summaryrefslogtreecommitdiff
path: root/parsing/ppconstr.ml
blob: 5405e523c5ce70643979e762b4799cfe6aa9363f (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
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

(*i*)
open Util
open Pp
open Nametab
open Names
open Nameops
open Libnames
open Ppextend
open Topconstr
open Term
open Pattern
open Glob_term
open Constrextern
open Termops
(*i*)

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 larrow = 90
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 && 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 p -> if Bigint.is_pos_or_zero p then lposint else lnegint
  | String _ -> latom

open Notation

let print_hunks n pr pr_binders (terms,termlists,binders) unp =
  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 rec aux = function
  | [] -> mt ()
  | UnpMetaVar (_,prec) :: l ->
      let c = pop env in pr (n,prec) c ++ aux l
  | UnpListMetaVar (_,prec,sl) :: l ->
      let cl = pop envlist in
      let pp1 = prlist_with_sep (fun () -> aux sl) (pr (n,prec)) cl in
      let pp2 = aux l in
      pp1 ++ pp2
  | UnpBinderListMetaVar (_,isopen,sl) :: l ->
      let cl = pop bll in pr_binders (fun () -> aux sl) isopen cl ++ aux l
  | UnpTerminal s :: l -> str s ++ aux l
  | UnpBox (b,sub) :: l ->
      (* Keep order: side-effects *)
      let pp1 = ppcmd_of_box b (aux sub) in
      let pp2 = aux l in
      pp1 ++ pp2
  | UnpCut cut :: l -> ppcmd_of_cut cut ++ aux l in
  aux unp

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.do_beautify() && n <> 0 then comment n
  else mt()

let pr_with_comments loc pp = pr_located (fun x -> x) (loc,pp)

let pr_sep_com sep f c = pr_with_comments (constr_loc c) (sep() ++ f c)

let pr_in_comment pr x = str "(* " ++ pr x ++ str " *)"

let pr_universe = Univ.pr_uni

let pr_glob_sort = function
  | GProp Term.Null -> str "Prop"
  | GProp Term.Pos -> str "Set"
  | GType u -> hov 0 (str "Type" ++ pr_opt (pr_in_comment pr_universe) u)

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

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

let pr_opt_type pr = function
  | CHole _ -> mt ()
  | t -> cut () ++ str ":" ++ pr t

let pr_opt_type_spc pr = function
  | CHole _ -> mt ()
  | t ->  str " :" ++ pr_sep_com (fun()->brk(1,2)) (pr ltop) t

let pr_lident (loc,id) =
  if loc <> dummy_loc then
    let (b,_) = unloc loc in
    pr_located pr_id (make_loc (b,b+String.length(string_of_id id)),id)
  else pr_id id

let pr_lname = function
    (loc,Name id) -> pr_lident (loc,id)
  | lna -> pr_located pr_name 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 -> str (Bigint.to_string n)
  | String s -> qs s

let pr_evar pr n l =
  hov 0 (str (Evd.string_of_existential n) ++
  (match l with
   | Some l ->
       spc () ++ pr_in_comment
         (fun l ->
	   str"[" ++ hov 0 (prlist_with_sep pr_comma (pr ltop) l) ++ str"]")
         (List.rev l)
   | None -> mt()))

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

let rec pr_patt sep inh p =
  let (strm,prec) = match p 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,[]) -> pr_reference c, latom
  | CPatCstr (_,c,args) ->
      pr_reference c ++ prlist (pr_patt spc (lapp,L)) args, lapp
  | CPatCstrExpl (_,c,args) ->
      str "@" ++ pr_reference c ++ prlist (pr_patt spc (lapp,L)) 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)) ->
      pr_notation (pr_patt mt) (fun _ _ _ -> mt()) s (l,ll,[])
  | CPatPrim (_,p) -> pr_prim_token p, latom
  | CPatDelimiters (_,k,p) -> pr_delimiters k (pr_patt mt lsimplepatt p), 1
  in
  let loc = cases_pattern_expr_loc p 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 = function
    LocalRawDef((loc,_),_) -> fst (unloc loc)
  | LocalRawAssum((loc,_)::_,_,_) -> fst (unloc 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 (b=Implicit);
      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 "List of generalized binders have alwais one element."
      end
    | Default b ->
      match t with
	| CHole _ ->
	  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
  | LocalRawAssum (nal,k,t) ->
      pr_binder true pr_c (nal,k,t)
  | LocalRawDef (na,c) ->
      let c,topt = match c with
        | CCast(_,c, CastConv (_,t)) -> c, t
        | _ -> c, CHole (dummy_loc, None) in
      surround (pr_lname na ++ pr_opt_type pr_c topt ++
         str":=" ++ cut() ++ pr_c c)

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
  | [LocalRawAssum (nal,k,t)] ->
      pr_com_at n ++ kw() ++ pr_binder false pr_c (nal,k,t)
  | LocalRawAssum _ :: _ as bdl ->
      pr_com_at n ++ kw() ++ 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 mt sep pr_c
  else pr_undelimited_binders sep pr_c

let rec extract_prod_binders = function
(*  | CLetIn (loc,na,b,c) as x ->
      let bl,c = extract_prod_binders c in
      if bl = [] then [], x else LocalRawDef (na,b) :: bl, c*)
  | CProdN (loc,[],c) ->
      extract_prod_binders c
  | CProdN (loc,(nal,bk,t)::bl,c) ->
      let bl,c = extract_prod_binders (CProdN(loc,bl,c)) in
      LocalRawAssum (nal,bk,t) :: bl, c
  | c -> [], c

let rec extract_lam_binders = function
(*  | CLetIn (loc,na,b,c) as x ->
      let bl,c = extract_lam_binders c in
      if bl = [] then [], x else LocalRawDef (na,b) :: bl, c*)
  | CLambdaN (loc,[],c) ->
      extract_lam_binders c
  | CLambdaN (loc,(nal,bk,t)::bl,c) ->
      let bl,c = extract_lam_binders (CLambdaN(loc,bl,c)) in
      LocalRawAssum (nal,bk,t) :: bl, c
  | c -> [], c

let split_lambda = function
  | CLambdaN (loc,[[na],bk,t],c) -> (na,t,c)
  | CLambdaN (loc,([na],bk,t)::bl,c) -> (na,t,CLambdaN(loc,bl,c))
  | CLambdaN (loc,(na::nal,bk,t)::bl,c) -> (na,t,CLambdaN(loc,(nal,bk,t)::bl,c))
  | _ -> anomaly "ill-formed fixpoint body"

let rename na na' t c =
  match (na,na') with
    | (_,Name id), (_,Name id') -> (na',t,replace_vars_constr_expr [id,id'] c)
    | (_,Name id), (_,Anonymous) -> (na,t,c)
    | _ -> (na',t,c)

let split_product na' = function
  | CArrow (loc,t,c) -> (na',t,c)
  | CProdN (loc,[[na],bk,t],c) -> rename na na' t c
  | CProdN (loc,([na],bk,t)::bl,c) -> rename na na' t (CProdN(loc,bl,c))
  | CProdN (loc,(na::nal,bk,t)::bl,c) ->
      rename na na' t (CProdN(loc,(nal,bk,t)::bl,c))
  | _ -> anomaly "ill-formed fixpoint body"

let rec split_fix n typ def =
  if 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
    (LocalRawAssum ([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 ++ 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 : Topconstr.recursion_order_expr) with
	| CStructRec ->
	  let names_of_binder = function
	    | LocalRawAssum (nal,_,_) -> nal
	    | LocalRawDef (_,_) -> []
	  in let ids = List.flatten (List.map names_of_binder bl) in
	     if List.length ids > 1 then
	       spc() ++ str "{struct " ++ pr_id id ++ str"}"
	     else mt()
	| CWfRec c ->
	  spc() ++ str "{wf " ++ pr_aux c ++ spc() ++ pr_id id ++ str"}"
	| CMeasureRec (m,r) ->
	  spc() ++ str "{measure " ++ 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 "(co)fixpoint with no definition"
  | [d1] -> pr_decl false d1
  | dl ->
      prlist_with_sep (fun () -> fnl() ++ str "with ")
        (pr_decl true) dl ++
      fnl() ++ str "for " ++ pr_id id

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

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

let pr_case_type pr po =
  match po with
    | None | Some (CHole _) -> mt()
    | Some p ->
        spc() ++ hov 2 (str "return" ++ pr_sep_com spc (pr lsimpleconstr) p)

let pr_simple_return_type pr na po =
  (match na with
    | Some (_,Name id) ->
        spc () ++ str "as " ++  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 l =
      hov 2 (
	str "@" ++ pr_reference f ++
	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_forall () = str"forall" ++ spc ()

let pr_fun () = str"fun" ++ spc ()

let pr_fun_sep = str " =>"


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

let pr pr sep inherited a =
  let (strm,prec) = match a with
  | CRef r -> pr_reference r, latom
  | CFix (_,id,fix) ->
      hov 0 (str"fix " ++
             pr_recursive
               (pr_fixdecl (pr mt) (pr_dangling_with_for mt pr)) (snd id) fix),
      lfix
  | CCoFix (_,id,cofix) ->
      hov 0 (str "cofix " ++
             pr_recursive
              (pr_cofixdecl (pr mt) (pr_dangling_with_for mt pr)) (snd id) cofix),
      lfix
  | CArrow (_,a,b) ->
      hov 0 (pr mt (larrow,L) a ++ str " ->" ++
             pr (fun () ->brk(1,0)) (-larrow,E) b),
      larrow
  | CProdN _ ->
      let (bl,a) = extract_prod_binders a in
      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
      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),(CFix(_,(_,x'),[_])|CCoFix(_,(_,x'),[_]) as fx), b)
      when x=x' ->
      hv 0 (
        hov 2 (str "let " ++ pr mt ltop fx ++ str " in") ++
        pr spc ltop b),
      lletin
  | CLetIn (_,x,a,b) ->
      hv 0 (
        hov 2 (str "let " ++ pr_lname x ++ str " :=" ++
               pr spc ltop a ++ str " in") ++
        pr spc ltop b),
      lletin
  | CAppExpl (_,(Some i,f),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 l1 in
      if l2<>[] then
	p ++ prlist (pr spc (lapp,L)) l2, lapp
      else
	p, lproj
  | CAppExpl (_,(None,Ident (_,var)),[t])
  | CApp (_,(_,CRef(Ident(_,var))),[t,None])
        when var = Topconstr.ldots_var ->
      hov 0 (str ".." ++ pr spc (latom,E) t ++ spc () ++ str ".."), larg
  | CAppExpl (_,(None,f),l) -> pr_appexpl (pr mt) f l, lapp
  | CApp (_,(Some i,f),l) ->
      let l1,l2 = list_chop i l in
      let c,l1 = list_sep_last l1 in
      assert (snd c = None);
      let p = pr_proj (pr mt) pr_app (fst c) f l1 in
      if l2<>[] then
	p ++ prlist (fun a -> spc () ++ pr_expl_args (pr mt) a) l2, lapp
      else
	p, lproj
  | CApp (_,(None,a),l) -> pr_app (pr mt) a l, lapp
  | CRecord (_,w,l) ->
      let beg =
	match w with
	| None -> spc ()
	| Some t -> spc () ++ pr spc ltop t ++ spc () ++ str"with" ++ spc ()
      in
	hv 0 (str"{|" ++ beg ++
	      prlist_with_sep pr_semicolon
		(fun (id, c) -> h 1 (pr_reference id ++ spc () ++ str":=" ++ pr spc ltop c)) l
	      ++ str" |}"), latom

  | CCases (_,LetPatternStyle,rtntypopt,[c,asin],[(_,[(loc,[p])],b)]) ->
      hv 0 (
	str "let '" ++
	  hov 0 (pr_patt ltop p ++
		 pr_asin (pr_dangling_with_for mt pr) asin ++
		 str " :=" ++ pr spc ltop c ++
		 pr_case_type (pr_dangling_with_for mt pr) rtntypopt ++
		 str " in" ++ pr spc ltop b)),
	lletpattern
  | CCases(_,_,rtntypopt,c,eqns) ->
      v 0
        (hv 0 (str "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 () ++ str "with") ++
		  prlist (pr_eqn (pr mt)) eqns ++ spc() ++ str "end"),
      latom
  | CLetTuple (_,nal,(na,po),c,b) ->
      hv 0 (
        str "let " ++
	hov 0 (str "(" ++
               prlist_with_sep sep_v pr_lname nal ++
               str ")" ++
	       pr_simple_return_type (pr mt) na po ++ str " :=" ++
               pr spc ltop c ++ str " 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) *)
      hv 0 (
	hov 1 (str "if " ++ pr mt ltop c ++ pr_simple_return_type (pr mt) na po) ++
	spc () ++
	hov 0 (str "then" ++ pr (fun () -> brk (1,1)) ltop b1) ++ spc () ++
	hov 0 (str "else" ++ pr (fun () -> brk (1,1)) ltop b2)),
      lif

  | CHole _ -> str "_", latom
  | CEvar (_,n,l) -> pr_evar (pr mt) n l, latom
  | CPatVar (_,(_,p)) -> str "?" ++ pr_patvar p, latom
  | CSort (_,s) -> pr_glob_sort s, latom
  | CCast (_,a,CastConv (k,b)) ->
      let s = match k with VMcast -> "<:" | DEFAULTcast | REVERTcast -> ":" in
      hv 0 (pr mt (lcast,L) a ++ cut () ++ str s ++ pr mt (-lcast,E) b),
      lcast
  | CCast (_,a,CastCoerce) ->
      hv 0 (pr mt (lcast,L) a ++ cut () ++ str ":>"),
      lcast
  | CNotation (_,"( _ )",([t],[],[])) ->
      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) -> pr_generalization bk ak (pr mt ltop c), latom
  | CPrim (_,p) -> pr_prim_token p, prec_of_prim_token p
  | CDelimiters (_,sc,a) -> 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 pr_simpleconstr = function
  | CAppExpl (_,(None,f),[]) -> str "@" ++ pr_reference f
  | 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_binders = pr_undelimited_binders spc (pr ltop)

let pr_with_occurrences pr occs =
  match occs with
    ((false,[]),c) -> pr c
  | ((nowhere_except_in,nl),c) ->
      hov 1 (pr c ++ spc() ++ str"at " ++
        (if nowhere_except_in then mt() else str "- ") ++
        hov 0 (prlist_with_sep spc (pr_or_var int) nl))

let pr_red_flag pr r =
  (if r.rBeta then pr_arg str "beta" else mt ()) ++
  (if r.rIota then pr_arg str "iota" else mt ()) ++
  (if r.rZeta then pr_arg str "zeta" else mt ()) ++
  (if r.rConst = [] then
     if r.rDelta then pr_arg str "delta"
     else mt ()
   else
     pr_arg str "delta " ++ (if r.rDelta then str "-" else mt ()) ++
     hov 0 (str "[" ++ prlist_with_sep spc pr r.rConst ++ str "]"))

open Genarg

let pr_metaid id = str"?" ++ pr_id id

let pr_red_expr (pr_constr,pr_lconstr,pr_ref,pr_pattern) = function
  | Red false -> str "red"
  | Hnf -> str "hnf"
  | Simpl o -> str "simpl" ++ pr_opt (pr_with_occurrences pr_pattern) o
  | Cbv f ->
      if f = {rBeta=true;rIota=true;rZeta=true;rDelta=true;rConst=[]} then
	str "compute"
      else
	hov 1 (str "cbv" ++ pr_red_flag pr_ref f)
  | Lazy f ->
      hov 1 (str "lazy" ++ pr_red_flag pr_ref f)
  | Unfold l ->
      hov 1 (str "unfold" ++ spc() ++
             prlist_with_sep pr_comma (pr_with_occurrences pr_ref) l)
  | Fold l -> hov 1 (str "fold" ++ prlist (pr_arg pr_constr) l)
  | Pattern l ->
      hov 1 (str "pattern" ++
        pr_arg (prlist_with_sep pr_comma (pr_with_occurrences pr_constr)) l)

  | Red true -> error "Shouldn't be accessible from user."
  | ExtraRedExpr s -> str s
  | CbvVm -> str "vm_compute"

let rec pr_may_eval test prc prlc pr2 pr3 = function
  | ConstrEval (r,c) ->
      hov 0
        (str "eval" ++ brk (1,1) ++
         pr_red_expr (prc,prlc,pr2,pr3) r ++
	 str " in" ++ spc() ++ prc c)
  | ConstrContext ((_,id),c) ->
      hov 0
	(str "context " ++ pr_id id ++ spc () ++
	 str "[" ++ prlc c ++ str "]")
  | ConstrTypeOf c -> hov 1 (str "type of" ++ spc() ++ prc c)
  | ConstrTerm c when test c -> h 0 (str "(" ++ prc c ++ str ")")
  | ConstrTerm c -> prc c

let pr_may_eval a = pr_may_eval (fun _ -> false) a