types.ml 46.4 KB
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open Ident
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open Encodings
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(* TODO:
   - I store hash in types to avoid computing it several times.
     Does not seem to help a lot.
*)

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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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module Const = struct
  include Custom.Dummy
  type t = const

  let rec serialize s = function
    | Integer x ->
	Serialize.Put.bits 3 s 0;
	Intervals.V.serialize s x
    | Atom x ->
	Serialize.Put.bits 3 s 1;
	Atoms.V.serialize s x
    | Char x ->
	Serialize.Put.bits 3 s 2;
	Chars.V.serialize s x
    | Pair (x,y) ->
	Serialize.Put.bits 3 s 3;
	serialize s x;
	serialize s y
    | Xml (x,y) ->
	Serialize.Put.bits 3 s 4;
	serialize s x;
	serialize s y
    | Record r ->
	Serialize.Put.bits 3 s 5;
	LabelMap.serialize serialize s r
    | String (i,j,st,q) ->
	Serialize.Put.bits 3 s 6;
	U.serialize_sub s st i j;
	serialize s q

  let rec deserialize s =
    match Serialize.Get.bits 3 s with
      | 0 ->
	  Integer (Intervals.V.deserialize s)
      | 1 ->
	  Char (Chars.V.deserialize s)
      | 2 ->
	  Atom (Atoms.V.deserialize s)
      | 3 ->
	  let x = deserialize s in
	  let y = deserialize s in
	  Pair (x,y)
      | 4 ->
	  let x = deserialize s in
	  let y = deserialize s in
	  Xml (x,y)
      | 5 ->
	  Record (LabelMap.deserialize deserialize s)
      | 6 ->
	  let st = U.deserialize s in
	  let q = deserialize s in
	  String (U.start_index st, U.end_index st, st, q)
      | _ ->
	  assert false

  let rec compare c1 c2 = match (c1,c2) with
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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) ->
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	let c = compare x1 y1 in
	if c <> 0 then c else compare x2 y2
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    | Pair (_,_), _ -> -1
    | _, Pair (_,_) -> 1
    | Xml (x1,x2), Xml (y1,y2) ->
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	let c = compare x1 y1 in
	if c <> 0 then c else compare x2 y2
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    | Xml (_,_), _ -> -1
    | _, Xml (_,_) -> 1
    | Record x, Record y ->
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	LabelMap.compare compare x y
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    | 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 *)
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	else compare r1 r2

  let rec hash = function
    | Integer x -> 1 + 17 * (Intervals.V.hash x)
    | Atom x -> 2 + 17 * (Atoms.V.hash x)
    | Char x -> 3 + 17 * (Chars.V.hash x)
    | Pair (x,y) -> 4 + 17 * (hash x) + 257 * (hash y)
    | Xml (x,y) -> 5 + 17 * (hash x) + 257 * (hash y)
    | Record x -> 6 + 17 * (LabelMap.hash hash x)
    | String (i,j,s,r) -> 7 + 17 * (U.hash s) + 257 * hash r
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      (* Note: improve hash for String *)
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  let equal c1 c2 = compare c1 c2 = 0
end
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type pair_kind = [ `Normal | `XML ]

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let count = State.ref "Types.count" 0
		
let () =
  Stats.register Stats.Summary
    (fun ppf -> Format.fprintf ppf "Allocated type nodes:%i@\n" !count)
      

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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 = {
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    mutable hash: int;
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    atoms : Atoms.t;
    ints  : Intervals.t;
    chars : Chars.t;
    times : BoolPair.t;
    xml   : BoolPair.t;
    arrow : BoolPair.t;
    record: BoolRec.t;
    absent: bool
  }
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  val empty: t
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  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 = {
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    mutable hash: int;
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    atoms : Atoms.t;
    ints  : Intervals.t;
    chars : Chars.t;
    times : BoolPair.t;
    xml   : BoolPair.t;
    arrow : BoolPair.t;
    record: BoolRec.t;
    absent: bool
  }
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  let empty = { 
    hash = 0;
    times = BoolPair.empty; 
    xml   = BoolPair.empty; 
    arrow = BoolPair.empty; 
    record= BoolRec.empty;
    ints  = Intervals.empty;
    atoms = Atoms.empty;
    chars = Chars.empty;
    absent= false;
  }

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  let equal a b =
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    (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)
    )
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  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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    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
    )
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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
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    { hash=0; 
      chars = chars; ints = ints; atoms = atoms; times = times; xml = xml;
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      arrow = arrow; record = record; absent = absent }
   
    
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end
and Node :
sig
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  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
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  let compare x y = x.id - y.id  (* ids are small enough ! *)
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  let equal x y = x == y
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  module SMemo = Set.Make(Custom.Int)
  let memo = Serialize.Put.mk_property (fun t -> ref SMemo.empty)
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  let serialize t n = 
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    let l = Serialize.Put.get_property memo t in
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    Serialize.Put.int t n.id;
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    if not (SMemo.mem n.id !l) then ( 
      l := SMemo.add n.id !l; 
      Descr.serialize t n.descr
    )
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  module DMemo = Map.Make(Custom.Int)
  let memo = Serialize.Get.mk_property (fun t -> ref DMemo.empty)
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  let deserialize t = 
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    let l = Serialize.Get.get_property memo t in
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    let id = Serialize.Get.int t in
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    try DMemo.find id !l
    with Not_found ->
      (* TODO: hash-consing ? *)
      incr count; 
      let n = { id = !count; descr = Descr.empty } in
      l := DMemo.add id n !l;
      n.descr <- Descr.deserialize t;
      n
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end

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(* It is also possible to use Boolean instead of Bool here;
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   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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module DescrHash = Hashtbl.Make(Descr)
module DescrMap = Map.Make(Descr)
module DescrSet = Set.Make(Descr)
module DescrSList = SortedList.Make(Descr)
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type descr = Descr.t
type node = Node.t
include Descr
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let hash_cons = DescrHash.create 17000  

let make () = incr count; { Node.id = !count; Node.descr = empty }
let define n d = 
  DescrHash.add hash_cons d n; 
  n.Node.descr <- d
let cons d = 
  try DescrHash.find hash_cons d 
  with Not_found ->
    incr count; 
    let n = { Node.id = !count; Node.descr = d } in
    DescrHash.add hash_cons d n; n  

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let any =  {
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  hash = 0;
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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 =
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  { any with  
      hash = 0;
      times = empty.times; xml = empty.xml; record = empty.record }
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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) }
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let record label t = 
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  { empty with hash = 0; 
      record = BoolRec.atom (true,LabelMap.singleton label t) }
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let record' (x : bool * node Ident.label_map) =
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  { 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 }
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let cup x y = 
  if x == y then x else {
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    hash = 0;
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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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    hash = 0;
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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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    hash = 0;
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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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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 any_or_absent = { any with hash=0; absent = true } 
let only_absent = { empty with hash=0; absent = true }

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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) <- cap descrs.(i) only_absent; (* 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_or_absent 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 hash = 0; 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) 

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654
(* TODO: need to invesigate when ClearEmpty is a good thing... *)

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

let rec slot d =
659
660
  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
668
       iter_s s check_times (BoolPair.get d.times);  
669
       iter_s s check_xml (BoolPair.get d.xml); 
670
       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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682
	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 (
685
          let accu1' = diff accu1 t1 in 
686
	  guard (slot accu1') (aux accu1' accu2 right) s;
687
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          let accu2' = diff accu2 t2 in 
689
	  guard (slot accu2') (aux accu1 accu2' right) s  
690
	)
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    | [] -> set s
  in
693
  let (accu1,accu2) = cap_product any any left in
694
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
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698
699

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
700
	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 
705
	  guard (slot accu1') (aux accu1' accu2 right) s;
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707

          let accu2' = diff accu2 t2 in 
708
	  guard (slot accu2') (aux accu1 accu2' right) s  
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712
	)
    | [] -> set s
  in
  let (accu1,accu2) = cap_product any any_pair left in
713
  guard (slot accu1) (guard (slot accu2) (aux accu1 accu2 right)) s
714

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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 ->
719
          let accu1' = diff_t accu1 t1 in 
720
	  guard (slot accu1') (aux accu1' accu2 left) s;
721
722

          let accu2' = cap_t  accu2 t2 in 
723
	  guard (slot accu2') (aux accu1 accu2' left) s
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      | [] -> set s
    in
    let accu1 = descr s1 in
727
    guard (slot accu1) (aux accu1 (neg (descr s2)) left) s
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  in
  big_conj single_right right s
730

731
and check_record (labels,(oleft,left),rights) s =
732
733
  let rec aux rights s = match rights with
    | [] -> set s
734
    | (oright,right)::rights ->
735
	let next =
736
	  (oleft && (not oright)) ||
737
	  exists (Array.length left)
738
	    (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;
747
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			aux rights s;
			left.(i) <- back;
		     ) s
750
(* TODO: are side effects correct ? *)
751
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755
	  done
  in
  let rec start i s =
    if (i < 0) then aux rights s
    else
756
      guard (slot left.(i)) (start (i - 1)) s
757
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760
  in
  start (Array.length left - 1) s


761
762
let timer_subtype = Stats.Timer.create "Types.is_empty"

763
let is_empty d =
764
  Stats.Timer.start timer_subtype;
765
766
  let s = slot d in
  List.iter 
767
768
    (fun s' -> 
       if s'.status == Maybe then s'.status <- Empty; s'.notify <- Nothing) 
769
770
    !marks;
  marks := [];
771
772
  Stats.Timer.stop timer_subtype 
    (s.status == Empty)
773

774
(*
775
let is_empty d =
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782
(*  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
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      | `Normal -> { d with hash = 0; times = empty.times }
      | `XML -> { d with hash = 0; xml = empty.xml }
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800
801
802

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

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

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805
806
  let normal_aux = function
    | ([] | [ _ ]) as d -> d
    | d ->

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    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*) 
814
(*	    if equal_descr d1 t1 then r := (d1,cup d2 t2) else*)
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838
	      
	      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)

839
*)
840
  let get_aux any_right d =
841
842
    let accu = ref [] in
    let line (left,right) =
843
      let (d1,d2) = cap_product any any_right left in
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      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
859
    List.iter line (BoolPair.get d);
860
    !accu
861
862
863
(* Maybe, can improve this function with:
     (t,s) \ (t1,s1) = (t&t',s\s') | (t\t',s),
   don't call normal_aux *)
864

865

866
867
  let get ?(kind=`Normal) d = 
    match kind with
868
869
      | `Normal -> get_aux any d.times
      | `XML -> get_aux any_pair d.xml
870
871
872

  let pi1 = List.fold_left (fun acc (t1,_) -> cup acc t1) empty
  let pi2 = List.fold_left (fun acc (_,t2) -> cup acc t2) empty
873
874
875
876
  let pi2_restricted restr = 
    List.fold_left (fun acc (t1,t2) -> 
		      if is_empty (cap t1 restr) then acc
		      else cup acc t2) empty
877
878

  let restrict_1 rects pi1 =
879
880
    let aux acc (t1,t2) = 
      let t1 = cap t1 pi1 in if is_empty t1 then acc else (t1,t2)::acc in
881
882
883
884
    List.fold_left aux [] rects
  
  type normal = t

885
  module Memo = Map.Make(BoolPair)
886

887
888
  (* TODO: try with an hashtable *)
  (* Also, avoid lookup for simple products (t1,t2) *)
889
  let memo = ref Memo.empty
890
  let normal_times d = 
891
892
893
    try Memo.find d !memo 
    with
	Not_found ->
894
	  let gd = get_aux any d in
895
	  let n = normal_aux gd in
896
897
(* Could optimize this call to normal_aux because one already
   know that each line is normalized ... *)
898
899
	  memo := Memo.add d n !memo;
	  n
900

901
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903
904
905
906
907
908
909
910
911
912
913
914
915
916
  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


917
918
919
920
921
922
923
924
925
926
  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 []
	 

927
928
929
930
931
932
933
  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

934
935
  let any = { empty with hash = 0; times = any.times }
  and any_xml = { empty with hash = 0; xml = any.xml }
936
  let is_empty d = d == []
937
end
938

939
module Record = 
940
struct
941
942
  let has_record d = not (is_empty { empty with hash= 0; record = d.record })
  let or_absent d = { d with hash = 0; absent = true }
943
944
945
  let any_or_absent = or_absent any
  let has_absent d = d.absent

946
  let only_absent = {empty with hash = 0; absent = true}
947
948
949
950
951
952
953
954
955
956
957
958
959
  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
960
    let any = { empty with hash = 0; record = any.record }
961
962
963
964
965
966
967
968
    let cap = cap
    let cup = cup
    let diff = diff
    let is_empty = is_empty
    let empty = empty
  end
  module TR = Normal.Make(T)(R)

969
  let any_record = { empty with hash = 0; record = BoolRec.full }
970
971
972

  let atom o l = 
    if o && LabelMap.is_empty l then any_record else
973
    { empty with hash = 0; record = BoolRec.atom (o,l) }
974
975
976
977
978
979
980
981
982
983
984

  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
985
	    Pair (any_or_absent, { empty with hash=0; record = BoolRec.atom (o,r) })
986
987
	else
	  Pair (only_absent,
988
		{ empty with hash = 0; record = BoolRec.atom (o,r) })
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
1020
1021
    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
1022
    { t with hash = 0; absent = false }
1023
1024
1025

  let condition d l t =
    TR.pi2_restricted t (split d l)
1026

1027
1028
1029
1030
1031
(* 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)
1032

1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
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1045
1046
1047
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1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
  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 
1085
	    then cup t1 { t2 with hash = 0; absent = false } 
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
	    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

1096
  let any = { empty with hash = 0; record = any.record }
1097
1098
1099
1100
1101
1102
1103
1104
1105

  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 
1106
	  (fun accu (t1,t2) -> 
1107
	     let x = (t1.absent, { t1 with hash = 0; absent = false }) in
1108
	     aux ((l,x)::r) accu t2)
1109
1110
1111
1112
1113
1114
1115
1116
1117
	  accu
	  (split d l)
    in
    aux [] [] d
end


module Print = 
struct
1118
  let rec print_const ppf = function
1119
1120
1121
    | Integer i -> Intervals.V.print ppf i
    | Atom a -> Atoms.V.print_quote ppf a
    | Char c -> Chars.V.print ppf c
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
    | 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
1137

1138
  let nil_atom = Atoms.V.mk_ascii "nil"
1139
1140
1141
1142
1143
1144
1145
1146
1147
  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

1148
1149
1150
  module S = struct
  type t = { id : int; 
	     mutable def : d list; 
1151
	     mutable state : [ `Expand | `None | `Marked | `Named of U.t ] }
1152
  and  d =
1153
    | Name of U.t
1154
1155
1156
    | Regexp of t Pretty.regexp
    | Atomic of (Format.formatter -> unit)
    | Pair of t * t
1157
    | Char of Chars.V.t
1158
    | Xml of [ `Tag of (Format.formatter -> unit) | `Type of t ] * t * t
1159
1160
    | Record of (bool * t) label_map * bool * bool
    | Arrows of (t * t) list * (t * t) list
1161
    | Neg of t
1162
1163
1164
1165
  let compare x y = x.id - y.id
  end
  module Decompile = Pretty.Decompile(DescrHash)(S)
  open S
1166

1167
  module DescrPairMap = Map.Make(Custom.Pair(Descr)(Descr))
1168
1169
1170

  let named = State.ref "Types.Print.named" DescrMap.empty
  let named_xml = State.ref "Types.Print.named_xml"  DescrPairMap.empty
1171
  let register_global (name : U.t) d = 
1172
    if equal { d with hash = 0; xml = BoolPair.empty } empty then 
1173
1174
1175
1176
      (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
	| _ -> ());
1177
    named := DescrMap.add d name !named
1178

1179
  let memo = DescrHash.create 63
1180
1181
  let counter = ref 0
  let alloc def = { id = (incr counter; !counter); def = def; state = `None }
1182

1183