types.ml 52.1 KB
Newer Older
1
open Ident
2
open Encodings
3

4
5
6
7
8
(* TODO:
   - I store hash in types to avoid computing it several times.
     Does not seem to help a lot.
*)

9
10
11
12
13
14
15
16
17
18
(*
To be sure not to use generic comparison ...
*)
let (=) : int -> int -> bool = (==)
let (<) : int -> int -> bool = (<)
let (<=) : int -> int -> bool = (<=)
let (<>) : int -> int -> bool = (<>)
let compare = 1


19
20
21
module CompUnit = struct   
  include Pool.Make(Utf8)
  module Tbl = Inttbl
22
      
23
  let pervasives = mk (U.mk "Pervasives") 
24
  let current = ref dummy_min
25
      
26
  let close_serialize_ref = ref (fun () -> assert false)
27
      
28
  let depend = Inttbl.create ()
29
      
30
  let serialize t cu =
31
    if (cu != pervasives) && (cu != !current) then Inttbl.add depend cu ();
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
    serialize t cu

  let close_serialize () =
    !close_serialize_ref ();
    let deps = Inttbl.fold depend (fun cu () l -> cu :: l) [] in
    Inttbl.clear depend;
    deps


  let stack = ref []
		
  let enter i = stack := !current :: !stack; current := i
		  
  let leave () =
    match !stack with
      | hd::tl -> current := hd; stack := tl
      | _ -> assert false


  let () = enter pervasives
end	  


55
type const = 
56
  | Integer of Intervals.V.t
57
  | Atom of Atoms.V.t 
58
  | Char of Chars.V.t
59
60
61
62
  | Pair of const * const
  | Xml of const * const
  | Record of const label_map
  | String of U.uindex * U.uindex * U.t * const
63

64
65
66
module Const = struct
  type t = const

67
68
69
70
71
72
73
74
75
76
77
  let rec check = function
    | Integer i -> Intervals.V.check i
    | Atom i -> Atoms.V.check i
    | Char i -> Chars.V.check i
    | Pair (x,y) | Xml (x,y) -> check x; check y
    | Record l -> LabelMap.iter check l
    | String (i,j,s,q) -> U.check s; check q

  let dump ppf _ =
    Format.fprintf ppf "<Types.Const.t>"

78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
  let rec serialize s = function
    | Integer x ->
	Serialize.Put.bits 3 s 0;
	Intervals.V.serialize s x
    | Atom x ->
	Serialize.Put.bits 3 s 1;
	Atoms.V.serialize s x
    | Char x ->
	Serialize.Put.bits 3 s 2;
	Chars.V.serialize s x
    | Pair (x,y) ->
	Serialize.Put.bits 3 s 3;
	serialize s x;
	serialize s y
    | Xml (x,y) ->
	Serialize.Put.bits 3 s 4;
	serialize s x;
	serialize s y
    | Record r ->
	Serialize.Put.bits 3 s 5;
	LabelMap.serialize serialize s r
    | String (i,j,st,q) ->
	Serialize.Put.bits 3 s 6;
	U.serialize_sub s st i j;
	serialize s q

  let rec deserialize s =
    match Serialize.Get.bits 3 s with
      | 0 ->
	  Integer (Intervals.V.deserialize s)
      | 1 ->
	  Atom (Atoms.V.deserialize s)
110
111
      | 2 ->
	  Char (Chars.V.deserialize s)
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
      | 3 ->
	  let x = deserialize s in
	  let y = deserialize s in
	  Pair (x,y)
      | 4 ->
	  let x = deserialize s in
	  let y = deserialize s in
	  Xml (x,y)
      | 5 ->
	  Record (LabelMap.deserialize deserialize s)
      | 6 ->
	  let st = U.deserialize s in
	  let q = deserialize s in
	  String (U.start_index st, U.end_index st, st, q)
      | _ ->
	  assert false

  let rec compare c1 c2 = match (c1,c2) with
130
    | Integer x, Integer y -> Intervals.V.compare x y
131
132
    | Integer _, _ -> -1
    | _, Integer _ -> 1
133
    | Atom x, Atom y -> Atoms.V.compare x y
134
135
    | Atom _, _ -> -1
    | _, Atom _ -> 1
136
    | Char x, Char y -> Chars.V.compare x y
137
138
139
    | Char _, _ -> -1
    | _, Char _ -> 1
    | Pair (x1,x2), Pair (y1,y2) ->
140
141
	let c = compare x1 y1 in
	if c <> 0 then c else compare x2 y2
142
143
144
    | Pair (_,_), _ -> -1
    | _, Pair (_,_) -> 1
    | Xml (x1,x2), Xml (y1,y2) ->
145
146
	let c = compare x1 y1 in
	if c <> 0 then c else compare x2 y2
147
148
149
    | Xml (_,_), _ -> -1
    | _, Xml (_,_) -> 1
    | Record x, Record y ->
150
	LabelMap.compare compare x y
151
152
153
154
155
156
157
    | Record _, _ -> -1
    | _, Record _ -> 1
    | String (i1,j1,s1,r1), String (i2,j2,s2,r2) ->
	let c = Pervasives.compare i1 i2 in if c <> 0 then c 
	else let c = Pervasives.compare j1 j2 in if c <> 0 then c
	else let c = U.compare s1 s2 in if c <> 0 then c (* Should compare
							    only the substring *)
158
159
160
161
162
163
164
165
166
167
	else compare r1 r2

  let rec hash = function
    | Integer x -> 1 + 17 * (Intervals.V.hash x)
    | Atom x -> 2 + 17 * (Atoms.V.hash x)
    | Char x -> 3 + 17 * (Chars.V.hash x)
    | Pair (x,y) -> 4 + 17 * (hash x) + 257 * (hash y)
    | Xml (x,y) -> 5 + 17 * (hash x) + 257 * (hash y)
    | Record x -> 6 + 17 * (LabelMap.hash hash x)
    | String (i,j,s,r) -> 7 + 17 * (U.hash s) + 257 * hash r
168
      (* Note: improve hash for String *)
169

170
171
  let equal c1 c2 = compare c1 c2 = 0
end
172

173
174
module Abstract =
struct
175
  module T = Custom.String
176
177
178
179
180
181
182
183
184
185
  type abs = T.t

  module V =
  struct
    type t = abs * Obj.t
  end

  include SortedList.FiniteCofinite(T)

  let print = function
186
    | Finite l -> List.map (fun x ppf -> Format.fprintf ppf "!%s" x) l
187
188
189
190
191
    | Cofinite l ->       
	[ fun ppf ->
	  Format.fprintf ppf "@[Abstract";
	  List.iter (fun x -> Format.fprintf ppf " \\@ !%s" x) l;
	  Format.fprintf ppf "@]" ]
192
193
194
195

end


196
197
type pair_kind = [ `Normal | `XML ]

198

199
200
201
202
203
204
module rec Descr : 
sig
(*
  Want to write:
    type s = { ... }
    include Custom.T with type t = s
205
  but a  bug (?) in OCaml 3.07 makes it impossible
206
207
*)
  type t = {
208
    mutable hash: int;
209
210
211
212
213
214
215
    atoms : Atoms.t;
    ints  : Intervals.t;
    chars : Chars.t;
    times : BoolPair.t;
    xml   : BoolPair.t;
    arrow : BoolPair.t;
    record: BoolRec.t;
216
    abstract: Abstract.t;
217
218
    absent: bool
  }
219
  val empty: t
220
221
222
223
224
225
226
227
228
229
  val dump: Format.formatter -> t -> unit
  val check: t -> unit
  val equal: t -> t -> bool
  val hash: t -> int
  val compare:t -> t -> int
  val serialize: t Serialize.Put.f
  val deserialize: t Serialize.Get.f
end =
struct
  type t = {
230
    mutable hash: int;
231
232
233
234
235
236
237
    atoms : Atoms.t;
    ints  : Intervals.t;
    chars : Chars.t;
    times : BoolPair.t;
    xml   : BoolPair.t;
    arrow : BoolPair.t;
    record: BoolRec.t;
238
    abstract: Abstract.t;
239
240
    absent: bool
  }
241

242
243
244
  let dump ppf _ =
    Format.fprintf ppf "<Types.Descr.t>"

245
246
247
248
249
250
251
252
253
  let empty = { 
    hash = 0;
    times = BoolPair.empty; 
    xml   = BoolPair.empty; 
    arrow = BoolPair.empty; 
    record= BoolRec.empty;
    ints  = Intervals.empty;
    atoms = Atoms.empty;
    chars = Chars.empty;
254
    abstract = Abstract.empty;
255
256
257
    absent= false;
  }

258
  let equal a b =
259
260
261
262
263
264
265
266
    (a == b) || (
      (Atoms.equal a.atoms b.atoms) &&
      (Chars.equal a.chars b.chars) &&
      (Intervals.equal a.ints  b.ints) &&
      (BoolPair.equal a.times b.times) &&
      (BoolPair.equal a.xml b.xml) &&
      (BoolPair.equal a.arrow b.arrow) &&
      (BoolRec.equal a.record b.record) &&
267
      (Abstract.equal a.abstract b.abstract) &&
268
269
      (a.absent == b.absent)
    )
270
271
272
273
274
275
276
277
278
279

  let compare a b =
    if a == b then 0 
    else let c = Atoms.compare a.atoms b.atoms in if c <> 0 then c
    else let c = Chars.compare a.chars b.chars in if c <> 0 then c
    else let c = Intervals.compare a.ints b.ints in if c <> 0 then c
    else let c = BoolPair.compare a.times b.times in if c <> 0 then c
    else let c = BoolPair.compare a.xml b.xml in if c <> 0 then c
    else let c = BoolPair.compare a.arrow b.arrow in if c <> 0 then c
    else let c = BoolRec.compare a.record b.record in if c <> 0 then c
280
    else let c = Abstract.compare a.abstract b.abstract in if c <> 0 then c
281
282
283
    else if a.absent && not b.absent then -1
    else if b.absent && not a.absent then 1
    else 0
284
      
285
  let hash a =
286
287
288
289
290
291
292
293
    if a.hash <> 0 then a.hash else (
      let accu = Chars.hash a.chars in
      let accu = 17 * accu + Intervals.hash a.ints in
      let accu = 17 * accu + Atoms.hash a.atoms in
      let accu = 17 * accu + BoolPair.hash a.times in
      let accu = 17 * accu + BoolPair.hash a.xml in
      let accu = 17 * accu + BoolPair.hash a.arrow in
      let accu = 17 * accu + BoolRec.hash a.record in
294
      let accu = 17 * accu + Abstract.hash a.abstract in
295
296
297
298
      let accu = if a.absent then accu+5 else accu in
      a.hash <- accu;
      accu
    )
299

300
301
302
303
304
305
306
307
  let check a =
    Chars.check a.chars;
    Intervals.check a.ints;
    Atoms.check a.atoms;
    BoolPair.check a.times;
    BoolPair.check a.xml;
    BoolPair.check a.arrow;
    BoolRec.check a.record;
308
    Abstract.check a.abstract;
309
310
311
    ()


312
313
314
315
316
317
318
319
  let serialize t a =
    Chars.serialize t a.chars;
    Intervals.serialize t a.ints;
    Atoms.serialize t a.atoms;
    BoolPair.serialize t a.times;
    BoolPair.serialize t a.xml;
    BoolPair.serialize t a.arrow;
    BoolRec.serialize t a.record;
320
    Abstract.serialize t a.abstract;
321
322
323
324
325
326
327
328
329
330
    Serialize.Put.bool t a.absent 

  let deserialize t =
    let chars = Chars.deserialize t in
    let ints = Intervals.deserialize t in
    let atoms = Atoms.deserialize t in
    let times = BoolPair.deserialize t in
    let xml = BoolPair.deserialize t in
    let arrow = BoolPair.deserialize t in
    let record = BoolRec.deserialize t in
331
    let abstract = Abstract.deserialize t in
332
    let absent = Serialize.Get.bool t in
333
    let d = { hash=0; 
334
      chars = chars; ints = ints; atoms = atoms; times = times; xml = xml;
335
      arrow = arrow; record = record; abstract = abstract; absent = absent } in
336
337
    check d;
    d
338
339
   
    
340
341
342
end
and Node :
sig
343
  type t = { id : int; comp_unit: CompUnit.t; mutable descr : Descr.t }
344
345
346
347
348
349
350
  val dump: Format.formatter -> t -> unit
  val check: t -> unit
  val equal: t -> t -> bool
  val hash: t -> int
  val compare:t -> t -> int
  val serialize: t Serialize.Put.f
  val deserialize: t Serialize.Get.f
351
  val mk: int -> Descr.t -> t
352
end =
353

354
struct
355
  type t = { id : int; comp_unit : CompUnit.t; mutable descr : Descr.t }
356
357
  let check n = ()
  let dump ppf n = failwith "Types.Node.dump"
358
359
360
361
  let hash x = x.id + 17 * x.comp_unit
  let compare x y = 
    let c = x.id - y.id in
    if c = 0 then x.comp_unit - y.comp_unit else c
362
  let equal x y = x == y
363

364
365
366
367
368
369
370
371
  let serialize_memo = Inttbl.create ()
  let counter_serialize = ref 0

  let () =
    CompUnit.close_serialize_ref := 
    (fun () ->
       Inttbl.clear serialize_memo;
       counter_serialize := 0)
372

373
  let serialize t n = 
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
    if n.comp_unit == !CompUnit.current then (
      Serialize.Put.bool t true;
      try 
	let i = Inttbl.find serialize_memo n.id in
	Serialize.Put.int t i
      with Not_found ->
	let i = !counter_serialize in
	incr counter_serialize;
	Inttbl.add serialize_memo n.id i;
	Serialize.Put.int t i;
	Descr.serialize t n.descr
    ) else (
      Serialize.Put.bool t false;
      CompUnit.serialize t n.comp_unit;
      Serialize.Put.int t n.id
389
    )
390
      
391

392
393
394
395
  let deserialize_memo = Inttbl.create ()

  let find_tbl id =
    try Inttbl.find deserialize_memo id
396
    with Not_found ->
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
      let tbl = Inttbl.create () in
      Inttbl.add deserialize_memo id tbl;
      tbl

  let mk id d =
    let n = { id = id; comp_unit = !CompUnit.current; descr = d } in
    if !CompUnit.current == CompUnit.pervasives then
      Inttbl.add (find_tbl CompUnit.pervasives) n.id n;
    n

  let deserialize t = 
    if Serialize.Get.bool t then
      let i = Serialize.Get.int t in
      let tbl = find_tbl !CompUnit.current in
      try Inttbl.find tbl i
      with Not_found ->
	let n = { id = i; comp_unit = !CompUnit.current;
		  descr = Descr.empty } in
	Inttbl.add tbl i n;
	n.descr <- Descr.deserialize t;
	n
    else
      let cu = CompUnit.deserialize t in
      let i = Serialize.Get.int t in
      try Inttbl.find (Inttbl.find deserialize_memo cu) i 
      with Not_found -> assert false

424
425
end

426
427
428
429
430
431
432
433
434
435
436
437
438
439
(* See PR#2920 in OCaml BTS *)
and NodeT : Custom.T with type t = Node.t =
struct
  type t = Node.t
  let dump x = Node.dump x
  let check x = Node.check x
  let equal x = Node.equal x
  let hash x = Node.hash x
  let compare x = Node.compare x
  let serialize x = Node.serialize x
  let deserialize x = Node.deserialize x
end


440
(* It is also possible to use Boolean instead of Bool here;
441
   need to analyze when each one is more efficient *)
442
and BoolPair : Bool.S with type elem = Node.t * Node.t = 
443
Bool.Make(Custom.Pair(NodeT)(NodeT))
444
445

and BoolRec : Bool.S with type elem = bool * Node.t label_map =
446
Bool.Make(Custom.Pair(Custom.Bool)(LabelSet.MakeMap(NodeT)))
447

448
449
450
451
module DescrHash = Hashtbl.Make(Descr)
module DescrMap = Map.Make(Descr)
module DescrSet = Set.Make(Descr)
module DescrSList = SortedList.Make(Descr)
452

453
454
455
type descr = Descr.t
type node = Node.t
include Descr
456
457
458

let hash_cons = DescrHash.create 17000  

459
460
461
462
463
464
465
466
467
468
let count = State.ref "Types.count" 0
		
let () =
  Stats.register Stats.Summary
    (fun ppf -> Format.fprintf ppf "Allocated type nodes:%i@\n" !count)
      
let make () = 
  incr count; 
  Node.mk !count empty

469
470
471
472
473
474
475
let define n d = 
  DescrHash.add hash_cons d n; 
  n.Node.descr <- d
let cons d = 
  try DescrHash.find hash_cons d 
  with Not_found ->
    incr count; 
476
    let n = Node.mk !count d in
477
478
    DescrHash.add hash_cons d n; n  

479
let any =  {
480
  hash = 0;
481
482
483
  times = BoolPair.full; 
  xml   = BoolPair.full; 
  arrow = BoolPair.full; 
484
  record= BoolRec.full; 
485
486
487
  ints  = Intervals.any;
  atoms = Atoms.any;
  chars = Chars.any;
488
  abstract = Abstract.any;
489
  absent= false;
490
}
491

492

493
let non_constructed =
494
495
496
  { any with  
      hash = 0;
      times = empty.times; xml = empty.xml; record = empty.record }
497
     
498
499
let non_constructed_or_absent = 
  { non_constructed with hash = 0; absent = true }
500
	     
501
502
503
504
let interval i = { empty with hash = 0; ints = i }
let times x y = { empty with hash = 0; times = BoolPair.atom (x,y) }
let xml x y = { empty with hash = 0; xml = BoolPair.atom (x,y) }
let arrow x y = { empty with hash = 0; arrow = BoolPair.atom (x,y) }
505
let record label t = 
506
507
  { empty with hash = 0; 
      record = BoolRec.atom (true,LabelMap.singleton label t) }
508
let record' (x : bool * node Ident.label_map) =
509
510
511
  { empty with hash = 0; record = BoolRec.atom x }
let atom a = { empty with hash = 0; atoms = a }
let char c = { empty with hash = 0; chars = c }
512
513
514
let abstract a = { empty with hash = 0; abstract = a }

let get_abstract t = t.abstract
515
      
516
517
let cup x y = 
  if x == y then x else {
518
    hash = 0;
519
520
521
    times = BoolPair.cup x.times y.times;
    xml   = BoolPair.cup x.xml y.xml;
    arrow = BoolPair.cup x.arrow y.arrow;
522
    record= BoolRec.cup x.record y.record;
523
524
525
    ints  = Intervals.cup x.ints  y.ints;
    atoms = Atoms.cup x.atoms y.atoms;
    chars = Chars.cup x.chars y.chars;
526
    abstract = Abstract.cup x.abstract y.abstract;
527
    absent= x.absent || y.absent;
528
529
530
531
  }
    
let cap x y = 
  if x == y then x else {
532
    hash = 0;
533
534
    times = BoolPair.cap x.times y.times;
    xml   = BoolPair.cap x.xml y.xml;
535
    record= BoolRec.cap x.record y.record;
536
    arrow = BoolPair.cap x.arrow y.arrow;
537
538
539
    ints  = Intervals.cap x.ints  y.ints;
    atoms = Atoms.cap x.atoms y.atoms;
    chars = Chars.cap x.chars y.chars;
540
    abstract = Abstract.cap x.abstract y.abstract;
541
    absent= x.absent && y.absent;
542
543
544
545
  }
    
let diff x y = 
  if x == y then empty else {
546
    hash = 0;
547
548
549
    times = BoolPair.diff x.times y.times;
    xml   = BoolPair.diff x.xml y.xml;
    arrow = BoolPair.diff x.arrow y.arrow;
550
    record= BoolRec.diff x.record y.record;
551
552
553
    ints  = Intervals.diff x.ints  y.ints;
    atoms = Atoms.diff x.atoms y.atoms;
    chars = Chars.diff x.chars y.chars;
554
    abstract = Abstract.diff x.abstract y.abstract;
555
    absent= x.absent && not y.absent;
556
557
  }
    
558

559

560

561
562
563
564
565
566
567
568
(* TODO: optimize disjoint check for boolean combinations *)
let trivially_disjoint a b =
  (Chars.disjoint a.chars b.chars) &&
  (Intervals.disjoint a.ints b.ints) &&
  (Atoms.disjoint a.atoms b.atoms) &&
  (BoolPair.trivially_disjoint a.times b.times) &&
  (BoolPair.trivially_disjoint a.xml b.xml) &&
  (BoolPair.trivially_disjoint a.arrow b.arrow) &&
569
  (BoolRec.trivially_disjoint a.record b.record) &&
570
  (Abstract.disjoint a.abstract b.abstract) &&
571
  (not (a.absent && b.absent))
572

573

574

575
let descr n = n.Node.descr
576
let internalize n = n
577
let id n = n.Node.id
578
579


580
581
582
583
584
585
586
587
588
589
590
591
592
let rec constant = function
  | Integer i -> interval (Intervals.atom i)
  | Atom a -> atom (Atoms.atom a)
  | Char c -> char (Chars.atom c)
  | Pair (x,y) -> times (const_node x) (const_node y)
  | Xml (x,y) -> times (const_node x) (const_node y)
  | Record x -> record' (false ,LabelMap.map const_node x)
  | String (i,j,s,c) ->
      if U.equal_index i j then constant c
      else 
	let (ch,i') = U.next s i in
	constant (Pair (Char (Chars.V.mk_int ch), String (i',j,s,c)))
and const_node c = cons (constant c)
593

594
595
let neg x = diff any x

596
let any_node = cons any
597
let empty_node = cons empty
598

599
module LabelS = Set.Make(LabelPool)
600

601
602
603
let any_or_absent = { any with hash=0; absent = true } 
let only_absent = { empty with hash=0; absent = true }

604
605
let get_record r =
  let labs accu (_,r) = 
606
607
    List.fold_left 
      (fun accu (l,_) -> LabelS.add l accu) accu (LabelMap.get r) in
608
  let extend descrs labs (o,r) =
609
610
611
612
613
    let rec aux i labs r =
      match labs with
	| [] -> ()
	| l1::labs ->
	    match r with
614
	      | (l2,x)::r when l1 == l2 -> 
615
616
617
		  descrs.(i) <- cap descrs.(i) (descr x);
		  aux (i+1) labs r
	      | r ->
618
619
		  if not o then 
		    descrs.(i) <- cap descrs.(i) only_absent; (* TODO:OPT *)
620
621
		  aux (i+1) labs r
    in
622
    aux 0 labs (LabelMap.get r);
623
624
625
626
    o
  in
  let line (p,n) =
    let labels = 
627
628
      List.fold_left labs (List.fold_left labs LabelS.empty p) n in
    let labels = LabelS.elements labels in
629
    let nlab = List.length labels in
630
    let mk () = Array.create nlab any_or_absent in
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645

    let pos = mk () in
    let opos = List.fold_left 
		 (fun accu x -> 
		    (extend pos labels x) && accu)
		 true p in
    let p = (opos, pos) in

    let n = List.map (fun x ->
			let neg = mk () in
			let o = extend neg labels x in
			(o,neg)
		     ) n in
    (labels,p,n)
  in
646
  List.map line (BoolRec.get r)
647
   
648

649

650
651
652
653
654
655
656


(* Subtyping algorithm *)

let diff_t d t = diff d (descr t)
let cap_t d t = cap d (descr t)
let cup_t d t = cup d (descr t)
657
let cap_product any_left any_right l =
658
659
  List.fold_left 
    (fun (d1,d2) (t1,t2) -> (cap_t d1 t1, cap_t d2 t2))
660
    (any_left,any_right)
661
    l
662
let any_pair = { empty with hash = 0; times = any.times }
663

664

665
666
667
let rec exists max f =
  (max > 0) && (f (max - 1) || exists (max - 1) f)

668
exception NotEmpty
669

670
671
672
673
674
675
676
677
678
679
680
681
type slot = { mutable status : status; 
	       mutable notify : notify;
	       mutable active : bool }
and status = Empty | NEmpty | Maybe
and notify = Nothing | Do of slot * (slot -> unit) * notify

let slot_empty = { status = Empty; active = false; notify = Nothing }
let slot_not_empty = { status = NEmpty; active = false; notify = Nothing }

let rec notify = function
  | Nothing -> ()
  | Do (n,f,rem) -> 
682
      if n.status == Maybe then (try f n with NotEmpty -> ());
683
684
685
686
687
688
689
690
691
692
      notify rem

let rec iter_s s f = function
  | [] -> ()
  | arg::rem -> f arg s; iter_s s f rem


let set s =
  s.status <- NEmpty;
  notify s.notify;
693
  s.notify <- Nothing; 
694
695
696
697
698
699
700
  raise NotEmpty

let rec big_conj f l n =
  match l with
    | [] -> set n
    | [arg] -> f arg n
    | arg::rem ->
701
702
703
	let s = 
	  { status = Maybe; active = false; 
	    notify = Do (n,(big_conj f rem), Nothing) } in
704
705
706
	try 
	  f arg s;
	  if s.active then n.active <- true
707
	with NotEmpty -> if n.status == NEmpty then raise NotEmpty
708

709
710
let guard a f n =
  match a with
711
    | { status = Empty } -> ()
712
713
714
    | { status = Maybe } as s -> 
	n.active <- true; 
	s.notify <- Do (n,f,s.notify)
715
    | { status = NEmpty } -> f n
716

717
718
719
720
721
722
723
724
725
726
727
728
729

(* Fast approximation *)

module ClearlyEmpty = 
struct

let memo = DescrHash.create 33000
let marks = ref [] 

let rec slot d =
  if not ((Intervals.is_empty d.ints) && 
	  (Atoms.is_empty d.atoms) &&
	  (Chars.is_empty d.chars) &&
730
	  (Abstract.is_empty d.abstract) &&
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
	  (not d.absent)) then slot_not_empty 
  else try DescrHash.find memo d
  with Not_found ->
    let s = { status = Maybe; active = false; notify = Nothing } in
    DescrHash.add memo d s;
    (try
       iter_s s check_times (BoolPair.get d.times);  
       iter_s s check_xml (BoolPair.get d.xml); 
       iter_s s check_arrow (BoolPair.get d.arrow);
       iter_s s check_record (get_record d.record);
       if s.active then marks := s :: !marks else s.status <- Empty;
     with
	 NotEmpty -> ());
    s

and check_times (left,right) s =
  let (accu1,accu2) = cap_product any any left in
  let single_right (t1,t2) s =
    let t1 = descr t1 and t2 = descr t2 in
    if trivially_disjoint accu1 t1 || trivially_disjoint accu2 t2 then set s 
    else
      let accu1 = diff accu1 t1 in guard (slot accu1) set s;
      let accu2 = diff accu2 t2 in guard (slot accu2) set s in
  guard (slot accu1) (guard (slot accu2) (big_conj single_right right)) s

and check_xml (left,right) s =
  let (accu1,accu2) = cap_product any any_pair left in
  let single_right (t1,t2) s =
    let t1 = descr t1 and t2 = descr t2 in
    if trivially_disjoint accu1 t1 || trivially_disjoint accu2 t2 then set s 
    else
      let accu1 = diff accu1 t1 in guard (slot accu1) set s;
      let accu2 = diff accu2 t2 in guard (slot accu2) set s in
  guard (slot accu1) (guard (slot accu2) (big_conj single_right right)) s

and check_arrow (left,right) s =
  let single_right (s1,s2) s =
    let accu1 = descr s1 and accu2 = neg (descr s2) in
    let single_left (t1,t2) s =
      let accu1 = diff_t accu1 t1 in guard (slot accu1) set s;
      let accu2 = cap_t  accu2 t2 in guard (slot accu2) set s
    in
    guard (slot accu1) (big_conj single_left left) s
  in
  big_conj single_right right s

and check_record (labels,(oleft,left),rights) s =
  let rec single_right (oright,right) s = 
    let next =
      (oleft && (not oright)) ||
      exists (Array.length left)
	(fun i -> trivially_disjoint left.(i) right.(i))
    in
    if next then set s
    else
      for i = 0 to Array.length left - 1 do
	let di = diff left.(i) right.(i) in guard (slot di) set s
      done
  in
  let rec start i s =
    if (i < 0) then big_conj single_right rights s
    else guard (slot left.(i)) (start (i - 1)) s
  in
  start (Array.length left - 1) s


let is_empty d =
  let s = slot d in
  List.iter 
    (fun s' -> 
       if s'.status == Maybe then s'.status <- Empty; s'.notify <- Nothing) 
    !marks;
  marks := [];
  s.status == Empty
end

let clearly_disjoint t1 t2 =
(*
  if trivially_disjoint t1 t2 then true
  else
    if ClearlyEmpty.is_empty (cap t1 t2) then
      (Printf.eprintf "!\n"; true) else false
*)
  trivially_disjoint t1 t2 || ClearlyEmpty.is_empty (cap t1 t2) 

816
817
(* TODO: need to invesigate when ClearEmpty is a good thing... *)

818
819
820
let memo = DescrHash.create 33000
let marks = ref [] 

821
822
let count_subtype = Stats.Counter.create "Subtyping internal loop" 

823
let rec slot d =
824
  Stats.Counter.incr count_subtype; 
825
826
  if not ((Intervals.is_empty d.ints) && 
	  (Atoms.is_empty d.atoms) &&
827
	  (Chars.is_empty d.chars) &&
828
	  (Abstract.is_empty d.abstract) &&
829
	  (not d.absent)) then slot_not_empty 
830
831
832
833
834
  else try DescrHash.find memo d
  with Not_found ->
    let s = { status = Maybe; active = false; notify = Nothing } in
    DescrHash.add memo d s;
    (try
835
       iter_s s check_times (BoolPair.get d.times);  
836
       iter_s s check_xml (BoolPair.get d.xml); 
837
       iter_s s check_arrow (BoolPair.get d.arrow);
838
839
840
841
842
843
844
845
846
       iter_s s check_record (get_record d.record);
       if s.active then marks := s :: !marks else s.status <- Empty;
     with
	 NotEmpty -> ());
    s

and check_times (left,right) s =
  let rec aux accu1 accu2 right s = match right with
    | (t1,t2)::right ->
847
848
849
	let t1 = descr t1 and t2 = descr t2 in
	if trivially_disjoint accu1 t1 || 
	   trivially_disjoint accu2 t2 then (
850
851
	     aux accu1 accu2 right s )
	else (
852
          let accu1' = diff accu1 t1 in 
853
	  guard (slot accu1') (aux accu1' accu2 right) s;
854
855

          let accu2' = diff accu2 t2 in 
856
	  guard (slot accu2') (aux accu1 accu2' right) s  
857
	)
858
859
    | [] -> set s
  in
860
  let (accu1,accu2) = cap_product any any left in
861
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
862
863
864
865
866

and check_xml (left,right) s =
  let rec aux accu1 accu2 right s = match right with
    | (t1,t2)::right ->
	let t1 = descr t1 and t2 = descr t2 in
867
	if clearly_disjoint accu1 t1 || 
868
869
870
871
	   trivially_disjoint accu2 t2 then (
	     aux accu1 accu2 right s )
	else (
          let accu1' = diff accu1 t1 in 
872
	  guard (slot accu1') (aux accu1' accu2 right) s;
873
874

          let accu2' = diff accu2 t2 in 
875
	  guard (slot accu2') (aux accu1 accu2' right) s  
876
877
878
879
	)
    | [] -> set s
  in
  let (accu1,accu2) = cap_product any any_pair left in
880
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
881

882
883
884
885
and check_arrow (left,right) s =
  let single_right (s1,s2) s =
    let rec aux accu1 accu2 left s = match left with
      | (t1,t2)::left ->
886
          let accu1' = diff_t accu1 t1 in 
887
	  guard (slot accu1') (aux accu1' accu2 left) s;
888
889

          let accu2' = cap_t  accu2 t2 in 
890
	  guard (slot accu2') (aux accu1 accu2' left) s
891
892
893
      | [] -> set s
    in
    let accu1 = descr s1 in
894
    guard (slot accu1) (aux accu1 (neg (descr s2)) left) s
895
896
  in
  big_conj single_right right s
897

898
and check_record (labels,(oleft,left),rights) s =
899
  let rec aux left rights s = match rights with
900
    | [] -> set s
901
    | (oright,right)::rights ->
902
	let next =
903
	  (oleft && (not oright)) ||
904
	  exists (Array.length left)
905
	    (fun i -> trivially_disjoint left.(i) right.(i))
906
	in
907
	if next then aux left rights s
908
909
	else
	  for i = 0 to Array.length left - 1 do
910
911
912
913
	    let left' = Array.copy left in
	    let di = diff left.(i) right.(i) in
	    left'.(i) <- di;
	    guard (slot di) (aux left' rights) s;
914
915
916
	  done
  in
  let rec start i s =
917
    if (i < 0) then aux left rights s
918
    else
919
      guard (slot left.(i)) (start (i - 1)) s
920
921
922
923
  in
  start (Array.length left - 1) s


924

925
let timer_subtype = Stats.Timer.create "Types.is_empty"
926

927

928
let is_empty d =
929
  Stats.Timer.start timer_subtype; 
930
931
  let s = slot d in
  List.iter 
932
933
    (fun s' -> 
       if s'.status == Maybe then s'.status <- Empty; s'.notify <- Nothing) 
934
935
    !marks;
  marks := [];
936
  Stats.Timer.stop timer_subtype 
937
    (s.status == Empty)
938

939
(*
940
let is_empty d =
941
942
943
944
945
946
947
(*  let b1 = ClearlyEmpty.is_empty d in
  let b2 = is_empty d in
  assert (b2 || not b1);
  Printf.eprintf "b1 = %b; b2 = %b\n" b1 b2;
  b2  *)
  if ClearlyEmpty.is_empty d then (Printf.eprintf "!\n"; true) else is_empty d
*)  
948
949
950
951
952
953
954

let non_empty d = 
  not (is_empty d)

let subtype d1 d2 =
  is_empty (diff d1 d2)

955
956
957
let disjoint d1 d2 =
  is_empty (cap d1 d2)

958
959
let equiv d1 d2 = (subtype d1 d2) && (subtype d2 d1)

960
961
962
963
964
965
module Product =
struct
  type t = (descr * descr) list

  let other ?(kind=`Normal) d = 
    match kind with
966
967
      | `Normal -> { d with hash = 0; times = empty.times }
      | `XML -> { d with hash = 0; xml = empty.xml }
968
969
970
971
972

  let is_product ?kind d = is_empty (other ?kind d)

  let need_second = function _::_::_ -> true | _ -> false

973
974
975
976
  let normal_aux = function
    | ([] | [ _ ]) as d -> d
    | d ->

977
978
979
980
981
982
983
    let res = ref [] in

    let add (t1,t2) =
      let rec loop t1 t2 = function
	| [] -> res := (ref (t1,t2)) :: !res
	| ({contents = (d1,d2)} as r)::l ->
	    (*OPT*) 
984
(*	    if equal_descr d1 t1 then r := (d1,cup d2 t2) else*)
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
	      
	      let i = cap t1 d1 in
	      if is_empty i then loop t1 t2 l
	      else (
		r := (i, cup t2 d2);
		let k = diff d1 t1 in 
		if non_empty k then res := (ref (k,d2)) :: !res;
		
		let j = diff t1 d1 in 
		if non_empty j then loop j t2 l
	      )
      in
      loop t1 t2 !res
    in
    List.iter add d;
    List.map (!) !res


(* Partitioning:

(t,s) - ((t1,s1) | (t2,s2) | ... | (tn,sn))
=
(t & t1, s - s1) | ... | (t & tn, s - sn) | (t - (t1|...|tn), s)

1009
*)
1010
  let get_aux any_right d =
1011
1012
    let accu = ref [] in
    let line (left,right) =
1013
      let (d1,d2) = cap_product any any_right left in
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
      if (non_empty d1) && (non_empty d2) then
	let right = List.map (fun (t1,t2) -> descr t1, descr t2) right in
	let right = normal_aux right in
	let resid1 = ref d1 in
	let () = 
	  List.iter
	    (fun (t1,t2) ->
	       let t1 = cap d1 t1 in
	       if (non_empty t1) then
		 let () = resid1 := diff !resid1 t1 in
		 let t2 = diff d2 t2 in
		 if (non_empty t2) then accu := (t1,t2) :: !accu
	    ) right in
	if non_empty !resid1 then accu := (!resid1, d2) :: !accu 
    in
1029
    List.iter line (BoolPair.get d);
1030
    !accu
1031
1032
1033
(* Maybe, can improve this function with:
     (t,s) \ (t1,s1) = (t&t',s\s') | (t\t',s),
   don't call normal_aux *)
1034

1035

1036
1037
  let get ?(kind=`Normal) d = 
    match kind with
1038
1039
      | `Normal -> get_aux any d.times
      | `XML -> get_aux any_pair d.xml
1040
1041
1042

  let pi1 = List.fold_left (fun acc (t1,_) -> cup acc t1) empty
  let pi2 = List.fold_left (fun acc (_,t2) -> cup acc t2) empty
1043
1044
1045
1046
  let pi2_restricted restr = 
    List.fold_left (fun acc (t1,t2) -> 
		      if is_empty (cap t1 restr) then acc
		      else cup acc t2) empty
1047
1048

  let restrict_1 rects pi1 =
1049
1050
    let aux acc (t1,t2) = 
      let t1 = cap t1 pi1 in if is_empty t1 then acc else (t1,t2)::acc in
1051
1052
1053
1054
    List.fold_left aux [] rects
  
  type normal = t

1055
  module Memo = Map.Make(BoolPair)
1056

1057
1058
  (* TODO: try with an hashtable *)
  (* Also, avoid lookup for simple products (t1,t2) *)
1059
  let memo = ref Memo.empty
1060
  let normal_times d = 
1061
1062
1063
    try Memo.find d !memo 
    with
	Not_found ->
1064
	  let gd = get_aux any d in
1065
	  let n = normal_aux gd in
1066
1067
(* Could optimize this call to normal_aux because one already
   know that each line is normalized ... *)
1068
1069
	  memo := Memo.add d n !memo;
	  n
1070

1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
  let memo_xml = ref Memo.empty
  let normal_xml d = 
    try Memo.find d !memo_xml
    with
	Not_found ->
	  let gd = get_aux any_pair d in
	  let n = normal_aux gd in
	  memo_xml :=