typer.ml 44.2 KB
Newer Older
1
(* TODO:
2
 - rewrite type-checking of operators to propagate constraint
3
4
 - optimize computation of pattern free variables
 - check whether it is worth using recursive hash-consing internally
5
6
*)

7
8
9
open Location
open Ast
open Ident
10

11
let warning loc msg =
12
  Format.fprintf !Location.warning_ppf "Warning %a:@\n%a%s@." 
13
14
    Location.print_loc (loc,`Full)
    Location.html_hilight (loc,`Full)
15
16
    msg

17
18
type item =
  | Type of Types.t
19
  | Val of Types.t
20

21
type t = {
22
  ids : item Env.t;
23
24
  ns: Ns.table;
  cu: Types.CompUnit.t Env.t;
25
}
26

27
28
29
30
31
let hash _ = failwith "Typer.hash"
let compare _ _ = failwith "Typer.compare"
let dump ppf _ = failwith "Typer.dump"
let equal _ _ = failwith "Typer.equal"
let check _ = failwith "Typer.check"
32
33

(* TODO: filter out builtin defs ? *)
34
35
36
37
let serialize_item s = function
  | Type t -> Serialize.Put.bits 1 s 0; Types.serialize s t
  | Val t -> Serialize.Put.bits 1 s 1; Types.serialize s t

38
let serialize s env =
39
  Serialize.Put.env Id.serialize serialize_item Env.iter s env.ids;
40
  Ns.serialize_table s env.ns
41

42
43
44
45
46
let deserialize_item s = match Serialize.Get.bits 1 s with
  | 0 -> Type (Types.deserialize s)
  | 1 -> Val (Types.deserialize s)
  | _ -> assert false

47
let deserialize s =
48
49
  let ids = 
    Serialize.Get.env Id.deserialize deserialize_item Env.add Env.empty s in
50
  let ns = Ns.deserialize_table s in
51
  { ids = ids; ns = ns; cu = Env.empty }
52
53


54
55
let empty_env = {
  ids = Env.empty;
56
57
  ns = Ns.empty_table;
  cu = Env.empty;
58
59
}

60
61
let from_comp_unit = ref (fun cu -> assert false)

62
63
64
65
66
67
68
69
let enter_type id t env =
  { env with ids = Env.add id (Type t) env.ids }
let enter_types l env =
  { env with ids = 
      List.fold_left (fun accu (id,t) -> Env.add id (Type t) accu) env.ids l }
let find_type id env =
  match Env.find id env.ids with
    | Type t -> t
70
    | Val _ -> raise Not_found
71

72
73
74
75
76
let find_type_global cu id env =
  let cu = Env.find cu env.cu in
  let env = !from_comp_unit cu in
  find_type id env

77
let enter_value id t env = 
78
  { env with ids = Env.add id (Val t) env.ids }
79
80
let enter_values l env =
  { env with ids = 
81
      List.fold_left (fun accu (id,t) -> Env.add id (Val t) accu) env.ids l }
82
83
let find_value id env =
  match Env.find id env.ids with
84
    | Val t -> t
85
    | _ -> raise Not_found
86
87
88
let find_value_global cu id env =
  let env = !from_comp_unit cu in
  find_value id env
89
	
90
91
92
93
94
95
let value_name_ok id env =
  try match Env.find id env.ids with
    | Val t -> true
    | _ -> false
  with Not_found -> true

96
97
98
99
let iter_values env f =
  Env.iter (fun x ->
	      function Val t -> f x t;
		| _ -> ()) env.ids
100

101
102
103
104

let enter_cu x cu env =
  { env with cu = Env.add (ident x) cu env.cu }

105
106
107
108
let find_cu x env =
  try Env.find x env.cu
  with Not_found -> failwith ("Unbound compunit prefix " ^ (Ident.to_string x))

109
(* Namespaces *)
110

111
let set_ns_table_for_printer env = 
112
  Ns.InternalPrinter.set_table env.ns
113

114
let get_ns_table tenv = tenv.ns
115

116
let enter_ns p ns env =
117
  { env with ns = Ns.add_prefix p ns env.ns }
118

119
120
121
122
123
let protect_error_ns loc f x =
  try f x
  with Ns.UnknownPrefix ns ->
    raise_loc_generic loc 
    ("Undefined namespace prefix " ^ (U.to_string ns))
124

125
let parse_atom env loc t =
126
  let (ns,l) = protect_error_ns loc (Ns.map_tag env.ns) t in
127
128
129
  Atoms.V.mk ns l
 
let parse_ns env loc ns =
130
  protect_error_ns loc (Ns.map_prefix env.ns) ns
131

132
let parse_label env loc t =
133
  let (ns,l) = protect_error_ns loc (Ns.map_attr env.ns) t in
134
  LabelPool.mk (ns,l)
135

136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
let parse_record env loc f r =
  let r = List.map (fun (l,x) -> (parse_label env loc l, f x)) r in
  LabelMap.from_list (fun _ _ -> raise_loc_generic loc "Duplicated record field") r

let rec const env loc = function
  | LocatedExpr (loc,e) -> const env loc e
  | Pair (x,y) -> Types.Pair (const env loc x, const env loc y)
  | Xml (x,y) -> Types.Xml (const env loc x, const env loc y)
  | RecordLitt x -> Types.Record (parse_record env loc (const env loc) x)
  | String (i,j,s,c) -> Types.String (i,j,s,const env loc c)
  | Atom t -> Types.Atom (parse_atom env loc t)
  | Integer i -> Types.Integer i
  | Char c -> Types.Char c
  | _ -> raise_loc_generic loc "This should be a scalar or structured constant"

(* I. Transform the abstract syntax of types and patterns into
      the internal form *)
153

154
exception NonExhaustive of Types.descr
155
exception Constraint of Types.descr * Types.descr
156
exception ShouldHave of Types.descr * string
157
exception ShouldHave2 of Types.descr * string * Types.descr
158
exception WrongLabel of Types.descr * label
159
exception UnboundId of id * bool
160
exception Error of string
161

162
163
let raise_loc loc exn = raise (Location (loc,`Full,exn))
let raise_loc_str loc ofs exn = raise (Location (loc,`Char ofs,exn))
164
let error loc msg = raise_loc loc (Error msg)
165

166
167
168
  (* Schema datastructures *)

module StringSet = Set.Make (String)
169
170
171

  (* just to remember imported schemas *)
let schemas = State.ref "Typer.schemas" StringSet.empty
172
173
174

let schema_types = State.ref "Typer.schema_types" (Hashtbl.create 51)
let schema_elements = State.ref "Typer.schema_elements" (Hashtbl.create 51)
175
let schema_attributes = State.ref "Typer.schema_attributes" (Hashtbl.create 51)
176

177
178
179
180
181
182
183
184
(* Eliminate Recursion, propagate Sequence Capture Variables *)

let rec seq_vars accu = function
  | Epsilon | Elem _ -> accu
  | Seq (r1,r2) | Alt (r1,r2) -> seq_vars (seq_vars accu r1) r2
  | Star r | WeakStar r -> seq_vars accu r
  | SeqCapture (v,r) -> seq_vars (IdSet.add v accu) r

185
186
187
188
189
190
191
192
193
194
195
196
197
198
(* We use two intermediate representation from AST types/patterns
   to internal ones:

      AST -(1)-> derecurs -(2)-> slot -(3)-> internal

   (1) eliminate recursion, schema, 
       propagate sequence capture variables, keep regexps

   (2) stratify, detect ill-formed recursion, compile regexps

   (3) check additional constraints on types / patterns;
       deep (recursive) hash-consing
*)     

199
200
201
202
type derecurs_slot = {
  ploc : Location.loc;
  pid  : int;
  mutable ploop : bool;
203
  mutable pdescr : derecurs;
204
} and derecurs =
205
  | PDummy
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
  | PAlias of derecurs_slot
  | PType of Types.descr
  | POr of derecurs * derecurs
  | PAnd of derecurs * derecurs
  | PDiff of derecurs * derecurs
  | PTimes of derecurs * derecurs
  | PXml of derecurs * derecurs
  | PArrow of derecurs * derecurs
  | POptional of derecurs
  | PRecord of bool * derecurs label_map
  | PCapture of id
  | PConstant of id * Types.const
  | PRegexp of derecurs_regexp * derecurs
and derecurs_regexp =
  | PEpsilon
  | PElem of derecurs
  | PSeq of derecurs_regexp * derecurs_regexp
  | PAlt of derecurs_regexp * derecurs_regexp
  | PStar of derecurs_regexp
  | PWeakStar of derecurs_regexp

227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246

type descr = 
  | IDummy
  | IType of Types.descr
  | IOr of descr * descr
  | IAnd of descr * descr
  | IDiff of descr * descr
  | ITimes of slot * slot
  | IXml of slot * slot
  | IArrow of slot * slot
  | IOptional of descr
  | IRecord of bool * slot label_map
  | ICapture of id
  | IConstant of id * Types.const
and slot = {
  mutable fv : fv option;
  mutable hash : int option;
  mutable rank1: int; mutable rank2: int;
  mutable gen1 : int; mutable gen2: int;
  mutable d    : descr;
247
}
248
249
250
251
252
253
254
255
256
257
258
259
260
    

let counter = ref 0
let mk_derecurs_slot loc = 
  incr counter; 
  { ploop = false; ploc = loc; pid = !counter; pdescr = PDummy }
	  
let mk_slot () = 
  { d=IDummy; fv=None; hash=None; rank1=0; rank2=0; gen1=0; gen2=0 } 


(* This environment is used in phase (1) to eliminate recursion *)
type penv = {
261
  penv_tenv : t;
262
263
264
265
  penv_derec : derecurs_slot Env.t;
}

let penv tenv = { penv_tenv = tenv; penv_derec = Env.empty }
266

267
let rec hash_derecurs = function
268
  | PDummy -> assert false
269
270
271
  | PAlias s -> 
      s.pid
  | PType t -> 
272
      1 + 17 * (Types.hash t)
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
  | POr (p1,p2) -> 
      2 + 17 * (hash_derecurs p1) + 257 * (hash_derecurs p2)
  | PAnd (p1,p2) -> 
      3 + 17 * (hash_derecurs p1) + 257 * (hash_derecurs p2)
  | PDiff (p1,p2) -> 
      4 + 17 * (hash_derecurs p1) + 257 * (hash_derecurs p2)
  | PTimes (p1,p2) -> 
      5 + 17 * (hash_derecurs p1) + 257 * (hash_derecurs p2)
  | PXml (p1,p2) -> 
      6 + 17 * (hash_derecurs p1) + 257 * (hash_derecurs p2)
  | PArrow (p1,p2) -> 
      7 + 17 * (hash_derecurs p1) + 257 * (hash_derecurs p2)
  | POptional p -> 
      8 + 17 * (hash_derecurs p)
  | PRecord (o,r) -> 
      (if o then 9 else 10) + 17 * (LabelMap.hash hash_derecurs r)
  | PCapture x -> 
      11 + 17 * (Id.hash x)
  | PConstant (x,c) -> 
292
      12 + 17 * (Id.hash x) + 257 * (Types.Const.hash c)
293
294
  | PRegexp (p,q) -> 
      13 + 17 * (hash_derecurs_regexp p) + 257 * (hash_derecurs q)
295
and hash_derecurs_regexp = function
296
297
298
299
300
301
302
303
304
305
306
307
  | PEpsilon -> 
      1
  | PElem p -> 
      2 + 17 * (hash_derecurs p)
  | PSeq (p1,p2) -> 
      3 + 17 * (hash_derecurs_regexp p1) + 257 * (hash_derecurs_regexp p2)
  | PAlt (p1,p2) -> 
      4 + 17 * (hash_derecurs_regexp p1) + 257 * (hash_derecurs_regexp p2)
  | PStar p -> 
      5 + 17 * (hash_derecurs_regexp p)
  | PWeakStar p -> 
      6 + 17 * (hash_derecurs_regexp p)
308
309

let rec equal_derecurs p1 p2 = (p1 == p2) || match p1,p2 with
310
311
312
  | PAlias s1, PAlias s2 -> 
      s1 == s2
  | PType t1, PType t2 -> 
313
      Types.equal t1 t2
314
315
316
317
318
  | POr (p1,q1), POr (p2,q2)
  | PAnd (p1,q1), PAnd (p2,q2)
  | PDiff (p1,q1), PDiff (p2,q2)
  | PTimes (p1,q1), PTimes (p2,q2)
  | PXml (p1,q1), PXml (p2,q2)
319
320
321
322
323
324
325
326
327
  | PArrow (p1,q1), PArrow (p2,q2) -> 
      (equal_derecurs p1 p2) && (equal_derecurs q1 q2)
  | POptional p1, POptional p2 -> 
      equal_derecurs p1 p2
  | PRecord (o1,r1), PRecord (o2,r2) -> 
      (o1 == o2) && (LabelMap.equal equal_derecurs r1 r2)
  | PCapture x1, PCapture x2 -> 
      Id.equal x1 x2
  | PConstant (x1,c1), PConstant (x2,c2) -> 
328
      (Id.equal x1 x2) && (Types.Const.equal c1 c2)
329
330
  | PRegexp (p1,q1), PRegexp (p2,q2) -> 
      (equal_derecurs_regexp p1 p2) && (equal_derecurs q1 q2)
331
332
  | _ -> false
and equal_derecurs_regexp r1 r2 = match r1,r2 with
333
334
335
336
  | PEpsilon, PEpsilon -> 
      true
  | PElem p1, PElem p2 -> 
      equal_derecurs p1 p2
337
  | PSeq (p1,q1), PSeq (p2,q2) 
338
339
  | PAlt (p1,q1), PAlt (p2,q2) -> 
      (equal_derecurs_regexp p1 p2) && (equal_derecurs_regexp q1 q2)
340
  | PStar p1, PStar p2
341
342
  | PWeakStar p1, PWeakStar p2 -> 
      equal_derecurs_regexp p1 p2
343
  | _ -> false
344

345
346
347
348
349
350
351
352
353
354
355
module DerecursTable = Hashtbl.Make(
  struct 
    type t = derecurs 
    let hash = hash_derecurs
    let equal = equal_derecurs
  end
)

module RE = Hashtbl.Make(
  struct 
    type t = derecurs_regexp * derecurs 
356
357
358
359
    let hash (p,q) = 
      (hash_derecurs_regexp p) + 17 * (hash_derecurs q)
    let equal (p1,q1) (p2,q2) = 
      (equal_derecurs_regexp p1 p2) && (equal_derecurs q1 q2)
360
361
  end
)
362

363
364
365
366
let gen = ref 0
let rank = ref 0
	     
let rec hash_descr = function
367
  | IDummy -> assert false
368
  | IType x -> Types.hash x
369
370
371
372
373
374
375
376
377
  | IOr (d1,d2) -> 1 + 17 * (hash_descr d1) + 257 * (hash_descr d2)
  | IAnd (d1,d2) -> 2 + 17 * (hash_descr d1) + 257 * (hash_descr d2)
  | IDiff (d1,d2) -> 3 + 17 * (hash_descr d1) + 257 * (hash_descr d2)
  | IOptional d -> 4 + 17 * (hash_descr d)
  | ITimes (s1,s2) -> 5 + 17 * (hash_slot s1) + 257 * (hash_slot s2)
  | IXml (s1,s2) -> 6 + 17 * (hash_slot s1) + 257 * (hash_slot s2)
  | IArrow (s1,s2) -> 7 + 17 * (hash_slot s1) + 257 * (hash_slot s2)
  | IRecord (o,r) -> (if o then 8 else 9) + 17 * (LabelMap.hash hash_slot r)
  | ICapture x -> 10 + 17 * (Id.hash x)
378
  | IConstant (x,y) -> 11 + 17 * (Id.hash x) + 257 * (Types.Const.hash y)
379
380
381
382
383
and hash_slot s =
  if s.gen1 = !gen then 13 * s.rank1
  else (
    incr rank;
    s.rank1 <- !rank; s.gen1 <- !gen;
384
    hash_descr s.d
385
386
387
388
  )
    
let rec equal_descr d1 d2 = 
  match (d1,d2) with
389
  | IType x1, IType x2 -> Types.equal x1 x2
390
391
392
393
394
395
396
  | IOr (x1,y1), IOr (x2,y2) 
  | IAnd (x1,y1), IAnd (x2,y2) 
  | IDiff (x1,y1), IDiff (x2,y2) -> (equal_descr x1 x2) && (equal_descr y1 y2)
  | IOptional x1, IOptional x2 -> equal_descr x1 x2
  | ITimes (x1,y1), ITimes (x2,y2) 
  | IXml (x1,y1), IXml (x2,y2) 
  | IArrow (x1,y1), IArrow (x2,y2) -> (equal_slot x1 x2) && (equal_slot y1 y2)
397
398
  | IRecord (o1,r1), IRecord (o2,r2) -> 
      (o1 = o2) && (LabelMap.equal equal_slot r1 r2)
399
  | ICapture x1, ICapture x2 -> Id.equal x1 x2
400
  | IConstant (x1,y1), IConstant (x2,y2) -> 
401
      (Id.equal x1 x2) && (Types.Const.equal y1 y2)
402
403
404
405
406
407
408
409
  | _ -> false
and equal_slot s1 s2 =
  ((s1.gen1 = !gen) && (s2.gen2 = !gen) && (s1.rank1 = s2.rank2))
  ||
  ((s1.gen1 <> !gen) && (s2.gen2 <> !gen) && (
     incr rank;
     s1.rank1 <- !rank; s1.gen1 <- !gen;
     s2.rank2 <- !rank; s2.gen2 <- !gen;
410
     equal_descr s1.d s2.d
411
412
   ))
  
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
module SlotTable = Hashtbl.Make(
  struct
    type t = slot
	
    let hash s =
      match s.hash with
	| Some h -> h
	| None ->
	    incr gen; rank := 0; 
	    let h = hash_slot s in
	    s.hash <- Some h;
	    h
	      
    let equal s1 s2 = 
      (s1 == s2) || 
      (incr gen; rank := 0; 
       let e = equal_slot s1 s2 in
       (*     if e then Printf.eprintf "Recursive hash-consing: Equal\n";  *)
       e)
  end)


let rec derecurs env p = match p.descr with
  | PatVar v ->
437
438
439
440
441
442
443
444
445
446
447
448
449
      (match Ns.split_qname v with
	 | "", v ->
	     let v = ident v in
	     (try PAlias (Env.find v env.penv_derec)
	      with Not_found -> 
		try PType (find_type v env.penv_tenv)
		with Not_found -> PCapture v)
	 | cu, v -> 
	     try 
	       let cu = ident (U.mk cu) in
	       PType (find_type_global cu (ident v) env.penv_tenv)
	     with Not_found ->
	       failwith ("Unbound external type " ^ cu ^ ":" ^ (U.to_string v)))
450
451
452
453
454
455
456
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
  | SchemaVar (kind, schema, item) ->
      PType (derecurs_schema env kind schema item)
  | Recurs (p,b) -> derecurs (derecurs_def env b) p
  | Internal t -> PType t
  | NsT ns -> PType (Types.atom (Atoms.any_in_ns (parse_ns env.penv_tenv p.loc ns)))
  | Or (p1,p2) -> POr (derecurs env p1, derecurs env p2)
  | And (p1,p2) -> PAnd (derecurs env p1, derecurs env p2)
  | Diff (p1,p2) -> PDiff (derecurs env p1, derecurs env p2)
  | Prod (p1,p2) -> PTimes (derecurs env p1, derecurs env p2)
  | XmlT (p1,p2) -> PXml (derecurs env p1, derecurs env p2)
  | Arrow (p1,p2) -> PArrow (derecurs env p1, derecurs env p2)
  | Optional p -> POptional (derecurs env p)
  | Record (o,r) -> PRecord (o, parse_record env.penv_tenv p.loc (derecurs env) r)
  | Constant (x,c) -> PConstant (x,const env.penv_tenv p.loc c)
  | Cst c -> PType (Types.constant (const env.penv_tenv p.loc c))
  | Regexp (r,q) -> 
      let constant_nil t v = 
	PAnd (t, PConstant (v, Types.Atom Sequence.nil_atom)) in
      let vars = seq_vars IdSet.empty r in
      let q = IdSet.fold constant_nil (derecurs env q) vars in
      let r = derecurs_regexp (fun p -> p) env r in
      PRegexp (r, q)
and derecurs_regexp vars env = function
  | Epsilon -> 
      PEpsilon
  | Elem p -> 
      PElem (vars (derecurs env p))
  | Seq (p1,p2) -> 
      PSeq (derecurs_regexp vars env p1, derecurs_regexp vars env p2)
  | Alt (p1,p2) -> 
      PAlt (derecurs_regexp vars env p1, derecurs_regexp vars env p2)
  | Star p -> 
      PStar (derecurs_regexp vars env p)
  | WeakStar p -> 
      PWeakStar (derecurs_regexp vars env p)
  | SeqCapture (x,p) -> 
      derecurs_regexp (fun p -> PAnd (vars p, PCapture x)) env p


and derecurs_def env b =
  let b = List.map (fun (v,p) -> (v,p,mk_derecurs_slot p.loc)) b in
  let n = 
    List.fold_left (fun env (v,p,s) -> Env.add v s env) env.penv_derec b in
  let env = { env with penv_derec = n } in
  List.iter (fun (v,p,s) -> s.pdescr <- derecurs env p) b;
  env

and derecurs_schema env kind schema item =
  let elt () = fst (Hashtbl.find !schema_elements (schema, item)) in
  let typ () = Hashtbl.find !schema_types (schema, item) in
  let att () = Hashtbl.find !schema_attributes (schema, item) in
  let rec do_try n = function
    | [] -> 
	let s = Printf.sprintf 
		  "No %s named '%s' found in schema '%s'" n item schema in
	failwith s
    | f :: rem -> (try f () with Not_found -> do_try n rem)  in
  match kind with
    | `Element -> do_try "element" [ elt ]
    | `Type -> do_try "type" [ typ ]
    | `Attribute -> do_try "atttribute" [ att ]
    | `Any -> do_try "item" [ elt; typ; att ]

    
514
515
516
517
518
let rec fv_slot s =
  match s.fv with
    | Some x -> x
    | None ->
	if s.gen1 = !gen then IdSet.empty 
519
	else (s.gen1 <- !gen; fv_descr s.d)
520
and fv_descr = function
521
  | IDummy -> assert false
522
  | IType _ -> IdSet.empty
523
524
525
526
527
528
529
  | IOr (d1,d2)
  | IAnd (d1,d2)  
  | IDiff (d1,d2) -> IdSet.cup (fv_descr d1) (fv_descr d2)
  | IOptional d -> fv_descr d
  | ITimes (s1,s2)  
  | IXml (s1,s2)  
  | IArrow (s1,s2) -> IdSet.cup (fv_slot s1) (fv_slot s2)
530
531
  | IRecord (o,r) -> 
      List.fold_left IdSet.cup IdSet.empty (LabelMap.map_to_list fv_slot r)
532
  | ICapture x | IConstant (x,_) -> IdSet.singleton x
533

534
535
536
537
538
539
540
541
let compute_fv s =
  match s.fv with
    | Some x -> ()
    | None ->
	incr gen;
	let x = fv_slot s in
	s.fv <- Some x
	  
542
543
544
let check_no_capture loc s =
  match IdSet.pick s with
    | Some x ->  
545
	raise_loc_generic loc ("Capture variable not allowed: " ^ (Ident.to_string x))
546
    | None -> ()
547
    
548
549
550
let compile_slot_hash = DerecursTable.create 67
let compile_hash = DerecursTable.create 67

551
552
let todo_defs = ref []
let todo_fv = ref []
553
554
555
556
557
558
559
560

let rec compile p =
  try DerecursTable.find compile_hash p
  with Not_found ->
    let c = real_compile p in
    DerecursTable.replace compile_hash p c;
    c
and real_compile = function
561
  | PDummy -> assert false
562
563
564
565
  | PAlias v ->
      if v.ploop then
	raise_loc_generic v.ploc ("Unguarded recursion on type/pattern");
      v.ploop <- true;
566
      let r = compile v.pdescr in
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
      v.ploop <- false;
      r
  | PType t -> IType t
  | POr (t1,t2) -> IOr (compile t1, compile t2)
  | PAnd (t1,t2) -> IAnd (compile t1, compile t2)
  | PDiff (t1,t2) -> IDiff (compile t1, compile t2)
  | PTimes (t1,t2) -> ITimes (compile_slot t1, compile_slot t2)
  | PXml (t1,t2) -> IXml (compile_slot t1, compile_slot t2)
  | PArrow (t1,t2) -> IArrow (compile_slot t1, compile_slot t2)
  | POptional t -> IOptional (compile t)
  | PRecord (o,r) ->  IRecord (o, LabelMap.map compile_slot r)
  | PConstant (x,v) -> IConstant (x,v)
  | PCapture x -> ICapture x
  | PRegexp (r,q) -> compile_regexp r q
and compile_regexp r q =
  let memo = RE.create 17 in
583
584
585
  let add accu i = 
    match accu with None -> Some i | Some j -> Some (IOr (j,i)) in
  let get = function Some x -> x | None -> assert false in
586
  let rec queue accu = function
587
588
589
    | PRegexp (r,q) -> aux accu r q 
    | _ -> add accu (compile q)
  and aux accu r q =
590
591
592
593
    if RE.mem memo (r,q) then accu
    else (
      RE.add memo (r,q) ();
      match r with
594
	| PEpsilon -> queue accu q
595
596
597
598
599
600
601
602
603
604
605
	| PElem p ->
(* Be careful not to create pairs with same second component *)
	    let rec extract = function
	      | PConstant (x,v) -> `Const (x,v)
	      | POr (x,y) ->
		  (match extract x, extract y with
		    | `Pat x, `Pat y -> `Pat (POr (x,y))
		    | x, y -> `Or (x,y))
	      | p -> `Pat p
	    in
	    let rec mk accu = function
606
607
608
609
	      | `Const (x,v) -> 
		  (match queue None q with 
		    | Some q -> add accu (IAnd (IConstant (x,v), q))
		    | None -> accu)
610
	      | `Or (x,y) -> mk (mk accu x) y
611
612
	      | `Pat p -> 
		  add accu (ITimes (compile_slot p, compile_slot q))
613
614
	    in
	    mk accu (extract p)
615
616
617
618
619
620
	| PSeq (r1,r2) -> aux accu r1 (PRegexp (r2,q))
	| PAlt (r1,r2) -> aux (aux accu r1 q) r2 q
	| PStar r1 -> aux (aux accu r1 (PRegexp (r,q))) PEpsilon q
	| PWeakStar r1 -> aux (aux accu PEpsilon q) r1 (PRegexp (r,q))
    )
  in
621
  get (aux None r q)
622
623
and compile_slot p =
  try DerecursTable.find compile_slot_hash p
624
  with Not_found ->
625
626
627
    let s = mk_slot () in
    todo_defs := (s,p) :: !todo_defs;
    todo_fv := s :: !todo_fv;
628
    DerecursTable.add compile_slot_hash p s;
629
    s
630

631
      
632
let timer_fv = Stats.Timer.create "Typer.fv"
633
let rec flush_defs () = 
634
635
636
637
  match !todo_defs with
    | [] -> 
	Stats.Timer.start timer_fv;
	List.iter compute_fv !todo_fv;
638
639
	todo_fv := [];
	Stats.Timer.stop timer_fv ()
640
641
642
643
    | (s,p)::t -> 
	todo_defs := t; 
	s.d <- compile p; 
	flush_defs ()
644
645
646
647
648
649
650
651
652
653
654
655
656
657
	
let typ_nodes = SlotTable.create 67
let pat_nodes = SlotTable.create 67
		  
let rec typ = function
  | IType t -> t
  | IOr (s1,s2) -> Types.cup (typ s1) (typ s2)
  | IAnd (s1,s2) ->  Types.cap (typ s1) (typ s2)
  | IDiff (s1,s2) -> Types.diff (typ s1) (typ s2)
  | ITimes (s1,s2) -> Types.times (typ_node s1) (typ_node s2)
  | IXml (s1,s2) -> Types.xml (typ_node s1) (typ_node s2)
  | IArrow (s1,s2) -> Types.arrow (typ_node s1) (typ_node s2)
  | IOptional s -> Types.Record.or_absent (typ s)
  | IRecord (o,r) -> Types.record' (o, LabelMap.map typ_node r)
658
  | IDummy | ICapture _ | IConstant (_,_) -> assert false
659
      
660
and typ_node s : Types.Node.t =
661
662
663
664
  try SlotTable.find typ_nodes s
  with Not_found ->
    let x = Types.make () in
    SlotTable.add typ_nodes s x;
665
    Types.define x (typ s.d);
666
667
668
669
670
671
672
673
    x
      
let rec pat d : Patterns.descr =
  if IdSet.is_empty (fv_descr d)
  then Patterns.constr (typ d)
  else pat_aux d
    
and pat_aux = function
674
  | IDummy -> assert false
675
676
677
678
679
680
  | IOr (s1,s2) -> Patterns.cup (pat s1) (pat s2)
  | IAnd (s1,s2) -> Patterns.cap (pat s1) (pat s2)
  | IDiff (s1,s2) when IdSet.is_empty (fv_descr s2) ->
      let s2 = Types.neg (typ s2) in
      Patterns.cap (pat s1) (Patterns.constr s2)
  | IDiff _ ->
681
      raise (Patterns.Error "Differences are not allowed in patterns")
682
683
684
  | ITimes (s1,s2) -> Patterns.times (pat_node s1) (pat_node s2)
  | IXml (s1,s2) -> Patterns.xml (pat_node s1) (pat_node s2)
  | IOptional _ -> 
685
      raise (Patterns.Error "Optional fields are not allowed in record patterns")
686
687
688
689
690
691
692
693
694
695
696
697
698
699
  | IRecord (o,r) ->
      let pats = ref [] in
      let aux l s = 
	if IdSet.is_empty (fv_slot s) then typ_node s
	else
	  ( pats := Patterns.record l (pat_node s) :: !pats;
	    Types.any_node )
      in
      let constr = Types.record' (o,LabelMap.mapi aux r) in
      List.fold_left Patterns.cap (Patterns.constr constr) !pats
	(* TODO: can avoid constr when o=true, and all fields have fv *)
  | ICapture x -> Patterns.capture x
  | IConstant (x,c) -> Patterns.constant x c
  | IArrow _ ->
700
      raise (Patterns.Error "Arrows are not allowed in patterns")
701
702
703
704
705
706
  | IType _ -> assert false
      
and pat_node s : Patterns.node =
  try SlotTable.find pat_nodes s
  with Not_found ->
    let x = Patterns.make (fv_slot s) in
707
708
    try
      SlotTable.add pat_nodes s x;
709
      Patterns.define x (pat s.d);
710
711
712
      x
    with exn -> SlotTable.remove pat_nodes s; raise exn
      (* For the toplevel ... *)
713

714

715
let type_defs env b =
716
717
  List.iter 
    (fun (v,p) ->
718
719
       if Env.mem v env.ids
       then raise_loc_generic p.loc ("Identifier " ^ (Ident.to_string v) ^ " is already bound")
720
    ) b;
721
722
  let penv = derecurs_def (penv env) b in
  let b = List.map (fun (v,p) -> (v,p,compile (derecurs penv p))) b in
723
724
725
726
  flush_defs ();
  let b = 
    List.map 
      (fun (v,p,s) -> 
727
	 check_no_capture p.loc (fv_descr s);
728
729
730
	 let t = typ s in
	 if (p.loc <> noloc) && (Types.is_empty t) then
	   warning p.loc 
731
	     ("This definition yields an empty type for " ^ (Ident.to_string v));
732
	 (v,t)) b in
733
  List.iter (fun (v,t) -> Types.Print.register_global (Id.value v) t) b;
734
  b
735
736


737
738
739
740
741
let dump_types ppf env =
  Env.iter (fun v -> 
	      function 
		  (Type _) -> Format.fprintf ppf " %a" Ident.print v
		| _ -> ()) env.ids
742

743
let dump_ns ppf env =
744
  Ns.dump_table ppf env.ns
745

746

747
748
let do_typ loc r = 
  let s = compile_slot r in
749
  flush_defs ();
750
751
  check_no_capture loc (fv_slot s);
  typ_node s
752
   
753
754
let typ env p =
  do_typ p.loc (derecurs (penv env) p)
755
    
756
757
let pat env p = 
  let s = compile_slot (derecurs (penv env) p) in
758
759
760
  flush_defs ();
  try pat_node s
  with Patterns.Error e -> raise_loc_generic p.loc e
761
    | Location (loc,_,exn) when loc = noloc -> raise (Location (p.loc, `Full, exn))
762
763


764
765
(* II. Build skeleton *)

766

767
768
769
770
771
type type_fun = Types.t -> bool -> Types.t
let mk_unary_op = ref (fun _ _ -> assert false)
let typ_unary_op = ref (fun _ _ _ -> assert false)
let mk_binary_op = ref (fun _ _ -> assert false)
let typ_binary_op = ref (fun _ _ _ _ -> assert false)
772
773


774
module Fv = IdSet
775

776
777
778
type branch = Branch of Typed.branch * branch list

let cur_branch : branch list ref = ref []
779

780
let exp loc fv e =
781
782
  fv,
  { Typed.exp_loc = loc;
783
    Typed.exp_typ = Types.empty;
784
    Typed.exp_descr = e;
785
  }
786
787


788
789
let rec expr env loc = function
  | LocatedExpr (loc,e) -> expr env loc e
790
  | Forget (e,t) ->
791
      let (fv,e) = expr env loc e and t = typ env t in
792
793
      exp loc fv (Typed.Forget (e,t))
  | Var s -> 
794
795
796
797
      (match Ns.split_qname s with
	| "", id -> let id = ident id in
	  exp loc (Fv.singleton id) (Typed.Var id)
	| cu, id -> 
798
	    let cu = find_cu (ident (U.mk cu)) env in
799
	    exp loc Fv.empty (Typed.ExtVar (cu, ident id)))
800
  | Apply (e1,e2) -> 
801
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
802
803
      exp loc (Fv.cup fv1 fv2) (Typed.Apply (e1,e2))
  | Abstraction a ->
804
      let iface = List.map (fun (t1,t2) -> (typ env t1, typ env t2)) 
805
806
807
808
809
810
811
		    a.fun_iface in
      let t = List.fold_left 
		(fun accu (t1,t2) -> Types.cap accu (Types.arrow t1 t2)) 
		Types.any iface in
      let iface = List.map 
		    (fun (t1,t2) -> (Types.descr t1, Types.descr t2)) 
		    iface in
812
      let (fv0,body) = branches env a.fun_body in
813
814
815
816
817
818
819
820
821
822
823
      let fv = match a.fun_name with
	| None -> fv0
	| Some f -> Fv.remove f fv0 in
      let e = Typed.Abstraction 
		{ Typed.fun_name = a.fun_name;
		  Typed.fun_iface = iface;
		  Typed.fun_body = body;
		  Typed.fun_typ = t;
		  Typed.fun_fv = fv
		} in
      exp loc fv e
824
  | (Integer _ | Char _ | Atom _) as c -> 
825
      exp loc Fv.empty (Typed.Cst (const env loc c))
826
  | Pair (e1,e2) ->
827
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
828
829
      exp loc (Fv.cup fv1 fv2) (Typed.Pair (e1,e2))
  | Xml (e1,e2) ->
830
      let (fv1,e1) = expr env loc e1 and (fv2,e2) = expr env loc e2 in
831
832
      exp loc (Fv.cup fv1 fv2) (Typed.Xml (e1,e2))
  | Dot (e,l) ->
833
834
      let (fv,e) = expr env loc e in
      exp loc fv (Typed.Dot (e,parse_label env loc l))
835
  | RemoveField (e,l) ->
836
837
      let (fv,e) = expr env loc e in
      exp loc fv (Typed.RemoveField (e,parse_label env loc l))
838
839
  | RecordLitt r -> 
      let fv = ref Fv.empty in
840
      let r = parse_record env loc
841
		(fun e -> 
842
		   let (fv2,e) = expr env loc e 
843
844
845
		   in fv := Fv.cup !fv fv2; e)
		r in
      exp loc !fv (Typed.RecordLitt r)
846
  | String (i,j,s,e) ->
847
      let (fv,e) = expr env loc e in
848
      exp loc fv (Typed.String (i,j,s,e))
849
  | Op (op,le) ->
850
      let (fvs,ltes) = List.split (List.map (expr env loc) le) in
851
      let fv = List.fold_left Fv.cup Fv.empty fvs in
852
      (try
853
854
855
	 (match ltes with
	    | [e] -> exp loc fv (Typed.UnaryOp (!mk_unary_op op env, e))
	    | [e1;e2] -> exp loc fv (Typed.BinaryOp (!mk_binary_op op env, e1,e2))
856
857
858
	    | _ -> assert false)
       with Not_found -> assert false)

859
  | Match (e,b) -> 
860
861
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
862
      exp loc (Fv.cup fv1 fv2) (Typed.Match (e, b))
863
  | Map (e,b) ->
864
865
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
866
867
      exp loc (Fv.cup fv1 fv2) (Typed.Map (e, b))
  | Transform (e,b) ->
868
869
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
870
      exp loc (Fv.cup fv1 fv2) (Typed.Transform (e, b))
871
  | Xtrans (e,b) ->
872
873
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
874
      exp loc (Fv.cup fv1 fv2) (Typed.Xtrans (e, b))
875
  | Validate (e,schema,elt) ->
876
      let (fv,e) = expr env loc e in
877
      exp loc fv (Typed.Validate (e, schema, elt))
878
  | Try (e,b) ->
879
880
      let (fv1,e) = expr env loc e
      and (fv2,b) = branches env b in
881
      exp loc (Fv.cup fv1 fv2) (Typed.Try (e, b))
882
  | NamespaceIn (pr,ns,e) ->
883
884
      let env = enter_ns pr ns env in
      expr env loc e
885
  | Ref (e,t) ->
886
      let (fv,e) = expr env loc e and t = typ env t in
887
      exp loc fv (Typed.Ref (e,t))
888
	      
889
  and branches env b = 
890
    let fv = ref Fv.empty in
891
    let accept = ref Types.empty in
892
    let branch (p,e) = 
893
894
      let cur_br = !cur_branch in
      cur_branch := [];
895
      let (fv2,e) = expr env noloc e in
896
      let br_loc = merge_loc p.loc e.Typed.exp_loc in
897
      let p = pat env p in
898
899
900
901
902
903
      (match Fv.pick (Fv.diff (Patterns.fv p) fv2) with
	| None -> ()
	| Some x ->
	    let x = U.to_string (Id.value x) in
	    warning br_loc 
	      ("The capture variable " ^ x ^ 
904
	       " is declared in the pattern but not used in the body of this branch. It might be a misspelled type or name (if not use _ instead)."));
905
906
907
908
909
910
911
912
913
      let fv2 = Fv.diff fv2 (Patterns.fv p) in
      fv := Fv.cup !fv fv2;
      accept := Types.cup !accept (Types.descr (Patterns.accept p));
      let br = 
	{ 
	  Typed.br_loc = br_loc;
	  Typed.br_used = br_loc = noloc;
	  Typed.br_pat = p;
	  Typed.br_body = e } in
914
      cur_branch := Branch (br, !cur_branch) :: cur_br;
915
916
      br in
    let b = List.map branch b in
917
918
919
920
    (!fv, 
     { 
       Typed.br_typ = Types.empty; 
       Typed.br_branches = b; 
921
922
       Typed.br_accept = !accept;
       Typed.br_compiled = None;
923
924
     } 
    )
925

926
let expr env e = snd (expr env noloc e)
927

928
929
let let_decl env p e =
  { Typed.let_pat = pat env p;
930
    Typed.let_body = expr env e;
931
932
    Typed.let_compiled = None }

933
934
935

(* Hide global "typing/parsing" environment *)

936

937
938
(* III. Type-checks *)

939
940
open Typed

941
942
let require loc t s = 
  if not (Types.subtype t s) then raise_loc loc (Constraint (t, s))
943

944
let verify loc t s = 
945
946
  require loc t s; t

947
948
949
950
951
let check_str loc ofs t s = 
  if not (Types.subtype t s) then raise_loc_str loc ofs (Constraint (t, s));
  t

let should_have loc constr s = 
952
953
  raise_loc loc (ShouldHave (constr,s))

954
955
956
let should_have_str loc ofs constr s = 
  raise_loc_str loc ofs (ShouldHave (constr,s))

957
958
959
960
961
962
963
964
965
966
967
let flatten loc arg constr precise =
  let constr' = Sequence.star 
		  (Sequence.approx (Types.cap Sequence.any constr)) in
  let sconstr' = Sequence.star constr' in
  let exact = Types.subtype constr' constr in
  if exact then
    let t = arg sconstr' precise in
    if precise then Sequence.flatten t else constr
  else
    let t = arg sconstr' true in
    Sequence.flatten t
968

969
970
let rec type_check env e constr precise = 
  let d = type_check' e.exp_loc env e.exp_descr constr precise in
971
  let d = if precise then d else constr in
972
973
974
  e.exp_typ <- Types.cup e.exp_typ d;
  d

975
and type_check' loc env e constr precise = match e with
976
977
978
  | Forget (e,t) ->
      let t = Types.descr t in
      ignore (type_check env e t false);
979
      verify loc t constr
980

981
  | Abstraction a ->
982
983
984
      let t =
	try Types.Arrow.check_strenghten a.fun_typ constr 
	with Not_found -> 
985
986
	  should_have loc constr
	    "but the interface of the abstraction is not compatible"
987
      in
988
989
      let env = match a.fun_name with
	| None -> env
990
	| Some f -> enter_value f a.fun_typ env in