types.ml 45 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
type const = 
20
  | Integer of Intervals.V.t
21
  | Atom of Atoms.V.t 
22
  | Char of Chars.V.t
23
24
25
26
  | Pair of const * const
  | Xml of const * const
  | Record of const label_map
  | String of U.uindex * U.uindex * U.t * const
27

28
29

let rec compare_const c1 c2 =
30
  match (c1,c2) with
31
    | Integer x, Integer y -> Intervals.V.compare x y
32
33
    | Integer _, _ -> -1
    | _, Integer _ -> 1
34
    | Atom x, Atom y -> Atoms.V.compare x y
35
36
    | Atom _, _ -> -1
    | _, Atom _ -> 1
37
    | Char x, Char y -> Chars.V.compare x y
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
    | Char _, _ -> -1
    | _, Char _ -> 1
    | Pair (x1,x2), Pair (y1,y2) ->
	let c = compare_const x1 y1 in
	if c <> 0 then c else compare_const x2 y2
    | Pair (_,_), _ -> -1
    | _, Pair (_,_) -> 1
    | Xml (x1,x2), Xml (y1,y2) ->
	let c = compare_const x1 y1 in
	if c <> 0 then c else compare_const x2 y2
    | Xml (_,_), _ -> -1
    | _, Xml (_,_) -> 1
    | Record x, Record y ->
	LabelMap.compare compare_const x y
    | 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 *)
	else compare_const r1 r2

let rec hash_const = 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_const x) + 257 * (hash_const y)
  | Xml (x,y) -> 5 + 17 * (hash_const x) + 257 * (hash_const y)
  | Record x -> 6 + 17 * (LabelMap.hash hash_const x)
  | String (i,j,s,r) -> 7 + 17 * (U.hash s) + 257 * hash_const r
      (* Note: improve hash for String *)
70

71
72
let equal_const c1 c2 = compare_const c1 c2 = 0

73
74
type pair_kind = [ `Normal | `XML ]

75
76
77
78
79
80
81
82
83
module rec Descr : 
sig
(*
  Want to write:
    type s = { ... }
    include Custom.T with type t = s
  but a  bug in OCaml 3.07+beta 2 makes it impossible
*)
  type t = {
84
    mutable hash: int;
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
    atoms : Atoms.t;
    ints  : Intervals.t;
    chars : Chars.t;
    times : BoolPair.t;
    xml   : BoolPair.t;
    arrow : BoolPair.t;
    record: BoolRec.t;
    absent: bool
  }
  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
  include Custom.Dummy
  type t = {
105
    mutable hash: int;
106
107
108
109
110
111
112
113
114
115
    atoms : Atoms.t;
    ints  : Intervals.t;
    chars : Chars.t;
    times : BoolPair.t;
    xml   : BoolPair.t;
    arrow : BoolPair.t;
    record: BoolRec.t;
    absent: bool
  }
  let equal a b =
116
117
118
119
120
121
122
123
124
125
    (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) &&
      (a.absent == b.absent)
    )
126
127
128
129
130
131
132
133
134
135
136
137
138

  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
    else if a.absent && not b.absent then -1
    else if b.absent && not a.absent then 1
    else 0
139
      
140
  let hash a =
141
142
143
144
145
146
147
148
149
150
151
152
    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
      let accu = if a.absent then accu+5 else accu in
      a.hash <- accu;
      accu
    )
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172

  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;
    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
    let absent = Serialize.Get.bool t in
173
174
    { hash=0; 
      chars = chars; ints = ints; atoms = atoms; times = times; xml = xml;
175
176
177
      arrow = arrow; record = record; absent = absent }
   
    
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
end
and Node :
sig
  type t = { id : int; mutable descr : Descr.t }
  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 = { id : int; mutable descr : Descr.t }
  include Custom.Dummy
  let hash x = x.id
  let compare x y = Pervasives.compare x.id y.id
  let equal x y = x == y
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212

  let buffer = Serialize.Put.mk_property (fun t -> ref [])
  let serialize t n = 
    let l = Serialize.Put.get_property buffer t in
    Printf.eprintf "Node.serialize %i\n" n.id;
    Serialize.Put.int t n.id;
    if not (List.memq n.id !l) then
      (
	Printf.eprintf "Recurs\n";
	l := n.id :: !l;
	Descr.serialize t n.descr
      )

  let deserialize t = 
    let id = Serialize.Get.int t in
    Printf.eprintf "Node.deserialize %i\n" id;
    failwith "deserialize"
213
214
end

215
216
(* It is also possible to use Boolean insteand of Bool here;
   need to analyze when each one is more efficient *)
217
218
219
220
221
222
and BoolPair : Bool.S with type elem = Node.t * Node.t = 
Bool.Make(Custom.Pair(Node)(Node))

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

223

224
225
226
type descr = Descr.t
type node = Node.t
include Descr
227
	       
228
let empty = { 
229
  hash = 0;
230
231
232
  times = BoolPair.empty; 
  xml   = BoolPair.empty; 
  arrow = BoolPair.empty; 
233
  record= BoolRec.empty;
234
235
236
  ints  = Intervals.empty;
  atoms = Atoms.empty;
  chars = Chars.empty;
237
  absent= false;
238
239
240
}
	      
let any =  {
241
  hash = 0;
242
243
244
  times = BoolPair.full; 
  xml   = BoolPair.full; 
  arrow = BoolPair.full; 
245
  record= BoolRec.full; 
246
247
248
  ints  = Intervals.any;
  atoms = Atoms.any;
  chars = Chars.any;
249
  absent= false;
250
}
251
252

let non_constructed =
253
254
255
  { any with  
      hash = 0;
      times = empty.times; xml = empty.xml; record = empty.record }
256
     
257
	     
258
259
260
261
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) }
262
let record label t = 
263
264
  { empty with hash = 0; 
      record = BoolRec.atom (true,LabelMap.singleton label t) }
265
let record' (x : bool * node Ident.label_map) =
266
267
268
  { 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 }
269
      
270
271
let cup x y = 
  if x == y then x else {
272
    hash = 0;
273
274
275
    times = BoolPair.cup x.times y.times;
    xml   = BoolPair.cup x.xml y.xml;
    arrow = BoolPair.cup x.arrow y.arrow;
276
    record= BoolRec.cup x.record y.record;
277
278
279
    ints  = Intervals.cup x.ints  y.ints;
    atoms = Atoms.cup x.atoms y.atoms;
    chars = Chars.cup x.chars y.chars;
280
    absent= x.absent || y.absent;
281
282
283
284
  }
    
let cap x y = 
  if x == y then x else {
285
    hash = 0;
286
287
    times = BoolPair.cap x.times y.times;
    xml   = BoolPair.cap x.xml y.xml;
288
    record= BoolRec.cap x.record y.record;
289
    arrow = BoolPair.cap x.arrow y.arrow;
290
291
292
    ints  = Intervals.cap x.ints  y.ints;
    atoms = Atoms.cap x.atoms y.atoms;
    chars = Chars.cap x.chars y.chars;
293
    absent= x.absent && y.absent;
294
295
296
297
  }
    
let diff x y = 
  if x == y then empty else {
298
    hash = 0;
299
300
301
    times = BoolPair.diff x.times y.times;
    xml   = BoolPair.diff x.xml y.xml;
    arrow = BoolPair.diff x.arrow y.arrow;
302
    record= BoolRec.diff x.record y.record;
303
304
305
    ints  = Intervals.diff x.ints  y.ints;
    atoms = Atoms.diff x.atoms y.atoms;
    chars = Chars.diff x.chars y.chars;
306
    absent= x.absent && not y.absent;
307
308
  }
    
309

310

311

312
313
314
315
316
317
318
319
(* 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) &&
320
321
  (BoolRec.trivially_disjoint a.record b.record) &&
  (not (a.absent && b.absent))
322

323

324
325
module DescrHash = Hashtbl.Make(Descr)
module DescrMap = Map.Make(Descr)
326
module DescrSet = Set.Make(Descr)
327
module DescrSList = SortedList.Make(Descr)
328

329
let hash_cons = DescrHash.create 17000  
330

331
let count = State.ref "Types.count" 0
332
333
334
335
336

let () =
  Stats.register Stats.Summary
    (fun ppf -> Format.fprintf ppf "Allocated type nodes:%i@\n" !count)

337
let make () = incr count; { Node.id = !count; Node.descr = empty }
338
let define n d = 
339
  DescrHash.add hash_cons d n; 
340
  n.Node.descr <- d
341
let cons d = 
342
343
344
345
346
347
348
  try DescrHash.find hash_cons d 
  with Not_found ->
    incr count; 
    let n = { Node.id = !count; Node.descr = d } in
    DescrHash.add hash_cons d n; n  


349
let descr n = n.Node.descr
350
let internalize n = n
351
let id n = n.Node.id
352
353


354
355
356
357
358
359
360
361
362
363
364
365
366
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)
367

368
369
let neg x = diff any x

370
371
let any_node = cons any

372
module LabelS = Set.Make(LabelPool)
373

374
375
376
let any_or_absent = { any with hash=0; absent = true } 
let only_absent = { empty with hash=0; absent = true }

377
378
let get_record r =
  let labs accu (_,r) = 
379
380
    List.fold_left 
      (fun accu (l,_) -> LabelS.add l accu) accu (LabelMap.get r) in
381
  let extend descrs labs (o,r) =
382
383
384
385
386
    let rec aux i labs r =
      match labs with
	| [] -> ()
	| l1::labs ->
	    match r with
387
	      | (l2,x)::r when l1 == l2 -> 
388
389
390
		  descrs.(i) <- cap descrs.(i) (descr x);
		  aux (i+1) labs r
	      | r ->
391
392
		  if not o then 
		    descrs.(i) <- cap descrs.(i) only_absent; (* TODO:OPT *)
393
394
		  aux (i+1) labs r
    in
395
    aux 0 labs (LabelMap.get r);
396
397
398
399
    o
  in
  let line (p,n) =
    let labels = 
400
401
      List.fold_left labs (List.fold_left labs LabelS.empty p) n in
    let labels = LabelS.elements labels in
402
    let nlab = List.length labels in
403
    let mk () = Array.create nlab any_or_absent in
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418

    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
419
  List.map line (BoolRec.get r)
420
   
421

422

423
424
425
426
427
428
429


(* 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)
430
let cap_product any_left any_right l =
431
432
  List.fold_left 
    (fun (d1,d2) (t1,t2) -> (cap_t d1 t1, cap_t d2 t2))
433
    (any_left,any_right)
434
    l
435
let any_pair = { empty with hash = 0; times = any.times }
436

437

438
439
440
let rec exists max f =
  (max > 0) && (f (max - 1) || exists (max - 1) f)

441
exception NotEmpty
442

443
444
445
446
447
448
449
450
451
452
453
454
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) -> 
455
      if n.status == Maybe then (try f n with NotEmpty -> ());
456
457
458
459
460
461
462
463
464
465
      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;
466
  s.notify <- Nothing; 
467
468
469
470
471
472
473
  raise NotEmpty

let rec big_conj f l n =
  match l with
    | [] -> set n
    | [arg] -> f arg n
    | arg::rem ->
474
475
476
	let s = 
	  { status = Maybe; active = false; 
	    notify = Do (n,(big_conj f rem), Nothing) } in
477
478
479
	try 
	  f arg s;
	  if s.active then n.active <- true
480
	with NotEmpty -> if n.status == NEmpty then raise NotEmpty
481

482
483
let guard a f n =
  match a with
484
    | { status = Empty } -> ()
485
486
487
    | { status = Maybe } as s -> 
	n.active <- true; 
	s.notify <- Do (n,f,s.notify)
488
    | { status = NEmpty } -> f n
489

490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
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

(* 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) &&
	  (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) 

588
589
(* TODO: need to invesigate when ClearEmpty is a good thing... *)

590
591
592
593
let memo = DescrHash.create 33000
let marks = ref [] 

let rec slot d =
594
595
  if not ((Intervals.is_empty d.ints) && 
	  (Atoms.is_empty d.atoms) &&
596
597
	  (Chars.is_empty d.chars) &&
	  (not d.absent)) then slot_not_empty 
598
599
600
601
602
  else try DescrHash.find memo d
  with Not_found ->
    let s = { status = Maybe; active = false; notify = Nothing } in
    DescrHash.add memo d s;
    (try
603
       iter_s s check_times (BoolPair.get d.times);  
604
       iter_s s check_xml (BoolPair.get d.xml); 
605
       iter_s s check_arrow (BoolPair.get d.arrow);
606
607
608
609
610
611
612
613
614
       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 ->
615
616
617
	let t1 = descr t1 and t2 = descr t2 in
	if trivially_disjoint accu1 t1 || 
	   trivially_disjoint accu2 t2 then (
618
619
	     aux accu1 accu2 right s )
	else (
620
          let accu1' = diff accu1 t1 in 
621
	  guard (slot accu1') (aux accu1' accu2 right) s;
622
623

          let accu2' = diff accu2 t2 in 
624
	  guard (slot accu2') (aux accu1 accu2' right) s  
625
	)
626
627
    | [] -> set s
  in
628
  let (accu1,accu2) = cap_product any any left in
629
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
630
631
632
633
634

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
635
	if clearly_disjoint accu1 t1 || 
636
637
638
639
	   trivially_disjoint accu2 t2 then (
	     aux accu1 accu2 right s )
	else (
          let accu1' = diff accu1 t1 in 
640
	  guard (slot accu1') (aux accu1' accu2 right) s;
641
642

          let accu2' = diff accu2 t2 in 
643
	  guard (slot accu2') (aux accu1 accu2' right) s  
644
645
646
647
	)
    | [] -> set s
  in
  let (accu1,accu2) = cap_product any any_pair left in
648
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
649

650
651
652
653
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 ->
654
          let accu1' = diff_t accu1 t1 in 
655
	  guard (slot accu1') (aux accu1' accu2 left) s;
656
657

          let accu2' = cap_t  accu2 t2 in 
658
	  guard (slot accu2') (aux accu1 accu2' left) s
659
660
661
      | [] -> set s
    in
    let accu1 = descr s1 in
662
    guard (slot accu1) (aux accu1 (neg (descr s2)) left) s
663
664
  in
  big_conj single_right right s
665

666
and check_record (labels,(oleft,left),rights) s =
667
668
  let rec aux rights s = match rights with
    | [] -> set s
669
    | (oright,right)::rights ->
670
	let next =
671
	  (oleft && (not oright)) ||
672
	  exists (Array.length left)
673
	    (fun i -> trivially_disjoint left.(i) right.(i))
674
675
676
677
678
679
	in
	if next then aux rights s
	else
	  for i = 0 to Array.length left - 1 do
	    let back = left.(i) in
	    let di = diff back right.(i) in
680
681
	    guard (slot di) (fun s ->
			left.(i) <- di;
682
683
684
			aux rights s;
			left.(i) <- back;
		     ) s
685
(* TODO: are side effects correct ? *)
686
687
688
689
690
	  done
  in
  let rec start i s =
    if (i < 0) then aux rights s
    else
691
      guard (slot left.(i)) (start (i - 1)) s
692
693
694
695
  in
  start (Array.length left - 1) s


696
697
let timer_subtype = Stats.Timer.create "Types.is_empty"

698
let is_empty d =
699
  Stats.Timer.start timer_subtype;
700
701
  let s = slot d in
  List.iter 
702
703
    (fun s' -> 
       if s'.status == Maybe then s'.status <- Empty; s'.notify <- Nothing) 
704
705
    !marks;
  marks := [];
706
  Stats.Timer.stop timer_subtype;
707
  s.status == Empty
708

709
(*
710
let is_empty d =
711
712
713
714
715
716
717
(*  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
*)  
718
719
720
721
722
723
724
725
726
727
728
729
730

let non_empty d = 
  not (is_empty d)

let subtype d1 d2 =
  is_empty (diff d1 d2)

module Product =
struct
  type t = (descr * descr) list

  let other ?(kind=`Normal) d = 
    match kind with
731
732
      | `Normal -> { d with hash = 0; times = empty.times }
      | `XML -> { d with hash = 0; xml = empty.xml }
733
734
735
736
737

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

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

738
739
740
741
  let normal_aux = function
    | ([] | [ _ ]) as d -> d
    | d ->

742
743
744
745
746
747
748
    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*) 
749
(*	    if equal_descr d1 t1 then r := (d1,cup d2 t2) else*)
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
	      
	      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)

774
*)
775
  let get_aux any_right d =
776
777
    let accu = ref [] in
    let line (left,right) =
778
      let (d1,d2) = cap_product any any_right left in
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
      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
794
    List.iter line (BoolPair.get d);
795
    !accu
796
797
798
(* Maybe, can improve this function with:
     (t,s) \ (t1,s1) = (t&t',s\s') | (t\t',s),
   don't call normal_aux *)
799

800

801
802
  let get ?(kind=`Normal) d = 
    match kind with
803
804
      | `Normal -> get_aux any d.times
      | `XML -> get_aux any_pair d.xml
805
806
807

  let pi1 = List.fold_left (fun acc (t1,_) -> cup acc t1) empty
  let pi2 = List.fold_left (fun acc (_,t2) -> cup acc t2) empty
808
809
810
811
  let pi2_restricted restr = 
    List.fold_left (fun acc (t1,t2) -> 
		      if is_empty (cap t1 restr) then acc
		      else cup acc t2) empty
812
813

  let restrict_1 rects pi1 =
814
815
    let aux acc (t1,t2) = 
      let t1 = cap t1 pi1 in if is_empty t1 then acc else (t1,t2)::acc in
816
817
818
819
    List.fold_left aux [] rects
  
  type normal = t

820
  module Memo = Map.Make(BoolPair)
821

822
823
  (* TODO: try with an hashtable *)
  (* Also, avoid lookup for simple products (t1,t2) *)
824
  let memo = ref Memo.empty
825
  let normal_times d = 
826
827
828
    try Memo.find d !memo 
    with
	Not_found ->
829
	  let gd = get_aux any d in
830
	  let n = normal_aux gd in
831
832
(* Could optimize this call to normal_aux because one already
   know that each line is normalized ... *)
833
834
	  memo := Memo.add d n !memo;
	  n
835

836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
  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 := Memo.add d n !memo_xml;
	  n

  let normal ?(kind=`Normal) d =
    match kind with 
      | `Normal -> normal_times d.times 
      | `XML -> normal_xml d.xml


852
853
854
855
856
857
858
859
860
861
  let merge_same_2 r =
    let r = 
      List.fold_left 
	(fun accu (t1,t2) ->
	   let t = try DescrMap.find t2 accu with Not_found -> empty in
	   DescrMap.add t2 (cup t t1) accu
	) DescrMap.empty r in
    DescrMap.fold (fun t2 t1 accu -> (t1,t2)::accu) r []
	 

862
863
864
865
866
867
868
  let constraint_on_2 n t1 =
    List.fold_left 
      (fun accu (d1,d2) ->
	 if is_empty (cap d1 t1) then accu else cap accu d2)
      any
      n

869
870
  let any = { empty with hash = 0; times = any.times }
  and any_xml = { empty with hash = 0; xml = any.xml }
871
  let is_empty d = d == []
872
end
873

874
module Record = 
875
struct
876
877
  let has_record d = not (is_empty { empty with hash= 0; record = d.record })
  let or_absent d = { d with hash = 0; absent = true }
878
879
880
  let any_or_absent = or_absent any
  let has_absent d = d.absent

881
  let only_absent = {empty with hash = 0; absent = true}
882
883
884
885
886
887
888
889
890
891
892
893
894
  let only_absent_node = cons only_absent

  module T = struct
    type t = descr
    let any = any_or_absent
    let cap = cap
    let cup = cup
    let diff = diff
    let is_empty = is_empty
    let empty = empty
  end
  module R = struct
    type t = descr
895
    let any = { empty with hash = 0; record = any.record }
896
897
898
899
900
901
902
903
    let cap = cap
    let cup = cup
    let diff = diff
    let is_empty = is_empty
    let empty = empty
  end
  module TR = Normal.Make(T)(R)

904
  let any_record = { empty with hash = 0; record = BoolRec.full }
905
906
907

  let atom o l = 
    if o && LabelMap.is_empty l then any_record else
908
    { empty with hash = 0; record = BoolRec.atom (o,l) }
909
910
911
912
913
914
915
916
917
918
919

  type zor = Pair of descr * descr | Any

  let aux_split d l=
    let f (o,r) =
      try
	let (lt,rem) = LabelMap.assoc_remove l r in
	Pair (descr lt, atom o rem)
      with Not_found -> 
	if o then
	  if LabelMap.is_empty r then Any else
920
	    Pair (any_or_absent, { empty with hash=0; record = BoolRec.atom (o,r) })
921
922
	else
	  Pair (only_absent,
923
		{ empty with hash = 0; record = BoolRec.atom (o,r) })
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
    in
    List.fold_left 
      (fun b (p,n) ->
	 let rec aux_p accu = function
	   | x::p -> 
	       (match f x with
		  | Pair (t1,t2) -> aux_p ((t1,t2)::accu) p
		  | Any -> aux_p accu p)
	   | [] -> aux_n accu [] n
	 and aux_n p accu = function
	   | x::n -> 
	       (match f x with
		  | Pair (t1,t2) -> aux_n p ((t1,t2)::accu) n
		  | Any -> b)
	   | [] -> (p,accu) :: b in
	 aux_p [] p)
      []
      (BoolRec.get d.record)

  let split (d : descr) l =
    TR.boolean (aux_split d l)

  let split_normal d l =
    TR.boolean_normal (aux_split d l)


  let project d l =
    let t = TR.pi1 (split d l) in
    if t.absent then raise Not_found;
    t

  let project_opt d l =
    let t = TR.pi1 (split d l) in
957
    { t with hash = 0; absent = false }
958
959
960

  let condition d l t =
    TR.pi2_restricted t (split d l)
961

962
963
964
965
966
(* TODO: eliminate this cap ... (reord l only_absent_node) when
   not necessary. eg. {| ..... |} \ l *)

  let remove_field d l = 
    cap (TR.pi2 (split d l)) (record l only_absent_node)
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
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
  let first_label d =
    let min = ref LabelPool.dummy_max in
    let aux (_,r) = 
      match LabelMap.get r with
	  (l,_)::_ -> if (l:int) < !min then min := l | _ -> () in
    BoolRec.iter aux d.record;
    !min

  let empty_cases d =
    let x = BoolRec.compute
	      ~empty:0 ~full:3 ~cup:(lor) ~cap:(land)
	      ~diff:(fun a b -> a land lnot b)
	      ~atom:(function (o,r) ->
		       assert (LabelMap.get r == []);
		       if o then 3 else 1
		    )
	      d.record in
    (x land 2 <> 0, x land 1 <> 0)

  let has_empty_record d =
    BoolRec.compute
      ~empty:false ~full:true ~cup:(||) ~cap:(&&)
      ~diff:(fun a b -> a && not b)
      ~atom:(function (o,r) ->
	       List.for_all 
	         (fun (l,t) -> (descr t).absent)
	         (LabelMap.get r)
	    )
      d.record
    

(*TODO: optimize merge
   - pre-compute the sequence of labels
   - remove empty or full { l = t }
*)

  let merge d1 d2 = 
    let res = ref empty in
    let rec aux accu d1 d2 =
      let l = min (first_label d1) (first_label d2) in
      if l = LabelPool.dummy_max then
	let (some1,none1) = empty_cases d1 
	and (some2,none2) = empty_cases d2 in
	let none = none1 && none2 and some = some1 || some2 in
	let accu = LabelMap.from_list (fun _ _ -> assert false) accu in
	(* approx for the case (some && not none) ... *)
	res := cup !res (record' (some, accu))
      else
	let l1 = split d1 l and l2 = split d2 l in
	let loop (t1,d1) (t2,d2) =
	  let t = 
	    if t2.absent 
1020
	    then cup t1 { t2 with hash = 0; absent = false } 
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
	    else t2 
	  in
	  aux ((l,cons t)::accu) d1 d2
	in
	List.iter (fun x -> List.iter (loop x) l2) l1
	  
    in
    aux [] d1 d2;
    !res

1031
  let any = { empty with hash = 0; record = any.record }
1032
1033
1034
1035
1036
1037
1038
1039
1040

  let get d =
    let rec aux r accu d =
      let l = first_label d in
      if l == LabelPool.dummy_max then
	let (o1,o2) = empty_cases d in 
	if o1 || o2 then (LabelMap.from_list_disj r,o1,o2)::accu else accu
      else
	List.fold_left 
1041
	  (fun accu (t1,t2) -> 
1042
	     let x = (t1.absent, { t1 with hash = 0; absent = false }) in
1043
	     aux ((l,x)::r) accu t2)
1044
1045
1046
1047
1048
1049
1050
1051
1052
	  accu
	  (split d l)
    in
    aux [] [] d
end


module Print = 
struct
1053
  let rec print_const ppf = function
1054
1055
1056
    | Integer i -> Intervals.V.print ppf i
    | Atom a -> Atoms.V.print_quote ppf a
    | Char c -> Chars.V.print ppf c
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
    | Pair (x,y) -> Format.fprintf ppf "(%a,%a)" print_const x print_const y
    | Xml (x,y) -> Format.fprintf ppf "XML(%a,%a)" print_const x print_const y
    | Record r -> 
	Format.fprintf ppf "Record{";
	List.iter 
	  (fun (l,c) -> 
	     Format.fprintf ppf "%a : %a; " 
	     Label.print (LabelPool.value l)
	     print_const c)
	  (LabelMap.get r);
	Format.fprintf ppf "}"
    | String (i,j,s,c) ->
	Format.fprintf ppf "\"%a\" @ %a"
	U.print (U.mk (U.get_substr s i j))
	print_const c
1072

1073
  let nil_atom = Atoms.V.mk_ascii "nil"
1074
1075
1076
1077
1078
1079
1080
1081
1082
  let nil_type = atom (Atoms.atom nil_atom)
  let (seqs_node,seqs_descr) = 
    let n = make () in
    let d = cup nil_type (times any_node n) in
    define n d;
    (n, d)

  let is_regexp t = subtype t seqs_descr

1083
1084
1085
  module S = struct
  type t = { id : int; 
	     mutable def : d list; 
1086
	     mutable state : [ `Expand | `None | `Marked | `Named of U.t ] }
1087
  and  d =
1088
    | Name of U.t
1089
1090
1091
    | Regexp of t Pretty.regexp
    | Atomic of (Format.formatter -> unit)
    | Pair of t * t
1092
    | Char of Chars.V.t
1093
    | Xml of [ `Tag of (Format.formatter -> unit) | `Type of t ] * t * t
1094
1095
    | Record of (bool * t) label_map * bool * bool
    | Arrows of (t * t) list * (t * t) list
1096
    | Neg of t
1097
1098
1099
1100
  let compare x y = x.id - y.id
  end
  module Decompile = Pretty.Decompile(DescrHash)(S)
  open S
1101

1102
  module DescrPairMap = Map.Make(Custom.Pair(Descr)(Descr))
1103
1104
1105

  let named = State.ref "Types.Print.named" DescrMap.empty
  let named_xml = State.ref "Types.Print.named_xml"  DescrPairMap.empty
1106
  let register_global (name : U.t) d = 
1107
    if equal { d with hash = 0; xml = BoolPair.empty } empty then 
1108
1109
1110
1111
      (let l = (*Product.merge_same_2*) (Product.get ~kind:`XML d) in
      match l with
	| [(t1,t2)] -> named_xml := DescrPairMap.add (t1,t2) name !named_xml
	| _ -> ());
1112
    named := DescrMap.add d name !named
1113

1114
  let memo = DescrHash.create 63
1115
1116
  let counter = ref 0
  let alloc def = { id = (incr counter; !counter); def = def; state = `None }
1117

1118
1119
1120
  let count_name = ref 0
  let name () =
    incr count_name;
1121
    U.mk ("X" ^ (string_of_int !count_name))
1122

1123
1124
  let to_print = ref []

1125
1126
  let trivial_rec b = 
    b == BoolRec.empty || 
1127
    (is_empty { empty with hash = 0; record = BoolRec.diff BoolRec.full b})
1128

1129
  let trivial_pair b = b == BoolPair.empty || b == BoolPair.full
1130
1131

  let worth_abbrev d = 
1132
1133
    not (trivial_pair d.times && trivial_pair d.xml && 
	 trivial_pair d.arrow && trivial_rec d.record) 
1134

1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
  let worth_complement d =
    let aux f x y = if f x y = 0 then 1 else 0 in
    let n = 
      aux Atoms.compare d.atoms any.atoms +
      aux Chars.compare d.chars any.chars +
      aux Intervals.compare d.ints any.ints +
      aux BoolPair.compare d.times any.times +
      aux BoolPair.compare d.xml any.xml +
      aux BoolPair.compare d.arrow any.arrow +
      aux BoolRec.compare d.record any.record in
    n >= 4

1147
  let rec prepare d =
1148
    try DescrHash.find memo d
1149
    with Not_found ->
1150
1151
      try 
	let n = DescrMap.find d !named in
1152
1153
	let s = alloc [] in
	s.state <- `Named n;
1154
1155
1156
	DescrHash.add memo d s;
	s
      with Not_found ->
1157
	if worth_complement d then 
1158
	  alloc [Neg (prepare (neg d))]
1159
	else
1160
1161
1162
	let slot = alloc [] in
	if not (worth_abbrev d) then slot.state <- `Expand;
	DescrHash.add memo d slot;
1163
	let (seq,not_seq) =
1164
	  if (subtype { empty with hash = 0; times = d.times } seqs_descr) then
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
	    (cap d seqs_descr, diff d seqs_descr)
	  else
	    (empty, d) in

	let add u = slot.def <- u :: slot.def in
	if (non_empty seq) then
	  add (Regexp (decompile seq));  
	List.iter
	  (fun (t1,t2) -> add (Pair (prepare t1, prepare t2)))
	  (Product.get not_seq);
	List.iter
	  (fun (t1,t2) ->
	     try 
	       let n = DescrPairMap.find (t1,t2) !named_xml in
	       add (Name n)
	     with
		 Not_found ->
	     let tag =