typer.ml 60 KB
Newer Older
1
(* TODO:
2
 - check whether it is worth using recursive hash-consing internally
3
4
*)

5
6
7
open Location
open Ast
open Ident
8

9
10
11
12
13
14
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

15
let warning loc msg =
16
  let v = Location.get_viewport () in
17
  let ppf = if Html.is_html v then Html.ppf v else Format.err_formatter in
18
19
20
  Format.fprintf ppf "Warning %a:@\n" Location.print_loc (loc,`Full);
  Location.html_hilight (loc,`Full);
  Format.fprintf ppf "%s@." msg
21

22
23
24
25
26
27
28
29
30
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
exception UnboundExtId of Types.CompUnit.t * id
exception Error of string

31
32
33

exception Warning of string * Types.t

34
35
36
37
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)

38

39
40
type item =
  | Type of Types.t
41
  | Val of Types.t
42

43
44
45
46
47
type ext =
  | ECDuce of Types.CompUnit.t   (* CDuce unit *)
  | EOCaml of string             (* OCaml module *)
  | ESchema of string            (* XML Schema *)

48
49
module UEnv = Map.Make(U)

50
type t = {
51
  ids : item Env.t;
52
  ns: Ns.table;
53
  cu: ext UEnv.t;
54
}
55

56
57
58
59
60
let hash _ = failwith "Typer.hash"
let compare _ _ = failwith "Typer.compare"
let dump ppf _ = failwith "Typer.dump"
let equal _ _ = failwith "Typer.equal"
let check _ = failwith "Typer.check"
61

62
63
64

let load_schema_fwd = ref (fun x uri -> assert false)

65
66
let type_schema env x uri =
  !load_schema_fwd x uri;
67
  { env with cu = UEnv.add x (ESchema uri) env.cu }
68

69
(* TODO: filter out builtin defs ? *)
70
71
72
73
let serialize_item s = function
  | Type t -> Serialize.Put.bits 1 s 0; Types.serialize s t
  | Val t -> Serialize.Put.bits 1 s 1; Types.serialize s t

74
let serialize s env =
75
  Serialize.Put.env Id.serialize serialize_item Env.iter s env.ids;
76
77
78
  Ns.serialize_table s env.ns;

  let schs =
79
80
81
    UEnv.fold (fun name cu accu -> 
		 match cu with ESchema uri -> (name,uri)::accu | _ -> accu) 
      env.cu [] in
82
  Serialize.Put.list (Serialize.Put.pair U.serialize Serialize.Put.string) s schs
83

84
85
86
87
88
let deserialize_item s = match Serialize.Get.bits 1 s with
  | 0 -> Type (Types.deserialize s)
  | 1 -> Val (Types.deserialize s)
  | _ -> assert false

89
let deserialize s =
90
  let ids = Serialize.Get.env Id.deserialize deserialize_item Env.add Env.empty s in
91
  let ns = Ns.deserialize_table s in
92
93
94
95
  let schs = 
    Serialize.Get.list 
      (Serialize.Get.pair U.deserialize Serialize.Get.string) s in
  let env = 
96
    { ids = ids; ns = ns; cu = UEnv.empty } in
97
  List.fold_left (fun env (name,uri) -> type_schema env name uri) env schs
98
99


100
101
let empty_env = {
  ids = Env.empty;
102
  ns = Ns.empty_table;
103
  cu = UEnv.empty;
104
105
}

106
107
108
let from_comp_unit = ref (fun (cu : Types.CompUnit.t) -> assert false)
let has_comp_unit = ref (fun cu -> assert false)
let has_ocaml_unit = ref (fun cu -> false)
109
110
let has_static_external = ref (fun _ -> assert false)

111

112
let enter_cu x cu env =
113
  { env with cu = UEnv.add x (ECDuce cu) env.cu }
114

115
let find_cu loc x env =
116
  try UEnv.find x env.cu
117
118
119
120
  with Not_found ->
    if !has_comp_unit x then (ECDuce (Types.CompUnit.mk x))
    else if !has_ocaml_unit x then (EOCaml (U.get_str x))
    else error loc ("Cannot find external unit " ^ (U.to_string x))
121
122


123
let find_schema x env =
124
125
126
127
128
129
  try 
    (match UEnv.find x env.cu with
      | ESchema s -> s 
      | _ -> raise Not_found)
  with Not_found -> 
    raise (Error (Printf.sprintf "%s: no such schema" (U.to_string x)))
130

131
132
133
134
135
136
137
138
let enter_type id t env =
  { env with ids = Env.add id (Type t) env.ids }
let enter_types l env =
  { env with ids = 
      List.fold_left (fun accu (id,t) -> Env.add id (Type t) accu) env.ids l }
let find_type id env =
  match Env.find id env.ids with
    | Type t -> t
139
    | Val _ -> raise Not_found
140

141

142
let enter_value id t env = 
143
  { env with ids = Env.add id (Val t) env.ids }
144
145
let enter_values l env =
  { env with ids = 
146
      List.fold_left (fun accu (id,t) -> Env.add id (Val t) accu) env.ids l }
147
148
149
let enter_values_dummy l env =
  { env with ids = 
      List.fold_left (fun accu id -> Env.add id (Val Types.empty) accu) env.ids l }
150
151
let find_value id env =
  match Env.find id env.ids with
152
    | Val t -> t
153
    | _ -> raise Not_found
154
155
156
let find_value_global loc cu id env =
  try find_value id (!from_comp_unit cu)
  with Not_found -> raise_loc loc (UnboundExtId (cu,id))
157
	
158
159
160
161
162
163
let value_name_ok id env =
  try match Env.find id env.ids with
    | Val t -> true
    | _ -> false
  with Not_found -> true

164
165
166
167
let iter_values env f =
  Env.iter (fun x ->
	      function Val t -> f x t;
		| _ -> ()) env.ids
168

169

170
let register_types cu env =
171
172
173
  Env.iter (fun x t -> match t with
	      | Type t -> Types.Print.register_global cu (Ident.value x) t
	      | _ -> ()) env.ids
174

175

176
(* Namespaces *)
177

178
let set_ns_table_for_printer env = 
179
  Ns.InternalPrinter.set_table env.ns
180

181
let get_ns_table tenv = tenv.ns
182

183
let type_ns env p ns =
184
  { env with ns = Ns.add_prefix p ns env.ns }
185

186
187
188
189
190
let protect_error_ns loc f x =
  try f x
  with Ns.UnknownPrefix ns ->
    raise_loc_generic loc 
    ("Undefined namespace prefix " ^ (U.to_string ns))
191

192
193
194
let qname env loc t = 
  protect_error_ns loc (Ns.map_tag env.ns) t
    
195
196
197
198
199
200
201
202
203
204
let ident env loc t =
  let q = protect_error_ns loc (Ns.map_attr env.ns) t in
  Ident.ident q

let has_value id env =
  try match Env.find (Ident.ident (Ns.map_attr env.ns id)) env.ids with
    | Val t -> true
    | _ -> false
  with Not_found | Ns.UnknownPrefix _ -> false

205
let parse_atom env loc t =
206
  Atoms.V.of_qname (qname env loc t)
207
208
 
let parse_ns env loc ns =
209
  protect_error_ns loc (Ns.map_prefix env.ns) ns
210

211
let parse_label env loc t =
212
  let (ns,l) = protect_error_ns loc (Ns.map_attr env.ns) t in
213
  LabelPool.mk (ns,l)
214

215
216
217
218
219
220
221
222
223
224
225
226
227
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

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
228
  | Const c -> c
229
230
231
232
  | _ -> 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 *)
233

234

235
(* Schema *)
236

237
(* uri -> schema binding *)
238
239
240
241
let schemas = Hashtbl.create 13

let find_schema_component uri name =
  Env.find (Ident.ident name) (Hashtbl.find schemas uri)
242

243
let find_schema_descr uri (name : Ns.qname) =
244
  try fst (find_schema_component uri name)
245
246
247
  with Not_found ->    
    raise (Error (Printf.sprintf "No component named '%s' found in schema '%s'"
		    (Ns.QName.to_string name) uri))
248
249


250
251
252
253
254
255
let find_type_global loc cu id env =
  match find_cu loc cu env with
    | ECDuce cu -> find_type id (!from_comp_unit cu)
    | EOCaml _ -> error loc "OCaml units don't export types" (* TODO *)
    | ESchema s -> find_schema_descr s (Ident.value id)
	
256

257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
module IType = struct
  type node = {
    mutable desc: desc;
    mutable smallhash: int;  (* Local hash *)
    mutable rechash: int;    (* Global (recursive) hash *)
    mutable sid: int;        (* Sequential id used to compute rechash *)
    mutable t: Types.t option;
    mutable tnode: Types.Node.t option;
    mutable p: Patterns.descr option;
    mutable pnode: Patterns.node option;
    mutable fv: fv option
  } 
  and desc =
    | ILink of node
    | IType of Types.descr * int
    | IOr of node * node
    | IAnd of node * node
    | IDiff of node * node
    | ITimes of node * node
    | IXml of node * node
    | IArrow of node * node
    | IOptional of node
    | IRecord of bool * (node * node option) label_map
    | ICapture of id
    | IConstant of id * Types.const
282
    | IConcat of node * node
283
    | IMerge of node * node
284
285
286
287
288
289
290
291

  let rec node_temp = { 
    desc = ILink node_temp;
    smallhash = 0; rechash = 0; sid = 0;
    t = None; tnode = None; p = None; pnode = None;
    fv = None
  }
			
292
(* Recursive hash-consing *)
293

294
295
296
297
298
299
  let hash_field f = function
    | (p, Some e) -> 1 + 17 * f p + 257 * f e
    | (p, None) -> 2 + 17 * f p

  let rec hash f n = match n.desc with
    | ILink n -> hash f n
300
    | IType (t,h) -> 1 + 17 * h
301
302
303
304
305
306
307
308
309
    | IOr (p1,p2) -> 2 + 17 * f p1 + 257 * f p2
    | IAnd (p1,p2) -> 3 + 17 * f p1 + 257 * f p2
    | IDiff (p1,p2) -> 4 + 17 * f p1 + 257 * f p2
    | ITimes (p1,p2) -> 5 + 17 * f p1 + 257 * f p2
    | IXml (p1,p2) -> 6 + 17 * f p1 + 257 * f p2
    | IArrow (p1,p2) -> 7 + 17 * f p1 + 257 * f p2
    | IOptional p -> 8 + 17 * f p
    | IRecord (o,r)->9+(if o then 17 else 0)+
	257*(LabelMap.hash (hash_field f) r)
310
311
    | ICapture x -> 10 + 17 * (Id.hash x)
    | IConstant (x,c) -> 11 + 17 * (Id.hash x) + 257*(Types.Const.hash c)
312
    | IConcat _ | IMerge _ -> assert false
313

314
315
316
317
318
  let hash0 = hash (fun n -> 1)
  let hash1 = hash hash0
  let hash2 = hash hash1
  let hash3 = hash hash2

319
320
  let smallhash n =
    if n.smallhash !=0 then n.smallhash
321
322
323
324
    else (
      let h = hash2 n in 
      n.smallhash <- h; h
    )
325
326

  let rec repr = function
327
    | { desc = ILink n } as m -> let z = repr n in m.desc <- ILink z; z
328
329
330
331
    | n -> n

  let back = ref []

332
333
334
335
  let rec prot_repr = function
    | { desc = ILink n } -> repr n
    | n -> n

336
337
338
339
340
341
342
343
344
  let link x y = match x,y with
    | { t = None } as x, y 
    | y, ({ t = None } as x) -> back := (x,x.desc) :: !back; x.desc <- ILink y
    | _ -> assert false

  exception Unify

  let rec unify x y =
    if x == y then ()
345
346
347
348
349
    else let x = prot_repr x and y = prot_repr y in if x == y then ()
    else if (smallhash x != smallhash y) then raise Unify 
    else if (x.t != None) && (y.t != None) then raise Unify
      (* x and y have been internalized; if they were equivalent,
	 they would be equal *)
350
    else match x.desc,y.desc with
351
      | IType (tx,_), IType (ty,_) when Types.equal tx ty -> link x y
352
353
354
355
356
      | IOr (x1,x2), IOr (y1,y2)
      | IAnd (x1,x2), IAnd (y1,y2)
      | IDiff (x1,x2), IDiff (y1,y2)
      | ITimes (x1,x2), ITimes (y1,y2)
      | IXml (x1,x2), IXml (y1,y2)
357
358
      | IArrow (x1,x2), IArrow (y1,y2) -> link x y; unify x1 y1; unify x2 y2
      | IOptional x1, IOptional y1 -> link x y; unify x1 y1
359
360
361
362
363
364
365
366
367
368
369
      | IRecord (xo,xr), IRecord (yo,yr) when xo == yo ->
	  link x y; LabelMap.may_collide unify_field Unify xr yr
      | ICapture xv, ICapture yv when Id.equal xv yv -> ()
      | IConstant (xv,xc), IConstant (yv,yc) when
	  Id.equal xv yv && Types.Const.equal xc yc -> ()
      | _ -> raise Unify
  and unify_field f1 f2 = match f1,f2 with
    | (p1, Some e1), (p2, Some e2) -> unify p1 p2; unify e1 e2
    | (p1, None), (p2, None) -> unify p1 p2
    | _ -> raise Unify

370

371
372
  let may_unify x y =
    try unify x y; back := []; true
373
    with Unify ->
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
      List.iter (fun (x,xd) -> x.desc <- xd) !back; back := []; false

  module SmallHash = Hashtbl.Make(
    struct 
      type t = node
      let equal = may_unify
      let hash = smallhash
    end
  )

  let iter_field f = function
    | (x, Some y) -> f x; f y
    | (x, None) -> f x
  let iter f = function
    | IOr (x,y) | IAnd (x,y) | IDiff (x,y)
    | ITimes (x,y) | IXml (x,y) | IArrow (x,y) -> f x; f y
    | IOptional x -> f x
    | IRecord (_,r) -> LabelMap.iter (iter_field f) r
    | _ -> ()

  let minimize ((mem,add) as h) =
    let rec aux n =
      let n = repr n in
397
398
399
400
      if mem n then () else (
	let n = repr n in add n (); 
	if n.t == None then iter aux n.desc
      )
401
402
403
404
405
406
407
    in aux

  let to_clear = ref []
  let sid = ref 0
  let rec rechash n =
    let n = repr n in
    if (n.sid != 0) then 17 * n.sid
408
    else (incr sid; n.sid <- !sid; to_clear := n :: !to_clear; hash rechash n)
409
410

  let clear () =
411
412
    sid := 0; List.iter (fun x -> x.sid <- 0) !to_clear;
    to_clear := []
413
414
415
416
417
418
419
420
421
422
423
424
425
426

  let rechash n =
    let n = repr n in
    if (n.rechash != 0) then n.rechash 
    else (let h = rechash n in clear (); n.rechash <- h; h)

  module RecHash = Hashtbl.Make(
    struct
      type t = node
      let equal = may_unify
      let hash = smallhash
    end
  )

427
428
429

(** Two-phases recursive hash-consing **)
(*
430
431
432
  let gtable = RecHash.create 17577

  let internalize n =
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
    let local = SmallHash.create 17 in
    minimize (SmallHash.mem local, SmallHash.add local) n; 
    minimize (RecHash.mem gtable, RecHash.add gtable) n;
    ()
*)

(** Single-phase hash-consing **)
  let gtable = SmallHash.create 17

  let internalize n =
    minimize (SmallHash.mem gtable, SmallHash.add gtable) n



(*  let internalize n = () *)
448
449
450
451
452
453
454
455
456

(* Compute free variables *)

  let fv n =
    let fv = ref IdSet.empty in
    let rec aux n =
      let n = repr n in
      if (n.sid = 0) then (
	n.sid <- 1;
457
	to_clear := n :: !to_clear; 
458
459
460
461
462
463
	match n.fv, n.desc with
	  | Some x, _ -> fv := IdSet.cup !fv x
	  | None, (ICapture x | IConstant (x,_)) -> fv := IdSet.add x !fv
	  | None, d -> iter aux d
      )
    in
464
    assert(!to_clear == []);
465
466
467
468
    match n.fv with
      | Some x -> x
      | None -> aux n; clear (); n.fv <- Some !fv; !fv

469
470
471
(* optimized version to check closedness *)

  let no_fv = Some IdSet.empty
472
473
474
  exception FoundFv of id
  let peek_fv n =
    let err x = raise (FoundFv x) in
475
476
477
478
479
480
    let rec aux n =
      let n = repr n in
      if (n.sid = 0) then (
	n.sid <- 1;
	to_clear := n :: !to_clear; 
	match n.fv, n.desc with
481
482
	  | Some x, _ when IdSet.is_empty x -> ()
	  | Some x, _ -> err (IdSet.choose x)
483
484
485
486
	  | None, (ICapture x | IConstant (x,_)) -> err x;
	  | None, d -> iter aux d
      )
    in
487
    assert(!to_clear == []);
488
489
    try
      match n.fv with
490
491
	| Some x when IdSet.is_empty x -> ()
	| Some x -> err (IdSet.choose x)
492
493
494
495
496
	| None -> aux n; 
	    List.iter (fun n -> n.sid <- 0; n.fv <- no_fv) !to_clear;
	    to_clear := []
    with exn -> clear (); raise exn

497
498
499
500
501
502
503
504
505
506
507
  let check_no_fv loc n =
    try peek_fv n 
    with FoundFv x ->
      raise_loc_generic loc 
	("Capture variable not allowed: " ^ (Ident.to_string x))

  let has_no_fv n =
    try peek_fv n; true
    with FoundFv _ -> false


508
(* From the intermediate representation to the internal one *)
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527


  let rec typ n =
    let n = repr n in
    match n.t with
      | Some t -> t
      | None -> let t = compute_typ n.desc in n.t <- Some t; t
  and compute_typ = function
    | IType (t,_) -> t
    | IOr (s1,s2) -> Types.cup (typ s1) (typ s2)
    | IAnd (s1,s2) ->  Types.cap (typ s1) (typ s2)
    | IDiff (s1,s2) -> Types.diff (typ s1) (typ s2)
    | ITimes (s1,s2) -> Types.times (typ_node s1) (typ_node s2)
    | IXml (s1,s2) -> Types.xml (typ_node s1) (typ_node s2)
    | IArrow (s1,s2) -> Types.arrow (typ_node s1) (typ_node s2)
    | IOptional s -> Types.Record.or_absent (typ s)
    | IRecord (o,r) ->  Types.record' (o, LabelMap.map compute_typ_field r)
    | ILink _ -> assert false
    | ICapture _ | IConstant (_,_) -> assert false
528
    | IConcat _ | IMerge _ -> assert false
529
530
531
532
533
534
  and compute_typ_field = function
    | (s, None) -> typ_node s
    | (s, Some _) -> 
	raise (Patterns.Error "Or-else clauses are not allowed in types")

  and typ_node n =
535
    let n = repr n in
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
    match n.tnode with
      | Some t -> t
      | None ->
	  let x = Types.make () in
	  n.tnode <- Some x;
	  Types.define x (typ n);
	  x
      
  let rec pat n =
    let n = repr n in
    if IdSet.is_empty (fv n)
    then Patterns.constr (typ n)
    else match n.p with
      | Some p -> p
      | None -> let p = compute_pat n.desc in n.p <- Some p; p

  and compute_pat = function
    | IOr (s1,s2) -> Patterns.cup (pat s1) (pat s2)
    | IAnd (s1,s2) -> Patterns.cap (pat s1) (pat s2)
    | IDiff (s1,s2) when IdSet.is_empty (fv s2) ->
	let s2 = Types.neg (typ s2) in
	Patterns.cap (pat s1) (Patterns.constr s2)
    | IDiff _ ->
	raise (Patterns.Error "Differences are not allowed in patterns")
    | ITimes (s1,s2) -> Patterns.times (pat_node s1) (pat_node s2)
    | IXml (s1,s2) -> Patterns.xml (pat_node s1) (pat_node s2)
    | IOptional _ -> 
	raise (Patterns.Error "Optional fields are not allowed in record patterns")
    | IRecord (o,r) ->
	let pats = ref [] in
	let aux l = function
	  | (s,None) ->
	      if IdSet.is_empty (fv s) then typ_node s
	      else
		( pats := Patterns.record l (pat_node s) :: !pats;
		  Types.any_node )
	  | (s,Some e) ->
	      if IdSet.is_empty (fv s) then
		raise (Patterns.Error "Or-else clauses are not allowed in types")
	      else
		( pats := Patterns.cup 
		    (Patterns.record l (pat_node s))
		    (pat e) :: !pats;
		  Types.Record.any_or_absent_node )
	in
	let constr = Types.record' (o,LabelMap.mapi aux r) in
	List.fold_left Patterns.cap (Patterns.constr constr) !pats
	  (* TODO: can avoid constr when o=true, and all fields have fv *)
    | ICapture x -> Patterns.capture x
    | IConstant (x,c) -> Patterns.constant x c
    | IArrow _ ->
	raise (Patterns.Error "Arrows are not allowed in patterns")
588
    | IType _ | ILink _ | IConcat _ | IMerge _ -> assert false
589
590
      
  and pat_node n =
591
    let n = repr n in
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
    match n.pnode with
      | Some p -> p
      | None ->
	  let x = Patterns.make (fv n) in
	  try
	    n.pnode <- Some x;
	    Patterns.define x (pat n);
	    x
	  with exn -> n.pnode <- None; raise exn

(* From AST to the intermediate representation *)

  type penv = {
    penv_tenv : t;
    penv_derec : node Env.t;
  }

  let penv tenv = { penv_tenv = tenv; penv_derec = Env.empty }

611
612
  let concats = ref []

613
614
615
616
617
618
  let mk d = { node_temp with desc = d }
  let mk_delayed () = { node_temp with desc = ILink node_temp }
  let itype t = mk (IType (t, Types.hash t))
  let iempty = itype Types.empty

  let ior p1 p2 =
619
620
    if p1.desc == iempty.desc then p2 
    else if p2.desc == iempty.desc then p1 
621
622
623
    else mk (IOr (p1,p2))

  let iand p1 p2 =
624
    if (p1.desc == iempty.desc) || (p2.desc == iempty.desc) then iempty 
625
626
627
628
629
    else mk (IAnd (p1,p2))

  type regexp =
    | PElem of node
    | PGuard of node
630
631
    | PSeq of regexp list
    | PAlt of regexp list
632
633
634
    | PStar of regexp
    | PWeakStar of regexp

635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
  let rec nullable = function
    | PElem _ -> false
    | PSeq rl -> List.for_all nullable rl
    | PAlt rl -> List.exists nullable rl
    | PStar _ | PWeakStar _ | PGuard _ -> true

  let eps = PSeq []
  let emp = PAlt []

  let seq r1 r2 =
    let r1 = match r1 with PSeq l -> l | x -> [ x ] in
    let r2 = match r2 with PSeq l -> l | x -> [ x ] in
    match r1 @ r2 with
      | [ x ] -> x
      | l -> PSeq l

  let alt r1 r2 =
    let r1 = match r1 with PAlt l -> l | x -> [ x ] in
    let r2 = match r2 with PAlt l -> l | x -> [ x ] in
    match r1 @ r2 with
      | [ x ] -> x
      | l -> PAlt l

  let rec merge_alt = function
659
    | PElem p::PElem q::l -> merge_alt (PElem (ior p q) :: l)
660
661
    | r::l -> r::(merge_alt l)
    | [] -> []
662
663
664
665
666
667
668
669
670

(* Works only for types, not patterns, because
   [ (x&Int|_) R' ] is possible *)
  let rec simplify_regexp = function
    | PSeq l -> PSeq (List.map simplify_regexp l)
    | PAlt l -> PAlt (merge_alt (List.map simplify_regexp l))
    | PStar r | PWeakStar r -> PStar (simplify_regexp r)
    | x -> x

671
672
673
674
675
676
677
678
679
  let rec print_regexp ppf = function
    | PElem _ -> Format.fprintf ppf "Elem"
    | PGuard _ -> Format.fprintf ppf "Guard"
    | PSeq l -> Format.fprintf ppf "Seq(%a)" print_regexp_list l
    | PAlt l -> Format.fprintf ppf "Alt(%a)" print_regexp_list l
    | PStar r -> Format.fprintf ppf "Star(%a)" print_regexp r
    | PWeakStar r -> Format.fprintf ppf "WStar(%a)" print_regexp r
  and print_regexp_list ppf l =
    List.iter (fun x -> Format.fprintf ppf "%a;" print_regexp x) l
680

681
682
  let rec remove_regexp r q = 
    match r with
683
684
685
686
    | PElem p ->
	mk (ITimes (p, q))
    | PGuard p ->
	iand p q
687
688
689
690
    | PSeq l ->
	List.fold_right (fun r a -> remove_regexp r a) l q
    | PAlt rl ->
	List.fold_left (fun a r -> ior a (remove_regexp r q)) iempty rl
691
692
693
    | PStar r ->
	let x = mk_delayed () in
	let res = ior x q in
694
	x.desc <- ILink (remove_regexp_nullable r res iempty);
695
696
697
698
	res
    | PWeakStar r ->
	let x = mk_delayed () in
	let res = ior q x in
699
	x.desc <- ILink (remove_regexp_nullable r res iempty);
700
	res
701
702
703
704
705

  and remove_regexp_nullable r q_nonempty q_empty =
    if nullable r then remove_regexp2 r q_nonempty q_empty
    else remove_regexp r q_nonempty

706
  and remove_regexp2 r q_nonempty q_empty =
707
708
    (* Assume r is nullable *)
    if q_nonempty == q_empty then remove_regexp r q_nonempty
709
    else match r with
710
      | PSeq [] ->
711
712
          q_empty
      | PElem p ->
713
	  assert false
714
715
      | PGuard p ->
	  iand p q_empty
716
717
718
719
720
721
722
723
      | PSeq (r::rl) ->
          remove_regexp2 r
            (remove_regexp (PSeq rl) q_nonempty)
            (remove_regexp2 (PSeq rl) q_nonempty q_empty)
      | PAlt rl ->
	  List.fold_left 
	    (fun a r -> ior a (remove_regexp_nullable r q_nonempty q_empty))
	    iempty rl
724
725
      | PStar r ->
 	  let x = mk_delayed () in
726
          x.desc <- ILink (remove_regexp_nullable r (ior x q_nonempty) iempty);
727
728
729
          ior x q_empty
      | PWeakStar r ->
 	  let x = mk_delayed () in
730
          x.desc <- ILink (remove_regexp_nullable r (ior q_nonempty x) iempty);
731
732
733
734
735
736
737
738
739
          ior q_empty x


  let cst_nil = Types.Atom Sequence.nil_atom
  let capture_all vars p = 
    IdSet.fold (fun p x -> iand p (mk (ICapture x))) p vars
  let termin b vars p = 
    if b then p 
    else IdSet.fold 
740
      (fun p x -> seq p (PGuard (mk (IConstant (x,cst_nil))))) p vars
741
742
743

  let rexp r = remove_regexp r (itype Sequence.nil_type)

744
745
  let all_delayed = ref []

746
747
  let clean_on_err () = all_delayed := []

748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
  let delayed loc =
    let s = mk_delayed () in
    all_delayed := (loc,s) :: !all_delayed;
    s

  let check_one_delayed (loc,p) =
    let rec aux q = if p == q then raise Exit; aux2 q.desc
    and aux2 = function
      | IOr (q1,q2) | IAnd (q1,q2) | IDiff (q1,q2) -> aux q1; aux q2
      | ILink q -> aux q
      | _ -> ()
    in
    try aux2 p.desc
    with Exit -> error loc "Ill-formed recursion"
    
  let check_delayed () =
    let l = !all_delayed in
    all_delayed := []; 
    List.iter check_one_delayed l
767

768
    
769
  let rec derecurs env p = match p.descr with
770
    | PatVar (cu,v) -> derecurs_var env p.loc cu v
771
    | Recurs (p,b) -> derecurs (fst (derecurs_def env b)) p
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
    | Internal t -> itype t
    | NsT ns -> 
	itype (Types.atom (Atoms.any_in_ns (parse_ns env.penv_tenv p.loc ns)))
    | Or (p1,p2) -> mk (IOr (derecurs env p1, derecurs env p2))
    | And (p1,p2) -> mk (IAnd (derecurs env p1, derecurs env p2))
    | Diff (p1,p2) -> mk (IDiff (derecurs env p1, derecurs env p2))
    | Prod (p1,p2) -> mk (ITimes (derecurs env p1, derecurs env p2))
    | XmlT (p1,p2) -> mk (IXml (derecurs env p1, derecurs env p2))
    | Arrow (p1,p2) -> mk (IArrow (derecurs env p1, derecurs env p2))
    | Optional p -> mk (IOptional (derecurs env p))
    | Record (o,r) -> 
	let aux = function
	  | (p,Some e) -> (derecurs env p, Some (derecurs env e))
	  | (p,None) -> derecurs env p, None in
	mk (IRecord (o, parse_record env.penv_tenv p.loc aux r))
787
788
    | Constant (x,c) -> mk (IConstant (ident env.penv_tenv p.loc x,
				       const env.penv_tenv p.loc c))
789
790
791
792
    | Cst c -> itype (Types.constant (const env.penv_tenv p.loc c))
    | Regexp r ->
	let r,_ = derecurs_regexp IdSet.empty false IdSet.empty true env r in
	rexp r
793
794
795
796
    | Concat (p1,p2) -> 
	let n = mk (IConcat (derecurs env p1, derecurs env p2)) in
	concats := n :: !concats;
	n
797
798
799
800
    | Merge (p1,p2) -> 
	let n = mk (IMerge (derecurs env p1, derecurs env p2)) in
	concats := n :: !concats;
	n
801
802
803
804
805
806
807
808
809
810
811
812
	  
  and derecurs_regexp vars b rvars f env = function
      (* - vars: seq variables to be propagated top-down and added
	 to each captured element
	 - b: below a star ?
	 - rvars: seq variables that appear on the right of the regexp
	 - f: tail position
	 
	 returns the set of seq variable of the regexp minus rvars
	 (they have already been terminated if not below a star)
      *)
    | Epsilon -> 
813
	PSeq [], IdSet.empty
814
815
816
817
818
819
820
    | Elem p -> 
	PElem (capture_all vars (derecurs env p)), IdSet.empty
    | Guard p ->
	PGuard (derecurs env p), IdSet.empty
    | Seq (p1,p2) -> 
	let (p2,v2) = derecurs_regexp vars b rvars f env p2 in
	let (p1,v1) = derecurs_regexp vars b (IdSet.cup rvars v2) false env p1 in
821
	seq p1 p2, IdSet.cup v1 v2
822
823
824
    | Alt (p1,p2) -> 
	let (p1,v1) = derecurs_regexp vars b rvars f env p1
	and (p2,v2) = derecurs_regexp vars b rvars f env p2 in
825
	alt (termin b (IdSet.diff v2 v1) p1) (termin b (IdSet.diff v1 v2) p2),
826
827
828
829
830
831
832
	IdSet.cup v1 v2
    | Star p -> 
	let (p,v) = derecurs_regexp vars true rvars false env p in
	termin b v (PStar p), v
    | WeakStar p -> 
	let (p,v) = derecurs_regexp vars true rvars false env p in
	termin b v (PWeakStar p), v
833
834
    | SeqCapture (loc,x,p) -> 
	let x = ident env.penv_tenv loc x in
835
836
837
838
839
	let vars = if f then vars else IdSet.add x vars in
	let after = IdSet.mem rvars x in
	let rvars = IdSet.add x rvars in
	let (p,v) = derecurs_regexp vars b rvars false env p in
	(if f 
840
	 then seq (PGuard (mk (ICapture x))) p 
841
842
843
844
	 else termin (after || b) (IdSet.singleton x) p), 
	(if after then v else IdSet.add x v)
	  
	  
845
846
847
848
849
  and derecurs_var env loc cu v =
    let v = ident env.penv_tenv loc v in
    match cu with
      | None ->
	  (try Env.find v env.penv_derec 
850
851
852
	   with Not_found -> 
	     try itype (find_type v env.penv_tenv)
	     with Not_found -> mk (ICapture v))
853
854
855
856
857
858
      | Some cu ->
	  (try itype (find_type_global loc cu v env.penv_tenv)
	   with Not_found ->
	     raise_loc_generic loc 
	       ("Unbound external type " ^ (U.get_str cu) ^ "." ^ 
		  (Ident.to_string v)))
859
860
	      
  and derecurs_def env b =
861
862
863
864
865
866
867
868
869
870
871
872
873
    let seen = ref IdSet.empty in
    let b = 
      List.map 
	(fun (loc,v,p) -> 
	   let v = ident env.penv_tenv loc v in
	   if IdSet.mem !seen v then 
	     raise_loc_generic loc
	       ("Multiple definitions for the type identifer " ^ 
		  (Ident.to_string v));
	   seen := IdSet.add v !seen;
	   (v,p,delayed loc))
	b in

874
875
876
877
    let n = 
      List.fold_left (fun env (v,p,s) -> Env.add v s env) env.penv_derec b in
    let env = { env with penv_derec = n } in
    List.iter (fun (v,p,s) -> s.desc <- ILink (derecurs env p)) b;
878
879
880
881
882
883
884
    (env, b)

  module H = Hashtbl.Make(Types)

  let rec elim_concat n =
    match n.desc with
      | IConcat (a,b) ->
885
886
	  if (n.sid > 0) 
	  then 	raise (Patterns.Error "Ill-formed concatenation loop");
887
888
	  n.sid <- 1;
	  n.desc <- ILink (elim_conc a b)
889
890
891
892
893
      | IMerge (a,b) ->
	  if (n.sid > 0) 
	  then 	raise (Patterns.Error "Ill-formed concatenation loop");
	  n.sid <- 1;
	  n.desc <- ILink (elim_merge a b)
894
      | _ -> ()
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
  and elim_merge a b =
    let get_rec t =
      let t = Types.Record.get t in
      List.map (fun (l,o,_) ->
		  o, 
		  LabelMap.map 
		    (fun (opt,x) ->
		       let x = itype x in 
		       (if opt then mk (IOptional x) else x),
		       None)
		    l) t in
    let merge (o1,l1) (o2,l2) =
      mk (IRecord (o1||o2, LabelMap.merge (fun _ x -> x) l1 l2)) in
    (* Problem: repr can loop with ill-formed recursion.
       type t = s + t where s = s | s;; *)
    match (repr a).desc, (repr b).desc with
      | IType (t1,_), IType (t2,_) -> 
	  if not (Types.subtype t1 Types.Record.any) then
	    raise 
	      (Patterns.Error 
		 "Left argument of record concatenation is not a record type");
	  if not (Types.subtype t2 Types.Record.any) then
	    raise 
	      (Patterns.Error 
		 "Right argument of record concatenation is not a record type");
	  itype (Types.Record.merge t1 t2)
      | IOr (a1,a2), _ -> ior (elim_merge a1 b) (elim_merge a2 b)
      | _, IOr (b1,b2) -> ior (elim_merge a b1) (elim_merge a b2)
      | IRecord (o1,l1), IRecord (o2,l2) -> merge (o1,l1) (o2,l2)
      | IType (t1,_), IRecord (o2,l2) ->
	  if not (Types.subtype t1 Types.Record.any) then
	    raise 
	      (Patterns.Error 
		 "Left argument of record concatenation is not a record type");
	  List.fold_left (fun accu (o1,l1) -> 
			    ior accu (merge (o1,l1) (o2,l2)))
	    iempty (get_rec t1)
      | IRecord (o1,l1), IType (t2,_) ->
	  if not (Types.subtype t2 Types.Record.any) then
	    raise 
	      (Patterns.Error 
		 "Right argument of record concatenation is not a record type");
	  List.fold_left (fun accu (o2,l2) -> 
			    ior accu (merge (o1,l1) (o2,l2)))
	    iempty (get_rec t2)
      | _ -> raise (Patterns.Error "Cannot compute record concatenation")
941
942
943
944
945
946
947
948
  and elim_conc n q =
    let mem = ref [] in
    let rec aux n =
      try List.assq n !mem
      with Not_found ->
	let r = mk_delayed () in
	mem := (n,r) :: !mem;
	let rec aux2 n =
949
	  match n.desc with
950
951
952
953
954
	    | ILink n' -> aux2 n'
	    | IOr (a,b) -> ior (aux a) (aux b)
	    | ITimes (a,b) -> mk (ITimes (a, aux b))
	    | IConcat (a,b) -> elim_concat n; aux2 n
	    | IType (t,_) -> elim_concat_type t q
955
	    | _ -> raise (Patterns.Error "Cannot compute concatenation")
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
	in
	r.desc <- ILink (aux2 n);
	r
    in
    aux n
  and elim_concat_type t q =
    if not (Types.subtype t Sequence.any) then
      raise (Patterns.Error "Left argument of concatenation is not a sequence type");
    (* TODO: check t <= [ Any* ] *)
    let mem = H.create 17 in
    let rec aux t =
      try H.find mem t 
      with Not_found ->
	let n = mk_delayed () in
	H.add mem t n;
	let d = 
	  List.fold_left
	    (fun accu (t1,t2) -> ior accu (mk (ITimes (itype t1, aux t2))))
	    (if Types.Atom.has_atom t Sequence.nil_atom then q else iempty)
	    (Types.Product.get t) in
	n.desc <- d.desc;
	n
    in
    aux t
    
   
    
  let elim_concats () =
    try
      List.iter elim_concat !concats;
      List.iter (fun n -> n.sid <- 0) !concats;
      concats := []
    with exn ->
      List.iter (fun n -> n.sid <- 0) !concats;
      concats := [];
      raise exn
992

993
994
  let derec penv p =
    let d = derecurs penv p in
995
    elim_concats ();
996
997
998
    check_delayed ();
    internalize d;
    d
999
1000


1001
(* API *)
1002
1003
1004

  module Ids = Set.Make(Id)
  let type_defs env b =
1005
1006
1007
1008
1009
1010
    let _,b' = derecurs_def (penv env) b in
    elim_concats ();
    check_delayed ();
    let aux loc d =
      internalize d;
      check_no_fv loc d;
1011
      try typ d
1012
      with Patterns.Error s -> raise_loc_generic loc s
1013
    in
1014
    let b = 
1015
1016
1017
      List.map2 
	(fun (loc,v,p) (v',_,d) ->
	   let t = aux loc d in
1018
1019
1020
1021
	   if (loc <> noloc) && (Types.is_empty t) then
	     warning loc 
	       ("This definition yields an empty type for " ^ (U.to_string v));
	   let v = ident env loc v in
1022
	   (v',t)) b b' in
1023
1024
    List.iter (fun (v,t) -> Types.Print.register_global 
		 (Types.CompUnit.get_current ()) (Id.value v) t) b;
1025
    enter_types b env
1026

1027
1028
1029
1030
  let type_defs env b =
    try type_defs env b
    with exn -> clean_on_err (); raise exn

1031

1032
  let typ_descr d =
1033
1034
    try internalize d; typ d
    with exn -> clean_on_err (); raise exn
1035

1036
  let typ env t = 
1037
1038
1039
1040
1041
1042
    try
      let d = derec (penv env) t in
      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
1043
1044

  let pat env t = 
1045
1046
1047
1048
1049
    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
1050
end
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066

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

let dump_types ppf env =
  Env.iter (fun v -> 
	      function 
		  (Type _) -> Format.fprintf ppf " %a" Ident.print v
		| _ -> ()) env.ids

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



1067

1068
1069
(* II. Build skeleton *)

1070

1071
type type_fun = Types.t -> bool -> Types.t
1072

1073
module Fv = IdSet
1074

1075
1076
1077
type branch = Branch of Typed.branch * branch list

let cur_branch : branch list ref = ref []
1078

1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
let exp' loc e = 
  { Typed.exp_loc = loc; Typed.exp_typ = Types.empty; Typed.exp_descr = e; }

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

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

let pat_true = 
  let n = Patterns.make Fv.empty in
  Patterns.define n (Patterns.constr Builtin_defs.true_type);
  n

let pat_false =   
  let n = Patterns.make Fv.empty in
  Patterns.define n (Patterns.constr Builtin_defs.false_type);
  n

1096

1097
let ops = Hashtbl.create 13
1098
1099
let register_op op arity f = Hashtbl.add ops op (arity,f)
let typ_op op = snd (Hashtbl.find ops op)
1100

1101
1102
1103
1104
1105
let fun_name env a =
  match a.fun_name with
    | None -> None
    | Some (loc,s) -> Some (ident env loc s)

1106
let is_op env s = 
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
  if (Env.mem s env.ids) then None
  else
    let (ns,s) = Id.value s in
    if Ns.equal ns Ns.empty then
      let s = U.get_str s in
      try 
	let o = Hashtbl.find ops s in
	Some (s, fst o)
      with Not_found -> None
    else None
1117

1118
1119
let rec expr env loc = function
  | LocatedExpr (loc,e) -> expr env loc e
1120
  | Forget (e,t) ->
1121
      let (fv,e) = expr env loc e and t = typ env t in
1122
      exp loc fv (Typed.Forget (e,t))
1123
1124
  | Check (e,t) ->
      let (fv,e) = expr env loc e and t = typ env t in
1125
      exp loc fv (Typed.Check (ref Types.empty,e,t))
1126
  | Var s -> var env loc s
1127
  | Apply (e1,e2) -> 
1128
1129
1130
1131
1132
1133
1134
1135
      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
	 | Typed.Op (op,arity,args) when arity > 0 -> 
	     exp loc fv (Typed.Op (op,arity - 1,args @ [e2]))
	 | _ ->
	     exp loc fv (Typed.Apply (e1,e2)))
  | Abstraction a -> abstraction env loc a
1136
  | (Integer _ | Char _ | Atom _ | Const _) as c -> 
1137
      exp loc Fv.empty (Typed.Cst (const env loc c))
1138
  | Pair (e1,e2) ->
1139
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
1140
1141
      exp loc (Fv.cup fv1 fv2) (Typed.Pair (e1,e2))
  | Xml (e1,e2) ->
1142
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
1143
      exp loc (Fv.cup fv1 fv2) (Typed.Xml (e1,e2))
1144
  | Dot (LocatedExpr (_,Var cu), id, tyargs) when not (has_value cu env) ->
1145
1146
      (match find_cu loc cu env with
	 | ECDuce cu ->