types.ml 43.9 KB
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open Ident
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open Encodings
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(*
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


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type const = 
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  | Integer of Intervals.V.t
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  | Atom of Atoms.V.t 
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  | Char of Chars.V.t
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  | Pair of const * const
  | Xml of const * const
  | Record of const label_map
  | String of U.uindex * U.uindex * U.t * const
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let rec compare_const c1 c2 =
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  match (c1,c2) with
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    | Integer x, Integer y -> Intervals.V.compare x y
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    | Integer _, _ -> -1
    | _, Integer _ -> 1
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    | Atom x, Atom y -> Atoms.V.compare x y
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    | Atom _, _ -> -1
    | _, Atom _ -> 1
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    | Char x, Char y -> Chars.V.compare x y
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    | 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 *)
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let equal_const c1 c2 = compare_const c1 c2 = 0

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type pair_kind = [ `Normal | `XML ]

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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
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  let hash a =
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    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
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    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
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  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 }
   
    
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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
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  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"
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end

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(* It is also possible to use Boolean insteand of Bool here;
   need to analyze when each one is more efficient *)
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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)))

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type descr = Descr.t
type node = Node.t
include Descr
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let empty = { 
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  times = BoolPair.empty; 
  xml   = BoolPair.empty; 
  arrow = BoolPair.empty; 
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  record= BoolRec.empty;
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  ints  = Intervals.empty;
  atoms = Atoms.empty;
  chars = Chars.empty;
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  absent= false;
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}
	      
let any =  {
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  times = BoolPair.full; 
  xml   = BoolPair.full; 
  arrow = BoolPair.full; 
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  record= BoolRec.full; 
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  ints  = Intervals.any;
  atoms = Atoms.any;
  chars = Chars.any;
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  absent= false;
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}
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let non_constructed =
  { any with times = empty.times; xml = empty.xml; record = empty.record }
     
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let interval i = { empty with ints = i }
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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) }
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let record label t = 
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  { empty with record = BoolRec.atom (true,LabelMap.singleton label t) }
let record' (x : bool * node Ident.label_map) =
  { empty with record = BoolRec.atom x }
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let atom a = { empty with atoms = a }
let char c = { empty with chars = c }
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let cup x y = 
  if x == y then x else {
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    times = BoolPair.cup x.times y.times;
    xml   = BoolPair.cup x.xml y.xml;
    arrow = BoolPair.cup x.arrow y.arrow;
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    record= BoolRec.cup x.record y.record;
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    ints  = Intervals.cup x.ints  y.ints;
    atoms = Atoms.cup x.atoms y.atoms;
    chars = Chars.cup x.chars y.chars;
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    absent= x.absent || y.absent;
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  }
    
let cap x y = 
  if x == y then x else {
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    times = BoolPair.cap x.times y.times;
    xml   = BoolPair.cap x.xml y.xml;
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    record= BoolRec.cap x.record y.record;
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    arrow = BoolPair.cap x.arrow y.arrow;
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    ints  = Intervals.cap x.ints  y.ints;
    atoms = Atoms.cap x.atoms y.atoms;
    chars = Chars.cap x.chars y.chars;
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    absent= x.absent && y.absent;
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  }
    
let diff x y = 
  if x == y then empty else {
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    times = BoolPair.diff x.times y.times;
    xml   = BoolPair.diff x.xml y.xml;
    arrow = BoolPair.diff x.arrow y.arrow;
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    record= BoolRec.diff x.record y.record;
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    ints  = Intervals.diff x.ints  y.ints;
    atoms = Atoms.diff x.atoms y.atoms;
    chars = Chars.diff x.chars y.chars;
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    absent= x.absent && not y.absent;
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  }
    
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(* 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) &&
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  (BoolRec.trivially_disjoint a.record b.record) &&
  (not (a.absent && b.absent))
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module DescrHash = Hashtbl.Make(Descr)
module DescrMap = Map.Make(Descr)
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module DescrSet = Set.Make(Descr)
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module DescrSList = SortedList.Make(Descr)
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(* let hash_cons = DescrHash.create 17000 *)
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let count = State.ref "Types.count" 0
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let make () = incr count; { Node.id = !count; Node.descr = empty }
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let define n d = 
(*  DescrHash.add hash_cons d n; *)
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  n.Node.descr <- d
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let cons d = 
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(*   try DescrHash.find hash_cons d with Not_found ->
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  incr count; let n = { id = !count; descr = d } in
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  DescrHash.add hash_cons d n; n  *)
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  incr count; { Node.id = !count; Node.descr = d }
let descr n = n.Node.descr
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let internalize n = n
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let id n = n.Node.id
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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)
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let neg x = diff any x

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let any_node = cons any

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module LabelS = Set.Make(LabelPool)
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let get_record r =
  let labs accu (_,r) = 
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    List.fold_left 
      (fun accu (l,_) -> LabelS.add l accu) accu (LabelMap.get r) in
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  let extend descrs labs (o,r) =
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    let rec aux i labs r =
      match labs with
	| [] -> ()
	| l1::labs ->
	    match r with
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	      | (l2,x)::r when l1 == l2 -> 
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		  descrs.(i) <- cap descrs.(i) (descr x);
		  aux (i+1) labs r
	      | r ->
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		  if not o then descrs.(i) <- 
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		    cap descrs.(i) { empty with absent = true }; (* TODO:OPT *)
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		  aux (i+1) labs r
    in
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    aux 0 labs (LabelMap.get r);
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    o
  in
  let line (p,n) =
    let labels = 
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      List.fold_left labs (List.fold_left labs LabelS.empty p) n in
    let labels = LabelS.elements labels in
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    let nlab = List.length labels in
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    let mk () = Array.create nlab { any with absent = true } in
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    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
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  List.map line (BoolRec.get r)
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(* 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)
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let cap_product any_left any_right l =
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  List.fold_left 
    (fun (d1,d2) (t1,t2) -> (cap_t d1 t1, cap_t d2 t2))
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    (any_left,any_right)
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    l
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let any_pair = { empty with times = any.times }

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

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exception NotEmpty
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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) -> 
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      if n.status == Maybe then (try f n with NotEmpty -> ());
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      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;
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  s.notify <- Nothing; 
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  raise NotEmpty

let rec big_conj f l n =
  match l with
    | [] -> set n
    | [arg] -> f arg n
    | arg::rem ->
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	let s = 
	  { status = Maybe; active = false; 
	    notify = Do (n,(big_conj f rem), Nothing) } in
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	try 
	  f arg s;
	  if s.active then n.active <- true
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	with NotEmpty -> if n.status == NEmpty then raise NotEmpty
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let guard a f n =
  match a with
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    | { status = Empty } -> ()
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    | { status = Maybe } as s -> 
	n.active <- true; 
	s.notify <- Do (n,f,s.notify)
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    | { status = NEmpty } -> f n
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(* 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 =
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  if not ((Intervals.is_empty d.ints) && 
	  (Atoms.is_empty d.atoms) &&
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	  (Chars.is_empty d.chars) &&
	  (not d.absent)) then slot_not_empty 
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  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);  
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       iter_s s check_xml (BoolPair.get d.xml); 
571
       iter_s s check_arrow (BoolPair.get d.arrow);
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       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 ->
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	let t1 = descr t1 and t2 = descr t2 in
	if trivially_disjoint accu1 t1 || 
	   trivially_disjoint accu2 t2 then (
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	     aux accu1 accu2 right s )
	else (
586
          let accu1' = diff accu1 t1 in 
587
	  guard (slot accu1') (aux accu1' accu2 right) s;
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          let accu2' = diff accu2 t2 in 
590
	  guard (slot accu2') (aux accu1 accu2' right) s  
591
	)
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    | [] -> 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
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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 || 
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	   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  
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	)
    | [] -> 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

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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 ->
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          let accu1' = diff_t accu1 t1 in 
621
	  guard (slot accu1') (aux accu1' accu2 left) s;
622
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          let accu2' = cap_t  accu2 t2 in 
624
	  guard (slot accu2') (aux accu1 accu2' left) s
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      | [] -> set s
    in
    let accu1 = descr s1 in
628
    guard (slot accu1) (aux accu1 (neg (descr s2)) left) s
629
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  in
  big_conj single_right right s
631

632
and check_record (labels,(oleft,left),rights) s =
633
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  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))
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	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
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	    guard (slot di) (fun s ->
			left.(i) <- di;
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650
			aux rights s;
			left.(i) <- back;
		     ) s
651
(* TODO: are side effects correct ? *)
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	  done
  in
  let rec start i s =
    if (i < 0) then aux rights s
    else
657
      guard (slot left.(i)) (start (i - 1)) s
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  in
  start (Array.length left - 1) s


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

671
(*
672
let is_empty d =
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(*  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
*)  
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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
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702
703
  let normal_aux = function
    | ([] | [ _ ]) as d -> d
    | d ->

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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*)
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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
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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
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913
914
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916
917
918
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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
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941
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988
989
990
991
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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
  let register_global (name : U.t) d = 
1069
    if equal { d with xml = BoolPair.empty } empty then 
1070
1071
1072
1073
      (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
	| _ -> ());
1074
    named := DescrMap.add d name !named
1075

1076
  let memo = DescrHash.create 63
1077
1078
  let counter = ref 0
  let alloc def = { id = (incr counter; !counter); def = def; state = `None }
1079

1080
1081
1082
  let count_name = ref 0
  let name () =
    incr count_name;
1083
    U.mk ("X" ^ (string_of_int !count_name))
1084

1085
1086
  let to_print = ref []

1087
1088
1089
  let trivial_rec b = 
    b == BoolRec.empty || 
    (is_empty { empty with record = BoolRec.diff BoolRec.full b})
1090

1091
  let trivial_pair b = b == BoolPair.empty || b == BoolPair.full
1092
1093

  let worth_abbrev d = 
1094
1095
    not (trivial_pair d.times && trivial_pair d.xml && 
	 trivial_pair d.arrow && trivial_rec d.record) 
1096

1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
  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

1109
  let rec prepare d =
1110
    try DescrHash.find memo d
1111
    with Not_found ->
1112
1113
      try 
	let n = DescrMap.find d !named in
1114
1115
	let s = alloc [] in
	s.state <- `Named n;
1116
1117
1118
	DescrHash.add memo d s;
	s
      with Not_found ->
1119
	if worth_complement d then 
1120
	  alloc [Neg (prepare (neg d))]
1121
	else
1122
1123
1124
	let slot = alloc [] in
	if not (worth_abbrev d) then slot.state <- `Expand;
	DescrHash.add memo d slot;
1125
1126
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	let (seq,not_seq) =
	  if (subtype { empty with times = d.times } seqs_descr) then
	    (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 = 
1145
	       match Atoms.print_tag t1.atoms with
1146
		 | Some a when is_empty { t1 with atoms = Atoms.empty } -> `Tag a
1147
		 | _ -> `Type (prepare t1) in
1148
	     assert (equal { t2 with times = empty.times } empty);
1149
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1151
	     List.iter
	       (fun (ta,tb) -> add (Xml (tag, prepare ta, prepare tb)))
	       (Product.get t2)
1152
	  )
1153
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1155
	  ((*Product.merge_same_2*) (Product.get ~kind:`XML not_seq));
	List.iter
	  (fun (r,some,none) -> 
1156
	     let r = LabelMap.map (fun (o,t) -> (o, prepare t)) r in
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	     add (Record (r,some,none)))
	  (Record.get not_seq);
	(match Chars.is_char not_seq.chars with
	  | Some c -> add (Char c)
	  | None ->
	      List.iter (fun x -> add (Atomic x)) (Chars.print not_seq.chars));
	List.iter (fun x -> add (Atomic x)) (Intervals.print not_seq.ints);
	List.iter (fun x -> add (Atomic x)) (Atoms.print not_seq.atoms);
	List.iter
	  (fun (p,n) ->
	     let aux (t,s) = prepare (descr t), prepare (descr s) in
	     let p = List.map aux p and n = List.map aux n in
	     add (Arrows (p,n)))
	  (BoolPair.get not_seq.arrow);
	slot.def <- List.rev slot.def;
	slot
	

  and decompile d =
    Decompile.decompile 
      (fun t -> 
	 let tr = Product.get t in
	 let tr = List.map (fun (l,t) -> prepare l, t) tr in
	 tr, Atoms.contains nil_atom t.atoms)
      d

1183
1184
  let gen = ref 0

1185
  let rec assign_name s =
1186
    incr gen;
1187
    match s.state with
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      | `None ->  
	  let g = !gen in
	  s.state <- `Marked; 
	  List.iter assign_name_rec s.def;
	  if (s.state == `Marked) && (!gen == g) then s.state <- `None
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      | `Marked -> s.state <- `Named (name ()); to_print := s :: !to_print
      | _ -> ()
  and assign_name_rec = function
    | Neg t -> assign_name t
    | Name _ | Char _ | Atomic _ -> ()
    | Regexp r -> assign_name_regexp r
    | Pair (t1,t2) -> assign_name t1; assign_name t2
    | Xml (tag,t2,t3) -> 
	(match tag with `Type t -> assign_name t | _ -> ());
	assign_name t2;
	assign_name t3
    | Record (r,_,_) ->
	List.iter (fun (_,(_,t)) -> assign_name t) (LabelMap.get r)
    | Arrows (p,n) ->
	List.iter (fun (t1,t2) -> assign_name t1; assign_name t2) p;
	List.iter (fun (t1,t2) -> assign_name t1; assign_name t2) n
  and assign_name_regexp = function
    | Pretty.Epsilon | Pretty.Empty -> ()
    | Pretty.Alt (r1,r2) 
    | Pretty.Seq (r1,r2) -> assign_name_regexp r1; assign_name_regexp r2
    | Pretty.Star r | Pretty.Plus r -> assign_name_regexp r
    | Pretty.Trans t -> assign_name t

1216
  let rec do_print_slot pri ppf s =
1217
    match s.state with
1218
      | `Named n -> Format.fprintf ppf "%a" U.print n
1219
      | _ -> do_print_slot_real pri ppf s.def
1220
1221
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1223
1224
  and do_print_slot_real pri ppf def =
    let rec aux ppf = function
      | [] -> Format.fprintf ppf "Empty"
      | [ h ] -> do_print ppf h
      | h :: t -> Format.fprintf ppf "%a |@ %a" do_print h aux t
1225
    in
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