typing.ml 30.1 KB
Newer Older
1 2
(**************************************************************************)
(*                                                                        *)
Jean-Christophe Filliâtre's avatar
headers  
Jean-Christophe Filliâtre committed
3 4 5 6 7
(*  Copyright (C) 2010-                                                   *)
(*    Francois Bobot                                                      *)
(*    Jean-Christophe Filliatre                                           *)
(*    Johannes Kanig                                                      *)
(*    Andrei Paskevich                                                    *)
8 9 10 11 12 13 14 15 16 17 18
(*                                                                        *)
(*  This software is free software; you can redistribute it and/or        *)
(*  modify it under the terms of the GNU Library General Public           *)
(*  License version 2.1, with the special exception on linking            *)
(*  described in file LICENSE.                                            *)
(*                                                                        *)
(*  This software 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.                  *)
(*                                                                        *)
(**************************************************************************)
19

20 21
open Util
open Format
22
open Pp
23
open Ident
24
open Ty
25
open Term
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
26
open Ptree
27
open Theory
28

29 30 31
(** errors *)

type error = 
32
  | Message of string
33
  | ClashType of string
34
  | DuplicateTypeVar of string
35
  | UnboundType of string
36
  | TypeArity of qualid * int * int
37
  | Clash of string
38 39
  | PredicateExpected
  | TermExpected
40
  | UnboundSymbol of string
41
  | BadNumberOfArguments of Ident.ident * int * int 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
42
  | ClashTheory of string
43
  | ClashNamespace of string
44
  | UnboundTheory of string
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
45
  | AlreadyTheory of string
46
  | UnboundNamespace of string
47 48 49 50
  | UnboundFile of string
  | UnboundDir of string
  | AmbiguousPath of string * string
  | NotInLoadpath of string
51 52
  | CyclicTypeDef
  | UnboundTypeVar of string
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
53
  | AnyMessage of string
54 55 56 57 58 59 60

exception Error of error

let error ?loc e = match loc with
  | None -> raise (Error e)
  | Some loc -> raise (Loc.Located (loc, Error e))

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
61 62 63 64 65 66 67 68 69 70 71
let errorm ?loc f =
  let buf = Buffer.create 512 in
  let fmt = Format.formatter_of_buffer buf in
  Format.kfprintf 
    (fun _ -> 
       Format.pp_print_flush fmt ();
       let s = Buffer.contents buf in
       Buffer.clear buf;
       error ?loc (AnyMessage s))
    fmt f

72
let rec print_qualid fmt = function
73
  | Qident s -> fprintf fmt "%s" s.id
74
  | Qdot (m, s) -> fprintf fmt "%a.%s" print_qualid m s.id
75

76
let report fmt = function
77 78
  | Message s ->
      fprintf fmt "%s" s
79 80
  | ClashType s ->
      fprintf fmt "clash with previous type %s" s
81
  | DuplicateTypeVar s ->
82
      fprintf fmt "duplicate type parameter %s" s
83
  | UnboundType s ->
84
       fprintf fmt "Unbound type '%s'" s
85
  | TypeArity (id, a, n) ->
86
      fprintf fmt "@[The type %a expects %d argument(s),@ " print_qualid id a;
87 88
      fprintf fmt "but is applied to %d argument(s)@]" n
  | Clash id ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
89
      fprintf fmt "Clash with previous symbol %s" id
90 91 92 93
  | PredicateExpected ->
      fprintf fmt "syntax error: predicate expected"
  | TermExpected ->
      fprintf fmt "syntax error: term expected"
94
  | UnboundSymbol s ->
95
       fprintf fmt "Unbound symbol '%s'" s
96
  | BadNumberOfArguments (s, n, m) ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
97
      fprintf fmt "@[Symbol `%s' is applied to %d terms,@ " s.id_short n;
98
      fprintf fmt "but is expecting %d arguments@]" m
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
99 100
  | ClashTheory s ->
      fprintf fmt "clash with previous theory %s" s
101 102
  | ClashNamespace s ->
      fprintf fmt "clash with previous namespace %s" s
103 104
  | UnboundTheory s ->
      fprintf fmt "unbound theory %s" s
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
105 106
  | AlreadyTheory s ->
      fprintf fmt "already using a theory with name %s" s
107 108
  | UnboundNamespace s ->
      fprintf fmt "unbound namespace %s" s
109 110 111 112 113 114 115 116
  | UnboundFile s ->
      fprintf fmt "no such file %s" s
  | UnboundDir s ->
      fprintf fmt "no such directory %s" s
  | AmbiguousPath (f1, f2) ->
      fprintf fmt "@[ambiguous path:@ both `%s'@ and `%s'@ match@]" f1 f2
  | NotInLoadpath f ->
      fprintf fmt "cannot find `%s' in loadpath" f
117 118 119 120
  | CyclicTypeDef ->
      fprintf fmt "cyclic type definition"
  | UnboundTypeVar s ->
      fprintf fmt "unbound type variable '%s" s
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
121 122
  | AnyMessage s ->
      fprintf fmt "%s" s
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
123

124 125
(** Environments *)

126
module S = Set.Make(String)
127 128 129 130
module M = Map.Make(String)

type env = {
  loadpath : string list;
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
131
  theories : theory M.t; (* local theories *)
132 133 134 135 136 137
}

let create lp = {
  loadpath = lp;
  theories = M.empty;
}
138 139

(** typing using destructive type variables 
140

141 142 143 144 145 146
    parsed trees        intermediate trees       typed trees
      (Ptree)               (D below)               (Term)
   -----------------------------------------------------------
     ppure_type  ---dty--->   dty       ---ty--->    ty
      lexpr      --dterm-->   dterm     --term-->    term
      lexpr      --dfmla-->   dfmla     --fmla-->    fmla
147

148 149 150 151 152 153 154 155 156 157 158 159 160
*)

(** types with destructive type variables *)

type dty =
  | Tyvar of type_var
  | Tyapp of tysymbol * dty list
      
and type_var = { 
  tag : int; 
  user : bool;
  tvsymbol : tvsymbol;
  mutable type_val : dty option;
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
161
  type_var_loc : loc option;
162
}
163

164 165 166 167
let rec print_dty fmt = function
  | Tyvar { type_val = Some t } ->
      print_dty fmt t
  | Tyvar { type_val = None; tvsymbol = v } ->
168
      fprintf fmt "'%s" v.id_short
169
  | Tyapp (s, []) ->
170
      fprintf fmt "%s" s.ts_name.id_short
171
  | Tyapp (s, [t]) -> 
172
      fprintf fmt "%a %s" print_dty t s.ts_name.id_short
173
  | Tyapp (s, l) -> 
174 175
      fprintf fmt "(%a) %s" 
	(print_list comma print_dty) l s.ts_name.id_short
176

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
177 178 179 180 181
let term_expected_type ~loc ty1 ty2 =
  errorm ~loc
    "@[This term has type %a@ but is expected to have type@ %a@]"
    print_dty ty1 print_dty ty2

182 183
let create_type_var =
  let t = ref 0 in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
184
  fun ?loc ~user tv -> 
185
    incr t; 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
186 187
    { tag = !t; user = user; tvsymbol = tv; type_val = None;
      type_var_loc = loc }
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

let rec occurs v = function
  | Tyvar { type_val = Some t } -> occurs v t
  | Tyvar { tag = t; type_val = None } -> v.tag = t
  | Tyapp (_, l) -> List.exists (occurs v) l

(* destructive type unification *)
let rec unify t1 t2 = match t1, t2 with
  | Tyvar { type_val = Some t1 }, _ ->
      unify t1 t2
  | _, Tyvar { type_val = Some t2 } ->
      unify t1 t2
  | Tyvar v1, Tyvar v2 when v1.tag = v2.tag ->
      true
	(* instantiable variables *)
  | Tyvar ({user=false} as v), t
  | t, Tyvar ({user=false} as v) ->
      not (occurs v t) && (v.type_val <- Some t; true)
	(* recursive types *)
  | Tyapp (s1, l1), Tyapp (s2, l2) ->
      s1 == s2 && List.length l1 = List.length l2 &&
	  List.for_all2 unify l1 l2
  | Tyapp _, _ | _, Tyapp _ ->
      false
	(* other cases *)
  | Tyvar {user=true; tag=t1}, Tyvar {user=true; tag=t2} -> 
      t1 = t2

216
(** Destructive typing environment, that is
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
217
    environment + local variables.
218
    It is only local to this module and created with [create_denv] below. *)
219 220

type denv = { 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
221
  th : theory_uc; (* the theory under construction *)
222 223
  utyvars : (string, type_var) Hashtbl.t; (* user type variables *)
  dvars : dty M.t; (* local variables, to be bound later *)
224 225
}

226 227
let create_denv th = { 
  th = th; 
228 229 230
  utyvars = Hashtbl.create 17; 
  dvars = M.empty;
}
231

232 233 234 235
let find_user_type_var x env =
  try
    Hashtbl.find env.utyvars x
  with Not_found ->
236
    (* TODO: shouldn't we localize this ident? *)
237 238
    let v = create_tvsymbol (id_fresh x) in
    let v = create_type_var ~user:true v in
239 240 241
    Hashtbl.add env.utyvars x v;
    v
 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
242 243
(* Specialize *)

244
module Htv = Hid
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
245

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
246
let find_type_var ~loc env tv =
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
247 248 249
  try
    Htv.find env tv
  with Not_found ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
250
    let v = create_type_var ~loc ~user:false tv in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
251 252 253
    Htv.add env tv v;
    v
 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
254
let rec specialize ~loc env t = match t.ty_node with
255
  | Ty.Tyvar tv -> 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
256
      Tyvar (find_type_var ~loc env tv)
257
  | Ty.Tyapp (s, tl) ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
258
      Tyapp (s, List.map (specialize ~loc env) tl)
259

260 261 262
(** generic find function using a path *)

let find_local_namespace {id=x; id_loc=loc} ns = 
263
  try Mnm.find x ns.ns_ns
264 265 266 267 268 269 270 271 272 273 274 275
  with Not_found -> error ~loc (UnboundNamespace x)

let rec find_namespace q ns = match q with
  | Qident t -> find_local_namespace t ns
  | Qdot (q, t) -> let ns = find_namespace q ns in find_local_namespace t ns

let rec find f q ns = match q with
  | Qident x -> f x ns
  | Qdot (m, x) -> let ns = find_namespace m ns in f x ns

(** specific find functions using a path *)

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
276
let find_local_tysymbol {id=x; id_loc=loc} ns = 
277
  try Mnm.find x ns.ns_ts
278 279
  with Not_found -> error ~loc (UnboundType x)

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
280 281 282
let find_tysymbol_ns p ns =
  find find_local_tysymbol p ns

283
let find_tysymbol p th = 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
284
  find_tysymbol_ns p (get_namespace th)
285

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
286
let specialize_tysymbol ~loc x env =
287
  let s = find_tysymbol x env.th in
288
  let env = Htv.create 17 in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
289
  s, List.map (find_type_var ~loc env) s.ts_args
290
	
291 292
let find_lsymbol {id=x; id_loc=loc} ns = 
  try Mnm.find x ns.ns_ls
293 294
  with Not_found -> error ~loc (UnboundSymbol x)

295 296
let find_lsymbol_ns p ns = 
  find find_lsymbol p ns
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
297

298 299
let find_lsymbol p th = 
  find_lsymbol_ns p (get_namespace th)
300

301 302 303
let specialize_lsymbol ~loc s =
  let tl = s.ls_args in
  let t = s.ls_value in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
304
  let env = Htv.create 17 in
305
  s, List.map (specialize ~loc env) tl, option_map (specialize ~loc env) t
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
306

307 308 309 310 311
let specialize_fsymbol ~loc s = 
  let s, tl, ty = specialize_lsymbol ~loc s in
  match ty with
    | None -> error ~loc TermExpected
    | Some ty -> s, tl, ty
312

313 314 315 316 317
let specialize_psymbol ~loc s = 
  let s, tl, ty = specialize_lsymbol ~loc s in
  match ty with
    | None -> s, tl
    | Some _ -> error ~loc PredicateExpected
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
318

319 320
(** Typing types *)

321
let rec qloc = function
322
  | Qident x -> x.id_loc
323
  | Qdot (m, x) -> Loc.join (qloc m) x.id_loc
324 325

(* parsed types -> intermediate types *)
326 327 328 329 330

let rec type_inst s ty = match ty.ty_node with
  | Ty.Tyvar n -> Mid.find n s
  | Ty.Tyapp (ts, tyl) -> Tyapp (ts, List.map (type_inst s) tyl)

331
let rec dty env = function
332
  | PPTtyvar {id=x} -> 
333
      Tyvar (find_user_type_var x env)
334
  | PPTtyapp (p, x) ->
335
      let loc = qloc x in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
336
      let ts, tv = specialize_tysymbol ~loc x env in
337 338 339
      let np = List.length p in
      let a = List.length tv in
      if np <> a then error ~loc (TypeArity (x, a, np));
340 341 342 343 344 345 346 347
      let tyl = List.map (dty env) p in
      match ts.ts_def with
	| None -> 
	    Tyapp (ts, tyl)
	| Some ty -> 
	    let add m v t = Mid.add v t m in
            let s = List.fold_left2 add Mid.empty ts.ts_args tyl in
	    type_inst s ty
348 349

(* intermediate types -> types *)
350
let rec ty_of_dty = function
351
  | Tyvar { type_val = Some t } ->
352
      ty_of_dty t
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
353 354
  | Tyvar { type_val = None; user = false; type_var_loc = loc } ->
      errorm ?loc "undefined type variable"
355 356 357
  | Tyvar { tvsymbol = tv } ->
      Ty.ty_var tv
  | Tyapp (s, tl) ->
358
      Ty.ty_app s (List.map ty_of_dty tl)
359

360
(** Typing terms and formulas *)
361

Andrei Paskevich's avatar
Andrei Paskevich committed
362 363 364 365 366 367 368 369
type dpattern = { dp_node : dpattern_node; dp_ty : dty }

and dpattern_node =
  | Pwild
  | Pvar of string
  | Papp of lsymbol * dpattern list
  | Pas of dpattern * string

370 371
type uquant = string list * dty

372 373 374
type dterm = { dt_node : dterm_node; dt_ty : dty }

and dterm_node =
375
  | Tvar of string
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
376
  | Tconst of constant
377
  | Tapp of lsymbol * dterm list
378
  | Tlet of dterm * string * dterm
Andrei Paskevich's avatar
Andrei Paskevich committed
379
  | Tmatch of dterm * (dpattern * dterm) list
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
380
  | Tnamed of string * dterm
381 382 383
  | Teps of string * dfmla

and dfmla = 
384
  | Fapp of lsymbol * dterm list
385
  | Fquant of quant * uquant list * dtrigger list list * dfmla
386 387 388 389 390
  | Fbinop of binop * dfmla * dfmla
  | Fnot of dfmla
  | Ftrue
  | Ffalse
  | Fif of dfmla * dfmla * dfmla
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
391
  | Flet of dterm * string * dfmla
Andrei Paskevich's avatar
Andrei Paskevich committed
392
  | Fmatch of dterm * (dpattern * dfmla) list
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
393
  | Fnamed of string * dfmla
394

395 396 397 398
and dtrigger =
  | TRterm of dterm
  | TRfmla of dfmla

399 400 401 402 403 404
let binop = function
  | PPand -> Fand
  | PPor -> For
  | PPimplies -> Fimplies
  | PPiff -> Fiff

Andrei Paskevich's avatar
Andrei Paskevich committed
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
let rec dpat env pat =
  let env, n, ty = dpat_node pat.pat_loc env pat.pat_desc in
  env, { dp_node = n; dp_ty = ty }

and dpat_node loc env = function
  | PPpwild -> 
      let tv = create_tvsymbol (id_user "a" loc) in
      let ty = Tyvar (create_type_var ~loc ~user:false tv) in
      env, Pwild, ty
  | PPpvar {id=x} ->
      if M.mem x env.dvars then assert false; (* FIXME? *)
      let tv = create_tvsymbol (id_user "a" loc) in
      let ty = Tyvar (create_type_var ~loc ~user:false tv) in
      let env = { env with dvars = M.add x ty env.dvars } in
      env, Pvar x, ty
  | PPpapp (x, pl) ->
      let s = find_lsymbol x env.th in
      let s, tyl, ty = specialize_fsymbol ~loc s in
      let env, pl = dpat_args s.ls_name loc env tyl pl in
      env, Papp (s, pl), ty
  | PPpas (p, {id=x}) ->
      let env, p = dpat env p in
      if M.mem x env.dvars then assert false; (* FIXME? *)
      let env = { env with dvars = M.add x p.dp_ty env.dvars } in
      env, Pas (p,x), p.dp_ty

and dpat_args s loc env el pl = assert false (* TODO *)
(*
  let n = List.length el and m = List.length tl in
  if n <> m then error ~loc (BadNumberOfArguments (s, m, n));
  let rec check_arg = function
    | [], [] -> 
	[]
    | a :: al, t :: bl ->
	let loc = t.pp_loc in
	let t = dterm env t in
	if not (unify a t.dt_ty) then
	  error ~loc (TermExpectedType ((fun f -> print_dty f t.dt_ty),
					(fun f -> print_dty f a)));
	t :: check_arg (al, bl)
    | _ ->
	assert false
  in
  check_arg (el, tl)
*)

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
451 452 453 454 455
let rec trigger_not_a_term_exn = function
  | Error (TermExpected | UnboundSymbol _) -> true
  | Loc.Located (_, exn) -> trigger_not_a_term_exn exn
  | _ -> false

456 457 458 459 460 461 462 463
let check_linearity uqu =
  let s = ref S.empty in
  let check id = 
    if S.mem id.id !s then errorm ~loc:id.id_loc "duplicate variable %s" id.id;
    s := S.add id.id !s
  in
  List.iter (fun (idl, _) -> List.iter check idl) uqu

464 465 466 467 468
let rec dterm env t = 
  let n, ty = dterm_node t.pp_loc env t.pp_desc in
  { dt_node = n; dt_ty = ty }

and dterm_node loc env = function
469 470 471 472 473 474
  | PPvar (Qident {id=x}) when M.mem x env.dvars ->
      (* local variable *)
      let ty = M.find x env.dvars in
      Tvar x, ty
  | PPvar x -> 
      (* 0-arity symbol (constant) *)
475
      let s = find_lsymbol x env.th in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
476
      let s, tyl, ty = specialize_fsymbol ~loc s in
477
      let n = List.length tyl in
478
      if n > 0 then error ~loc (BadNumberOfArguments (s.ls_name, 0, n));
479
      Tapp (s, []), ty
480
  | PPapp (x, tl) ->
481
      let s = find_lsymbol x env.th in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
482
      let s, tyl, ty = specialize_fsymbol ~loc s in
483
      let tl = dtype_args s.ls_name loc env tyl tl in
484
      Tapp (s, tl), ty
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
485
  | PPconst (ConstInt _ as c) ->
486
      Tconst c, Tyapp (Ty.ts_int, [])
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
487
  | PPconst (ConstReal _ as c) ->
488
      Tconst c, Tyapp (Ty.ts_real, [])
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
489 490 491 492 493 494
  | PPlet ({id=x}, e1, e2) ->
      let e1 = dterm env e1 in
      let ty = e1.dt_ty in
      let env = { env with dvars = M.add x ty env.dvars } in
      let e2 = dterm env e2 in
      Tlet (e1, x, e2), e2.dt_ty
Andrei Paskevich's avatar
Andrei Paskevich committed
495 496 497 498 499 500 501 502 503 504
  | PPmatch (e1, bl) ->
      (* TODO: unify e1.type with patterns *)
      (* TODO: unify branch types with each other *)
      let branch (pat, e) =
        let env, pat = dpat env pat in
        pat, dterm env e
      in
      let bl = List.map branch bl in
      let ty = (snd (List.hd bl)).dt_ty in
      Tmatch (dterm env e1, bl), ty
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
505 506 507
  | PPnamed (x, e1) ->
      let e1 = dterm env e1 in
      Tnamed (x, e1), e1.dt_ty
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
508 509 510 511 512 513
  | PPcast (e1, ty) ->
      let loc = e1.pp_loc in
      let e1 = dterm env e1 in
      let ty = dty env ty in
      if not (unify e1.dt_ty ty) then term_expected_type ~loc e1.dt_ty ty;
      e1.dt_node, ty
514
  | PPquant _ | PPif _ 
515 516
  | PPprefix _ | PPinfix _ | PPfalse | PPtrue ->
      error ~loc TermExpected
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
517

518 519 520 521 522 523 524 525 526 527 528
and dfmla env e = match e.pp_desc with
  | PPtrue ->
      Ftrue
  | PPfalse ->
      Ffalse
  | PPprefix (PPnot, a) ->
      Fnot (dfmla env a)
  | PPinfix (a, (PPand | PPor | PPimplies | PPiff as op), b) ->
      Fbinop (binop op, dfmla env a, dfmla env b)
  | PPif (a, b, c) ->
      Fif (dfmla env a, dfmla env b, dfmla env c)  
529
  | PPquant (q, uqu, trl, a) ->
530
      check_linearity uqu;
531 532 533 534 535 536 537 538
      let uquant env (idl,ty) =
        let ty = dty env ty in
        let env, idl = 
          map_fold_left
            (fun env {id=x} -> { env with dvars = M.add x ty env.dvars }, x)
            env idl
        in
        env, (idl,ty)
539
      in
540
      let env, uqu = map_fold_left uquant env uqu in
541 542 543
      let trigger e = (* FIXME? *)
	try 
	  TRterm (dterm env e) 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
544 545
	with exn when trigger_not_a_term_exn exn ->
	  TRfmla (dfmla env e) 
546 547
      in
      let trl = List.map (List.map trigger) trl in
548 549 550 551 552
      let q = match q with 
        | PPforall -> Fforall 
        | PPexists -> Fexists
      in
      Fquant (q, uqu, trl, dfmla env a)
553
  | PPapp (x, tl) ->
554
      let s = find_lsymbol x env.th in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
555
      let s, tyl = specialize_psymbol ~loc:e.pp_loc s in
556
      let tl = dtype_args s.ls_name e.pp_loc env tyl tl in
557
      Fapp (s, tl)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
558 559 560 561 562 563
  | PPlet ({id=x}, e1, e2) ->
      let e1 = dterm env e1 in
      let ty = e1.dt_ty in
      let env = { env with dvars = M.add x ty env.dvars } in
      let e2 = dfmla env e2 in
      Flet (e1, x, e2)
Andrei Paskevich's avatar
Andrei Paskevich committed
564 565 566 567 568 569 570 571
  | PPmatch (e1, bl) ->
      (* TODO: unify e1.type with patterns *)
      (* TODO: unify branch types with each other *)
      let branch (pat, e) =
        let env, pat = dpat env pat in
        pat, dfmla env e
      in
      Fmatch (dterm env e1, List.map branch bl)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
572 573 574
  | PPnamed (x, f1) ->
      let f1 = dfmla env f1 in
      Fnamed (x, f1)
575 576
  | PPvar _ -> 
      assert false (* TODO *)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
577
  | PPconst _ | PPcast _ ->
578
      error ~loc:e.pp_loc PredicateExpected
579

580 581 582 583 584 585 586 587 588
and dtype_args s loc env el tl =
  let n = List.length el and m = List.length tl in
  if n <> m then error ~loc (BadNumberOfArguments (s, m, n));
  let rec check_arg = function
    | [], [] -> 
	[]
    | a :: al, t :: bl ->
	let loc = t.pp_loc in
	let t = dterm env t in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
589
	if not (unify a t.dt_ty) then term_expected_type ~loc t.dt_ty a;
590 591 592 593 594 595
	t :: check_arg (al, bl)
    | _ ->
	assert false
  in
  check_arg (el, tl)

Andrei Paskevich's avatar
Andrei Paskevich committed
596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612
let rec pattern env p = 
  let ty = ty_of_dty p.dp_ty in
  match p.dp_node with
  | Pwild -> env, pat_wild ty
  | Pvar x -> 
      if M.mem x env then assert false; (* FIXME? *)
      let v = create_vsymbol (id_fresh x) ty in
      M.add x v env, pat_var v
  | Papp (s, pl) -> 
      let env, pl = map_fold_left pattern env pl in
      env, pat_app s pl ty
  | Pas (p, x) ->
      if M.mem x env then assert false; (* FIXME? *)
      let v = create_vsymbol (id_fresh x) ty in
      let env, p = pattern (M.add x v env) p in
      env, pat_as p v

613 614 615 616
let rec term env t = match t.dt_node with
  | Tvar x ->
      assert (M.mem x env);
      t_var (M.find x env)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
617
  | Tconst c ->
618
      t_const c (ty_of_dty t.dt_ty)
619
  | Tapp (s, tl) ->
620
      t_app s (List.map (term env) tl) (ty_of_dty t.dt_ty)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
621 622 623 624 625 626 627
  | Tlet (e1, x, e2) ->
      let ty = ty_of_dty e1.dt_ty in
      let e1 = term env e1 in 
      let v = create_vsymbol (id_fresh x) ty in
      let env = M.add x v env in
      let e2 = term env e2 in
      t_let v e1 e2
Andrei Paskevich's avatar
Andrei Paskevich committed
628 629 630 631 632 633 634 635
  | Tmatch (e1, bl) ->
      let branch (pat,e) =
        let env, pat = pattern env pat in
        (pat, term env e)
      in
      let bl = List.map branch bl in
      let ty = (snd (List.hd bl)).t_ty in
      t_case (term env e1) bl ty
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
636 637 638
  | Tnamed (x, e1) ->
      let e1 = term env e1 in
      t_label_add x e1
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
639 640
  | Teps _ ->
      assert false (*TODO*)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
641

642 643 644 645 646 647 648 649 650 651 652
and fmla env = function
  | Ftrue ->
      f_true
  | Ffalse ->
      f_false 
  | Fnot f ->
      f_not (fmla env f)
  | Fbinop (op, f1, f2) ->
      f_binary op (fmla env f1) (fmla env f2)
  | Fif (f1, f2, f3) ->
      f_if (fmla env f1) (fmla env f2) (fmla env f3)
653
  | Fquant (q, uqu, trl, f1) ->
654
      (* TODO: shouldn't we localize this ident? *)
655 656 657 658 659 660
      let uquant env (xl,ty) =
        let ty = ty_of_dty ty in
        map_fold_left
          (fun env x -> 
             let v = create_vsymbol (id_fresh x) ty in M.add x v env, v) 
          env xl 
661
      in
662 663 664
      let env, vl = map_fold_left uquant env uqu in
      (* TODO: triggers *)
      f_quant q (List.concat vl) [] (fmla env f1)
665 666
  | Fapp (s, tl) ->
      f_app s (List.map (term env) tl)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
667
  | Flet (e1, x, f2) ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
668 669 670 671
      let ty = ty_of_dty e1.dt_ty in
      let e1 = term env e1 in 
      let v = create_vsymbol (id_fresh x) ty in
      let env = M.add x v env in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
672 673
      let f2 = fmla env f2 in
      f_let v e1 f2
Andrei Paskevich's avatar
Andrei Paskevich committed
674 675 676 677 678 679
  | Fmatch (e1, bl) ->
      let branch (pat,e) =
        let env, pat = pattern env pat in
        (pat, fmla env e)
      in
      f_case (term env e1) (List.map branch bl)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
680
  | Fnamed (x, f1) ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
681
      let f1 = fmla env f1 in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
682
      f_label_add x f1
683

684
(** Typing declarations, that is building environments. *)
685 686 687

open Ptree

688
let add_types loc dl th =
689
  let ns = get_namespace th in
690 691 692 693
  let def = 
    List.fold_left 
      (fun def d -> 
	 let id = d.td_ident in
694 695
	 if M.mem id.id def || Mnm.mem id.id ns.ns_ts then 
	   error ~loc:id.id_loc (ClashType id.id);
696 697
	 M.add id.id d def) 
      M.empty dl 
698
  in
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714
  let tysymbols = Hashtbl.create 17 in
  let rec visit x = 
    try
      match Hashtbl.find tysymbols x with
	| None -> error CyclicTypeDef
	| Some ts -> ts
    with Not_found ->
      Hashtbl.add tysymbols x None;
      let d = M.find x def in
      let id = d.td_ident.id in
      let vars = Hashtbl.create 17 in
      let vl = 
	List.map 
	  (fun v -> 
	     if Hashtbl.mem vars v.id then 
	       error ~loc:v.id_loc (DuplicateTypeVar v.id);
715
	     let i = create_tvsymbol (id_user v.id v.id_loc) in
716 717 718 719
	     Hashtbl.add vars v.id i;
	     i)
	  d.td_params 
      in
720
      let id = id_user id d.td_ident.id_loc in
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
      let ts = match d.td_def with
	| TDalias ty -> 
	    let rec apply = function
	      | PPTtyvar v -> 
		  begin 
		    try ty_var (Hashtbl.find vars v.id)
		    with Not_found -> error ~loc:v.id_loc (UnboundTypeVar v.id)
		  end
	      | PPTtyapp (tyl, q) ->
		  let ts = match q with
		    | Qident x when M.mem x.id def ->
			visit x.id
		    | Qident _ | Qdot _ ->
			find_tysymbol q th
		  in
		  try
		    ty_app ts (List.map apply tyl)
		  with Ty.BadTypeArity ->
		    error ~loc:(qloc q) (TypeArity (q, List.length ts.ts_args,
						    List.length tyl))
	    in
	    create_tysymbol id vl (Some (apply ty))
	| TDabstract | TDalgebraic _ -> 
	    create_tysymbol id vl None
      in
      Hashtbl.add tysymbols x (Some ts);
      ts
  in
749 750 751 752 753 754
  let th' = 
    let tsl = 
      M.fold (fun x _ tsl -> let ts = visit x in (ts, Tabstract) :: tsl) def []
    in
    add_decl th (create_type tsl)
  in
755
  let decl d = 
756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775
    let ts, th' = match Hashtbl.find tysymbols d.td_ident.id with
      | None -> 
	  assert false
      | Some ts -> 
	  let th' = create_denv th' in
	  let vars = th'.utyvars in
	  List.iter 
	    (fun v -> 
	       Hashtbl.add vars v.id_short (create_type_var ~user:true v)) 
	    ts.ts_args;
	  ts, th'
    in
    let d = match d.td_def with
      | TDabstract | TDalias _ -> 
	  Tabstract
      | TDalgebraic cl -> 
	  let ty = ty_app ts (List.map ty_var ts.ts_args) in
	  let constructor (loc, id, pl) = 
	    let param (_, t) = ty_of_dty (dty th' t) in
	    let tyl = List.map param pl in
776
	    create_fconstr (id_user id.id id.id_loc) tyl ty
777 778 779 780
	  in
	  Talgebraic (List.map constructor cl)
    in
    ts, d
781 782
  in
  let dl = List.map decl dl in
783
  add_decl th (create_type dl)
784

Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
785 786 787 788
let env_of_vsymbol_list vl =
  List.fold_left (fun env v -> M.add v.vs_name.id_short v env) M.empty vl

let add_logics loc dl th =
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
789
  let ns = get_namespace th in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
790 791
  let fsymbols = Hashtbl.create 17 in
  let psymbols = Hashtbl.create 17 in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
792
  let denvs = Hashtbl.create 17 in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
793 794 795
  (* 1. create all symbols and make an environment with these symbols *)
  let create_symbol th d = 
    let id = d.ld_ident.id in
796
    if Hashtbl.mem denvs id || Mnm.mem id ns.ns_ls then error ~loc (Clash id);
797
    let v = id_user id loc in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
798
    let denv = create_denv th in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
799
    Hashtbl.add denvs id denv;
800
    let type_ty (_,t) = ty_of_dty (dty denv t) in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
801 802 803 804 805
    let pl = List.map type_ty d.ld_params in
    match d.ld_type with
      | None -> (* predicate *)
	  let ps = create_psymbol v pl in
	  Hashtbl.add psymbols id ps;
806
	  add_decl th (create_logic [Lpredicate (ps, None)])
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
807 808
      | Some t -> (* function *)
	  let t = type_ty (None, t) in
809
	  let fs = create_fsymbol v pl t in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
810
	  Hashtbl.add fsymbols id fs;
811
	  add_decl th (create_logic [Lfunction (fs, None)])
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
812 813 814 815 816 817 818 819 820
  in
  let th' = List.fold_left create_symbol th dl in
  (* 2. then type-check all definitions *)
  let type_decl d = 
    let id = d.ld_ident.id in
    let dadd_var denv (x, ty) = match x with
      | None -> denv
      | Some id -> { denv with dvars = M.add id.id (dty denv ty) denv.dvars }
    in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
821 822 823
    let denv = Hashtbl.find denvs id in
    let denv = { denv with th = th' } in
    let denv = List.fold_left dadd_var denv d.ld_params in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
824 825
    let create_var (x, _) ty = 
      let id = match x with 
826 827
	| None -> id_fresh "%x"
	| Some id -> id_user id.id id.id_loc
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
828 829 830
      in
      create_vsymbol id ty
    in
831
    let mk_vlist = List.map2 create_var d.ld_params in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
832 833 834
    match d.ld_type with
    | None -> (* predicate *)
	let ps = Hashtbl.find psymbols id in
835 836
        let defn = match d.ld_def with
	  | None -> None
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
837 838
	  | Some f -> 
	      let f = dfmla denv f in
839 840 841 842
              let vl = match ps.ls_value with
                | None -> mk_vlist ps.ls_args
                | _ -> assert false
              in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
843
	      let env = env_of_vsymbol_list vl in
844 845 846
              Some (make_ps_defn ps vl (fmla env f))
        in
        Lpredicate (ps, defn)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
847
    | Some ty -> (* function *)
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
848
	let fs = Hashtbl.find fsymbols id in
849 850
        let defn = match d.ld_def with
	  | None -> None
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
851
	  | Some t -> 
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
852
	      let loc = t.pp_loc in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
853
	      let t = dterm denv t in
854 855 856 857
              let vl = match fs.ls_value with
                | Some _ -> mk_vlist fs.ls_args
                | _ -> assert false
              in
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
858
	      let env = env_of_vsymbol_list vl in
859
              try Some (make_fs_defn fs vl (term env t))
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
860
	      with _ -> term_expected_type ~loc t.dt_ty (dty denv ty)
861 862
        in
        Lfunction (fs, defn)
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
863 864
  in
  let dl = List.map type_decl dl in
865
  add_decl th (create_logic dl)
866

867

868 869 870
let term env t =
  let denv = create_denv env in
  let t = dterm denv t in
871
  term M.empty t
872

Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
873 874 875 876 877
let fmla env f =
  let denv = create_denv env in
  let f = dfmla denv f in
  fmla M.empty f

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
878 879 880
let add_prop k loc s f th =
  let f = fmla th f in
  try
881
    add_decl th (create_prop k (id_user s.id loc) f)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
882 883
  with ClashSymbol _ ->
    error ~loc (Clash s.id)
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
let find_in_loadpath env f =
  let rec find c lp = match lp, c with
    | [], None -> 
	error ~loc:f.id_loc (NotInLoadpath f.id)
    | [], Some file ->
	file
    | dir :: lp, _ ->
	let file = Filename.concat dir f.id in
	if Sys.file_exists file then begin match c with
	  | None -> find (Some file) lp
	  | Some file' -> error ~loc:f.id_loc (AmbiguousPath (file, file'))
	end else
	  find c lp
  in
  find None env.loadpath

let locate_file env q = 
  let rec locate_dir = function
    | Qident d ->
	find_in_loadpath env d
    | Qdot (q, d) -> 
	let dir = locate_dir q in
	let dir = Filename.concat dir d.id in
	if not (Sys.file_exists dir) then error ~loc:d.id_loc (UnboundDir dir);
	dir
  in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
911 912 913 914 915 916 917 918 919
  match q with
    | Qident f -> 
	find_in_loadpath env { f with id = f.id ^ ".why" }
    | Qdot (p, f) -> 
	let dir = locate_dir p in 
	let file = Filename.concat dir f.id ^ ".why" in
	if not (Sys.file_exists file) then 
	  error ~loc:(qloc q) (UnboundFile file);
	file
920

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
921
let loaded_theories = Hashtbl.create 17 (* file -> string -> Theory.t *)
922 923

(* parse file and store all theories into parsed_theories *)
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
924 925 926 927 928 929 930
let load_file file =
  let c = open_in file in
  let lb = Lexing.from_channel c in
  Loc.set_file file lb;
  let tl = Lexer.parse_logic_file lb in 
  close_in c;
  tl
931

Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
932
let prop_kind = function
933 934 935
  | Kaxiom -> Paxiom
  | Kgoal -> Pgoal
  | Klemma -> Plemma
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
936

937
let rec find_theory env q = match q with
938
  | Qident id -> 
939
      (* local theory *)
940 941 942 943 944
      begin 
	try M.find id.id env.theories 
	with Not_found -> error ~loc:id.id_loc (UnboundTheory id.id) 
      end
  | Qdot (f, id) ->
945 946
      (* theory in file f *)
      let file = locate_file env f in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
947 948 949 950 951 952 953 954 955 956 957 958
      if not (Hashtbl.mem loaded_theories file) then begin
	let tl = load_file file in
	let h = Hashtbl.create 17 in
	Hashtbl.add loaded_theories file h;
	let env = { env with theories = M.empty } in
	let add env pt =
	  let t, env = add_theory env pt in
	  Hashtbl.add h t.th_name.id_short t;
	  env
	in
	ignore (List.fold_left add env tl);
      end;
959
      let h = Hashtbl.find loaded_theories file in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
960 961
      try Hashtbl.find h id.id
      with Not_found -> error ~loc:id.id_loc (UnboundTheory id.id)
962 963

and type_theory env id pt =
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
964
  (* TODO: use long name *)
965
  let n = id_user id.id id.id_loc in
966
  let th = create_theory n in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
967
  let th = add_decls env th pt.pt_decl in
968 969 970
  close_theory th

and add_decls env th = List.fold_left (add_decl env) th
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
971

972
and add_decl env th = function
973 974
  | TypeDecl (loc, dl) ->
      add_types loc dl th
Jean-Christophe Filliâtre's avatar
logic  
Jean-Christophe Filliâtre committed
975 976
  | Logic (loc, dl) ->
      add_logics loc dl th
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
977 978
  | Prop (loc, k, s, f) ->
      add_prop (prop_kind k) loc s f th
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
979
  | UseClone (loc, use, subst) ->
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
980
      let t = find_theory env use.use_theory in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
981 982 983 984 985 986 987
      let use_or_clone th = match subst with
	| None -> 
	    use_export th t
	| Some s -> 
	    let add_ts m (p, q) = 
	      Mts.add (find_tysymbol_ns p t.th_export) (find_tysymbol q th) m
	    in
988 989
	    let add_ls m (p, q) = 
	      Mls.add (find_lsymbol_ns p t.th_export) (find_lsymbol q th) m
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
990 991 992
	    in
	    let s = 
	      { inst_ts = List.fold_left add_ts Mts.empty s.ts_subst;
993
                inst_ls = List.fold_left add_ls Mls.empty s.ls_subst; }
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
994 995 996
	    in
	    clone_export th t s
      in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
997
      let n = match use.use_as with 
998 999
	| None -> t.th_name.id_short
	| Some x -> x.id
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
1000
      in
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
1001
      begin try match use.use_imp_exp with
Jean-Christophe Filliâtre's avatar
Jean-Christophe Filliâtre committed
1002 1003 1004
	| Nothing ->
	    (* use T = namespace T use_export T end *)