types.ml 43.9 KB
Newer Older
1
open Ident
2
open Encodings
3

4 5 6 7 8 9 10 11 12 13
(*
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


14
type const = 
15
  | Integer of Intervals.V.t
16
  | Atom of Atoms.V.t 
17
  | Char of Chars.V.t
18 19 20 21
  | Pair of const * const
  | Xml of const * const
  | Record of const label_map
  | String of U.uindex * U.uindex * U.t * const
22

23 24

let rec compare_const c1 c2 =
25
  match (c1,c2) with
26
    | Integer x, Integer y -> Intervals.V.compare x y
27 28
    | Integer _, _ -> -1
    | _, Integer _ -> 1
29
    | Atom x, Atom y -> Atoms.V.compare x y
30 31
    | Atom _, _ -> -1
    | _, Atom _ -> 1
32
    | Char x, Char y -> Chars.V.compare x y
33 34 35 36 37 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
    | 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 *)
65

66 67
let equal_const c1 c2 = compare_const c1 c2 = 0

68 69
type pair_kind = [ `Normal | `XML ]

70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129
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 = {
    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 = {
    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 =
    (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)

  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
130
      
131
  let hash a =
132 133 134
    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
135 136 137 138 139 140
    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
    accu
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164

  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
    { chars = chars; ints = ints; atoms = atoms; times = times; xml = xml;
      arrow = arrow; record = record; absent = absent }
   
    
165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182
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
183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199

  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"
200 201
end

202 203
(* It is also possible to use Boolean insteand of Bool here;
   need to analyze when each one is more efficient *)
204 205 206 207 208 209
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)))

210

211 212 213
type descr = Descr.t
type node = Node.t
include Descr
214
	       
215
let empty = { 
216 217 218
  times = BoolPair.empty; 
  xml   = BoolPair.empty; 
  arrow = BoolPair.empty; 
219
  record= BoolRec.empty;
220 221 222
  ints  = Intervals.empty;
  atoms = Atoms.empty;
  chars = Chars.empty;
223
  absent= false;
224 225 226
}
	      
let any =  {
227 228 229
  times = BoolPair.full; 
  xml   = BoolPair.full; 
  arrow = BoolPair.full; 
230
  record= BoolRec.full; 
231 232 233
  ints  = Intervals.any;
  atoms = Atoms.any;
  chars = Chars.any;
234
  absent= false;
235
}
236 237 238 239

let non_constructed =
  { any with times = empty.times; xml = empty.xml; record = empty.record }
     
240 241
	     
let interval i = { empty with ints = i }
242 243 244
let times x y = { empty with times = BoolPair.atom (x,y) }
let xml x y = { empty with xml = BoolPair.atom (x,y) }
let arrow x y = { empty with arrow = BoolPair.atom (x,y) }
245
let record label t = 
246 247 248
  { empty with record = BoolRec.atom (true,LabelMap.singleton label t) }
let record' (x : bool * node Ident.label_map) =
  { empty with record = BoolRec.atom x }
249 250
let atom a = { empty with atoms = a }
let char c = { empty with chars = c }
251
      
252 253
let cup x y = 
  if x == y then x else {
254 255 256
    times = BoolPair.cup x.times y.times;
    xml   = BoolPair.cup x.xml y.xml;
    arrow = BoolPair.cup x.arrow y.arrow;
257
    record= BoolRec.cup x.record y.record;
258 259 260
    ints  = Intervals.cup x.ints  y.ints;
    atoms = Atoms.cup x.atoms y.atoms;
    chars = Chars.cup x.chars y.chars;
261
    absent= x.absent || y.absent;
262 263 264 265
  }
    
let cap x y = 
  if x == y then x else {
266 267
    times = BoolPair.cap x.times y.times;
    xml   = BoolPair.cap x.xml y.xml;
268
    record= BoolRec.cap x.record y.record;
269
    arrow = BoolPair.cap x.arrow y.arrow;
270 271 272
    ints  = Intervals.cap x.ints  y.ints;
    atoms = Atoms.cap x.atoms y.atoms;
    chars = Chars.cap x.chars y.chars;
273
    absent= x.absent && y.absent;
274 275 276 277
  }
    
let diff x y = 
  if x == y then empty else {
278 279 280
    times = BoolPair.diff x.times y.times;
    xml   = BoolPair.diff x.xml y.xml;
    arrow = BoolPair.diff x.arrow y.arrow;
281
    record= BoolRec.diff x.record y.record;
282 283 284
    ints  = Intervals.diff x.ints  y.ints;
    atoms = Atoms.diff x.atoms y.atoms;
    chars = Chars.diff x.chars y.chars;
285
    absent= x.absent && not y.absent;
286 287
  }
    
288

289

290

291 292 293 294 295 296 297 298
(* 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) &&
299 300
  (BoolRec.trivially_disjoint a.record b.record) &&
  (not (a.absent && b.absent))
301

302

303 304
module DescrHash = Hashtbl.Make(Descr)
module DescrMap = Map.Make(Descr)
305
module DescrSet = Set.Make(Descr)
306
module DescrSList = SortedList.Make(Descr)
307

308
(* let hash_cons = DescrHash.create 17000 *)
309

310
let count = State.ref "Types.count" 0
311
let make () = incr count; { Node.id = !count; Node.descr = empty }
312 313
let define n d = 
(*  DescrHash.add hash_cons d n; *)
314
  n.Node.descr <- d
315
let cons d = 
316
(*   try DescrHash.find hash_cons d with Not_found ->
317
  incr count; let n = { id = !count; descr = d } in
318
  DescrHash.add hash_cons d n; n  *)
319 320
  incr count; { Node.id = !count; Node.descr = d }
let descr n = n.Node.descr
321
let internalize n = n
322
let id n = n.Node.id
323 324


325 326 327 328 329 330 331 332 333 334 335 336 337
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)
338

339 340
let neg x = diff any x

341 342
let any_node = cons any

343
module LabelS = Set.Make(LabelPool)
344 345 346

let get_record r =
  let labs accu (_,r) = 
347 348
    List.fold_left 
      (fun accu (l,_) -> LabelS.add l accu) accu (LabelMap.get r) in
349
  let extend descrs labs (o,r) =
350 351 352 353 354
    let rec aux i labs r =
      match labs with
	| [] -> ()
	| l1::labs ->
	    match r with
355
	      | (l2,x)::r when l1 == l2 -> 
356 357 358
		  descrs.(i) <- cap descrs.(i) (descr x);
		  aux (i+1) labs r
	      | r ->
359
		  if not o then descrs.(i) <- 
360
		    cap descrs.(i) { empty with absent = true }; (* TODO:OPT *)
361 362
		  aux (i+1) labs r
    in
363
    aux 0 labs (LabelMap.get r);
364 365 366 367
    o
  in
  let line (p,n) =
    let labels = 
368 369
      List.fold_left labs (List.fold_left labs LabelS.empty p) n in
    let labels = LabelS.elements labels in
370
    let nlab = List.length labels in
371
    let mk () = Array.create nlab { any with absent = true } in
372 373 374 375 376 377 378 379 380 381 382 383 384 385 386

    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
387
  List.map line (BoolRec.get r)
388
   
389

390

391 392 393 394 395 396 397


(* 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)
398
let cap_product any_left any_right l =
399 400
  List.fold_left 
    (fun (d1,d2) (t1,t2) -> (cap_t d1 t1, cap_t d2 t2))
401
    (any_left,any_right)
402
    l
403 404
let any_pair = { empty with times = any.times }

405

406 407 408
let rec exists max f =
  (max > 0) && (f (max - 1) || exists (max - 1) f)

409
exception NotEmpty
410

411 412 413 414 415 416 417 418 419 420 421 422
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) -> 
423
      if n.status == Maybe then (try f n with NotEmpty -> ());
424 425 426 427 428 429 430 431 432 433
      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;
434
  s.notify <- Nothing; 
435 436 437 438 439 440 441
  raise NotEmpty

let rec big_conj f l n =
  match l with
    | [] -> set n
    | [arg] -> f arg n
    | arg::rem ->
442 443 444
	let s = 
	  { status = Maybe; active = false; 
	    notify = Do (n,(big_conj f rem), Nothing) } in
445 446 447
	try 
	  f arg s;
	  if s.active then n.active <- true
448
	with NotEmpty -> if n.status == NEmpty then raise NotEmpty
449

450 451
let guard a f n =
  match a with
452
    | { status = Empty } -> ()
453 454 455
    | { status = Maybe } as s -> 
	n.active <- true; 
	s.notify <- Do (n,f,s.notify)
456
    | { status = NEmpty } -> f n
457

458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559

(* 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) 

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

let rec slot d =
560 561
  if not ((Intervals.is_empty d.ints) && 
	  (Atoms.is_empty d.atoms) &&
562 563
	  (Chars.is_empty d.chars) &&
	  (not d.absent)) then slot_not_empty 
564 565 566 567 568
  else try DescrHash.find memo d
  with Not_found ->
    let s = { status = Maybe; active = false; notify = Nothing } in
    DescrHash.add memo d s;
    (try
569
       iter_s s check_times (BoolPair.get d.times);  
570
       iter_s s check_xml (BoolPair.get d.xml); 
571
       iter_s s check_arrow (BoolPair.get d.arrow);
572 573 574 575 576 577 578 579 580
       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 ->
581 582 583
	let t1 = descr t1 and t2 = descr t2 in
	if trivially_disjoint accu1 t1 || 
	   trivially_disjoint accu2 t2 then (
584 585
	     aux accu1 accu2 right s )
	else (
586
          let accu1' = diff accu1 t1 in 
587
	  guard (slot accu1') (aux accu1' accu2 right) s;
588 589

          let accu2' = diff accu2 t2 in 
590
	  guard (slot accu2') (aux accu1 accu2' right) s  
591
	)
592 593
    | [] -> set s
  in
594
  let (accu1,accu2) = cap_product any any left in
595
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
596 597 598 599 600

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
601
	if clearly_disjoint accu1 t1 || 
602 603 604 605
	   trivially_disjoint accu2 t2 then (
	     aux accu1 accu2 right s )
	else (
          let accu1' = diff accu1 t1 in 
606
	  guard (slot accu1') (aux accu1' accu2 right) s;
607 608

          let accu2' = diff accu2 t2 in 
609
	  guard (slot accu2') (aux accu1 accu2' right) s  
610 611 612 613
	)
    | [] -> set s
  in
  let (accu1,accu2) = cap_product any any_pair left in
614
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
615

616 617 618 619
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 ->
620
          let accu1' = diff_t accu1 t1 in 
621
	  guard (slot accu1') (aux accu1' accu2 left) s;
622 623

          let accu2' = cap_t  accu2 t2 in 
624
	  guard (slot accu2') (aux accu1 accu2' left) s
625 626 627
      | [] -> set s
    in
    let accu1 = descr s1 in
628
    guard (slot accu1) (aux accu1 (neg (descr s2)) left) s
629 630
  in
  big_conj single_right right s
631

632
and check_record (labels,(oleft,left),rights) s =
633 634
  let rec aux rights s = match rights with
    | [] -> set s
635
    | (oright,right)::rights ->
636
	let next =
637
	  (oleft && (not oright)) ||
638
	  exists (Array.length left)
639
	    (fun i -> trivially_disjoint left.(i) right.(i))
640 641 642 643 644 645
	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
646 647
	    guard (slot di) (fun s ->
			left.(i) <- di;
648 649 650
			aux rights s;
			left.(i) <- back;
		     ) s
651
(* TODO: are side effects correct ? *)
652 653 654 655 656
	  done
  in
  let rec start i s =
    if (i < 0) then aux rights s
    else
657
      guard (slot left.(i)) (start (i - 1)) s
658 659 660 661 662 663 664
  in
  start (Array.length left - 1) s


let is_empty d =
  let s = slot d in
  List.iter 
665 666
    (fun s' -> 
       if s'.status == Maybe then s'.status <- Empty; s'.notify <- Nothing) 
667 668
    !marks;
  marks := [];
669
  s.status == Empty
670

671
(*
672
let is_empty d =
673 674 675 676 677 678 679
(*  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
*)  
680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699

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
      | `Normal -> { d with times = empty.times }
      | `XML -> { d with xml = empty.xml }

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

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

700 701 702 703
  let normal_aux = function
    | ([] | [ _ ]) as d -> d
    | d ->

704 705 706 707 708 709 710
    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*) 
711
(*	    if equal_descr d1 t1 then r := (d1,cup d2 t2) else*)
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735
	      
	      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)

736
*)
737
  let get_aux any_right d =
738 739
    let accu = ref [] in
    let line (left,right) =
740
      let (d1,d2) = cap_product any any_right left in
741 742 743 744 745 746 747 748 749 750 751 752 753 754 755
      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
756
    List.iter line (BoolPair.get d);
757
    !accu
758 759 760
(* Maybe, can improve this function with:
     (t,s) \ (t1,s1) = (t&t',s\s') | (t\t',s),
   don't call normal_aux *)
761

762

763 764
  let get ?(kind=`Normal) d = 
    match kind with
765 766
      | `Normal -> get_aux any d.times
      | `XML -> get_aux any_pair d.xml
767 768 769

  let pi1 = List.fold_left (fun acc (t1,_) -> cup acc t1) empty
  let pi2 = List.fold_left (fun acc (_,t2) -> cup acc t2) empty
770 771 772 773
  let pi2_restricted restr = 
    List.fold_left (fun acc (t1,t2) -> 
		      if is_empty (cap t1 restr) then acc
		      else cup acc t2) empty
774 775

  let restrict_1 rects pi1 =
776 777
    let aux acc (t1,t2) = 
      let t1 = cap t1 pi1 in if is_empty t1 then acc else (t1,t2)::acc in
778 779 780 781
    List.fold_left aux [] rects
  
  type normal = t

782
  module Memo = Map.Make(BoolPair)
783

784 785
  (* TODO: try with an hashtable *)
  (* Also, avoid lookup for simple products (t1,t2) *)
786
  let memo = ref Memo.empty
787
  let normal_times d = 
788 789 790
    try Memo.find d !memo 
    with
	Not_found ->
791
	  let gd = get_aux any d in
792
	  let n = normal_aux gd in
793 794
(* Could optimize this call to normal_aux because one already
   know that each line is normalized ... *)
795 796
	  memo := Memo.add d n !memo;
	  n
797

798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813
  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


814 815 816 817 818 819 820 821 822 823
  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 []
	 

824 825 826 827 828 829 830
  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

831 832
  let any = { empty with times = any.times }
  and any_xml = { empty with xml = any.xml }
833
  let is_empty d = d == []
834
end
835

836
module Record = 
837
struct
838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
  let has_record d = not (is_empty { empty with record = d.record })
  let or_absent d = { d with absent = true }
  let any_or_absent = or_absent any
  let has_absent d = d.absent

  let only_absent = {empty with absent = true}
  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
    let any = { empty with record = any.record }
    let cap = cap
    let cup = cup
    let diff = diff
    let is_empty = is_empty
    let empty = empty
  end
  module TR = Normal.Make(T)(R)

  let any_record = { empty with record = BoolRec.full }

  let atom o l = 
    if o && LabelMap.is_empty l then any_record else
    { empty with record = BoolRec.atom (o,l) }

  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
	    Pair (any_or_absent, { empty with record = BoolRec.atom (o,r) })
	else
	  Pair (only_absent,
		{ empty with record = BoolRec.atom (o,r) })
    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
    { t with absent = false }

  let condition d l t =
    TR.pi2_restricted t (split d l)
923

924 925 926 927 928
(* 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)
929

930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002
  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 
	    then cup t1 { t2 with absent = false } 
	    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

  let any = { empty with record = any.record }

  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 
1003 1004 1005
	  (fun accu (t1,t2) -> 
	     let x = (t1.absent, { t1 with absent = false }) in
	     aux ((l,x)::r) accu t2)
1006 1007 1008 1009 1010 1011 1012 1013 1014
	  accu
	  (split d l)
    in
    aux [] [] d
end


module Print = 
struct
1015
  let rec print_const ppf = function
1016 1017 1018
    | Integer i -> Intervals.V.print ppf i
    | Atom a -> Atoms.V.print_quote ppf a
    | Char c -> Chars.V.print ppf c
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
    | 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
1034

1035
  let nil_atom = Atoms.V.mk_ascii "nil"
1036 1037 1038 1039 1040 1041 1042 1043 1044
  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

1045 1046 1047
  module S = struct
  type t = { id : int; 
	     mutable def : d list; 
1048
	     mutable state : [ `Expand | `None | `Marked | `Named of U.t ] }
1049
  and  d =
1050
    | Name of U.t
1051 1052 1053
    | Regexp of t Pretty.regexp
    | Atomic of (Format.formatter -> unit)
    | Pair of t * t
1054
    | Char of Chars.V.t
1055
    | Xml of [ `Tag of (Format.formatter -> unit) | `Type of t ] * t * t
1056 1057
    | Record of (bool * t) label_map * bool * bool
    | Arrows of (t * t) list * (t * t) list
1058
    | Neg of t
1059 1060 1061 1062
  let compare x y = x.id - y.id
  end
  module Decompile = Pretty.Decompile(DescrHash)(S)
  open S
1063

1064
  module DescrPairMap = Map.Make(Custom.Pair(Descr)(Descr))
1065 1066 1067

  let named = State.ref "Types.Print.named" DescrMap.empty
  let named_xml = State.ref "Types.Print.named_xml"  DescrPairMap.empty
1068