_class _
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| Ptyp_object (_, Open)
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| Ptyp_variant (_, Open, _)
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| Ptyp_variant (_, Closed, Some _) -> true
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| _ -> false
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in
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match sd.ptype_manifest with
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None -> false
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| Some sty ->
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sd.ptype_kind = Ptype_abstract &&
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sd.ptype_private = Private &&
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has_row_var sty
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(* Set the row variable in a fixed type *)
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let set_fixed_row env loc p decl =
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let tm =
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match decl.type_manifest with
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None -> assert false
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| Some t -> Ctype.expand_head env t
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in
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let rv =
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match tm.desc with
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Tvariant row ->
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let row = Btype.row_repr row in
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tm.desc <- Tvariant {row with row_fixed = true};
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if Btype.static_row row then Btype.newgenty Tnil
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else row.row_more
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| Tobject (ty, _) ->
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snd (Ctype.flatten_fields ty)
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| _ ->
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raise (Error (loc, Bad_fixed_type "is not an object or variant"))
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in
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if not (Btype.is_Tvar rv) then
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raise (Error (loc, Bad_fixed_type "has no row variable"));
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rv.desc <- Tconstr (p, decl.type_params, ref Mnil)
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(* Translate one type declaration *)
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module StringSet =
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Set.Make(struct
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type t = string
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let compare (x:t) y = compare x y
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end)
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let make_params env params =
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let make_param (sty, v) =
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try
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(transl_type_param env sty, v)
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with Already_bound ->
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raise(Error(sty.ptyp_loc, Repeated_parameter))
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in
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List.map make_param params
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let transl_labels loc env closed lbls =
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if lbls = [] then
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Syntaxerr.ill_formed_ast loc "Records cannot be empty.";
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let all_labels = ref StringSet.empty in
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List.iter
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(fun {pld_name = {txt=name; loc}} ->
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if StringSet.mem name !all_labels then
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raise(Error(loc, Duplicate_label name));
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all_labels := StringSet.add name !all_labels)
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lbls;
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let mk {pld_name=name;pld_mutable=mut;pld_type=arg;pld_loc=loc;pld_attributes=attrs} =
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let arg = Ast_helper.Typ.force_poly arg in
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let cty = transl_simple_type env closed arg in
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{ld_id = Ident.create name.txt; ld_name = name; ld_mutable = mut; ld_type = cty;
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ld_loc = loc; ld_attributes = attrs}
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in
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let lbls = List.map mk lbls in
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let lbls' =
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List.map
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(fun ld ->
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let ty = ld.ld_type.ctyp_type in
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let ty = match ty.desc with Tpoly(t,[]) -> t | _ -> ty in
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{Types.ld_id = ld.ld_id;
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ld_mutable = ld.ld_mutable;
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ld_type = ty;
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ld_loc = ld.ld_loc;
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ld_attributes = ld.ld_attributes
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}
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)
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lbls in
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lbls, lbls'
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let transl_constructor_arguments loc env closed = function
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| Pcstr_tuple l ->
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let l = List.map (transl_simple_type env closed) l in
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Types.Cstr_tuple (List.map (fun t -> t.ctyp_type) l),
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Cstr_tuple l
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| Pcstr_record l ->
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let lbls, lbls' = transl_labels loc env closed l in
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Types.Cstr_record lbls',
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Cstr_record lbls
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let make_constructor loc env type_path type_params sargs sret_type =
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match sret_type with
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| None ->
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let args, targs =
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transl_constructor_arguments loc env true sargs
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in
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targs, None, args, None
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| Some sret_type ->
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(* if it's a generalized constructor we must first narrow and
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then widen so as to not introduce any new constraints *)
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let z = narrow () in
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reset_type_variables ();
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let args, targs =
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transl_constructor_arguments loc env false sargs
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in
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let tret_type = transl_simple_type env false sret_type in
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let ret_type = tret_type.ctyp_type in
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begin
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match (Ctype.repr ret_type).desc with
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Tconstr (p', _, _) when Path.same type_path p' -> ()
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| _ ->
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raise (Error (sret_type.ptyp_loc, Constraint_failed
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(ret_type, Ctype.newconstr type_path type_params)))
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end;
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widen z;
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targs, Some tret_type, args, Some ret_type
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let transl_declaration env sdecl id =
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(* Bind type parameters *)
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reset_type_variables();
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Ctype.begin_def ();
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let tparams = make_params env sdecl.ptype_params in
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let params = List.map (fun (cty, _) -> cty.ctyp_type) tparams in
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let cstrs = List.map
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(fun (sty, sty', loc) ->
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transl_simple_type env false sty,
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transl_simple_type env false sty', loc)
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sdecl.ptype_cstrs
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in
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let (tkind, kind) =
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match sdecl.ptype_kind with
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Ptype_abstract -> Ttype_abstract, Type_abstract
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| Ptype_variant scstrs ->
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if scstrs = [] then
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Syntaxerr.ill_formed_ast sdecl.ptype_loc
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"Variant types cannot be empty.";
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let all_constrs = ref StringSet.empty in
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List.iter
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(fun {pcd_name = {txt = name}} ->
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if StringSet.mem name !all_constrs then
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raise(Error(sdecl.ptype_loc, Duplicate_constructor name));
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all_constrs := StringSet.add name !all_constrs)
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scstrs;
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if List.length
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(List.filter (fun cd -> cd.pcd_args <> Pcstr_tuple []) scstrs)
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> (Config.max_tag + 1) then
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raise(Error(sdecl.ptype_loc, Too_many_constructors));
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let make_cstr scstr =
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let name = Ident.create scstr.pcd_name.txt in
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let targs, tret_type, args, ret_type =
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make_constructor scstr.pcd_loc env (Path.Pident id) params
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scstr.pcd_args scstr.pcd_res
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in
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let tcstr =
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{ cd_id = name;
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cd_name = scstr.pcd_name;
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cd_args = targs;
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cd_res = tret_type;
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cd_loc = scstr.pcd_loc;
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cd_attributes = scstr.pcd_attributes }
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in
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let cstr =
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{ Types.cd_id = name;
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cd_args = args;
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cd_res = ret_type;
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cd_loc = scstr.pcd_loc;
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cd_attributes = scstr.pcd_attributes }
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in
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tcstr, cstr
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in
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let tcstrs, cstrs = List.split (List.map make_cstr scstrs) in
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Ttype_variant tcstrs, Type_variant cstrs
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| Ptype_record lbls ->
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let lbls, lbls' = transl_labels sdecl.ptype_loc env true lbls in
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let rep =
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if List.for_all (fun l -> is_float env l.Types.ld_type) lbls'
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then Record_float
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else Record_regular
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in
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Ttype_record lbls, Type_record(lbls', rep)
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| Ptype_open -> Ttype_open, Type_open
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in
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let (tman, man) = match sdecl.ptype_manifest with
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None -> None, None
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| Some sty ->
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let no_row = not (is_fixed_type sdecl) in
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let cty = transl_simple_type env no_row sty in
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Some cty, Some cty.ctyp_type
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in
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let decl =
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{ type_params = params;
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type_arity = List.length params;
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type_kind = kind;
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type_private = sdecl.ptype_private;
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type_manifest = man;
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type_variance = List.map (fun _ -> Variance.full) params;
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type_newtype_level = None;
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type_loc = sdecl.ptype_loc;
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type_attributes = sdecl.ptype_attributes;
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} in
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(* Check constraints *)
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List.iter
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(fun (cty, cty', loc) ->
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let ty = cty.ctyp_type in
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let ty' = cty'.ctyp_type in
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try Ctype.unify env ty ty' with Ctype.Unify tr ->
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raise(Error(loc, Inconsistent_constraint (env, tr))))
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cstrs;
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Ctype.end_def ();
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(* Add abstract row *)
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if is_fixed_type sdecl then begin
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let (p, _) =
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try Env.lookup_type (Longident.Lident(Ident.name id ^ "#row")) env
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with Not_found -> assert false in
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set_fixed_row env sdecl.ptype_loc p decl
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end;
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(* Check for cyclic abbreviations *)
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begin match decl.type_manifest with None -> ()
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| Some ty ->
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if Ctype.cyclic_abbrev env id ty then
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raise(Error(sdecl.ptype_loc, Recursive_abbrev sdecl.ptype_name.txt));
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end;
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{
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typ_id = id;
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typ_name = sdecl.ptype_name;
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typ_params = tparams;
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typ_type = decl;
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typ_cstrs = cstrs;
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typ_loc = sdecl.ptype_loc;
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typ_manifest = tman;
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typ_kind = tkind;
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typ_private = sdecl.ptype_private;
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typ_attributes = sdecl.ptype_attributes;
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}
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(* Generalize a type declaration *)
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let generalize_decl decl =
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List.iter Ctype.generalize decl.type_params;
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Btype.iter_type_expr_kind Ctype.generalize decl.type_kind;
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begin match decl.type_manifest with
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| None -> ()
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| Some ty -> Ctype.generalize ty
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end
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(* Check that all constraints are enforced *)
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module TypeSet = Btype.TypeSet
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module TypeMap = Btype.TypeMap
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let rec check_constraints_rec env loc visited ty =
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let ty = Ctype.repr ty in
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if TypeSet.mem ty !visited then () else begin
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visited := TypeSet.add ty !visited;
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match ty.desc with
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| Tconstr (path, args, _) ->
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let args' = List.map (fun _ -> Ctype.newvar ()) args in
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let ty' = Ctype.newconstr path args' in
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begin try Ctype.enforce_constraints env ty'
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with Ctype.Unify _ -> assert false
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| Not_found -> raise (Error(loc, Unavailable_type_constructor path))
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end;
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if not (Ctype.matches env ty ty') then
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raise (Error(loc, Constraint_failed (ty, ty')));
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List.iter (check_constraints_rec env loc visited) args
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| Tpoly (ty, tl) ->
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let _, ty = Ctype.instance_poly false tl ty in
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check_constraints_rec env loc visited ty
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| _ ->
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Btype.iter_type_expr (check_constraints_rec env loc visited) ty
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end
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module SMap = Map.Make(String)
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let check_constraints_labels env visited l pl =
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let rec get_loc name = function
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[] -> assert false
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| pld :: tl ->
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if name = pld.pld_name.txt then pld.pld_type.ptyp_loc
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else get_loc name tl
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in
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List.iter
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(fun {Types.ld_id=name; ld_type=ty} ->
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check_constraints_rec env (get_loc (Ident.name name) pl) visited ty)
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l
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let check_constraints env sdecl (_, decl) =
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let visited = ref TypeSet.empty in
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begin match decl.type_kind with
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| Type_abstract -> ()
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| Type_variant l ->
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let find_pl = function
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Ptype_variant pl -> pl
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| Ptype_record _ | Ptype_abstract | Ptype_open -> assert false
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in
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let pl = find_pl sdecl.ptype_kind in
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let pl_index =
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let foldf acc x =
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SMap.add x.pcd_name.txt x acc
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in
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List.fold_left foldf SMap.empty pl
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in
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List.iter
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(fun {Types.cd_id=name; cd_args; cd_res} ->
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let {pcd_args; pcd_res; _} =
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try SMap.find (Ident.name name) pl_index
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with Not_found -> assert false in
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begin match cd_args, pcd_args with
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| Cstr_tuple tyl, Pcstr_tuple styl ->
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List.iter2
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(fun sty ty ->
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check_constraints_rec env sty.ptyp_loc visited ty)
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styl tyl
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| Cstr_record tyl, Pcstr_record styl ->
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check_constraints_labels env visited tyl styl
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| _ -> assert false
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end;
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match pcd_res, cd_res with
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| Some sr, Some r ->
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check_constraints_rec env sr.ptyp_loc visited r
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| _ ->
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() )
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l
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| Type_record (l, _) ->
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let find_pl = function
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Ptype_record pl -> pl
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| Ptype_variant _ | Ptype_abstract | Ptype_open -> assert false
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in
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let pl = find_pl sdecl.ptype_kind in
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check_constraints_labels env visited l pl
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| Type_open -> ()
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end;
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begin match decl.type_manifest with
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| None -> ()
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| Some ty ->
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let sty =
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match sdecl.ptype_manifest with Some sty -> sty | _ -> assert false
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in
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check_constraints_rec env sty.ptyp_loc visited ty
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end
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|
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(*
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If both a variant/record definition and a type equation are given,
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need to check that the equation refers to a type of the same kind
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with the same constructors and labels.
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*)
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let check_coherence env loc id decl =
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match decl with
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{ type_kind = (Type_variant _ | Type_record _| Type_open);
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type_manifest = Some ty } ->
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begin match (Ctype.repr ty).desc with
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Tconstr(path, args, _) ->
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begin try
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let decl' = Env.find_type path env in
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let err =
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if List.length args <> List.length decl.type_params
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then [Includecore.Arity]
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else if not (Ctype.equal env false args decl.type_params)
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then [Includecore.Constraint]
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else
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Includecore.type_declarations ~equality:true env
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(Path.last path)
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decl'
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id
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(Subst.type_declaration
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(Subst.add_type id path Subst.identity) decl)
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in
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if err <> [] then
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raise(Error(loc, Definition_mismatch (ty, err)))
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with Not_found ->
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raise(Error(loc, Unavailable_type_constructor path))
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end
|
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| _ -> raise(Error(loc, Definition_mismatch (ty, [])))
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end
|
|
| _ -> ()
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|
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let check_abbrev env sdecl (id, decl) =
|
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check_coherence env sdecl.ptype_loc id decl
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|
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(* Check that recursion is well-founded *)
|
|
|
|
let check_well_founded env loc path to_check ty =
|
|
let visited = ref TypeMap.empty in
|
|
let rec check ty0 exp_nodes ty =
|
|
let ty = Btype.repr ty in
|
|
if TypeSet.mem ty exp_nodes then begin
|
|
(*Format.eprintf "@[%a@]@." Printtyp.raw_type_expr ty;*)
|
|
if match ty0.desc with
|
|
| Tconstr (p, _, _) -> Path.same p path
|
|
| _ -> false
|
|
then raise (Error (loc, Recursive_abbrev (Path.name path)))
|
|
else raise (Error (loc, Cycle_in_def (Path.name path, ty0)))
|
|
end;
|
|
let (fini, exp_nodes) =
|
|
try
|
|
let prev = TypeMap.find ty !visited in
|
|
if TypeSet.subset exp_nodes prev then (true, exp_nodes) else
|
|
(false, TypeSet.union exp_nodes prev)
|
|
with Not_found ->
|
|
(false, exp_nodes)
|
|
in
|
|
let snap = Btype.snapshot () in
|
|
if fini then () else try
|
|
visited := TypeMap.add ty exp_nodes !visited;
|
|
match ty.desc with
|
|
| Tconstr(p, args, _)
|
|
when not (TypeSet.is_empty exp_nodes) || to_check p ->
|
|
let ty' = Ctype.try_expand_once_opt env ty in
|
|
let ty0 = if TypeSet.is_empty exp_nodes then ty else ty0 in
|
|
check ty0 (TypeSet.add ty exp_nodes) ty'
|
|
| _ -> raise Ctype.Cannot_expand
|
|
with
|
|
| Ctype.Cannot_expand ->
|
|
let nodes =
|
|
if !Clflags.recursive_types && Ctype.is_contractive env ty
|
|
|| match ty.desc with Tobject _ | Tvariant _ -> true | _ -> false
|
|
then TypeSet.empty
|
|
else exp_nodes in
|
|
Btype.iter_type_expr (check ty0 nodes) ty
|
|
| Ctype.Unify _ ->
|
|
(* Will be detected by check_recursion *)
|
|
Btype.backtrack snap
|
|
in
|
|
check ty TypeSet.empty ty
|
|
|
|
let check_well_founded_manifest env loc path decl =
|
|
if decl.type_manifest = None then () else
|
|
let args = List.map (fun _ -> Ctype.newvar()) decl.type_params in
|
|
check_well_founded env loc path (Path.same path) (Ctype.newconstr path args)
|
|
|
|
let check_well_founded_decl env loc path decl to_check =
|
|
let open Btype in
|
|
let it =
|
|
{type_iterators with
|
|
it_type_expr = (fun _ -> check_well_founded env loc path to_check)} in
|
|
it.it_type_declaration it (Ctype.instance_declaration decl)
|
|
|
|
(* Check for ill-defined abbrevs *)
|
|
|
|
let check_recursion env loc path decl to_check =
|
|
(* to_check is true for potentially mutually recursive paths.
|
|
(path, decl) is the type declaration to be checked. *)
|
|
|
|
if decl.type_params = [] then () else
|
|
|
|
let visited = ref [] in
|
|
|
|
let rec check_regular cpath args prev_exp ty =
|
|
let ty = Ctype.repr ty in
|
|
if not (List.memq ty !visited) then begin
|
|
visited := ty :: !visited;
|
|
match ty.desc with
|
|
| Tconstr(path', args', _) ->
|
|
if Path.same path path' then begin
|
|
if not (Ctype.equal env false args args') then
|
|
raise (Error(loc,
|
|
Parameters_differ(cpath, ty, Ctype.newconstr path args)))
|
|
end
|
|
(* Attempt to expand a type abbreviation if:
|
|
1- [to_check path'] holds
|
|
(otherwise the expansion cannot involve [path]);
|
|
2- we haven't expanded this type constructor before
|
|
(otherwise we could loop if [path'] is itself
|
|
a non-regular abbreviation). *)
|
|
else if to_check path' && not (List.mem path' prev_exp) then begin
|
|
try
|
|
(* Attempt expansion *)
|
|
let (params0, body0, _) = Env.find_type_expansion path' env in
|
|
let (params, body) =
|
|
Ctype.instance_parameterized_type params0 body0 in
|
|
begin
|
|
try List.iter2 (Ctype.unify env) params args'
|
|
with Ctype.Unify _ ->
|
|
raise (Error(loc, Constraint_failed
|
|
(ty, Ctype.newconstr path' params0)));
|
|
end;
|
|
check_regular path' args (path' :: prev_exp) body
|
|
with Not_found -> ()
|
|
end;
|
|
List.iter (check_regular cpath args prev_exp) args'
|
|
| Tpoly (ty, tl) ->
|
|
let (_, ty) = Ctype.instance_poly ~keep_names:true false tl ty in
|
|
check_regular cpath args prev_exp ty
|
|
| _ ->
|
|
Btype.iter_type_expr (check_regular cpath args prev_exp) ty
|
|
end in
|
|
|
|
Misc.may
|
|
(fun body ->
|
|
let (args, body) =
|
|
Ctype.instance_parameterized_type
|
|
~keep_names:true decl.type_params body in
|
|
check_regular path args [] body)
|
|
decl.type_manifest
|
|
|
|
let check_abbrev_recursion env id_loc_list to_check tdecl =
|
|
let decl = tdecl.typ_type in
|
|
let id = tdecl.typ_id in
|
|
check_recursion env (List.assoc id id_loc_list) (Path.Pident id) decl to_check
|
|
|
|
(* Compute variance *)
|
|
|
|
let get_variance ty visited =
|
|
try TypeMap.find ty !visited with Not_found -> Variance.null
|
|
|
|
let compute_variance env visited vari ty =
|
|
let rec compute_variance_rec vari ty =
|
|
(* Format.eprintf "%a: %x@." Printtyp.type_expr ty (Obj.magic vari); *)
|
|
let ty = Ctype.repr ty in
|
|
let vari' = get_variance ty visited in
|
|
if Variance.subset vari vari' then () else
|
|
let vari = Variance.union vari vari' in
|
|
visited := TypeMap.add ty vari !visited;
|
|
let compute_same = compute_variance_rec vari in
|
|
match ty.desc with
|
|
Tarrow (_, ty1, ty2, _) ->
|
|
let open Variance in
|
|
let v = conjugate vari in
|
|
let v1 =
|
|
if mem May_pos v || mem May_neg v
|
|
then set May_weak true v else v
|
|
in
|
|
compute_variance_rec v1 ty1;
|
|
compute_same ty2
|
|
| Ttuple tl ->
|
|
List.iter compute_same tl
|
|
| Tconstr (path, tl, _) ->
|
|
let open Variance in
|
|
if tl = [] then () else begin
|
|
try
|
|
let decl = Env.find_type path env in
|
|
let cvari f = mem f vari in
|
|
List.iter2
|
|
(fun ty v ->
|
|
let cv f = mem f v in
|
|
let strict =
|
|
cvari Inv && cv Inj || (cvari Pos || cvari Neg) && cv Inv
|
|
in
|
|
if strict then compute_variance_rec full ty else
|
|
let p1 = inter v vari
|
|
and n1 = inter v (conjugate vari) in
|
|
let v1 =
|
|
union (inter covariant (union p1 (conjugate p1)))
|
|
(inter (conjugate covariant) (union n1 (conjugate n1)))
|
|
and weak =
|
|
cvari May_weak && (cv May_pos || cv May_neg) ||
|
|
(cvari May_pos || cvari May_neg) && cv May_weak
|
|
in
|
|
let v2 = set May_weak weak v1 in
|
|
compute_variance_rec v2 ty)
|
|
tl decl.type_variance
|
|
with Not_found ->
|
|
List.iter (compute_variance_rec may_inv) tl
|
|
end
|
|
| Tobject (ty, _) ->
|
|
compute_same ty
|
|
| Tfield (_, _, ty1, ty2) ->
|
|
compute_same ty1;
|
|
compute_same ty2
|
|
| Tsubst ty ->
|
|
compute_same ty
|
|
| Tvariant row ->
|
|
let row = Btype.row_repr row in
|
|
List.iter
|
|
(fun (_,f) ->
|
|
match Btype.row_field_repr f with
|
|
Rpresent (Some ty) ->
|
|
compute_same ty
|
|
| Reither (_, tyl, _, _) ->
|
|
let open Variance in
|
|
let upper =
|
|
List.fold_left (fun s f -> set f true s)
|
|
null [May_pos; May_neg; May_weak]
|
|
in
|
|
let v = inter vari upper in
|
|
List.iter (compute_variance_rec v) tyl
|
|
| _ -> ())
|
|
row.row_fields;
|
|
compute_same row.row_more
|
|
| Tpoly (ty, _) ->
|
|
compute_same ty
|
|
| Tvar _ | Tnil | Tlink _ | Tunivar _ -> ()
|
|
| Tpackage (_, _, tyl) ->
|
|
let v =
|
|
Variance.(if mem Pos vari || mem Neg vari then full else may_inv)
|
|
in
|
|
List.iter (compute_variance_rec v) tyl
|
|
in
|
|
compute_variance_rec vari ty
|
|
|
|
let make p n i =
|
|
let open Variance in
|
|
set May_pos p (set May_neg n (set May_weak n (set Inj i null)))
|
|
|
|
let compute_variance_type env check (required, loc) decl tyl =
|
|
(* Requirements *)
|
|
let required =
|
|
List.map (fun (c,n,i) -> if c || n then (c,n,i) else (true,true,i))
|
|
required
|
|
in
|
|
(* Prepare *)
|
|
let params = List.map Btype.repr decl.type_params in
|
|
let tvl = ref TypeMap.empty in
|
|
(* Compute occurences in body *)
|
|
let open Variance in
|
|
List.iter
|
|
(fun (cn,ty) ->
|
|
compute_variance env tvl (if cn then full else covariant) ty)
|
|
tyl;
|
|
if check then begin
|
|
(* Check variance of parameters *)
|
|
let pos = ref 0 in
|
|
List.iter2
|
|
(fun ty (c, n, i) ->
|
|
incr pos;
|
|
let var = get_variance ty tvl in
|
|
let (co,cn) = get_upper var and ij = mem Inj var in
|
|
if Btype.is_Tvar ty && (co && not c || cn && not n || not ij && i)
|
|
then raise (Error(loc, Bad_variance (!pos, (co,cn,ij), (c,n,i)))))
|
|
params required;
|
|
(* Check propagation from constrained parameters *)
|
|
let args = Btype.newgenty (Ttuple params) in
|
|
let fvl = Ctype.free_variables args in
|
|
let fvl = List.filter (fun v -> not (List.memq v params)) fvl in
|
|
(* If there are no extra variables there is nothing to do *)
|
|
if fvl = [] then () else
|
|
let tvl2 = ref TypeMap.empty in
|
|
List.iter2
|
|
(fun ty (p,n,i) ->
|
|
if Btype.is_Tvar ty then () else
|
|
let v =
|
|
if p then if n then full else covariant else conjugate covariant in
|
|
compute_variance env tvl2 v ty)
|
|
params required;
|
|
let visited = ref TypeSet.empty in
|
|
let rec check ty =
|
|
let ty = Ctype.repr ty in
|
|
if TypeSet.mem ty !visited then () else
|
|
let visited' = TypeSet.add ty !visited in
|
|
visited := visited';
|
|
let v1 = get_variance ty tvl in
|
|
let snap = Btype.snapshot () in
|
|
let v2 =
|
|
TypeMap.fold
|
|
(fun t vt v ->
|
|
if Ctype.equal env false [ty] [t] then union vt v else v)
|
|
!tvl2 null in
|
|
Btype.backtrack snap;
|
|
let (c1,n1) = get_upper v1 and (c2,n2,_,i2) = get_lower v2 in
|
|
if c1 && not c2 || n1 && not n2 then
|
|
if List.memq ty fvl then
|
|
let code = if not i2 then -2 else if c2 || n2 then -1 else -3 in
|
|
raise (Error (loc, Bad_variance (code, (c1,n1,false), (c2,n2,false))))
|
|
else
|
|
Btype.iter_type_expr check ty
|
|
in
|
|
List.iter (fun (_,ty) -> check ty) tyl;
|
|
end;
|
|
List.map2
|
|
(fun ty (p, n, i) ->
|
|
let v = get_variance ty tvl in
|
|
let tr = decl.type_private in
|
|
(* Use required variance where relevant *)
|
|
let concr = decl.type_kind <> Type_abstract (*|| tr = Type_new*) in
|
|
let (p, n) =
|
|
if tr = Private || not (Btype.is_Tvar ty) then (p, n) (* set *)
|
|
else (false, false) (* only check *)
|
|
and i = concr || i && tr = Private in
|
|
let v = union v (make p n i) in
|
|
let v =
|
|
if not concr then v else
|
|
if mem Pos v && mem Neg v then full else
|
|
if Btype.is_Tvar ty then v else
|
|
union v
|
|
(if p then if n then full else covariant else conjugate covariant)
|
|
in
|
|
if decl.type_kind = Type_abstract && tr = Public then v else
|
|
set May_weak (mem May_neg v) v)
|
|
params required
|
|
|
|
let add_false = List.map (fun ty -> false, ty)
|
|
|
|
(* A parameter is constrained if either is is instantiated,
|
|
or it is a variable appearing in another parameter *)
|
|
let constrained vars ty =
|
|
match ty.desc with
|
|
| Tvar _ -> List.exists (fun tl -> List.memq ty tl) vars
|
|
| _ -> true
|
|
|
|
let for_constr = function
|
|
| Types.Cstr_tuple l -> add_false l
|
|
| Types.Cstr_record l ->
|
|
List.map
|
|
(fun {Types.ld_mutable; ld_type} -> (ld_mutable = Mutable, ld_type))
|
|
l
|
|
|
|
let compute_variance_gadt env check (required, loc as rloc) decl
|
|
(tl, ret_type_opt) =
|
|
match ret_type_opt with
|
|
| None ->
|
|
compute_variance_type env check rloc {decl with type_private = Private}
|
|
(for_constr tl)
|
|
| Some ret_type ->
|
|
match Ctype.repr ret_type with
|
|
| {desc=Tconstr (_, tyl, _)} ->
|
|
(* let tyl = List.map (Ctype.expand_head env) tyl in *)
|
|
let tyl = List.map Ctype.repr tyl in
|
|
let fvl = List.map (Ctype.free_variables ?env:None) tyl in
|
|
let _ =
|
|
List.fold_left2
|
|
(fun (fv1,fv2) ty (c,n,i) ->
|
|
match fv2 with [] -> assert false
|
|
| fv :: fv2 ->
|
|
(* fv1 @ fv2 = free_variables of other parameters *)
|
|
if (c||n) && constrained (fv1 @ fv2) ty then
|
|
raise (Error(loc, Varying_anonymous));
|
|
(fv :: fv1, fv2))
|
|
([], fvl) tyl required
|
|
in
|
|
compute_variance_type env check rloc
|
|
{decl with type_params = tyl; type_private = Private}
|
|
(for_constr tl)
|
|
| _ -> assert false
|
|
|
|
let compute_variance_extension env check decl ext rloc =
|
|
compute_variance_gadt env check rloc
|
|
{decl with type_params = ext.ext_type_params}
|
|
(ext.ext_args, ext.ext_ret_type)
|
|
|
|
let compute_variance_decl env check decl (required, _ as rloc) =
|
|
if (decl.type_kind = Type_abstract || decl.type_kind = Type_open)
|
|
&& decl.type_manifest = None then
|
|
List.map
|
|
(fun (c, n, i) ->
|
|
make (not n) (not c) (decl.type_kind <> Type_abstract || i))
|
|
required
|
|
else
|
|
let mn =
|
|
match decl.type_manifest with
|
|
None -> []
|
|
| Some ty -> [false, ty]
|
|
in
|
|
match decl.type_kind with
|
|
Type_abstract | Type_open ->
|
|
compute_variance_type env check rloc decl mn
|
|
| Type_variant tll ->
|
|
if List.for_all (fun c -> c.Types.cd_res = None) tll then
|
|
compute_variance_type env check rloc decl
|
|
(mn @ List.flatten (List.map (fun c -> for_constr c.Types.cd_args)
|
|
tll))
|
|
else begin
|
|
let mn =
|
|
List.map (fun (_,ty) -> (Types.Cstr_tuple [ty],None)) mn in
|
|
let tll =
|
|
mn @ List.map (fun c -> c.Types.cd_args, c.Types.cd_res) tll in
|
|
match List.map (compute_variance_gadt env check rloc decl) tll with
|
|
| vari :: rem ->
|
|
let varl = List.fold_left (List.map2 Variance.union) vari rem in
|
|
List.map
|
|
Variance.(fun v -> if mem Pos v && mem Neg v then full else v)
|
|
varl
|
|
| _ -> assert false
|
|
end
|
|
| Type_record (ftl, _) ->
|
|
compute_variance_type env check rloc decl
|
|
(mn @ List.map (fun {Types.ld_mutable; ld_type} ->
|
|
(ld_mutable = Mutable, ld_type)) ftl)
|
|
|
|
let is_sharp id =
|
|
let s = Ident.name id in
|
|
String.length s > 0 && s.[0] = '#'
|
|
|
|
let rec compute_variance_fixpoint env decls required variances =
|
|
let new_decls =
|
|
List.map2
|
|
(fun (id, decl) variance -> id, {decl with type_variance = variance})
|
|
decls variances
|
|
in
|
|
let new_env =
|
|
List.fold_right
|
|
(fun (id, decl) env -> Env.add_type ~check:true id decl env)
|
|
new_decls env
|
|
in
|
|
let new_variances =
|
|
List.map2
|
|
(fun (id, decl) -> compute_variance_decl new_env false decl)
|
|
new_decls required
|
|
in
|
|
let new_variances =
|
|
List.map2 (List.map2 Variance.union) new_variances variances in
|
|
if new_variances <> variances then
|
|
compute_variance_fixpoint env decls required new_variances
|
|
else begin
|
|
(* List.iter (fun (id, decl) ->
|
|
Printf.eprintf "%s:" (Ident.name id);
|
|
List.iter (fun (v : Variance.t) ->
|
|
Printf.eprintf " %x" (Obj.magic v : int))
|
|
decl.type_variance;
|
|
prerr_endline "")
|
|
new_decls; *)
|
|
List.iter2
|
|
(fun (id, decl) req -> if not (is_sharp id) then
|
|
ignore (compute_variance_decl new_env true decl req))
|
|
new_decls required;
|
|
new_decls, new_env
|
|
end
|
|
|
|
let init_variance (id, decl) =
|
|
List.map (fun _ -> Variance.null) decl.type_params
|
|
|
|
let add_injectivity =
|
|
List.map
|
|
(function
|
|
| Covariant -> (true, false, false)
|
|
| Contravariant -> (false, true, false)
|
|
| Invariant -> (false, false, false)
|
|
)
|
|
|
|
(* for typeclass.ml *)
|
|
let compute_variance_decls env cldecls =
|
|
let decls, required =
|
|
List.fold_right
|
|
(fun (obj_id, obj_abbr, cl_abbr, clty, cltydef, ci) (decls, req) ->
|
|
let variance = List.map snd ci.ci_params in
|
|
(obj_id, obj_abbr) :: decls,
|
|
(add_injectivity variance, ci.ci_loc) :: req)
|
|
cldecls ([],[])
|
|
in
|
|
let variances = List.map init_variance decls in
|
|
let (decls, _) = compute_variance_fixpoint env decls required variances in
|
|
List.map2
|
|
(fun (_,decl) (_, _, cl_abbr, clty, cltydef, _) ->
|
|
let variance = decl.type_variance in
|
|
(decl, {cl_abbr with type_variance = variance},
|
|
{clty with cty_variance = variance},
|
|
{cltydef with clty_variance = variance}))
|
|
decls cldecls
|
|
|
|
(* Check multiple declarations of labels/constructors *)
|
|
|
|
let check_duplicates sdecl_list =
|
|
let labels = Hashtbl.create 7 and constrs = Hashtbl.create 7 in
|
|
List.iter
|
|
(fun sdecl -> match sdecl.ptype_kind with
|
|
Ptype_variant cl ->
|
|
List.iter
|
|
(fun pcd ->
|
|
try
|
|
let name' = Hashtbl.find constrs pcd.pcd_name.txt in
|
|
Location.prerr_warning pcd.pcd_loc
|
|
(Warnings.Duplicate_definitions
|
|
("constructor", pcd.pcd_name.txt, name',
|
|
sdecl.ptype_name.txt))
|
|
with Not_found ->
|
|
Hashtbl.add constrs pcd.pcd_name.txt sdecl.ptype_name.txt)
|
|
cl
|
|
| Ptype_record fl ->
|
|
List.iter
|
|
(fun {pld_name=cname;pld_loc=loc} ->
|
|
try
|
|
let name' = Hashtbl.find labels cname.txt in
|
|
Location.prerr_warning loc
|
|
(Warnings.Duplicate_definitions
|
|
("label", cname.txt, name', sdecl.ptype_name.txt))
|
|
with Not_found -> Hashtbl.add labels cname.txt sdecl.ptype_name.txt)
|
|
fl
|
|
| Ptype_abstract -> ()
|
|
| Ptype_open -> ())
|
|
sdecl_list
|
|
|
|
(* Force recursion to go through id for private types*)
|
|
let name_recursion sdecl id decl =
|
|
match decl with
|
|
| { type_kind = Type_abstract;
|
|
type_manifest = Some ty;
|
|
type_private = Private; } when is_fixed_type sdecl ->
|
|
let ty = Ctype.repr ty in
|
|
let ty' = Btype.newty2 ty.level ty.desc in
|
|
if Ctype.deep_occur ty ty' then
|
|
let td = Tconstr(Path.Pident id, decl.type_params, ref Mnil) in
|
|
Btype.link_type ty (Btype.newty2 ty.level td);
|
|
{decl with type_manifest = Some ty'}
|
|
else decl
|
|
| _ -> decl
|
|
|
|
(* Translate a set of mutually recursive type declarations *)
|
|
let transl_type_decl env sdecl_list =
|
|
(* Add dummy types for fixed rows *)
|
|
let fixed_types = List.filter is_fixed_type sdecl_list in
|
|
let sdecl_list =
|
|
List.map
|
|
(fun sdecl ->
|
|
let ptype_name =
|
|
mkloc (sdecl.ptype_name.txt ^"#row") sdecl.ptype_name.loc in
|
|
{sdecl with
|
|
ptype_name; ptype_kind = Ptype_abstract; ptype_manifest = None})
|
|
fixed_types
|
|
@ sdecl_list
|
|
in
|
|
|
|
(* Create identifiers. *)
|
|
let id_list =
|
|
List.map (fun sdecl -> Ident.create sdecl.ptype_name.txt) sdecl_list
|
|
in
|
|
(*
|
|
Since we've introduced fresh idents, make sure the definition
|
|
level is at least the binding time of these events. Otherwise,
|
|
passing one of the recursively-defined type constrs as argument
|
|
to an abbreviation may fail.
|
|
*)
|
|
Ctype.init_def(Ident.current_time());
|
|
Ctype.begin_def();
|
|
(* Enter types. *)
|
|
let temp_env = List.fold_left2 enter_type env sdecl_list id_list in
|
|
(* Translate each declaration. *)
|
|
let current_slot = ref None in
|
|
let warn_unused = Warnings.is_active (Warnings.Unused_type_declaration "") in
|
|
let id_slots id =
|
|
if not warn_unused then id, None
|
|
else
|
|
(* See typecore.ml for a description of the algorithm used
|
|
to detect unused declarations in a set of recursive definitions. *)
|
|
let slot = ref [] in
|
|
let td = Env.find_type (Path.Pident id) temp_env in
|
|
let name = Ident.name id in
|
|
Env.set_type_used_callback
|
|
name td
|
|
(fun old_callback ->
|
|
match !current_slot with
|
|
| Some slot -> slot := (name, td) :: !slot
|
|
| None ->
|
|
List.iter (fun (name, d) -> Env.mark_type_used env name d)
|
|
(get_ref slot);
|
|
old_callback ()
|
|
);
|
|
id, Some slot
|
|
in
|
|
let transl_declaration name_sdecl (id, slot) =
|
|
current_slot := slot; transl_declaration temp_env name_sdecl id in
|
|
let tdecls =
|
|
List.map2 transl_declaration sdecl_list (List.map id_slots id_list) in
|
|
let decls =
|
|
List.map (fun tdecl -> (tdecl.typ_id, tdecl.typ_type)) tdecls in
|
|
current_slot := None;
|
|
(* Check for duplicates *)
|
|
check_duplicates sdecl_list;
|
|
(* Build the final env. *)
|
|
let newenv =
|
|
List.fold_right
|
|
(fun (id, decl) env -> Env.add_type ~check:true id decl env)
|
|
decls env
|
|
in
|
|
(* Update stubs *)
|
|
List.iter2
|
|
(fun id sdecl -> update_type temp_env newenv id sdecl.ptype_loc)
|
|
id_list sdecl_list;
|
|
(* Generalize type declarations. *)
|
|
Ctype.end_def();
|
|
List.iter (fun (_, decl) -> generalize_decl decl) decls;
|
|
(* Check for ill-formed abbrevs *)
|
|
let id_loc_list =
|
|
List.map2 (fun id sdecl -> (id, sdecl.ptype_loc))
|
|
id_list sdecl_list
|
|
in
|
|
List.iter (fun (id, decl) ->
|
|
check_well_founded_manifest newenv (List.assoc id id_loc_list)
|
|
(Path.Pident id) decl)
|
|
decls;
|
|
let to_check =
|
|
function Path.Pident id -> List.mem_assoc id id_loc_list | _ -> false in
|
|
List.iter (fun (id, decl) ->
|
|
check_well_founded_decl newenv (List.assoc id id_loc_list) (Path.Pident id)
|
|
decl to_check)
|
|
decls;
|
|
List.iter (check_abbrev_recursion newenv id_loc_list to_check) tdecls;
|
|
(* Check that all type variable are closed *)
|
|
List.iter2
|
|
(fun sdecl tdecl ->
|
|
let decl = tdecl.typ_type in
|
|
match Ctype.closed_type_decl decl with
|
|
Some ty -> raise(Error(sdecl.ptype_loc, Unbound_type_var(ty,decl)))
|
|
| None -> ())
|
|
sdecl_list tdecls;
|
|
(* Check that constraints are enforced *)
|
|
List.iter2 (check_constraints newenv) sdecl_list decls;
|
|
(* Name recursion *)
|
|
let decls =
|
|
List.map2 (fun sdecl (id, decl) -> id, name_recursion sdecl id decl)
|
|
sdecl_list decls
|
|
in
|
|
(* Add variances to the environment *)
|
|
let required =
|
|
List.map
|
|
(fun sdecl ->
|
|
add_injectivity (List.map snd sdecl.ptype_params),
|
|
sdecl.ptype_loc
|
|
)
|
|
sdecl_list
|
|
in
|
|
let final_decls, final_env =
|
|
compute_variance_fixpoint env decls required (List.map init_variance decls)
|
|
in
|
|
(* Check re-exportation *)
|
|
List.iter2 (check_abbrev final_env) sdecl_list final_decls;
|
|
(* Keep original declaration *)
|
|
let final_decls =
|
|
List.map2
|
|
(fun tdecl (id2, decl) ->
|
|
{ tdecl with typ_type = decl }
|
|
) tdecls final_decls
|
|
in
|
|
(* Done *)
|
|
(final_decls, final_env)
|
|
|
|
(* Translating type extensions *)
|
|
|
|
let transl_extension_constructor env type_path type_params
|
|
typext_params priv sext =
|
|
let id = Ident.create sext.pext_name.txt in
|
|
let args, ret_type, kind =
|
|
match sext.pext_kind with
|
|
Pext_decl(sargs, sret_type) ->
|
|
let targs, tret_type, args, ret_type =
|
|
make_constructor sext.pext_loc env type_path typext_params
|
|
sargs sret_type
|
|
in
|
|
args, ret_type, Text_decl(targs, tret_type)
|
|
| Pext_rebind lid ->
|
|
let cdescr = Typetexp.find_constructor env sext.pext_loc lid.txt in
|
|
let usage =
|
|
if cdescr.cstr_private = Private || priv = Public
|
|
then Env.Positive else Env.Privatize
|
|
in
|
|
Env.mark_constructor usage env (Longident.last lid.txt) cdescr;
|
|
let (args, cstr_res) = Ctype.instance_constructor cdescr in
|
|
let res, ret_type =
|
|
if cdescr.cstr_generalized then
|
|
let params = Ctype.instance_list env type_params in
|
|
let res = Ctype.newconstr type_path params in
|
|
let ret_type = Some (Ctype.newconstr type_path params) in
|
|
res, ret_type
|
|
else (Ctype.newconstr type_path typext_params), None
|
|
in
|
|
begin
|
|
try
|
|
Ctype.unify env cstr_res res
|
|
with Ctype.Unify trace ->
|
|
raise (Error(lid.loc,
|
|
Rebind_wrong_type(lid.txt, env, trace)))
|
|
end;
|
|
(* Remove "_" names from parameters used in the constructor *)
|
|
if not cdescr.cstr_generalized then begin
|
|
let vars =
|
|
Ctype.free_variables (Btype.newgenty (Ttuple args))
|
|
in
|
|
List.iter
|
|
(function {desc = Tvar (Some "_")} as ty ->
|
|
if List.memq ty vars then ty.desc <- Tvar None
|
|
| _ -> ())
|
|
typext_params
|
|
end;
|
|
(* Ensure that constructor's type matches the type being extended *)
|
|
let cstr_type_path, cstr_type_params =
|
|
match cdescr.cstr_res.desc with
|
|
Tconstr (p, _, _) ->
|
|
let decl = Env.find_type p env in
|
|
p, decl.type_params
|
|
| _ -> assert false
|
|
in
|
|
let cstr_types =
|
|
(Btype.newgenty
|
|
(Tconstr(cstr_type_path, cstr_type_params, ref Mnil)))
|
|
:: cstr_type_params
|
|
in
|
|
let ext_types =
|
|
(Btype.newgenty
|
|
(Tconstr(type_path, type_params, ref Mnil)))
|
|
:: type_params
|
|
in
|
|
if not (Ctype.equal env true cstr_types ext_types) then
|
|
raise (Error(lid.loc,
|
|
Rebind_mismatch(lid.txt, cstr_type_path, type_path)));
|
|
(* Disallow rebinding private constructors to non-private *)
|
|
begin
|
|
match cdescr.cstr_private, priv with
|
|
Private, Public ->
|
|
raise (Error(lid.loc, Rebind_private lid.txt))
|
|
| _ -> ()
|
|
end;
|
|
let path =
|
|
match cdescr.cstr_tag with
|
|
Cstr_extension(path, _) -> path
|
|
| _ -> assert false
|
|
in
|
|
let args =
|
|
match cdescr.cstr_inlined with
|
|
| None ->
|
|
Types.Cstr_tuple args
|
|
| Some decl ->
|
|
let tl =
|
|
match args with
|
|
| [ {desc=Tconstr(_, tl, _)} ] -> tl
|
|
| _ -> assert false
|
|
in
|
|
let decl = Ctype.instance_declaration decl in
|
|
assert (List.length decl.type_params = List.length tl);
|
|
List.iter2 (Ctype.unify env) decl.type_params tl;
|
|
let lbls =
|
|
match decl.type_kind with
|
|
| Type_record (lbls, Record_extension) -> lbls
|
|
| _ -> assert false
|
|
in
|
|
Types.Cstr_record lbls
|
|
in
|
|
args, ret_type, Text_rebind(path, lid)
|
|
in
|
|
let ext =
|
|
{ ext_type_path = type_path;
|
|
ext_type_params = typext_params;
|
|
ext_args = args;
|
|
ext_ret_type = ret_type;
|
|
ext_private = priv;
|
|
Types.ext_loc = sext.pext_loc;
|
|
Types.ext_attributes = sext.pext_attributes; }
|
|
in
|
|
{ ext_id = id;
|
|
ext_name = sext.pext_name;
|
|
ext_type = ext;
|
|
ext_kind = kind;
|
|
Typedtree.ext_loc = sext.pext_loc;
|
|
Typedtree.ext_attributes = sext.pext_attributes; }
|
|
|
|
let transl_type_extension check_open env loc styext =
|
|
reset_type_variables();
|
|
Ctype.begin_def();
|
|
let (type_path, type_decl) =
|
|
Typetexp.find_type env loc styext.ptyext_path.txt
|
|
in
|
|
begin
|
|
match type_decl.type_kind with
|
|
Type_open -> ()
|
|
| Type_abstract ->
|
|
if check_open then begin
|
|
try
|
|
let {pext_loc} =
|
|
List.find (function {pext_kind = Pext_decl _} -> true
|
|
| {pext_kind = Pext_rebind _} -> false)
|
|
styext.ptyext_constructors
|
|
in
|
|
raise (Error(pext_loc, Not_open_type type_path))
|
|
with Not_found -> ()
|
|
end
|
|
| _ -> raise (Error(loc, Not_extensible_type type_path))
|
|
end;
|
|
let type_variance =
|
|
List.map (fun v ->
|
|
let (co, cn) = Variance.get_upper v in
|
|
(not cn, not co, false))
|
|
type_decl.type_variance
|
|
in
|
|
let err =
|
|
if type_decl.type_arity <> List.length styext.ptyext_params then
|
|
[Includecore.Arity]
|
|
else
|
|
if List.for_all2
|
|
(fun (c1, n1, _) (c2, n2, _) -> (not c2 || c1) && (not n2 || n1))
|
|
type_variance
|
|
(add_injectivity (List.map snd styext.ptyext_params))
|
|
then [] else [Includecore.Variance]
|
|
in
|
|
if err <> [] then
|
|
raise (Error(loc, Extension_mismatch (type_path, err)));
|
|
let ttype_params = make_params env styext.ptyext_params in
|
|
let type_params = List.map (fun (cty, _) -> cty.ctyp_type) ttype_params in
|
|
List.iter2 (Ctype.unify_var env)
|
|
(Ctype.instance_list env type_decl.type_params)
|
|
type_params;
|
|
let constructors =
|
|
List.map (transl_extension_constructor env type_path
|
|
type_decl.type_params type_params styext.ptyext_private)
|
|
styext.ptyext_constructors
|
|
in
|
|
Ctype.end_def();
|
|
(* Generalize types *)
|
|
List.iter Ctype.generalize type_params;
|
|
List.iter
|
|
(fun ext ->
|
|
Btype.iter_type_expr_cstr_args Ctype.generalize ext.ext_type.ext_args;
|
|
may Ctype.generalize ext.ext_type.ext_ret_type)
|
|
constructors;
|
|
(* Check that all type variable are closed *)
|
|
List.iter
|
|
(fun ext ->
|
|
match Ctype.closed_extension_constructor ext.ext_type with
|
|
Some ty ->
|
|
raise(Error(ext.ext_loc, Unbound_type_var_ext(ty, ext.ext_type)))
|
|
| None -> ())
|
|
constructors;
|
|
(* Check variances are correct *)
|
|
List.iter
|
|
(fun ext->
|
|
ignore (compute_variance_extension env true type_decl
|
|
ext.ext_type (type_variance, loc)))
|
|
constructors;
|
|
(* Add extension constructors to the environment *)
|
|
let newenv =
|
|
List.fold_left
|
|
(fun env ext ->
|
|
Env.add_extension ~check:true ext.ext_id ext.ext_type env)
|
|
env constructors
|
|
in
|
|
let tyext =
|
|
{ tyext_path = type_path;
|
|
tyext_txt = styext.ptyext_path;
|
|
tyext_params = ttype_params;
|
|
tyext_constructors = constructors;
|
|
tyext_private = styext.ptyext_private;
|
|
tyext_attributes = styext.ptyext_attributes; }
|
|
in
|
|
(tyext, newenv)
|
|
|
|
let transl_exception env sext =
|
|
reset_type_variables();
|
|
Ctype.begin_def();
|
|
let ext =
|
|
transl_extension_constructor env
|
|
Predef.path_exn [] [] Asttypes.Public sext
|
|
in
|
|
Ctype.end_def();
|
|
(* Generalize types *)
|
|
Btype.iter_type_expr_cstr_args Ctype.generalize ext.ext_type.ext_args;
|
|
may Ctype.generalize ext.ext_type.ext_ret_type;
|
|
(* Check that all type variable are closed *)
|
|
begin match Ctype.closed_extension_constructor ext.ext_type with
|
|
Some ty ->
|
|
raise (Error(ext.ext_loc, Unbound_type_var_ext(ty, ext.ext_type)))
|
|
| None -> ()
|
|
end;
|
|
let newenv = Env.add_extension ~check:true ext.ext_id ext.ext_type env in
|
|
ext, newenv
|
|
|
|
(* Translate a value declaration *)
|
|
let transl_value_decl env loc valdecl =
|
|
let cty = Typetexp.transl_type_scheme env valdecl.pval_type in
|
|
let ty = cty.ctyp_type in
|
|
let v =
|
|
match valdecl.pval_prim with
|
|
[] ->
|
|
{ val_type = ty; val_kind = Val_reg; Types.val_loc = loc;
|
|
val_attributes = valdecl.pval_attributes }
|
|
| decl ->
|
|
let arity = Ctype.arity ty in
|
|
let prim = Primitive.parse_declaration arity decl in
|
|
if arity = 0 && prim.prim_name.[0] <> '%' then
|
|
raise(Error(valdecl.pval_type.ptyp_loc, Null_arity_external));
|
|
if !Clflags.native_code
|
|
&& prim.prim_arity > 5
|
|
&& prim.prim_native_name = ""
|
|
then raise(Error(valdecl.pval_type.ptyp_loc, Missing_native_external));
|
|
{ val_type = ty; val_kind = Val_prim prim; Types.val_loc = loc;
|
|
val_attributes = valdecl.pval_attributes }
|
|
in
|
|
let (id, newenv) =
|
|
Env.enter_value valdecl.pval_name.txt v env
|
|
~check:(fun s -> Warnings.Unused_value_declaration s)
|
|
in
|
|
let desc =
|
|
{
|
|
val_id = id;
|
|
val_name = valdecl.pval_name;
|
|
val_desc = cty; val_val = v;
|
|
val_prim = valdecl.pval_prim;
|
|
val_loc = valdecl.pval_loc;
|
|
val_attributes = valdecl.pval_attributes;
|
|
}
|
|
in
|
|
desc, newenv
|
|
|
|
(* Translate a "with" constraint -- much simplified version of
|
|
transl_type_decl. *)
|
|
let transl_with_constraint env id row_path orig_decl sdecl =
|
|
Env.mark_type_used env (Ident.name id) orig_decl;
|
|
reset_type_variables();
|
|
Ctype.begin_def();
|
|
let tparams = make_params env sdecl.ptype_params in
|
|
let params = List.map (fun (cty, _) -> cty.ctyp_type) tparams in
|
|
let orig_decl = Ctype.instance_declaration orig_decl in
|
|
let arity_ok = List.length params = orig_decl.type_arity in
|
|
if arity_ok then
|
|
List.iter2 (Ctype.unify_var env) params orig_decl.type_params;
|
|
let constraints = List.map
|
|
(function (ty, ty', loc) ->
|
|
try
|
|
let cty = transl_simple_type env false ty in
|
|
let cty' = transl_simple_type env false ty' in
|
|
let ty = cty.ctyp_type in
|
|
let ty' = cty'.ctyp_type in
|
|
Ctype.unify env ty ty';
|
|
(cty, cty', loc)
|
|
with Ctype.Unify tr ->
|
|
raise(Error(loc, Inconsistent_constraint (env, tr))))
|
|
sdecl.ptype_cstrs
|
|
in
|
|
let no_row = not (is_fixed_type sdecl) in
|
|
let (tman, man) = match sdecl.ptype_manifest with
|
|
None -> None, None
|
|
| Some sty ->
|
|
let cty = transl_simple_type env no_row sty in
|
|
Some cty, Some cty.ctyp_type
|
|
in
|
|
let priv =
|
|
if sdecl.ptype_private = Private then Private else
|
|
if arity_ok && orig_decl.type_kind <> Type_abstract
|
|
then orig_decl.type_private else sdecl.ptype_private
|
|
in
|
|
if arity_ok && orig_decl.type_kind <> Type_abstract
|
|
&& sdecl.ptype_private = Private then
|
|
Location.prerr_warning sdecl.ptype_loc
|
|
(Warnings.Deprecated "spurious use of private");
|
|
let decl =
|
|
{ type_params = params;
|
|
type_arity = List.length params;
|
|
type_kind =
|
|
if arity_ok && man <> None then orig_decl.type_kind else Type_abstract;
|
|
type_private = priv;
|
|
type_manifest = man;
|
|
type_variance = [];
|
|
type_newtype_level = None;
|
|
type_loc = sdecl.ptype_loc;
|
|
type_attributes = sdecl.ptype_attributes;
|
|
}
|
|
in
|
|
begin match row_path with None -> ()
|
|
| Some p -> set_fixed_row env sdecl.ptype_loc p decl
|
|
end;
|
|
begin match Ctype.closed_type_decl decl with None -> ()
|
|
| Some ty -> raise(Error(sdecl.ptype_loc, Unbound_type_var(ty,decl)))
|
|
end;
|
|
let decl = name_recursion sdecl id decl in
|
|
let decl =
|
|
{decl with type_variance =
|
|
compute_variance_decl env false decl
|
|
(add_injectivity (List.map snd sdecl.ptype_params), sdecl.ptype_loc)} in
|
|
Ctype.end_def();
|
|
generalize_decl decl;
|
|
{
|
|
typ_id = id;
|
|
typ_name = sdecl.ptype_name;
|
|
typ_params = tparams;
|
|
typ_type = decl;
|
|
typ_cstrs = constraints;
|
|
typ_loc = sdecl.ptype_loc;
|
|
typ_manifest = tman;
|
|
typ_kind = Ttype_abstract;
|
|
typ_private = sdecl.ptype_private;
|
|
typ_attributes = sdecl.ptype_attributes;
|
|
}
|
|
|
|
(* Approximate a type declaration: just make all types abstract *)
|
|
|
|
let abstract_type_decl arity =
|
|
let rec make_params n =
|
|
if n <= 0 then [] else Ctype.newvar() :: make_params (n-1) in
|
|
Ctype.begin_def();
|
|
let decl =
|
|
{ type_params = make_params arity;
|
|
type_arity = arity;
|
|
type_kind = Type_abstract;
|
|
type_private = Public;
|
|
type_manifest = None;
|
|
type_variance = replicate_list Variance.full arity;
|
|
type_newtype_level = None;
|
|
type_loc = Location.none;
|
|
type_attributes = [];
|
|
} in
|
|
Ctype.end_def();
|
|
generalize_decl decl;
|
|
decl
|
|
|
|
let approx_type_decl env sdecl_list =
|
|
List.map
|
|
(fun sdecl ->
|
|
(Ident.create sdecl.ptype_name.txt,
|
|
abstract_type_decl (List.length sdecl.ptype_params)))
|
|
sdecl_list
|
|
|
|
(* Variant of check_abbrev_recursion to check the well-formedness
|
|
conditions on type abbreviations defined within recursive modules. *)
|
|
|
|
let check_recmod_typedecl env loc recmod_ids path decl =
|
|
(* recmod_ids is the list of recursively-defined module idents.
|
|
(path, decl) is the type declaration to be checked. *)
|
|
let to_check path =
|
|
List.exists (fun id -> Path.isfree id path) recmod_ids in
|
|
check_well_founded_decl env loc path decl to_check;
|
|
check_recursion env loc path decl to_check
|
|
|
|
|
|
(**** Error report ****)
|
|
|
|
open Format
|
|
|
|
let explain_unbound_gen ppf tv tl typ kwd pr =
|
|
try
|
|
let ti = List.find (fun ti -> Ctype.deep_occur tv (typ ti)) tl in
|
|
let ty0 = (* Hack to force aliasing when needed *)
|
|
Btype.newgenty (Tobject(tv, ref None)) in
|
|
Printtyp.reset_and_mark_loops_list [typ ti; ty0];
|
|
fprintf ppf
|
|
".@.@[<hov2>In %s@ %a@;<1 -2>the variable %a is unbound@]"
|
|
kwd pr ti Printtyp.type_expr tv
|
|
with Not_found -> ()
|
|
|
|
let explain_unbound ppf tv tl typ kwd lab =
|
|
explain_unbound_gen ppf tv tl typ kwd
|
|
(fun ppf ti -> fprintf ppf "%s%a" (lab ti) Printtyp.type_expr (typ ti))
|
|
|
|
let explain_unbound_single ppf tv ty =
|
|
let trivial ty =
|
|
explain_unbound ppf tv [ty] (fun t -> t) "type" (fun _ -> "") in
|
|
match (Ctype.repr ty).desc with
|
|
Tobject(fi,_) ->
|
|
let (tl, rv) = Ctype.flatten_fields fi in
|
|
if rv == tv then trivial ty else
|
|
explain_unbound ppf tv tl (fun (_,_,t) -> t)
|
|
"method" (fun (lab,_,_) -> lab ^ ": ")
|
|
| Tvariant row ->
|
|
let row = Btype.row_repr row in
|
|
if row.row_more == tv then trivial ty else
|
|
explain_unbound ppf tv row.row_fields
|
|
(fun (l,f) -> match Btype.row_field_repr f with
|
|
Rpresent (Some t) -> t
|
|
| Reither (_,[t],_,_) -> t
|
|
| Reither (_,tl,_,_) -> Btype.newgenty (Ttuple tl)
|
|
| _ -> Btype.newgenty (Ttuple[]))
|
|
"case" (fun (lab,_) -> "`" ^ lab ^ " of ")
|
|
| _ -> trivial ty
|
|
|
|
|
|
let tys_of_constr_args = function
|
|
| Types.Cstr_tuple tl -> tl
|
|
| Types.Cstr_record lbls -> List.map (fun l -> l.Types.ld_type) lbls
|
|
|
|
let report_error ppf = function
|
|
| Repeated_parameter ->
|
|
fprintf ppf "A type parameter occurs several times"
|
|
| Duplicate_constructor s ->
|
|
fprintf ppf "Two constructors are named %s" s
|
|
| Too_many_constructors ->
|
|
fprintf ppf
|
|
"@[Too many non-constant constructors@ -- maximum is %i %s@]"
|
|
(Config.max_tag + 1) "non-constant constructors"
|
|
| Duplicate_label s ->
|
|
fprintf ppf "Two labels are named %s" s
|
|
| Recursive_abbrev s ->
|
|
fprintf ppf "The type abbreviation %s is cyclic" s
|
|
| Cycle_in_def (s, ty) ->
|
|
Printtyp.reset_and_mark_loops ty;
|
|
fprintf ppf "@[<v>The definition of %s contains a cycle:@ %a@]"
|
|
s Printtyp.type_expr ty
|
|
| Definition_mismatch (ty, errs) ->
|
|
Printtyp.reset_and_mark_loops ty;
|
|
fprintf ppf "@[<v>@[<hov>%s@ %s@;<1 2>%a@]%a@]"
|
|
"This variant or record definition" "does not match that of type"
|
|
Printtyp.type_expr ty
|
|
(Includecore.report_type_mismatch "the original" "this" "definition")
|
|
errs
|
|
| Constraint_failed (ty, ty') ->
|
|
Printtyp.reset_and_mark_loops ty;
|
|
Printtyp.mark_loops ty';
|
|
fprintf ppf "@[%s@ @[<hv>Type@ %a@ should be an instance of@ %a@]@]"
|
|
"Constraints are not satisfied in this type."
|
|
Printtyp.type_expr ty Printtyp.type_expr ty'
|
|
| Parameters_differ (path, ty, ty') ->
|
|
Printtyp.reset_and_mark_loops ty;
|
|
Printtyp.mark_loops ty';
|
|
fprintf ppf
|
|
"@[<hv>In the definition of %s, type@ %a@ should be@ %a@]"
|
|
(Path.name path) Printtyp.type_expr ty Printtyp.type_expr ty'
|
|
| Inconsistent_constraint (env, trace) ->
|
|
fprintf ppf "The type constraints are not consistent.@.";
|
|
Printtyp.report_unification_error ppf env trace
|
|
(fun ppf -> fprintf ppf "Type")
|
|
(fun ppf -> fprintf ppf "is not compatible with type")
|
|
| Type_clash (env, trace) ->
|
|
Printtyp.report_unification_error ppf env trace
|
|
(function ppf ->
|
|
fprintf ppf "This type constructor expands to type")
|
|
(function ppf ->
|
|
fprintf ppf "but is used here with type")
|
|
| Null_arity_external ->
|
|
fprintf ppf "External identifiers must be functions"
|
|
| Missing_native_external ->
|
|
fprintf ppf "@[<hv>An external function with more than 5 arguments \
|
|
requires a second stub function@ \
|
|
for native-code compilation@]"
|
|
| Unbound_type_var (ty, decl) ->
|
|
fprintf ppf "A type variable is unbound in this type declaration";
|
|
let ty = Ctype.repr ty in
|
|
begin match decl.type_kind, decl.type_manifest with
|
|
| Type_variant tl, _ ->
|
|
explain_unbound_gen ppf ty tl (fun c ->
|
|
let tl = tys_of_constr_args c.cd_args in
|
|
Btype.newgenty (Ttuple tl)
|
|
)
|
|
"case" (fun ppf c ->
|
|
fprintf ppf
|
|
"%s of %a" (Ident.name c.Types.cd_id)
|
|
Printtyp.constructor_arguments c.cd_args)
|
|
| Type_record (tl, _), _ ->
|
|
explain_unbound ppf ty tl (fun l -> l.Types.ld_type)
|
|
"field" (fun l -> Ident.name l.Types.ld_id ^ ": ")
|
|
| Type_abstract, Some ty' ->
|
|
explain_unbound_single ppf ty ty'
|
|
| _ -> ()
|
|
end
|
|
| Unbound_type_var_ext (ty, ext) ->
|
|
fprintf ppf "A type variable is unbound in this extension constructor";
|
|
let args = tys_of_constr_args ext.ext_args in
|
|
explain_unbound ppf ty args (fun c -> c) "type" (fun _ -> "")
|
|
| Not_open_type path ->
|
|
fprintf ppf "@[%s@ %a@]"
|
|
"Cannot extend type definition"
|
|
Printtyp.path path
|
|
| Not_extensible_type path ->
|
|
fprintf ppf "@[%s@ %a@ %s@]"
|
|
"Type"
|
|
Printtyp.path path
|
|
"is not extensible"
|
|
| Extension_mismatch (path, errs) ->
|
|
fprintf ppf "@[<v>@[<hov>%s@ %s@;<1 2>%s@]%a@]"
|
|
"This extension" "does not match the definition of type"
|
|
(Path.name path)
|
|
(Includecore.report_type_mismatch
|
|
"the type" "this extension" "definition")
|
|
errs
|
|
| Rebind_wrong_type (lid, env, trace) ->
|
|
Printtyp.report_unification_error ppf env trace
|
|
(function ppf ->
|
|
fprintf ppf "The constructor %a@ has type"
|
|
Printtyp.longident lid)
|
|
(function ppf ->
|
|
fprintf ppf "but was expected to be of type")
|
|
| Rebind_mismatch (lid, p, p') ->
|
|
fprintf ppf
|
|
"@[%s@ %a@ %s@ %s@ %s@ %s@ %s@]"
|
|
"The constructor" Printtyp.longident lid
|
|
"extends type" (Path.name p)
|
|
"whose declaration does not match"
|
|
"the declaration of type" (Path.name p')
|
|
| Rebind_private lid ->
|
|
fprintf ppf "@[%s@ %a@ %s@]"
|
|
"The constructor"
|
|
Printtyp.longident lid
|
|
"is private"
|
|
| Bad_variance (n, v1, v2) ->
|
|
let variance (p,n,i) =
|
|
let inj = if i then "injective " else "" in
|
|
match p, n with
|
|
true, true -> inj ^ "invariant"
|
|
| true, false -> inj ^ "covariant"
|
|
| false, true -> inj ^ "contravariant"
|
|
| false, false -> if inj = "" then "unrestricted" else inj
|
|
in
|
|
let suffix n =
|
|
let teen = (n mod 100)/10 = 1 in
|
|
match n mod 10 with
|
|
| 1 when not teen -> "st"
|
|
| 2 when not teen -> "nd"
|
|
| 3 when not teen -> "rd"
|
|
| _ -> "th"
|
|
in
|
|
if n = -1 then
|
|
fprintf ppf "@[%s@ %s@ It"
|
|
"In this definition, a type variable has a variance that"
|
|
"is not reflected by its occurrence in type parameters."
|
|
else if n = -2 then
|
|
fprintf ppf "@[%s@ %s@]"
|
|
"In this definition, a type variable cannot be deduced"
|
|
"from the type parameters."
|
|
else if n = -3 then
|
|
fprintf ppf "@[%s@ %s@ It"
|
|
"In this definition, a type variable has a variance that"
|
|
"cannot be deduced from the type parameters."
|
|
else
|
|
fprintf ppf "@[%s@ %s@ The %d%s type parameter"
|
|
"In this definition, expected parameter"
|
|
"variances are not satisfied."
|
|
n (suffix n);
|
|
if n <> -2 then
|
|
fprintf ppf " was expected to be %s,@ but it is %s.@]"
|
|
(variance v2) (variance v1)
|
|
| Unavailable_type_constructor p ->
|
|
fprintf ppf "The definition of type %a@ is unavailable" Printtyp.path p
|
|
| Bad_fixed_type r ->
|
|
fprintf ppf "This fixed type %s" r
|
|
| Varying_anonymous ->
|
|
fprintf ppf "@[%s@ %s@ %s@]"
|
|
"In this GADT definition," "the variance of some parameter"
|
|
"cannot be checked"
|
|
|
|
let () =
|
|
Location.register_error_of_exn
|
|
(function
|
|
| Error (loc, err) ->
|
|
Some (Location.error_of_printer loc report_error err)
|
|
| _ ->
|
|
None
|
|
)
|