aboutsummaryrefslogtreecommitdiffhomepage
path: root/printing/ppconstr.ml
blob: cf513321fbf4865a5e9fc949903d50a9de3ee3ca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
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
437
438
439
440
441
442
443
444
445
446
447
448
449
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
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2017     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

(*i*)
open CErrors
open Util
open Pp
open Names
open Nameops
open Libnames
open Pputils
open Ppextend
open Constrexpr
open Constrexpr_ops
open Decl_kinds
open Misctypes
(*i*)

module Tag =
struct
  let keyword   = "constr.keyword"
  let evar      = "constr.evar"
  let univ      = "constr.type"
  let notation  = "constr.notation"
  let variable  = "constr.variable"
  let reference = "constr.reference"
  let path      = "constr.path"

end

let do_not_tag _ x = x
let tag t s = Pp.tag t s
let tag_keyword     = tag Tag.keyword
let tag_evar        = tag Tag.evar
let tag_type        = tag Tag.univ
let tag_unparsing   = function
| UnpTerminal s -> tag Tag.notation
| _ -> do_not_tag ()
let tag_constr_expr = do_not_tag
let tag_path = tag Tag.path
let tag_ref = tag Tag.reference
let tag_var = tag Tag.variable


  let keyword s = tag_keyword (str s)
  let sep_v = fun _ -> str"," ++ spc()
  let pr_tight_coma () = str "," ++ cut ()

  let latom = 0
  let lprod = 200
  let llambda = 200
  let lif = 200
  let lletin = 200
  let lletpattern = 200
  let lfix = 200
  let lcast = 100
  let larg = 9
  let lapp = 10
  let lposint = 0
  let lnegint = 35 (* must be consistent with Notation "- x" *)
  let ltop = (200,E)
  let lproj = 1
  let ldelim = 1
  let lsimpleconstr = (8,E)
  let lsimplepatt = (1,E)

  let prec_less child (parent,assoc) =
    if parent < 0 && Int.equal child lprod then true
    else
      let parent = abs parent in
      match assoc with
        | E -> (<=) child parent
        | L -> (<) child parent
        | Prec n -> child<=n
        | Any -> true

  let prec_of_prim_token = function
    | Numeral (_,b) -> if b then lposint else lnegint
    | String _ -> latom

  open Notation

  let print_hunks n pr pr_binders (terms, termlists, binders) unps =
    let env = ref terms and envlist = ref termlists and bll = ref binders in
    let pop r = let a = List.hd !r in r := List.tl !r; a in
    let return unp pp1 pp2 = (tag_unparsing unp pp1) ++ pp2 in
    (* Warning:
       The following function enforces a very precise order of
       evaluation of sub-components.
       Do not modify it unless you know what you are doing! *)
    let rec aux = function
      | [] ->
        mt ()
      | UnpMetaVar (_, prec) as unp :: l ->
        let c = pop env in
        let pp2 = aux l in
        let pp1 = pr (n, prec) c in
        return unp pp1 pp2
      | UnpListMetaVar (_, prec, sl) as unp :: l ->
        let cl = pop envlist in
        let pp1 = prlist_with_sep (fun () -> aux sl) (pr (n,prec)) cl in
        let pp2 = aux l in
        return unp pp1 pp2
      | UnpBinderListMetaVar (_, isopen, sl) as unp :: l ->
        let cl = pop bll in
        let pp2 = aux l in
        let pp1 = pr_binders (fun () -> aux sl) isopen cl in
        return unp pp1 pp2
      | UnpTerminal s as unp :: l ->
        let pp2 = aux l in
        let pp1 = str s in
        return unp pp1 pp2
      | UnpBox (b,sub) as unp :: l ->
        let pp1 = ppcmd_of_box b (aux sub) in
        let pp2 = aux l in
        return unp pp1 pp2
      | UnpCut cut as unp :: l ->
        let pp2 = aux l in
        let pp1 = ppcmd_of_cut cut in
        return unp pp1 pp2
    in
    aux unps

  let pr_notation pr pr_binders s env =
    let unpl, level = find_notation_printing_rule s in
    print_hunks level pr pr_binders env unpl, level

  let pr_delimiters key strm =
    strm ++ str ("%"^key)

  let pr_generalization bk ak c =
    let hd, tl =
      match bk with
        | Implicit -> "{", "}"
        | Explicit -> "(", ")"
    in (* TODO: syntax Abstraction Kind *)
    str "`" ++ str hd ++ c ++ str tl

  let pr_com_at n =
    if !Flags.beautify && not (Int.equal n 0) then comment (CLexer.extract_comments n)
    else mt()

  let pr_with_comments ?loc pp = pr_located (fun x -> x) (Loc.tag ?loc pp)

  let pr_sep_com sep f c = pr_with_comments ?loc:(constr_loc c) (sep() ++ f c)

  let pr_univ l =
    match l with
      | [_,x] -> Name.print x
      | l -> str"max(" ++ prlist_with_sep (fun () -> str",") (fun x -> Name.print (snd x)) l ++ str")"

  let pr_univ_annot pr x = str "@{" ++ pr x ++ str "}"

  let pr_glob_sort = function
    | GProp -> tag_type (str "Prop")
    | GSet -> tag_type (str "Set")
    | GType [] -> tag_type (str "Type")
    | GType u -> hov 0 (tag_type (str "Type") ++ pr_univ_annot pr_univ u)

  let pr_glob_level = function
    | GProp -> tag_type (str "Prop")
    | GSet -> tag_type (str "Set")
    | GType None -> tag_type (str "Type")
    | GType (Some (_, u)) -> tag_type (Name.print u)

  let pr_qualid sp =
    let (sl, id) = repr_qualid sp in
    let id = tag_ref (pr_id id) in
    let sl = match List.rev (DirPath.repr sl) with
    | [] -> mt ()
    | sl ->
      let pr dir = tag_path (pr_id dir) ++ str "." in
      prlist pr sl
    in
    sl ++ id

  let pr_id = pr_id
  let pr_name = pr_name
  let pr_qualid = pr_qualid
  let pr_patvar = pr_id

  let pr_glob_sort_instance = function
    | GProp ->
      tag_type (str "Prop")
    | GSet ->
      tag_type (str "Set")
    | GType u ->
      (match u with
        | Some (_,u) -> Name.print u
        | None -> tag_type (str "Type"))

  let pr_universe_instance l =
    pr_opt_no_spc (pr_univ_annot (prlist_with_sep spc pr_glob_sort_instance)) l

  let pr_reference = function
  | Qualid (_, qid) -> pr_qualid qid
  | Ident (_, id) -> tag_var (pr_id id)

  let pr_cref ref us =
    pr_reference ref ++ pr_universe_instance us

  let pr_expl_args pr (a,expl) =
    match expl with
      | None -> pr (lapp,L) a
      | Some (_,ExplByPos (n,_id)) ->
        anomaly (Pp.str "Explicitation by position not implemented.")
      | Some (_,ExplByName id) ->
        str "(" ++ pr_id id ++ str ":=" ++ pr ltop a ++ str ")"

  let pr_opt_type_spc pr = function
    | { CAst.v = CHole (_,Misctypes.IntroAnonymous,_) } -> mt ()
    | t ->  str " :" ++ pr_sep_com (fun()->brk(1,2)) (pr ltop) t

  let pr_lident (loc,id) =
    match loc with
    | None     -> pr_id id
    | Some loc -> let (b,_) = Loc.unloc loc in
                  pr_located pr_id @@ Loc.tag ~loc:(Loc.make_loc (b,b + String.length (Id.to_string id))) id

  let pr_lname = function
    | (loc,Name id) -> pr_lident (loc,id)
    | lna -> pr_located Name.print lna

  let pr_or_var pr = function
    | ArgArg x -> pr x
    | ArgVar (loc,s) -> pr_lident (loc,s)

  let pr_prim_token = function
    | Numeral (n,s) -> str (if s then n else "-"^n)
    | String s -> qs s

  let pr_evar pr id l =
    hov 0 (
      tag_evar (str "?" ++ pr_id id) ++
        (match l with
          | [] -> mt()
          | l ->
            let f (id,c) = pr_id id ++ str ":=" ++ pr ltop c in
            str"@{" ++ hov 0 (prlist_with_sep pr_semicolon f (List.rev l)) ++ str"}"))

  let las = lapp
  let lpator = 100
  let lpatrec = 0

  let rec pr_patt sep inh p =
    let (strm,prec) = match CAst.(p.v) with
      | CPatRecord l ->
        let pp (c, p) =
          pr_reference c ++ spc() ++ str ":=" ++ pr_patt spc (lpatrec, Any) p
        in
        str "{| " ++ prlist_with_sep pr_semicolon pp l ++ str " |}", lpatrec

      | CPatAlias (p, id) ->
        pr_patt mt (las,E) p ++ str " as " ++ pr_id id, las

      | CPatCstr (c, None, []) ->
        pr_reference c, latom

      | CPatCstr (c, None, args) ->
        pr_reference c ++ prlist (pr_patt spc (lapp,L)) args, lapp

      | CPatCstr (c, Some args, []) ->
        str "@" ++ pr_reference c ++ prlist (pr_patt spc (lapp,L)) args, lapp

      | CPatCstr (c, Some expl_args, extra_args) ->
        surround (str "@" ++ pr_reference c ++ prlist (pr_patt spc (lapp,L)) expl_args)
        ++ prlist (pr_patt spc (lapp,L)) extra_args, lapp

      | CPatAtom (None) ->
        str "_", latom

      | CPatAtom (Some r) ->
        pr_reference r, latom

      | CPatOr pl ->
        hov 0 (prlist_with_sep pr_bar (pr_patt spc (lpator,L)) pl), lpator

      | CPatNotation ("( _ )",([p],[]),[]) ->
        pr_patt (fun()->str"(") (max_int,E) p ++ str")", latom

      | CPatNotation (s,(l,ll),args) ->
        let strm_not, l_not = pr_notation (pr_patt mt) (fun _ _ _ -> mt()) s (l,ll,[]) in
        (if List.is_empty args||prec_less l_not (lapp,L) then strm_not else surround strm_not)
        ++ prlist (pr_patt spc (lapp,L)) args, if not (List.is_empty args) then lapp else l_not

      | CPatPrim p ->
        pr_prim_token p, latom

      | CPatDelimiters (k,p) ->
        pr_delimiters k (pr_patt mt lsimplepatt p), 1
      | CPatCast _ ->
        assert false
    in
    let loc = p.CAst.loc in
    pr_with_comments ?loc
      (sep() ++ if prec_less prec inh then strm else surround strm)

  let pr_patt = pr_patt mt

  let pr_eqn pr (loc,(pl,rhs)) =
    let pl = List.map snd pl in
    spc() ++ hov 4
      (pr_with_comments ?loc
         (str "| " ++
            hov 0 (prlist_with_sep pr_bar (prlist_with_sep sep_v (pr_patt ltop)) pl
                   ++ str " =>") ++
            pr_sep_com spc (pr ltop) rhs))

  let begin_of_binder l_bi = 
    let b_loc l = fst (Option.cata Loc.unloc (0,0) l) in
    match l_bi with
    | CLocalDef((loc,_),_,_) -> b_loc loc
    | CLocalAssum((loc,_)::_,_,_) -> b_loc loc
    | CLocalPattern(loc,(_,_)) -> b_loc loc
    | _ -> assert false

  let begin_of_binders = function
    | b::_ -> begin_of_binder b
    | _ -> 0

  let surround_impl k p =
    match k with
      | Explicit -> str"(" ++ p ++ str")"
      | Implicit -> str"{" ++ p ++ str"}"

  let surround_implicit k p =
    match k with
      | Explicit -> p
      | Implicit -> (str"{" ++ p ++ str"}")

  let pr_binder many pr (nal,k,t) =
    match k with
      | Generalized (b, b', t') ->
        assert (match b with Implicit -> true | _ -> false);
        begin match nal with
          |[loc,Anonymous] ->
            hov 1 (str"`" ++ (surround_impl b'
                                ((if t' then str "!" else mt ()) ++ pr t)))
          |[loc,Name id] ->
            hov 1 (str "`" ++ (surround_impl b'
                                 (pr_lident (loc,id) ++ str " : " ++
                                    (if t' then str "!" else mt()) ++ pr t)))
          |_ -> anomaly (Pp.str "List of generalized binders have alwais one element.")
        end
      | Default b ->
        match t with
          | { CAst.v = CHole (_,Misctypes.IntroAnonymous,_) } ->
            let s = prlist_with_sep spc pr_lname nal in
            hov 1 (surround_implicit b s)
          | _ ->
            let s = prlist_with_sep spc pr_lname nal ++ str " : " ++ pr t in
            hov 1 (if many then surround_impl b s else surround_implicit b s)

  let pr_binder_among_many pr_c = function
    | CLocalAssum (nal,k,t) ->
      pr_binder true pr_c (nal,k,t)
    | CLocalDef (na,c,topt) ->
      surround (pr_lname na ++
                pr_opt_no_spc (fun t -> str " :" ++ ws 1 ++ pr_c t) topt ++
                str" :=" ++ spc() ++ pr_c c)
    | CLocalPattern (loc,(p,tyo)) ->
      let p = pr_patt lsimplepatt p in
      match tyo with
        | None ->
          str "'" ++ p
        | Some ty ->
          str "'" ++ surround (p ++ spc () ++ str ":" ++ ws 1 ++ pr_c ty)

  let pr_undelimited_binders sep pr_c =
    prlist_with_sep sep (pr_binder_among_many pr_c)

  let pr_delimited_binders kw sep pr_c bl =
    let n = begin_of_binders bl in
    match bl with
      | [CLocalAssum (nal,k,t)] ->
        kw n ++ pr_binder false pr_c (nal,k,t)
      | (CLocalAssum _ | CLocalPattern _) :: _ as bdl ->
        kw n ++ pr_undelimited_binders sep pr_c bdl
      | _ -> assert false

  let pr_binders_gen pr_c sep is_open =
    if is_open then pr_delimited_binders pr_com_at sep pr_c
    else pr_undelimited_binders sep pr_c

  let rec extract_prod_binders = let open CAst in function
  (*  | CLetIn (loc,na,b,c) as x ->
      let bl,c = extract_prod_binders c in
      if bl = [] then [], x else CLocalDef (na,b) :: bl, c*)
    | { v = CProdN ([],c) } ->
      extract_prod_binders c
    | { loc; v = CProdN ([[_,Name id],bk,t],
              { v = CCases (LetPatternStyle,None, [{ v = CRef (Ident (_,id'),None)},None,None],[(_,([_,[p]],b))])} ) }
         when Id.equal id id' && not (Id.Set.mem id (Topconstr.free_vars_of_constr_expr b)) ->
      let bl,c = extract_prod_binders b in
      CLocalPattern (loc, (p,None)) :: bl, c
    | { loc; v = CProdN ((nal,bk,t)::bl,c) } ->
      let bl,c = extract_prod_binders (CAst.make ?loc @@ CProdN(bl,c)) in
      CLocalAssum (nal,bk,t) :: bl, c
    | c -> [], c

  let rec extract_lam_binders ce = let open CAst in match ce.v with
  (*  | CLetIn (loc,na,b,c) as x ->
      let bl,c = extract_lam_binders c in
      if bl = [] then [], x else CLocalDef (na,b) :: bl, c*)
    | CLambdaN ([],c) ->
      extract_lam_binders c
    | CLambdaN ([[_,Name id],bk,t],
                { v = CCases (LetPatternStyle,None, [{ v = CRef (Ident (_,id'),None)},None,None],[(_,([_,[p]],b))])} )
         when Id.equal id id' && not (Id.Set.mem id (Topconstr.free_vars_of_constr_expr b)) ->
      let bl,c = extract_lam_binders b in
      CLocalPattern (ce.loc,(p,None)) :: bl, c
    | CLambdaN ((nal,bk,t)::bl,c) ->
      let bl,c = extract_lam_binders (CAst.make ?loc:ce.loc @@ CLambdaN(bl,c)) in
      CLocalAssum (nal,bk,t) :: bl, c
    | _ -> [], ce

  let split_lambda = CAst.with_loc_val (fun ?loc -> function
    | CLambdaN ([[na],bk,t],c) -> (na,t,c)
    | CLambdaN (([na],bk,t)::bl,c) -> (na,t, CAst.make ?loc @@ CLambdaN(bl,c))
    | CLambdaN ((na::nal,bk,t)::bl,c) -> (na,t, CAst.make ?loc @@ CLambdaN((nal,bk,t)::bl,c))
    | _ -> anomaly (Pp.str "ill-formed fixpoint body.")
    )

  let rename na na' t c =
    match (na,na') with
      | (_,Name id), (_,Name id') ->
        (na',t,Topconstr.replace_vars_constr_expr (Id.Map.singleton id id') c)
      | (_,Name id), (_,Anonymous) -> (na,t,c)
      | _ -> (na',t,c)

  let split_product na' = CAst.with_loc_val (fun ?loc -> function
    | CProdN ([[na],bk,t],c) -> rename na na' t c
    | CProdN (([na],bk,t)::bl,c) -> rename na na' t (CAst.make ?loc @@ CProdN(bl,c))
    | CProdN ((na::nal,bk,t)::bl,c) ->
      rename na na' t (CAst.make ?loc @@ CProdN((nal,bk,t)::bl,c))
    | _ -> anomaly (Pp.str "ill-formed fixpoint body.")
    )

  let rec split_fix n typ def =
    if Int.equal n 0 then ([],typ,def)
    else
      let (na,_,def) = split_lambda def in
      let (na,t,typ) = split_product na typ in
      let (bl,typ,def) = split_fix (n-1) typ def in
      (CLocalAssum ([na],default_binder_kind,t)::bl,typ,def)

  let pr_recursive_decl pr pr_dangling dangling_with_for id bl annot t c =
    let pr_body =
      if dangling_with_for then pr_dangling else pr in
    pr_id id ++ (if bl = [] then mt () else str" ") ++
      hov 0 (pr_undelimited_binders spc (pr ltop) bl ++ annot) ++
      pr_opt_type_spc pr t ++ str " :=" ++
      pr_sep_com (fun () -> brk(1,2)) (pr_body ltop) c

  let pr_guard_annot pr_aux bl (n,ro) =
    match n with
      | None -> mt ()
      | Some (loc, id) ->
        match (ro : Constrexpr.recursion_order_expr) with
          | CStructRec ->
            let names_of_binder = function
              | CLocalAssum (nal,_,_) -> nal
              | CLocalDef (_,_,_) -> []
              | CLocalPattern _ -> assert false
            in let ids = List.flatten (List.map names_of_binder bl) in
               if List.length ids > 1 then
                 spc() ++ str "{" ++ keyword "struct" ++ spc () ++ pr_id id ++ str"}"
               else mt()
          | CWfRec c ->
            spc() ++ str "{" ++ keyword "wf" ++ spc () ++ pr_aux c ++ spc() ++ pr_id id ++ str"}"
          | CMeasureRec (m,r) ->
            spc() ++ str "{" ++ keyword "measure" ++ spc () ++ pr_aux m ++ spc() ++ pr_id id++
              (match r with None -> mt() | Some r -> str" on " ++ pr_aux r) ++ str"}"

  let pr_fixdecl pr prd dangling_with_for ((_,id),ro,bl,t,c) =
    let annot = pr_guard_annot (pr lsimpleconstr) bl ro in
    pr_recursive_decl pr prd dangling_with_for id bl annot t c

  let pr_cofixdecl pr prd dangling_with_for ((_,id),bl,t,c) =
    pr_recursive_decl pr prd dangling_with_for id bl (mt()) t c

  let pr_recursive pr_decl id = function
    | [] -> anomaly (Pp.str "(co)fixpoint with no definition.")
    | [d1] -> pr_decl false d1
    | dl ->
      prlist_with_sep (fun () -> fnl() ++ keyword "with" ++ spc ())
        (pr_decl true) dl ++
        fnl() ++ keyword "for" ++ spc () ++ pr_id id

  let pr_asin pr na indnalopt =
    (match na with (* Decision of printing "_" or not moved to constrextern.ml *)
      | Some na -> spc () ++ keyword "as" ++ spc () ++  pr_lname na
      | None -> mt ()) ++
      (match indnalopt with
        | None -> mt ()
        | Some t -> spc () ++ keyword "in" ++ spc () ++ pr_patt lsimplepatt t)

  let pr_case_item pr (tm,as_clause, in_clause) =
    hov 0 (pr (lcast,E) tm ++ pr_asin pr as_clause in_clause)

  let pr_case_type pr po =
    match po with
      | None | Some { CAst.v = CHole (_,Misctypes.IntroAnonymous,_) } -> mt()
      | Some p ->
        spc() ++ hov 2 (keyword "return" ++ pr_sep_com spc (pr lsimpleconstr) p)

  let pr_simple_return_type pr na po =
    (match na with
      | Some (_,Name id) ->
        spc () ++ keyword "as" ++ spc () ++ pr_id id
      | _ -> mt ()) ++
      pr_case_type pr po

  let pr_proj pr pr_app a f l =
    hov 0 (pr (lproj,E) a ++ cut() ++ str ".(" ++ pr_app pr f l ++ str ")")

  let pr_appexpl pr (f,us) l =
    hov 2 (
      str "@" ++ pr_reference f ++
        pr_universe_instance us ++
        prlist (pr_sep_com spc (pr (lapp,L))) l)

  let pr_app pr a l =
    hov 2 (
      pr (lapp,L) a  ++
        prlist (fun a -> spc () ++ pr_expl_args pr a) l)

  let pr_record_body_gen pr l =
    spc () ++
    prlist_with_sep pr_semicolon
      (fun (id, c) -> h 1 (pr_reference id ++ spc () ++ str":=" ++ pr ltop c)) l

  let pr_forall n = keyword "forall" ++ pr_com_at n ++ spc ()

  let pr_fun n = keyword "fun" ++ pr_com_at n ++ spc ()

  let pr_fun_sep = spc () ++ str "=>"

  let pr_dangling_with_for sep pr inherited a =
    match a.CAst.v with
      | (CFix (_,[_])|CCoFix(_,[_])) ->
        pr sep (latom,E) a
      | _ ->
        pr sep inherited a

  let pr pr sep inherited a =
    let return (cmds, prec) = (tag_constr_expr a cmds, prec) in
    let (strm, prec) = match CAst.(a.v) with
      | CRef (r, us) ->
        return (pr_cref r us, latom)
      | CFix (id,fix) ->
        return (
          hov 0 (keyword "fix" ++ spc () ++
                   pr_recursive
                   (pr_fixdecl (pr mt) (pr_dangling_with_for mt pr)) (snd id) fix),
          lfix
        )
      | CCoFix (id,cofix) ->
        return (
          hov 0 (keyword "cofix" ++ spc () ++
                   pr_recursive
                   (pr_cofixdecl (pr mt) (pr_dangling_with_for mt pr)) (snd id) cofix),
          lfix
        )
      | CProdN _ ->
        let (bl,a) = extract_prod_binders a in
        return (
          hov 0 (
            hov 2 (pr_delimited_binders pr_forall spc
                     (pr mt ltop) bl) ++
              str "," ++ pr spc ltop a),
          lprod
        )
      | CLambdaN _ ->
        let (bl,a) = extract_lam_binders a in
        return (
          hov 0 (
            hov 2 (pr_delimited_binders pr_fun spc
                     (pr mt ltop) bl) ++
              pr_fun_sep ++ pr spc ltop a),
          llambda
        )
      | CLetIn ((_,Name x), ({ CAst.v = CFix((_,x'),[_])}
                          |  { CAst.v = CCoFix((_,x'),[_]) } as fx), t, b)
          when Id.equal x x' ->
        return (
          hv 0 (
            hov 2 (keyword "let" ++ spc () ++ pr mt ltop fx
                   ++ spc ()
                   ++ keyword "in") ++
              pr spc ltop b),
          lletin
        )
      | CLetIn (x,a,t,b) ->
        return (
          hv 0 (
            hov 2 (keyword "let" ++ spc () ++ pr_lname x
                   ++ pr_opt_no_spc (fun t -> str " :" ++ ws 1 ++ pr mt ltop t) t
                   ++ str " :=" ++ pr spc ltop a ++ spc ()
                   ++ keyword "in") ++
              pr spc ltop b),
          lletin
        )
      | CAppExpl ((Some i,f,us),l) ->
        let l1,l2 = List.chop i l in
        let c,l1 = List.sep_last l1 in
        let p = pr_proj (pr mt) pr_appexpl c (f,us) l1 in
        if not (List.is_empty l2) then
          return (p ++ prlist (pr spc (lapp,L)) l2, lapp)
        else
          return (p, lproj)
      | CAppExpl ((None,Ident (_,var),us),[t])
      | CApp ((_, {CAst.v = CRef(Ident(_,var),us)}),[t,None])
          when Id.equal var Notation_ops.ldots_var ->
        return (
          hov 0 (str ".." ++ pr spc (latom,E) t ++ spc () ++ str ".."),
          larg
        )
      | CAppExpl ((None,f,us),l) ->
        return (pr_appexpl (pr mt) (f,us) l, lapp)
      | CApp ((Some i,f),l) ->
        let l1,l2 = List.chop i l in
        let c,l1 = List.sep_last l1 in
        assert (Option.is_empty (snd c));
        let p = pr_proj (pr mt) pr_app (fst c) f l1 in
        if not (List.is_empty l2) then
          return (
            p ++ prlist (fun a -> spc () ++ pr_expl_args (pr mt) a) l2,
            lapp
          )
        else
          return (p, lproj)
      | CApp ((None,a),l) ->
        return (pr_app (pr mt) a l, lapp)
      | CRecord l ->
        return (
          hv 0 (str"{|" ++ pr_record_body_gen (pr spc) l ++ str" |}"),
          latom
        )
      | CCases (LetPatternStyle,rtntypopt,[c,as_clause,in_clause],[(_,([(loc,[p])],b))]) ->
        return (
          hv 0 (
            keyword "let" ++ spc () ++ str"'" ++
              hov 0 (pr_patt ltop p ++
                       pr_asin (pr_dangling_with_for mt pr) as_clause in_clause ++
                       str " :=" ++ pr spc ltop c ++
                       pr_case_type (pr_dangling_with_for mt pr) rtntypopt ++
                       spc () ++ keyword "in" ++ pr spc ltop b)),
          lletpattern
        )
      | CCases(_,rtntypopt,c,eqns) ->
        return (
          v 0
            (hv 0 (keyword "match" ++ brk (1,2) ++
                     hov 0 (
                       prlist_with_sep sep_v
                         (pr_case_item (pr_dangling_with_for mt pr)) c
                       ++ pr_case_type (pr_dangling_with_for mt pr) rtntypopt) ++
                     spc () ++ keyword "with") ++
               prlist (pr_eqn (pr mt)) eqns ++ spc()
             ++ keyword "end"),
          latom
        )
      | CLetTuple (nal,(na,po),c,b) ->
        return (
          hv 0 (
            hov 2 (keyword "let" ++ spc () ++
              hov 1 (str "(" ++
                       prlist_with_sep sep_v pr_lname nal ++
                       str ")" ++
                       pr_simple_return_type (pr mt) na po ++ str " :=") ++
                       pr spc ltop c
                     ++ keyword " in") ++
              pr spc ltop b),
          lletin
        )
      | CIf (c,(na,po),b1,b2) ->
      (* On force les parenthèses autour d'un "if" sous-terme (même si le
         parsing est lui plus tolérant) *)
        return (
          hv 0 (
            hov 1 (keyword "if" ++ spc () ++ pr mt ltop c
                   ++ pr_simple_return_type (pr mt) na po) ++
              spc () ++
              hov 0 (keyword "then"
                     ++ pr (fun () -> brk (1,1)) ltop b1) ++ spc () ++
              hov 0 (keyword "else" ++ pr (fun () -> brk (1,1)) ltop b2)),
        lif
        )

      | CHole (_,Misctypes.IntroIdentifier id,_) ->
        return (str "?[" ++ pr_id id ++ str "]", latom)
      | CHole (_,Misctypes.IntroFresh id,_) ->
        return (str "?[?" ++ pr_id id ++ str "]", latom)
      | CHole (_,_,_) ->
        return (str "_", latom)
      | CEvar (n,l) ->
        return (pr_evar (pr mt) n l, latom)
      | CPatVar p ->
        return (str "@?" ++ pr_patvar p, latom)
      | CSort s ->
        return (pr_glob_sort s, latom)
      | CCast (a,b) ->
        return (
          hv 0 (pr mt (lcast,L) a ++ spc () ++
                  match b with
                    | CastConv b -> str ":" ++ ws 1 ++ pr mt (-lcast,E) b
                    | CastVM b -> str "<:" ++ ws 1 ++ pr mt (-lcast,E) b
                    | CastNative b -> str "<<:" ++ ws 1 ++ pr mt (-lcast,E) b
                    | CastCoerce -> str ":>"),
          lcast
        )
      | CNotation ("( _ )",([t],[],[])) ->
        return (pr (fun()->str"(") (max_int,L) t ++ str")", latom)
      | CNotation (s,env) ->
        pr_notation (pr mt) (pr_binders_gen (pr mt ltop)) s env
      | CGeneralization (bk,ak,c) ->
        return (pr_generalization bk ak (pr mt ltop c), latom)
      | CPrim p ->
        return (pr_prim_token p, prec_of_prim_token p)
      | CDelimiters (sc,a) ->
        return (pr_delimiters sc (pr mt (ldelim,E) a), ldelim)
    in
    let loc = constr_loc a in
    pr_with_comments ?loc
      (sep() ++ if prec_less prec inherited then strm else surround strm)

  type term_pr = {
    pr_constr_expr   : constr_expr -> std_ppcmds;
    pr_lconstr_expr  : constr_expr -> std_ppcmds;
    pr_constr_pattern_expr  : constr_pattern_expr -> std_ppcmds;
    pr_lconstr_pattern_expr : constr_pattern_expr -> std_ppcmds
  }

  type precedence =  Ppextend.precedence * Ppextend.parenRelation
  let modular_constr_pr = pr
  let rec fix rf x = rf (fix rf) x
  let pr = fix modular_constr_pr mt

  let transf env c =
    if !Flags.beautify_file then
      let r = Constrintern.for_grammar (Constrintern.intern_constr env) c in
      Constrextern.extern_glob_constr (Termops.vars_of_env env) r
    else c

  let pr prec c = pr prec (transf (Global.env()) c)

  let pr_simpleconstr = function
    | { CAst.v = CAppExpl ((None,f,us),[]) } -> str "@" ++ pr_cref f us
    | c -> pr lsimpleconstr c

  let default_term_pr = {
    pr_constr_expr   = pr_simpleconstr;
    pr_lconstr_expr  = pr ltop;
    pr_constr_pattern_expr  = pr_simpleconstr;
    pr_lconstr_pattern_expr = pr ltop
  }

  let term_pr = ref default_term_pr

  let set_term_pr = (:=) term_pr

  let pr_constr_expr c   = !term_pr.pr_constr_expr   c
  let pr_lconstr_expr c  = !term_pr.pr_lconstr_expr  c
  let pr_constr_pattern_expr c  = !term_pr.pr_constr_pattern_expr  c
  let pr_lconstr_pattern_expr c = !term_pr.pr_lconstr_pattern_expr c

  let pr_cases_pattern_expr = pr_patt ltop

  let pr_record_body = pr_record_body_gen pr

  let pr_binders = pr_undelimited_binders spc (pr ltop)