typer.ml 42.3 KB
Newer Older
1
open Cduce_loc
2
3
open Ast
open Ident
4

5
6
7
8
9
10
let (=) (x:int) y = x = y
let (<=) (x:int) y = x <= y
let (<) (x:int) y = x < y
let (>=) (x:int) y = x >= y
let (>) (x:int) y = x > y

11
let warning loc msg =
12
  let v = Cduce_loc.get_viewport () in
13
  let ppf = if Html.is_html v then Html.ppf v else Format.err_formatter in
14
15
  Cduce_loc.print_loc ppf (loc,`Full);
  Cduce_loc.html_hilight (loc,`Full);
16
  Format.fprintf ppf "Warning: %s@." msg
17

18
19
20
21
22
23
exception NonExhaustive of Types.descr
exception Constraint of Types.descr * Types.descr
exception ShouldHave of Types.descr * string
exception ShouldHave2 of Types.descr * string * Types.descr
exception WrongLabel of Types.descr * label
exception UnboundId of id * bool
24
exception UnboundExtId of Compunit.t * id
25
exception Error of string
26
27
exception Warning of string * Types.t

28
29
30
31
let raise_loc loc exn = raise (Location (loc,`Full,exn))
let raise_loc_str loc ofs exn = raise (Location (loc,`Char ofs,exn))
let error loc msg = raise_loc loc (Error msg)

32
33
34
35
36
37
type schema = {
  sch_uri: string;
  sch_ns: Ns.Uri.t;
  sch_comps: (Types.t * Schema_validator.t) Ident.Env.t;
}

38
type item =
39
(* These are really exported by CDuce units: *)
Pietro Abate's avatar
Pietro Abate committed
40
  | Type of (Types.t * Var.t array)
41
  | Val of Types.t
42
43
44
45
46
47
48
49
  | ECDuce of Compunit.t
  | ESchema of schema
  | ENamespace of Ns.Uri.t
(* These are only used internally: *)
  | EVal of Compunit.t * id * Types.t
  | EOCaml of string
  | EOCamlComponent of string
  | ESchemaComponent of (Types.t * Schema_validator.t)
50

51
type t = {
52
  ids : item Env.t;
53
  delta : Var.Set.t;
54
  ns: Ns.table;
55
  keep_ns: bool
56
}
57

58
let pp_env ppf env =
Pietro Abate's avatar
Pietro Abate committed
59
60
  let pp_item ppf (s,t) = match t with
    |Val t -> Format.fprintf ppf "val %s : %a" s Types.Print.pp_type t
Pietro Abate's avatar
Pietro Abate committed
61
62
    |Type (t,[||]) -> Format.fprintf ppf "type %s = %a" s Types.Print.pp_noname t
    |Type (t,al) ->
Pietro Abate's avatar
Pietro Abate committed
63
64
        Format.fprintf ppf "type %s(%a) = %a" s 
          (Utils.pp_list ~delim:("","") Var.pp) (Array.to_list al) 
Pietro Abate's avatar
Pietro Abate committed
65
          Types.Print.pp_noname t
66
67
    |_ -> ()
  in
Pietro Abate's avatar
Pietro Abate committed
68
69
70
71
72
73
74
75
76
77
78
79
  let t = [ 
    "Empty";"Any";"Int";"Char";"Byte";"Atom";
    "Pair";"Arrow";"Record";
    "String";"Latin1";
    "Bool";"Float";"AnyXml";
    "Namespaces";"Caml_int" ]
  in
  let ids = 
    Env.filter (fun n _ ->
      not(List.mem (Id.to_string n) t)
    ) env.ids 
  in
Pietro Abate's avatar
Pietro Abate committed
80
  Format.printf "{ids=%a;delta=%a}"
Pietro Abate's avatar
Pietro Abate committed
81
  (Ident.pp_env pp_item) ids
Pietro Abate's avatar
Pietro Abate committed
82
  Var.Set.pp env.delta
83
84
;;

85
86
(* Namespaces *)

87
let set_ns_table_for_printer env =
88
89
90
91
92
93
94
95
96
97
  Ns.InternalPrinter.set_table env.ns

let get_ns_table tenv = tenv.ns

let type_keep_ns env k =
  { env with keep_ns = k }

let protect_error_ns loc f x =
  try f x
  with Ns.UnknownPrefix ns ->
98
    raise_loc_generic loc
99
100
    ("Undefined namespace prefix " ^ (U.to_string ns))

101
let qname env loc t =
102
  protect_error_ns loc (Ns.map_tag env.ns) t
103

104
105
106
107
let ident env loc t =
  protect_error_ns loc (Ns.map_attr env.ns) t

let parse_atom env loc t = Atoms.V.mk (qname env loc t)
108

109
110
111
112
113
114
115
116
117
118
let parse_ns env loc ns =
  protect_error_ns loc (Ns.map_prefix env.ns) ns

let parse_label env loc t =
  Label.mk (protect_error_ns loc (Ns.map_attr env.ns) t)

let parse_record env loc f r =
  let r = List.map (fun (l,x) -> (parse_label env loc l, f x)) r in
  LabelMap.from_list (fun _ _ -> raise_loc_generic loc "Duplicated record field") r

119
120
let load_schema = ref (fun _ _ -> assert false)
let from_comp_unit = ref (fun _ -> assert false)
121
let load_comp_unit = ref (fun _ -> assert false)
122
123
let has_ocaml_unit = ref (fun _ -> false)
let has_static_external = ref (fun _ -> assert false)
124

125
126
127
128
129
let type_schema env loc name uri =
  let x = ident env loc name in
  let (ns,sch) = !load_schema (U.to_string name) uri in
  let sch = { sch_uri = uri; sch_comps = sch; sch_ns = ns } in
  { env with ids = Env.add x (ESchema sch) env.ids }
130

131
let empty_env = {
Pietro Abate's avatar
Pietro Abate committed
132
  ids = Env.empty; (* map from expression variables to items *)
133
  delta = Var.Set.empty; (* set of bounded type variables *)
134
135
  ns = Ns.def_table;
  keep_ns = false
136
137
}

138
139
let enter_id x i env =
  { env with ids = Env.add x i env.ids }
140

141
142
let type_using env loc x cu =
  try
143
144
145
146
147
    let cu = !load_comp_unit cu in
    enter_id (ident env loc x) (ECDuce cu) env
  with Not_found ->
    error loc ("Cannot find external unit " ^ (U.to_string cu))

Pietro Abate's avatar
Pietro Abate committed
148
let enter_type id t env = enter_id id (Type (t,[||])) env
149
let enter_types l env =
150
  { env with ids =
Pietro Abate's avatar
Pietro Abate committed
151
152
153
154
      List.fold_left (fun accu (id,t,al) ->
        Env.add id (Type (t,al)) accu
      ) env.ids l
  }
155

156
157
158
159
160
161
let find_id env0 env loc head x =
  let id = ident env0 loc x in
  try Env.find id env.ids
  with Not_found when head ->
    try ECDuce (!load_comp_unit x)
    with Not_found ->
Pietro Abate's avatar
Pietro Abate committed
162
      error loc "Cannot resolve this identifier"
163
164
165
166
167
168
169

let find_id_comp env0 env loc x =
  if ((match (U.get_str x).[0] with 'A'..'Z' -> true | _ -> false)
    && !has_ocaml_unit x)
  then EOCaml (U.get_str x)
  else find_id env0 env loc true x

170

171
let enter_value id t env =
172
  { env with ids = Env.add id (Val t) env.ids }
173

174
let enter_values l env =
175
  { env with ids =
176
177
178
    List.fold_left (fun accu (id,t) -> Env.add id (Val t) accu) env.ids l;
  }

179
let enter_values_dummy l env =
180
  { env with ids =
181
      List.fold_left (fun accu id -> Env.add id (Val Types.empty) accu) env.ids l }
182

183
184
let value_name_ok id env =
  try match Env.find id env.ids with
185
    | Val _ | EVal _ -> true
186
187
188
    | _ -> false
  with Not_found -> true

189
190
191
192
let iter_values env f =
  Env.iter (fun x ->
	      function Val t -> f x t;
		| _ -> ()) env.ids
193

194
let register_types cu env =
Pietro Abate's avatar
Pietro Abate committed
195
  Env.iter (fun x -> function
196
    | Type (t,_) -> Types.Print.register_global (cu,(Ident.value x),[||]) t
Pietro Abate's avatar
Pietro Abate committed
197
198
    | _ -> ()
  ) env.ids
199

200
201
202
203
204
205
206
207
208
let rec const env loc = function
  | LocatedExpr (loc,e) -> const env loc e
  | Pair (x,y) -> Types.Pair (const env loc x, const env loc y)
  | Xml (x,y) -> Types.Xml (const env loc x, const env loc y)
  | RecordLitt x -> Types.Record (parse_record env loc (const env loc) x)
  | String (i,j,s,c) -> Types.String (i,j,s,const env loc c)
  | Atom t -> Types.Atom (parse_atom env loc t)
  | Integer i -> Types.Integer i
  | Char c -> Types.Char c
209
  | Const c -> c
210
211
212
213
  | _ -> raise_loc_generic loc "This should be a scalar or structured constant"

(* I. Transform the abstract syntax of types and patterns into
      the internal form *)
214

215
216
let find_schema_component sch name =
  try ESchemaComponent (Env.find name sch.sch_comps)
217
  with Not_found ->
218
    raise (Error (Printf.sprintf "No component named '%s' found in schema '%s'"
219
220
221
222
223
224
		    (Ns.QName.to_string name) sch.sch_uri))

let navig loc env0 (env,comp) id =
  match comp with
    | ECDuce cu ->
	let env = !from_comp_unit cu in
225
	let c =
226
	  try find_id env0 env loc false id
Pietro Abate's avatar
Pietro Abate committed
227
228
	  with Not_found -> error loc "Unbound identifier" 
      in
229
230
	let c = match c with
	  | Val t -> EVal (cu,ident env0 loc id,t)
Pietro Abate's avatar
Pietro Abate committed
231
232
	  | c -> c 
      in
233
234
235
236
237
238
239
240
	env,c
    | EOCaml cu ->
	let s = cu ^ "." ^ (U.get_str id) in
	(match (U.get_str id).[0] with
	   | 'A'..'Z' -> env,EOCaml s
	   | _ -> env,EOCamlComponent s)
    | ESchema sch ->
	env,find_schema_component sch (ident env0 loc id)
241
242
243
244
245
246
    | Type _ -> error loc "Types don't have components"
    | Val _ | EVal _ -> error loc "Values don't have components"
    | ENamespace _ -> error loc "Namespaces don't have components"
    | EOCamlComponent _ -> error loc "Caml values don't have components"
    | ESchemaComponent _ -> error loc "Schema components don't have components"
(*
247
    | _ -> error loc "Invalid dot access"
248
*)
249

250
251
252
253
254
255
let rec find_global env loc ids =
  match ids with
    | id::rest ->
	let comp = find_id env env loc true id in
	snd (List.fold_left (navig loc env) (env,comp) rest)
    | _ -> assert false
256

257
258
259
260
261
262
263
264
265
266
267
let eval_ns env loc = function
  | `Uri ns -> ns
  | `Path ids ->
      match find_global env loc ids with
	| ENamespace ns -> ns
	| ESchema sch -> sch.sch_ns
	| _ -> error loc "This path does not refer to a namespace or schema"

let type_ns env loc p ns =
  (* TODO: check that p has no prefix *)
  let ns = eval_ns env loc ns in
268
  { env with
269
270
      ns = Ns.add_prefix p ns env.ns;
      ids = Env.add (Ns.empty,p) (ENamespace ns) env.ids }
271

272
273
let find_global_type env loc ids =
  match find_global env loc ids with
274
275
    | Type (t,pargs) -> (t,pargs)
    | ESchemaComponent (t,_) -> (t,[||]) (* XXX *)
276
277
278
279
280
281
    | _ -> error loc "This path does not refer to a type"

let find_global_schema_component env loc ids =
  match find_global env loc ids with
    | ESchemaComponent c -> c
    | _ -> error loc "This path does not refer to a schema component"
282

283
284
let find_local_type env loc id =
  match Env.find id env.ids with
285
    | Type (t,pargs) -> (t,pargs)
286
    | _ -> raise Not_found
287
288

let find_value id env =
289
  match Env.find id env.ids with
290
    | Val t | EVal (_,_,t) -> t
291
    | _ -> raise Not_found
292

293
294
let do_open env cu =
  let env_cu = !from_comp_unit cu in
295
  let ids =
296
297
298
299
300
301
302
303
    Env.fold
      (fun n d ids ->
	 let d = match d with
	   | Val t -> EVal (cu,n,t)
	   | d -> d in
	 Env.add n d ids)
      env_cu.ids
      env.ids in
304
  { env with
305
306
      ids = ids;
      ns = Ns.merge_tables env.ns env_cu.ns }
307

308
309
310
311
312
313

let type_open env loc ids =
  match find_global env loc ids with
    | ECDuce cu -> do_open env cu
    | _ -> error loc "This path does not refer to a CDuce unit"

314
module IType = struct
315
  open Typepat
316
317
318
319
320
321

(* From AST to the intermediate representation *)

  type penv = {
    penv_tenv : t;
    penv_derec : node Env.t;
322
    penv_var : (string, Var.var) Hashtbl.t;
323
324
  }

325
  let penv tenv = { penv_tenv = tenv; penv_derec = Env.empty ; penv_var = Hashtbl.create 17 }
326

327
328
  let all_delayed = ref []

329
330
  let clean_on_err () = all_delayed := []

331
332
333
334
335
336
  let delayed loc =
    let s = mk_delayed () in
    all_delayed := (loc,s) :: !all_delayed;
    s

  let check_one_delayed (loc,p) =
337
    if not (check_wf p) then error loc "Ill-formed recursion"
338

339
340
  let check_delayed () =
    let l = !all_delayed in
341
    all_delayed := [];
342
    List.iter check_one_delayed l
343

Pietro Abate's avatar
Pietro Abate committed
344
  (* Ast -> symbolic type *)
345
  let rec derecurs env p =
Pietro Abate's avatar
Pietro Abate committed
346
    match p.descr with
347
    | PatVar ids -> derecurs_var env p.loc ids
348
    | Recurs (p,b) -> derecurs (fst (derecurs_def env b)) p
349
    | Internal t -> mk_type t
350
    | NsT ns ->
351
	mk_type (Types.atom (Atoms.any_in_ns (parse_ns env.penv_tenv p.loc ns)))
352
353
354
355
356
357
358
    | Or (p1,p2) -> mk_or (derecurs env p1) (derecurs env p2)
    | And (p1,p2) -> mk_and (derecurs env p1) (derecurs env p2)
    | Diff (p1,p2) -> mk_diff (derecurs env p1) (derecurs env p2)
    | Prod (p1,p2) -> mk_prod (derecurs env p1) (derecurs env p2)
    | XmlT (p1,p2) -> mk_xml (derecurs env p1) (derecurs env p2)
    | Arrow (p1,p2) -> mk_arrow (derecurs env p1) (derecurs env p2)
    | Optional p -> mk_optional (derecurs env p)
359
    | Record (o,r) ->
360
	let aux = function
361
362
	  | (p,Some e) -> (derecurs env p, Some (derecurs env e))
	  | (p,None) -> derecurs env p, None in
363
	mk_record o (parse_record env.penv_tenv p.loc aux r)
364
    | Constant (x,c) ->
365
366
	mk_constant (ident env.penv_tenv p.loc x) (const env.penv_tenv p.loc c)
    | Cst c -> mk_type (Types.constant (const env.penv_tenv p.loc c))
367
368
369
    | Regexp r -> rexp (derecurs_regexp env r)
    | Concat (p1,p2) ->  mk_concat (derecurs env p1) (derecurs env p2)
    | Merge (p1,p2) -> mk_merge (derecurs env p1) (derecurs env p2)
370

371
  and derecurs_regexp env = function
372
    | Epsilon -> mk_epsilon
373
374
375
376
377
378
    | Elem p -> mk_elem (derecurs env p)
    | Guard p -> mk_guard (derecurs env p)
    | Seq (p1,p2) -> mk_seq (derecurs_regexp env p1) (derecurs_regexp env p2)
    | Alt (p1,p2) -> mk_alt (derecurs_regexp env p1) (derecurs_regexp env p2)
    | Star p -> mk_star (derecurs_regexp env p)
    | WeakStar p -> mk_weakstar (derecurs_regexp env p)
Pietro Abate's avatar
Pietro Abate committed
379
    | SeqCapture ((loc,x),p) -> mk_seqcapt (ident env.penv_tenv loc x) (derecurs_regexp env p)
380

381
382
  and derecurs_var env loc ids =
    match ids with
383
      | ([v],a) ->
384
	  let v = ident env.penv_tenv loc v in
Pietro Abate's avatar
Pietro Abate committed
385
386
387
	  begin 
          try Env.find v env.penv_derec
	    with Not_found ->
388
389
390
391
392
393
394
395
396
	     try 
             let (t,pargs) = find_local_type env.penv_tenv loc v in
             let palen = Array.length pargs in
             if palen <> List.length a then
               raise_loc_generic loc
                 (Printf.sprintf "Parametric type %s is not fully qualified" (Ident.to_string v));
             let a = Array.of_list a in
             let l = ref [] in
             for i=0 to (Array.length pargs) - 1 do
397
398
399
400
401
402
               try
                 let err s = Error s in
                 l := (pargs.(i), typ ~err (derecurs env a.(i)))::!l
               with 
               |Error s -> raise_loc_generic loc s
               |_ -> assert false
403
404
             done;
             mk_type (Types.Positive.substitute_list t !l)
405
406
407
408
409
410
	     with Not_found ->
             if List.length a >= 1 then
               raise_loc_generic loc
                (Printf.sprintf "Parametric type %s does not exists" (Ident.to_string v))
             else
               mk_capture v
Pietro Abate's avatar
Pietro Abate committed
411
412
        end
      | (ids,_) ->
413
          mk_type (fst(find_global_type env.penv_tenv loc ids))
414

415
  and derecurs_def env b =
416
    let seen = ref IdSet.empty in
417
    let b =
Pietro Abate's avatar
Pietro Abate committed
418
      List.map (fun ((loc,v),_,p) ->
419
	   let v = ident env.penv_tenv loc v in
420
	   if IdSet.mem !seen v then
421
	     raise_loc_generic loc
422
	       ("Multiple definitions for the type identifer " ^
423
424
		  (Ident.to_string v));
	   seen := IdSet.add v !seen;
Pietro Abate's avatar
Pietro Abate committed
425
426
427
	   (v,p,delayed loc)
      ) b 
    in
428
    let n = List.fold_left (fun env (v,p,s) -> Env.add v s env) env.penv_derec b in
429
    let env = { env with penv_derec = n } in
430
    List.iter (fun (v,p,s) -> link s (derecurs env p)) b;
431
432
    (env, b)

433
434
  let derec penv p =
    let d = derecurs penv p in
435
    elim_concats ();
436
    check_delayed ();
437
    internalize d;
438
    d
439

440
(* API *)
441

442
443
444
445
  let check_no_fv loc n =
    match peek_fv n with
      | None -> ()
      | Some x ->
446
	  raise_loc_generic loc
447
448
	    ("Capture variable not allowed: " ^ (Ident.to_string x))

449
  let type_defs env b =
450
    let _,b' = derecurs_def (penv env) b in
451
452
453
454
455
    elim_concats ();
    check_delayed ();
    let aux loc d =
      internalize d;
      check_no_fv loc d;
456
      try typ d
457
      with Patterns.Error s -> raise_loc_generic loc s
458
    in
459
    let b =
Pietro Abate's avatar
Pietro Abate committed
460
      List.map2 (fun ((loc,v),pl,p) (v',_,d) ->
Pietro Abate's avatar
Pietro Abate committed
461
462
463
464
        let t = aux loc d in
        if (loc <> noloc) && (Types.is_empty t) then
         warning loc
           ("This definition yields an empty type for " ^ (U.to_string v));
Pietro Abate's avatar
Pietro Abate committed
465
466
467
468
469
470
        let al =
          let a = Array.make (List.length pl) (Var.mk "dummy")in
          List.iteri (fun i v -> a.(i) <- Var.mk (Ident.U.to_string v)) pl;
          a
        in 
        (v',t,al)
Pietro Abate's avatar
Pietro Abate committed
471
472
      ) b b' 
    in
473
474
475
    List.iter (fun (v,t,al) ->
      Types.Print.register_global ("",v,Array.map Types.var al) t
    ) b;
476
    enter_types b env
477

478
479
480
481
  let type_defs env b =
    try type_defs env b
    with exn -> clean_on_err (); raise exn

482
  let typ env t =
483
    try
484
      let d = derec (penv env) t in
485
486
487
488
      check_no_fv t.loc d;
      try typ_node d
      with Patterns.Error s -> raise_loc_generic t.loc s
    with exn -> clean_on_err (); raise exn
489

490
  let pat env t =
491
492
493
494
495
    try
      let d = derec (penv env) t in
      try pat_node d
      with Patterns.Error s -> raise_loc_generic t.loc s
    with exn -> clean_on_err (); raise exn
496

497
end
498
499
500
501
502
503

let typ = IType.typ
let pat = IType.pat
let type_defs = IType.type_defs

let dump_types ppf env =
504
505
  Env.iter (fun v ->
	      function
506
507
508
509
510
511
512
513
		  (Type _) -> Format.fprintf ppf " %a" Ident.print v
		| _ -> ()) env.ids

let dump_ns ppf env =
  Ns.dump_table ppf env.ns



514

515
516
(* II. Build skeleton *)

517

518
type type_fun = Types.t -> bool -> Types.t
519

520
module Fv = IdSet
521

522
523
524
type branch = Branch of Typed.branch * branch list

let cur_branch : branch list ref = ref []
525

526
let exp' loc e =
Pietro Abate's avatar
Pietro Abate committed
527
528
529
530
  { Typed.exp_loc = loc;
    Typed.exp_typ = Types.empty;
    Typed.exp_descr = e
  }
531
532
533
534
535

let exp loc fv e = fv, exp' loc e

let exp_nil = exp' noloc (Typed.Cst Sequence.nil_cst)

536
let pat_true =
537
538
539
540
  let n = Patterns.make Fv.empty in
  Patterns.define n (Patterns.constr Builtin_defs.true_type);
  n

541
let pat_false =
542
543
544
545
  let n = Patterns.make Fv.empty in
  Patterns.define n (Patterns.constr Builtin_defs.false_type);
  n

546
let ops = Hashtbl.create 13
547
548
let register_op op arity f = Hashtbl.add ops op (arity,f)
let typ_op op = snd (Hashtbl.find ops op)
549

550
551
552
553
554
let fun_name env a =
  match a.fun_name with
    | None -> None
    | Some (loc,s) -> Some (ident env loc s)

555
556
557
558
559
let count_arg_name = ref 0
let fresh_arg_name () =
    incr count_arg_name;
    "__abstr_arg" ^ (string_of_int !count_arg_name)

560
let is_op env s =
561
562
  if (Env.mem s env.ids) then None
  else
563
564
    let (ns,s) = s in
    if Ns.Uri.equal ns Ns.empty then
565
      let s = U.get_str s in
566
      try
567
568
569
570
	let o = Hashtbl.find ops s in
	Some (s, fst o)
      with Not_found -> None
    else None
571

572
573
let rec expr env loc = function
  | LocatedExpr (loc,e) -> expr env loc e
574
  | Forget (e,t) ->
575
      let (fv,e) = expr env loc e and t = typ env t in
576
      exp loc fv (Typed.Forget (e,t))
577
578
  | Check (e,t) ->
      let (fv,e) = expr env loc e and t = typ env t in
579
      exp loc fv (Typed.Check (ref Types.empty,e,t))
580
  | Var s -> var env loc s
581
  | Apply (e1,e2) ->
582
583
584
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
      let fv = Fv.cup fv1 fv2 in
      (match e1.Typed.exp_descr with
585
	 | Typed.Op (op,arity,args) when arity > 0 ->
586
587
588
589
	     exp loc fv (Typed.Op (op,arity - 1,args @ [e2]))
	 | _ ->
	     exp loc fv (Typed.Apply (e1,e2)))
  | Abstraction a -> abstraction env loc a
590
  | (Integer _ | Char _ | Atom _ | Const _ ) as c ->
591
      exp loc Fv.empty (Typed.Cst (const env loc c))
592
  | Pair (e1,e2) ->
593
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
594
595
      exp loc (Fv.cup fv1 fv2) (Typed.Pair (e1,e2))
  | Xml (e1,e2) ->
596
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
597
598
      let n = if env.keep_ns then Some env.ns else None in
      exp loc (Fv.cup fv1 fv2) (Typed.Xml (e1,e2,n))
599
  | Dot _ as e ->
600
601
602
603
604
      dot loc env e []
  | TyArgs (Dot _ as e, args) ->
      dot loc env e args
  | TyArgs _ ->
      error loc "Only OCaml external can have type arguments"
605
  | RemoveField (e,l) ->
606
607
      let (fv,e) = expr env loc e in
      exp loc fv (Typed.RemoveField (e,parse_label env loc l))
608
  | RecordLitt r ->
609
      let fv = ref Fv.empty in
610
      let r = parse_record env loc
611
612
		(fun e ->
		   let (fv2,e) = expr env loc e
613
614
615
		   in fv := Fv.cup !fv fv2; e)
		r in
      exp loc !fv (Typed.RecordLitt r)
616
  | String (i,j,s,e) ->
617
      let (fv,e) = expr env loc e in
618
      exp loc fv (Typed.String (i,j,s,e))
619
  | Match (e,b) ->
620
621
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
622
      exp loc (Fv.cup fv1 fv2) (Typed.Match (e, b))
623
  | Map (e,b) ->
624
625
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
626
627
      exp loc (Fv.cup fv1 fv2) (Typed.Map (e, b))
  | Transform (e,b) ->
628
629
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
630
      exp loc (Fv.cup fv1 fv2) (Typed.Transform (e, b))
631
  | Xtrans (e,b) ->
632
633
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
634
      exp loc (Fv.cup fv1 fv2) (Typed.Xtrans (e, b))
635
  | Validate (e,ids) ->
636
      let (fv,e) = expr env loc e in
637
      let (t,v) = find_global_schema_component env loc ids  in
638
      exp loc fv (Typed.Validate (e, t, v))
639
640
  | SelectFW (e,from,where) ->
      select_from_where env loc e from where
641
  | Try (e,b) ->
642
643
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
644
      exp loc (Fv.cup fv1 fv2) (Typed.Try (e, b))
645
  | NamespaceIn (pr,ns,e) ->
646
      let env = type_ns env loc pr ns in
647
      expr env loc e
648
649
  | KeepNsIn (k,e) ->
      expr (type_keep_ns env k) loc e
650
  | Ref (e,t) ->
651
      let (fv,e) = expr env loc e and t = typ env t in
652
      exp loc fv (Typed.Ref (e,t))
653
654
655
656
657
658
659

and if_then_else loc cond yes no =
  let b = {
    Typed.br_typ = Types.empty;
    Typed.br_branches = [
      { Typed.br_loc = yes.Typed.exp_loc;
	Typed.br_used = false;
660
	Typed.br_ghost = false;
661
	Typed.br_vars_empty = Fv.empty;
662
	Typed.br_vars_poly = IdMap.empty;
663
664
665
666
	Typed.br_pat = pat_true;
	Typed.br_body = yes };
      { Typed.br_loc = no.Typed.exp_loc;
	Typed.br_used = false;
667
	Typed.br_ghost = false;
668
	Typed.br_vars_empty = Fv.empty;
669
	Typed.br_vars_poly = IdMap.empty;
670
671
672
673
674
	Typed.br_pat = pat_false;
	Typed.br_body = no } ];
    Typed.br_accept = Builtin_defs.bool;
  } in
  exp' loc (Typed.Match (cond,b))
675
676


677
and dot loc env0 e args =
678
  let dot_access loc (fv,e) l =
679
680
681
682
683
684
685
686
687
688
689
    exp loc fv (Typed.Dot (e,parse_label env0 loc l)) in

  let no_args () =
    if args <> [] then
      error loc "Only OCaml externals can have type arguments" in
  let rec aux loc = function
    | LocatedExpr (loc,e) -> aux loc e
    | Dot (e,id) ->
	(match aux loc e with
	   | `Val e -> `Val (dot_access loc e id)
	   | `Comp c -> `Comp (navig loc env0 c id))
690
    | Var id ->
691
	(match find_id_comp env0 env0 loc id with
692
693
694
695
696
697
	   | Val _ -> `Val (var env0 loc id)
	   | c -> `Comp (env0,c))
    | e -> `Val (expr env0 loc e)
  in
  match aux loc e with
    | `Val e -> no_args (); e
698
    | `Comp (_,EVal (cu,id,t)) ->
699
700
701
	no_args (); exp loc Fv.empty (Typed.ExtVar (cu,id,t))
    | `Comp (_,EOCamlComponent s) -> extern loc env0 s args
    | _ -> error loc "This dot notation does not refer to a value"
702
703

and extern loc env s args =
704
705
  let args = List.map (typ env) args in
  try
706
707
708
709
710
711
    let (i,t) =
      if !has_static_external s then
	(`Builtin s, Externals.typ s args)
      else
	let (i,t) = Externals.resolve s args in
	(`Ext i, t) in
712
713
    exp loc Fv.empty (Typed.External (t,i))
  with exn -> raise_loc loc exn
714

715
and var env loc s =
716
717
  let id = ident env loc s in
  match is_op env id with
718
719
    | Some (s,arity) ->
	let e = match s with
720
721
722
723
	  | "print_xml" | "print_xml_utf8" ->
	      Typed.NsTable (env.ns,Typed.Op (s, arity, []))
	  | "load_xml" when env.keep_ns ->
	      Typed.Op ("!load_xml",arity,[])
724
	  | _ -> Typed.Op (s, arity, [])
725
	in
726
	exp loc Fv.empty e
727
    | None ->
728
729
730
731
732
733
	try match Env.find id env.ids with
	  | Val _ -> exp loc (Fv.singleton id) (Typed.Var id)
	  | EVal (cu,id,t) -> exp loc Fv.empty (Typed.ExtVar (cu,id,t))
	  | _ ->  error loc "This identifier does not refer to a value"
	with Not_found -> error loc "Unbound identifier"

734
and abstraction env loc a =
735
736
  let iface =
    List.map
737
      (fun (t1,t2) -> (typ env t1, typ env t2)) a.fun_iface in
738
739
740
  let t =
    List.fold_left
      (fun accu (t1,t2) -> Types.cap accu (Types.arrow t1 t2))
741
      Types.any iface in
742
743
744
  let iface =
    List.map
      (fun (t1,t2) -> (Types.descr t1, Types.descr t2))
745
      iface in
746
  let fun_name = fun_name env a in
747
748
  let env' =
    match fun_name with
749
750
751
752
      | None -> env
      | Some f -> enter_values_dummy [ f ] env
  in
  let (fv0,body) = branches env' a.fun_body in
753
  let fv = match fun_name with
754
755
    | None -> fv0
    | Some f -> Fv.remove f fv0 in
756
  let e = Typed.Abstraction
757
	    { Typed.fun_name = fun_name;
758
759
760
761
762
763
	      Typed.fun_iface = iface;
	      Typed.fun_body = body;
	      Typed.fun_typ = t;
	      Typed.fun_fv = fv
	    } in
  exp loc fv e
764
765

and branches env b =
766
767
  let fv = ref Fv.empty in
  let accept = ref Types.empty in
768
  let branch (p,e) =
769
770
    let cur_br = !cur_branch in
    cur_branch := [];
771
772
    let ploc = p.loc in
    let p = pat env p in
773
774
775
776
    let () =
      let t = Types.descr (Patterns.accept p) in
      if not (Types.no_var t) then error ploc "Type variables cannot occur in patterns"
    in
777
778
779
    let fvp = Patterns.fv p in
    let (fv2,e) = expr (enter_values_dummy fvp env) noloc e in
    let br_loc = merge_loc ploc e.Typed.exp_loc in
780
781
782
    (match Fv.pick (Fv.diff fvp fv2) with
       | None -> ()
       | Some x ->
783
	   let x = Ident.to_string x in
784
785
	   warning br_loc
	     ("The capture variable " ^ x ^
Pietro Abate's avatar
Pietro Abate committed
786
787
	      " is declared in the pattern but not used in the body of this branch." ^
            " It might be a misspelled or undeclared type or name (if it isn't, use _ instead)."));
788
789
    let fv2 = Fv.diff fv2 fvp in
    fv := Fv.cup !fv fv2;
790
    accept := Types.cup !accept (Types.descr (Patterns.accept p));
791
    let ghost = br_loc == noloc in
792
793
    let br =
      {
794
	Typed.br_loc = br_loc;
795
796
	Typed.br_used = ghost;
	Typed.br_ghost = ghost;
797
	Typed.br_vars_empty = fvp;
798
	Typed.br_vars_poly = IdMap.empty;
799
	Typed.br_pat = p;
800
801
802
803
	Typed.br_body = e } in
    cur_branch := Branch (br, !cur_branch) :: cur_br;
    br in
  let b = List.map branch b in
804
805
806
807
  (!fv,
   {
     Typed.br_typ = Types.empty;
     Typed.br_branches = b;
808
     Typed.br_accept = !accept;
809
   }
810
  )
811

812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
and select_from_where env loc e from where =
  let env = ref env in
  let all_fv = ref Fv.empty in
  let bound_fv = ref Fv.empty in
  let clause (p,e) =
    let ploc = p.loc in
    let p = pat !env p in
    let fvp = Patterns.fv p in
    let (fv2,e) = expr !env noloc e in
    env := enter_values_dummy fvp !env;
    all_fv := Fv.cup (Fv.diff fv2 !bound_fv) !all_fv;
    bound_fv := Fv.cup fvp !bound_fv;
    (ploc,p,fvp,e) in
  let from = List.map clause from in
  let where = List.map (expr !env noloc) where in

828
  let put_cond rest (fv,cond) =
829
830
    all_fv := Fv.cup (Fv.diff fv !bound_fv) !all_fv;
    if_then_else loc cond rest exp_nil in
831
  let aux (ploc,p,fvp,e) (where,rest) =
832
833
834
835
836
    (* Put here the conditions that depends on variables in fvp *)
    let (above,here) = List.partition (fun (v,_) -> Fv.disjoint v fvp) where in
    (* if cond then ... else [] *)
    let rest = List.fold_left put_cond rest here in
    (* transform e with p -> ... *)
837
    let br = { Typed.br_loc = ploc;
838
	  Typed.br_used = false;
839
	  Typed.br_ghost = false;
840
	  Typed.br_vars_empty = fvp;
841
        Typed.br_vars_poly = IdMap.empty;
842
	  Typed.br_pat = p;
843
844
845
846
847
	  Typed.br_body = rest } in
    cur_branch := [ Branch (br, !cur_branch) ];
    let b = {
      Typed.br_typ = Types.empty;
      Typed.br_branches = [ br ];
848
849
850
851
852
      Typed.br_accept = Types.descr (Patterns.accept p);
    } in
    let br_loc = merge_loc ploc e.Typed.exp_loc in
    (above,exp' br_loc (Typed.Transform (e, b)))
  in
853
854
  let cur_br = !cur_branch in
  cur_branch := [];
855
  let (fv,e) = expr !env noloc (Pair(e,cst_nil)) in
856
  cur_branch := !cur_branch @ cur_br;
857
858
859
860
861
862
863
864
865
866
  let (where,rest) = List.fold_right aux from (where,e) in
  (* The remaining conditions are constant. Gives a warning for that. *)
  (match where with
     | (_,e) :: _ ->
	 warning e.Typed.exp_loc
	   "This 'where' condition does not depend on any captured variable"
     | _ -> ());
  let rest = List.fold_left put_cond rest where in
  (Fv.cup !all_fv (Fv.diff fv !bound_fv)), rest

867
let expr env e = snd (expr env noloc e)
868

869
870
let let_decl env p e =
  { Typed.let_pat = pat env p;
871
    Typed.let_body = expr env e }
872

873
874
875

(* Hide global "typing/parsing" environment *)

876

877
878
(* III. Type-checks *)

879
880
open Typed

881
let localize loc f x =
882
883
  try f x with
  | (Error _ | Constraint (_,_)) as exn ->
Pietro Abate's avatar
Pietro Abate committed
884
885
      raise (Cduce_loc.Location (loc,`Full,exn))
  | Warning (s,t) -> warning loc s; t
886