summaryrefslogtreecommitdiff
path: root/lib/util.ml
blob: a8a99c0bd699d5c91bd0aff9cbb69438c9871071 (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
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
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
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
(***********************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team    *)
(* <O___,, *        INRIA-Rocquencourt  &  LRI-CNRS-Orsay              *)
(*   \VV/  *************************************************************)
(*    //   *      This file is distributed under the terms of the      *)
(*         *       GNU Lesser General Public License Version 2.1       *)
(***********************************************************************)

(* $Id: util.ml 11897 2009-02-09 19:28:02Z barras $ *)

open Pp

(* Errors *)

exception Anomaly of string * std_ppcmds  (* System errors *)
let anomaly string = raise (Anomaly(string, str string))
let anomalylabstrm string pps = raise (Anomaly(string,pps))

exception UserError of string * std_ppcmds (* User errors *)
let error string = raise (UserError(string, str string))
let errorlabstrm l pps = raise (UserError(l,pps))

let todo s = prerr_string ("TODO: "^s^"\n")

type loc = Compat.loc
let dummy_loc = Compat.dummy_loc
let unloc = Compat.unloc
let make_loc = Compat.make_loc
let join_loc = Compat.join_loc

(* raising located exceptions *)
type 'a located = loc * 'a
let anomaly_loc (loc,s,strm) = Stdpp.raise_with_loc loc (Anomaly (s,strm))
let user_err_loc (loc,s,strm) = Stdpp.raise_with_loc loc (UserError (s,strm))
let invalid_arg_loc (loc,s) = Stdpp.raise_with_loc loc (Invalid_argument s)

let located_fold_left f x (_,a) = f x a 
let located_iter2 f (_,a) (_,b) = f a b

(* Like Exc_located, but specifies the outermost file read, the filename
   associated to the location of the error, and the error itself. *)

exception Error_in_file of string * (bool * string * loc) * exn

(* Mapping under pairs *)

let on_fst f (a,b) = (f a,b)
let on_snd f (a,b) = (a,f b)

(* Projections from triplets *)

let pi1 (a,_,_) = a
let pi2 (_,a,_) = a
let pi3 (_,_,a) = a

(* Characters *)

let is_letter c = (c >= 'a' && c <= 'z') or (c >= 'A' && c <= 'Z')
let is_digit c = (c >= '0' && c <= '9')
let is_ident_tail c =
  is_letter c or is_digit c or c = '\'' or c = '_'
let is_blank = function
  | ' ' | '\r' | '\t' | '\n' -> true
  | _ -> false

(* Strings *)

let explode s = 
  let rec explode_rec n =
    if n >= String.length s then
      []
    else 
      String.make 1 (String.get s n) :: explode_rec (succ n)
  in 
  explode_rec 0

let implode sl = String.concat "" sl

let strip s =
  let n = String.length s in
  let rec lstrip_rec i =
    if i < n && is_blank s.[i] then
      lstrip_rec (i+1)
    else i
  in
  let rec rstrip_rec i =
    if i >= 0 && is_blank s.[i] then
      rstrip_rec (i-1)
    else i
  in
  let a = lstrip_rec 0 and b = rstrip_rec (n-1) in
  String.sub s a (b-a+1)

(* substring searching... *)

(* gdzie = where, co = what *)
(* gdzie=gdzie(string) gl=gdzie(length) gi=gdzie(index) *)
let rec is_sub gdzie gl gi co cl ci = 
  (ci>=cl) ||
  ((String.unsafe_get gdzie gi = String.unsafe_get co ci) && 
   (is_sub gdzie gl (gi+1) co cl (ci+1)))

let rec raw_str_index i gdzie l c co cl = 
  (* First adapt to ocaml 3.11 new semantics of index_from *)
  if (i+cl > l) then raise Not_found;
  (* Then proceed as in ocaml < 3.11 *)
  let i' = String.index_from gdzie i c in
    if (i'+cl <= l) && (is_sub gdzie l i' co cl 0) then i' else
      raw_str_index (i'+1) gdzie l c co cl

let string_index_from gdzie i co = 
  if co="" then i else
    raw_str_index i gdzie (String.length gdzie)
      (String.unsafe_get co 0) co (String.length co)

let string_string_contains ~where ~what =
  try
    let _ = string_index_from where 0 what in true
  with
      Not_found -> false

let plural n s = if n>1 then s^"s" else s

let ordinal n =
  let s = match n mod 10 with 1 -> "st" | 2 -> "nd" | 3 -> "rd" | _ -> "th" in
  string_of_int n ^ s

(* string parsing *)

let split_string_at c s =
  let len = String.length s in
  let rec split n =
    try  
      let pos = String.index_from s n c in
      let dir = String.sub s n (pos-n) in
      dir :: split (succ pos)
    with
      | Not_found -> [String.sub s n (len-n)]
  in
  if len = 0 then [] else split 0

let parse_loadpath s =
  let l = split_string_at '/' s in
  if List.mem "" l then
    invalid_arg "parse_loadpath: find an empty dir in loadpath";
  l

module Stringset = Set.Make(struct type t = string let compare = compare end)

module Stringmap = Map.Make(struct type t = string let compare = compare end)

type utf8_status = UnicodeLetter | UnicodeIdentPart | UnicodeSymbol

exception UnsupportedUtf8

let classify_unicode unicode =
    match unicode land 0x1F000 with
    | 0x0 ->
    begin match unicode with
    (* utf-8 Basic Latin underscore *)
    | x when x = 0x005F -> UnicodeLetter
    (* utf-8 Basic Latin letters *)
    | x when 0x0041 <= x & x <= 0x005A -> UnicodeLetter
    | x when 0x0061 <= x & x <= 0x007A -> UnicodeLetter
    (* utf-8 Basic Latin digits and quote *)
    | x when 0x0030 <= x & x <= 0x0039 or x = 0x0027 -> UnicodeIdentPart
    (* utf-8 Basic Latin symbols *)
    | x when x <= 0x007F -> UnicodeSymbol
    (* utf-8 Latin-1 non breaking space U00A0 *)
    | 0x00A0 -> UnicodeLetter
    (* utf-8 Latin-1 symbols U00A1-00BF *)
    | x when 0x00A0 <= x & x <= 0x00BF -> UnicodeSymbol
    (* utf-8 Latin-1 letters U00C0-00D6 *)
    | x when 0x00C0 <= x & x <= 0x00D6 -> UnicodeLetter
    (* utf-8 Latin-1 symbol U00D7 *)
    | 0x00D7 -> UnicodeSymbol
    (* utf-8 Latin-1 letters U00D8-00F6 *)
    | x when 0x00D8 <= x & x <= 0x00F6 -> UnicodeLetter
    (* utf-8 Latin-1 symbol U00F7 *)
    | 0x00F7 -> UnicodeSymbol
    (* utf-8 Latin-1 letters U00F8-00FF *)
    | x when 0x00F8 <= x & x <= 0x00FF -> UnicodeLetter
    (* utf-8 Latin Extended A U0100-017F and Latin Extended B U0180-U0241 *)
    | x when 0x0100 <= x & x <= 0x0241 -> UnicodeLetter
    (* utf-8 Phonetic letters U0250-02AF *)
    | x when 0x0250 <= x & x <= 0x02AF -> UnicodeLetter
    (* utf-8 what do to with diacritics U0300-U036F ? *)
    (* utf-8 Greek letters U0380-03FF *)
    | x when 0x0380 <= x & x <= 0x03FF -> UnicodeLetter
    (* utf-8 Cyrillic letters U0400-0481 *)
    | x when 0x0400 <= x & x <= 0x0481 -> UnicodeLetter
    (* utf-8 Cyrillic symbol U0482 *)
    | 0x0482 -> UnicodeSymbol
    (* utf-8 what do to with diacritics U0483-U0489 \ U0487 ? *)
    (* utf-8 Cyrillic letters U048A-U4F9 (Warning: 04CF) *)
    | x when 0x048A <= x & x <= 0x04F9 -> UnicodeLetter
    (* utf-8 Cyrillic supplement letters U0500-U050F *)
    | x when 0x0500 <= x & x <= 0x050F -> UnicodeLetter
    (* utf-8 Hebrew letters U05D0-05EA *)
    | x when 0x05D0 <= x & x <= 0x05EA -> UnicodeLetter
    (* utf-8 Arabic letters U0621-064A *)
    | x when 0x0621 <= x & x <= 0x064A -> UnicodeLetter
    (* utf-8 Arabic supplement letters U0750-076D *)
    | x when 0x0750 <= x & x <= 0x076D -> UnicodeLetter
    | _ -> raise UnsupportedUtf8
    end
    | 0x1000 ->
    begin match unicode with
    (* utf-8 Georgian U10A0-10FF (has holes) *)
    | x when 0x10A0 <= x & x <= 0x10FF -> UnicodeLetter
    (* utf-8 Hangul Jamo U1100-11FF (has holes) *)
    | x when 0x1100 <= x & x <= 0x11FF -> UnicodeLetter
    (* utf-8 Latin additional letters U1E00-1E9B and U1EA0-1EF9 *)
    | x when 0x1E00 <= x & x <= 0x1E9B -> UnicodeLetter
    | x when 0x1EA0 <= x & x <= 0x1EF9 -> UnicodeLetter
    | _ -> raise UnsupportedUtf8
    end
    | 0x2000 ->
    begin match unicode with
    (* utf-8 general punctuation U2080-2089 *)
    (* Hyphens *)
    | x when 0x2010 <= x & x <= 0x2011 -> UnicodeLetter 
    (* Dashes and other symbols *)
    | x when 0x2012 <= x & x <= 0x2027 -> UnicodeSymbol
    (* Per mille and per ten thousand signs *)
    | x when 0x2030 <= x & x <= 0x2031 -> UnicodeSymbol
    (* Prime letters *)
    | x when 0x2032 <= x & x <= 0x2034 or x = 0x2057 -> UnicodeIdentPart
    (* Miscellaneous punctuation *)
    | x when 0x2039 <= x & x <= 0x2056 -> UnicodeSymbol
    | x when 0x2058 <= x & x <= 0x205E -> UnicodeSymbol
    (* Invisible mathematical operators *)
    | x when 0x2061 <= x & x <= 0x2063 -> UnicodeSymbol
    (* utf-8 superscript U2070-207C *) 
    | x when 0x2070 <= x & x <= 0x207C -> UnicodeSymbol
    (* utf-8 subscript U2080-2089 *) 
    | x when 0x2080 <= x & x <= 0x2089 -> UnicodeIdentPart
    (* utf-8 letter-like U2100-214F *)
    | x when 0x2100 <= x & x <= 0x214F -> UnicodeLetter
    (* utf-8 number-forms U2153-2183 *)
    | x when 0x2153 <= x & x <= 0x2183 -> UnicodeSymbol
    (* utf-8 arrows A U2190-21FF *)
    (* utf-8 mathematical operators U2200-22FF *)
    (* utf-8 miscellaneous technical U2300-23FF *)
    | x when 0x2190 <= x & x <= 0x23FF -> UnicodeSymbol
    (* utf-8 box drawing U2500-257F has ceiling, etc. *)
    (* utf-8 block elements U2580-259F *)
    (* utf-8 geom. shapes U25A0-25FF (has triangles, losange, etc) *)
    (* utf-8 miscellaneous symbols U2600-26FF *)
    | x when 0x2500 <= x & x <= 0x26FF -> UnicodeSymbol
    (* utf-8 arrows B U2900-297F *)
    | x when 0x2900 <= x & x <= 0x297F -> UnicodeSymbol
    (* utf-8 mathematical operators U2A00-2AFF *)
    | x when 0x2A00 <= x & x <= 0x2AFF -> UnicodeSymbol
    (* utf-8 bold symbols U2768-U2775 *)
    | x when 0x2768 <= x & x <= 0x2775 -> UnicodeSymbol
    (* utf-8 arrows and brackets U27E0-U27FF *)
    | x when 0x27E0 <= x & x <= 0x27FF -> UnicodeSymbol
    (* utf-8 brackets, braces and parentheses *)
    | x when 0x2980 <= x & x <= 0x299F -> UnicodeSymbol
    (* utf-8 miscellaneous including double-plus U29F0-U29FF *)
    | x when 0x29F0 <= x & x <= 0x29FF -> UnicodeSymbol
    | _ -> raise UnsupportedUtf8
    end
    | _ ->
    begin match unicode with
    (* utf-8 CJC Symbols and Punctuation  *)
    | x when 0x3008 <= x & x <= 0x3020 -> UnicodeSymbol
    (* utf-8 Hiragana U3040-309F and Katakana U30A0-30FF *)
    | x when 0x3040 <= x & x <= 0x30FF -> UnicodeLetter
    (* utf-8 Unified CJK Ideographs U4E00-9FA5 *)
    | x when 0x4E00 <= x & x <= 0x9FA5 -> UnicodeLetter
    (* utf-8 Hangul syllables UAC00-D7AF *)
    | x when 0xAC00 <= x & x <= 0xD7AF -> UnicodeLetter
    (* utf-8 Gothic U10330-1034A *)
    | x when 0x10330 <= x & x <= 0x1034A -> UnicodeLetter
    (* utf-8 Math Alphanumeric Symbols U1D400-1D7FF (letters) (has holes) *)
    | x when 0x1D400 <= x & x <= 0x1D7CB -> UnicodeLetter
    (* utf-8 Math Alphanumeric Symbols U1D400-1D7FF (digits) *)
    | x when 0x1D7CE <= x & x <= 0x1D7FF -> UnicodeIdentPart
    | _ -> raise UnsupportedUtf8
    end

exception End_of_input

let utf8_of_unicode n =
  if n < 128 then 
    String.make 1 (Char.chr n)
  else if n < 2048 then
    let s = String.make 2 (Char.chr (128 + n mod 64)) in
    begin
      s.[0] <- Char.chr (192 + n / 64);
      s
    end
  else if n < 65536 then
    let s = String.make 3 (Char.chr (128 + n mod 64)) in
    begin 
      s.[1] <- Char.chr (128 + (n / 64) mod 64);
      s.[0] <- Char.chr (224 + n / 4096); 
      s
    end
  else
    let s = String.make 4 (Char.chr (128 + n mod 64)) in
    begin 
      s.[2] <- Char.chr (128 + (n / 64) mod 64);
      s.[1] <- Char.chr (128 + (n / 4096) mod 64);
      s.[0] <- Char.chr (240 + n / 262144);
      s 
    end

let next_utf8 s i =
  let err () = invalid_arg "utf8" in
  let l = String.length s - i in
  if l = 0 then raise End_of_input
  else let a = Char.code s.[i] in if a <= 0x7F then
    1, a
  else if a land 0x40 = 0 or l = 1 then err ()
  else let b = Char.code s.[i+1] in if b land 0xC0 <> 0x80 then err ()
  else if a land 0x20 = 0 then
    2, (a land 0x1F) lsl 6 + (b land 0x3F)
  else if l = 2 then err ()
  else let c = Char.code s.[i+2] in if c land 0xC0 <> 0x80 then err ()
  else if a land 0x10 = 0 then
    3, (a land 0x0F) lsl 12 + (b land 0x3F) lsl 6 + (c land 0x3F)
  else if l = 3 then err ()
  else let d = Char.code s.[i+3] in if d land 0xC0 <> 0x80 then err ()
  else if a land 0x08 = 0 then
    4, (a land 0x07) lsl 18 + (b land 0x3F) lsl 12 +
       (c land 0x3F) lsl 6 + (d land 0x3F)
  else err ()

(* Check the well-formedness of an identifier *)

let check_initial handle j n s =
  match classify_unicode n with
  | UnicodeLetter -> ()
  | _ ->
      let c = String.sub s 0 j in
      handle ("Invalid character '"^c^"' at beginning of identifier \""^s^"\".")

let check_trailing handle i j n s =
  match classify_unicode n with
  | UnicodeLetter | UnicodeIdentPart -> ()
  | _ ->
      let c = String.sub s i j in
      handle ("Invalid character '"^c^"' in identifier \""^s^"\".")

let check_ident_gen handle s =
  let i = ref 0 in
  if s <> ".." then try
    let j, n = next_utf8 s 0 in
    check_initial handle j n s;
    i := !i + j;
    try
      while true do
	let j, n = next_utf8 s !i in
	check_trailing handle !i j n s;
	i := !i + j
      done
    with End_of_input -> ()
  with 
  | End_of_input -> error "The empty string is not an identifier."
  | UnsupportedUtf8 -> error (s^": unsupported character in utf8 sequence.")
  | Invalid_argument _ -> error (s^": invalid utf8 sequence.")

let check_ident_soft = check_ident_gen warning
let check_ident = check_ident_gen error

let lowercase_unicode s unicode =
    match unicode land 0x1F000 with
    | 0x0 ->
    begin match unicode with
    (* utf-8 Basic Latin underscore *)
    | x when x = 0x005F -> x
    (* utf-8 Basic Latin letters *)
    | x when 0x0041 <= x & x <= 0x005A -> x + 32
    | x when 0x0061 <= x & x <= 0x007A -> x
    (* utf-8 Latin-1 non breaking space U00A0 *)
    | 0x00A0 as x -> x
    (* utf-8 Latin-1 letters U00C0-00D6 *)
    | x when 0x00C0 <= x & x <= 0x00D6 -> x + 32
    (* utf-8 Latin-1 letters U00D8-00F6 *)
    | x when 0x00D8 <= x & x <= 0x00DE -> x + 32
    | x when 0x00E0 <= x & x <= 0x00F6 -> x
    (* utf-8 Latin-1 letters U00F8-00FF *)
    | x when 0x00F8 <= x & x <= 0x00FF -> x
    (* utf-8 Latin Extended A U0100-017F and Latin Extended B U0180-U0241 *)
    | x when 0x0100 <= x & x <= 0x017F ->
	if x mod 2 = 1 then x else x + 1
    | x when 0x0180 <= x & x <= 0x0241 ->
	warning ("Unable to decide which lowercase letter to map to "^s); x
    (* utf-8 Phonetic letters U0250-02AF *)
    | x when 0x0250 <= x & x <= 0x02AF -> x
    (* utf-8 what do to with diacritics U0300-U036F ? *)
    (* utf-8 Greek letters U0380-03FF *)
    | x when 0x0380 <= x & x <= 0x0385 -> x
    | 0x0386 -> 0x03AC
    | x when 0x0388 <= x & x <= 0x038A -> x + 37
    | 0x038C -> 0x03CC
    | x when 0x038E <= x & x <= 0x038F -> x + 63
    | x when 0x0390 <= x & x <= 0x03AB & x <> 0x03A2 -> x + 32
    (* utf-8 Greek lowercase letters U03B0-03CE *)	
    | x when 0x03AC <= x & x <= 0x03CE -> x
    | x when 0x03CF <= x & x <= 0x03FF ->
	warning ("Unable to decide which lowercase letter to map to "^s); x
    (* utf-8 Cyrillic letters U0400-0481 *)
    | x when 0x0400 <= x & x <= 0x040F -> x + 80
    | x when 0x0410 <= x & x <= 0x042F -> x + 32
    | x when 0x0430 <= x & x <= 0x045F -> x 
    | x when 0x0460 <= x & x <= 0x0481 ->
	if x mod 2 = 1 then x else x + 1
    (* utf-8 Cyrillic letters U048A-U4F9 (Warning: 04CF) *)
    | x when 0x048A <= x & x <= 0x04F9 & x <> 0x04CF -> 
	if x mod 2 = 1 then x else x + 1
    (* utf-8 Cyrillic supplement letters U0500-U050F *)
    | x when 0x0500 <= x & x <= 0x050F ->
	if x mod 2 = 1 then x else x + 1
    (* utf-8 Hebrew letters U05D0-05EA *)
    | x when 0x05D0 <= x & x <= 0x05EA -> x
    (* utf-8 Arabic letters U0621-064A *)
    | x when 0x0621 <= x & x <= 0x064A -> x
    (* utf-8 Arabic supplement letters U0750-076D *)
    | x when 0x0750 <= x & x <= 0x076D -> x
    | _ -> raise UnsupportedUtf8
    end
    | 0x1000 ->
    begin match unicode with
    (* utf-8 Georgian U10A0-10FF (has holes) *)
    | x when 0x10A0 <= x & x <= 0x10FF -> x
    (* utf-8 Hangul Jamo U1100-11FF (has holes) *)
    | x when 0x1100 <= x & x <= 0x11FF -> x
    (* utf-8 Latin additional letters U1E00-1E9B and U1EA0-1EF9 *)
    | x when 0x1E00 <= x & x <= 0x1E95 ->
	if x mod 2 = 1 then x else x + 1
    | x when 0x1E96 <= x & x <= 0x1E9B -> x
    | x when 0x1EA0 <= x & x <= 0x1EF9 ->
	if x mod 2 = 1 then x else x + 1
    | _ -> raise UnsupportedUtf8
    end
    | 0x2000 ->
    begin match unicode with
    (* utf-8 general punctuation U2080-2089 *)
    (* Hyphens *)
    | x when 0x2010 <= x & x <= 0x2011 -> x
    (* utf-8 letter-like U2100-214F *)
    | 0x2102 (* double-struck C *) -> Char.code 'x'
    | 0x2115 (* double-struck N *) -> Char.code 'n'
    | 0x2119 (* double-struck P *) -> Char.code 'x'
    | 0x211A (* double-struck Q *) -> Char.code 'x'
    | 0x211D (* double-struck R *) -> Char.code 'r'
    | 0x2124 (* double-struck Z *) -> Char.code 'x'
    | x when 0x2100 <= x & x <= 0x214F ->
	warning ("Unable to decide which lowercase letter to map to "^s); x
    | _ -> raise UnsupportedUtf8
    end
    | _ ->
    begin match unicode with
    (* utf-8 Hiragana U3040-309F and Katakana U30A0-30FF *)
    | x when 0x3040 <= x & x <= 0x30FF -> x
    (* utf-8 Unified CJK Ideographs U4E00-9FA5 *)
    | x when 0x4E00 <= x & x <= 0x9FA5 -> x
    (* utf-8 Hangul syllables UAC00-D7AF *)
    | x when 0xAC00 <= x & x <= 0xD7AF -> x
    (* utf-8 Gothic U10330-1034A *)
    | x when 0x10330 <= x & x <= 0x1034A -> x
    (* utf-8 Math Alphanumeric Symbols U1D400-1D7FF (letters) (has holes) *)
    | x when 0x1D6A8 <= x & x <= 0x1D7C9 ->
        let a = (x - 0x1D6A8) mod 58 in
        if a <= 16 or (18 <= a & a <= 24)
        then x + 26 (* all but nabla and theta symbol *)
        else x
    | x when 0x1D538 <= x & x <= 0x1D56B ->
        (* Use ordinary lowercase in both small and capital double-struck *)
        (x - 0x1D538) mod 26 + Char.code 'a'
    | x when 0x1D468 <= x & x <= 0x1D6A3 -> (* General case *)
        if (x - 0x1D400 / 26) mod 2 = 0 then x + 26 else x
    | x when 0x1D400 <= x & x <= 0x1D7CB -> (* fallback *)
        x
    (* utf-8 Math Alphanumeric Symbols U1D400-1D7FF (digits) *)
    | x when 0x1D7CE <= x & x <= 0x1D7FF -> x
    | _ -> raise UnsupportedUtf8
    end

let lowercase_first_char_utf8 s =
  assert (s <> "");
  let j, n = next_utf8 s 0 in
  utf8_of_unicode (lowercase_unicode (String.sub s 0 j) n)

(* Lists *)

let list_intersect l1 l2 = 
  List.filter (fun x -> List.mem x l2) l1

let list_union l1 l2 = 
  let rec urec = function
    | [] -> l2
    | a::l -> if List.mem a l2 then urec l else a::urec l
  in 
  urec l1

let list_unionq l1 l2 = 
  let rec urec = function
    | [] -> l2
    | a::l -> if List.memq a l2 then urec l else a::urec l
  in 
  urec l1

let list_subtract l1 l2 =
  if l2 = [] then l1 else List.filter (fun x -> not (List.mem x l2)) l1

let list_subtractq l1 l2 = 
  if l2 = [] then l1 else List.filter (fun x -> not (List.memq x l2)) l1

let list_chop n l = 
  let rec chop_aux acc = function
    | (0, l2) -> (List.rev acc, l2)
    | (n, (h::t)) -> chop_aux (h::acc) (pred n, t)
    | (_, []) -> failwith "list_chop"
  in 
  chop_aux [] (n,l)

let list_tabulate f len = 
  let rec tabrec n =
    if n = len then [] else (f n)::(tabrec (n+1))
  in 
  tabrec 0

let rec list_make n v =
  if n = 0 then []
  else if n < 0 then invalid_arg "list_make"
  else v::list_make (n-1) v

let list_assign l n e = 
  let rec assrec stk = function
    | ((h::t), 0) -> List.rev_append stk (e::t)
    | ((h::t), n) -> assrec (h::stk) (t, n-1)
    | ([], _) -> failwith "list_assign"
  in 
  assrec [] (l,n)

let rec list_smartmap f l = match l with
    [] -> l
  | h::tl -> 
      let h' = f h and tl' = list_smartmap f tl in
	if h'==h && tl'==tl then l
	else h'::tl'

let list_map_left f = (* ensures the order in case of side-effects *)
  let rec map_rec = function
    | [] -> [] 
    | x::l -> let v = f x in v :: map_rec l
  in 
  map_rec

let list_map_i f = 
  let rec map_i_rec i = function
    | [] -> [] 
    | x::l -> let v = f i x in v :: map_i_rec (i+1) l
  in 
  map_i_rec

let list_map2_i f i l1 l2 =  
  let rec map_i i = function
    | ([], []) -> []
    | ((h1::t1), (h2::t2)) -> let v = f i h1 h2 in v :: map_i (succ i) (t1,t2)
    | (_, _) -> invalid_arg "map2_i"
  in 
  map_i i (l1,l2)

let list_map3 f l1 l2 l3 =
  let rec map = function
    | ([], [], []) -> []
    | ((h1::t1), (h2::t2), (h3::t3)) -> let v = f h1 h2 h3 in v::map (t1,t2,t3)
    | (_, _, _) -> invalid_arg "map3"
  in 
  map (l1,l2,l3)

let list_map4 f l1 l2 l3 l4 =
  let rec map = function
    | ([], [], [], []) -> []
    | ((h1::t1), (h2::t2), (h3::t3), (h4::t4)) -> let v = f h1 h2 h3 h4 in v::map (t1,t2,t3,t4)
    | (_, _, _, _) -> invalid_arg "map4"
  in 
  map (l1,l2,l3,l4)

let list_index x = 
  let rec index_x n = function
    | y::l -> if x = y then n else index_x (succ n) l
    | [] -> raise Not_found
  in 
  index_x 1

let list_index0 x l = list_index x l - 1 

let list_unique_index x = 
  let rec index_x n = function
    | y::l -> 
	if x = y then 
	  if List.mem x l then raise Not_found
	  else n 
	else index_x (succ n) l
    | [] -> raise Not_found 
  in index_x 1

let list_fold_right_i f i l =
  let rec it_list_f i l a = match l with
    | [] -> a
    | b::l -> f (i-1) b (it_list_f (i-1) l a)
  in 
  it_list_f (List.length l + i) l

let list_fold_left_i f = 
  let rec it_list_f i a = function
    | [] -> a 
    | b::l -> it_list_f (i+1) (f i a b) l
  in 
  it_list_f 

let rec list_fold_left3 f accu l1 l2 l3 =
  match (l1, l2, l3) with
    ([], [], []) -> accu
  | (a1::l1, a2::l2, a3::l3) -> list_fold_left3 f (f accu a1 a2 a3) l1 l2 l3
  | (_, _, _) -> invalid_arg "list_fold_left3"

(* [list_fold_right_and_left f [a1;...;an] hd =
   f (f (... (f (f hd
                   an
                   [an-1;...;a1])
              an-1
              [an-2;...;a1])
         ...)
        a2
        [a1])
     a1
     []] *)

let rec list_fold_right_and_left f l hd =
  let rec aux tl = function
    | [] -> hd
    | a::l -> let hd = aux (a::tl) l in f hd a tl
   in aux [] l

let list_iter3 f l1 l2 l3 =
  let rec iter = function
    | ([], [], []) -> ()
    | ((h1::t1), (h2::t2), (h3::t3)) -> f h1 h2 h3; iter (t1,t2,t3)
    | (_, _, _) -> invalid_arg "map3"
  in 
  iter (l1,l2,l3)

let list_iter_i f l = list_fold_left_i (fun i _ x -> f i x) 0 () l

let list_for_all_i p = 
  let rec for_all_p i = function
    | [] -> true 
    | a::l -> p i a && for_all_p (i+1) l
  in 
  for_all_p

let list_except x l = List.filter (fun y -> not (x = y)) l

let list_remove = list_except (* Alias *)

let rec list_remove_first a = function
  | b::l when a = b -> l
  | b::l -> b::list_remove_first a l
  | [] -> raise Not_found

let rec list_remove_assoc_in_triple x = function
  | [] -> []
  | (y,_,_ as z)::l -> if x = y then l else z::list_remove_assoc_in_triple x l

let list_add_set x l = if List.mem x l then l else x::l

let list_eq_set l1 l2 =
  let rec aux l1 = function
  | [] -> l1 = []
  | a::l2 -> aux (list_remove_first a l1) l2 in
  try aux l1 l2 with Not_found -> false

let list_for_all2eq f l1 l2 = try List.for_all2 f l1 l2 with Failure _ -> false

let list_map_i f = 
  let rec map_i_rec i = function
    | [] -> [] 
    | x::l -> let v = f i x in v::map_i_rec (i+1) l
  in 
  map_i_rec

let rec list_sep_last = function
  | [] -> failwith "sep_last"
  | hd::[] -> (hd,[])
  | hd::tl -> let (l,tl) = list_sep_last tl in (l,hd::tl)

let list_try_find_i f = 
  let rec try_find_f n = function
    | [] -> failwith "try_find_i"
    | h::t -> try f n h with Failure _ -> try_find_f (n+1) t
  in 
  try_find_f

let list_try_find f = 
  let rec try_find_f = function
    | [] -> failwith "try_find"
    | h::t -> try f h with Failure _ -> try_find_f t
  in 
  try_find_f

let list_uniquize l =
  let visited = Hashtbl.create 23 in
  let rec aux acc = function
    | h::t -> if Hashtbl.mem visited h then aux acc t else
	  begin
	    Hashtbl.add visited h h;
	    aux (h::acc) t
	  end
    | [] -> List.rev acc
  in aux [] l

let rec list_distinct l = 
  let visited = Hashtbl.create 23 in
  let rec loop = function
    | h::t ->
	if Hashtbl.mem visited h then false
	else 
	  begin
	    Hashtbl.add visited h h;
	    loop t
	  end
    | [] -> true
  in loop l

let rec list_merge_uniq cmp l1 l2 =
  match l1, l2 with
  | [], l2 -> l2
  | l1, [] -> l1
  | h1 :: t1, h2 :: t2 ->
      let c = cmp h1 h2 in 
      if c = 0 
      then h1 :: list_merge_uniq cmp t1 t2
      else if c <= 0 
      then h1 :: list_merge_uniq cmp t1 l2
      else h2 :: list_merge_uniq cmp l1 t2

let rec list_duplicates = function
  | [] -> []
  | x::l ->
      let l' = list_duplicates l in
      if List.mem x l then list_add_set x l' else l'

let rec list_filter2 f = function
  | [], [] as p -> p
  | d::dp, l::lp ->
     let (dp',lp' as p) = list_filter2 f (dp,lp) in
      if f d l then d::dp', l::lp' else p
  | _ -> invalid_arg "list_filter2"

let rec list_map_filter f = function
  | [] -> []
  | x::l ->
      let l' = list_map_filter f l in
      match f x with None -> l' | Some y -> y::l'

let list_subset l1 l2 =
  let t2 = Hashtbl.create 151 in
  List.iter (fun x -> Hashtbl.add t2 x ()) l2;
  let rec look = function
    | [] -> true
    | x::ll -> try Hashtbl.find t2 x; look ll with Not_found -> false
  in 
  look l1

let list_split_at p = 
  let rec split_at_loop x y = 
    match y with 
      | []      -> ([],[])
      | (a::l)  -> if (p a) then (List.rev x,y) else split_at_loop (a::x) l
  in 
  split_at_loop []

let list_split_by p = 
  let rec split_loop = function
  | []      -> ([],[])
  | (a::l)  ->
      let (l1,l2) = split_loop l in if (p a) then (a::l1,l2) else (l1,a::l2)
  in 
  split_loop

let rec list_split3 = function
  | [] -> ([], [], [])
  | (x,y,z)::l ->
      let (rx, ry, rz) = list_split3 l in (x::rx, y::ry, z::rz)

let rec list_insert_in_class f a = function
  | [] -> [[a]]
  | (b::_ as l)::classes when f a b -> (a::l)::classes
  | l::classes -> l :: list_insert_in_class f a classes

let list_partition_by f l =
  List.fold_right (list_insert_in_class f) l []

let list_firstn n l =
  let rec aux acc = function
    | (0, l) -> List.rev acc
    | (n, (h::t)) -> aux (h::acc) (pred n, t)
    | _ -> failwith "firstn"
  in 
  aux [] (n,l)

let rec list_last = function
  | [] -> failwith "list_last"
  | [x] -> x
  | _ :: l -> list_last l

let list_lastn n l =
  let len = List.length l in
  let rec aux m l =
    if m = n then l else aux (m - 1) (List.tl l)
  in
  if len < n then failwith "lastn" else aux len l

let rec list_skipn n l = match n,l with 
  | 0, _ -> l 
  | _, [] -> failwith "list_fromn"
  | n, _::l -> list_skipn (pred n) l

let rec list_addn n x l = 
  if n = 0 then l else x :: (list_addn (pred n) x l)

let list_prefix_of prefl l = 
  let rec prefrec = function
    | (h1::t1, h2::t2) -> h1 = h2 && prefrec (t1,t2)
    | ([], _) -> true
    | (_, _) -> false
  in 
    prefrec (prefl,l)

let list_drop_prefix p l =
(* if l=p++t then return t else l *)
  let rec list_drop_prefix_rec = function
    | ([], tl) -> Some tl
    | (_, []) -> None
    | (h1::tp, h2::tl) -> 
	if h1 = h2 then list_drop_prefix_rec (tp,tl) else None
  in
    match list_drop_prefix_rec (p,l) with
      | Some r -> r
      | None -> l

let list_map_append f l = List.flatten (List.map f l)
let list_join_map = list_map_append   (* Alias *)

let list_map_append2 f l1 l2 = List.flatten (List.map2 f l1 l2)

let list_share_tails l1 l2 =
  let rec shr_rev acc = function
    | ((x1::l1), (x2::l2)) when x1 == x2 -> shr_rev (x1::acc) (l1,l2)
    | (l1,l2) -> (List.rev l1, List.rev l2, acc)
  in 
  shr_rev [] (List.rev l1, List.rev l2)

let rec list_fold_map f e = function
  |  []  -> (e,[])
  |  h::t ->
       let e',h' = f e h in
       let e'',t' = list_fold_map f e' t in
         e'',h'::t'

(* (* tail-recursive version of the above function *)
let list_fold_map f e l = 
  let g (e,b') h = 
    let (e',h') = f e h in
      (e',h'::b') 
  in
  let (e',lrev) = List.fold_left g (e,[]) l in
    (e',List.rev lrev)
*)

(* The same, based on fold_right, with the effect accumulated on the right *)
let list_fold_map' f l e =
  List.fold_right (fun x (l,e) -> let (y,e) = f x e in (y::l,e)) l ([],e)

let list_map_assoc f = List.map (fun (x,a) -> (x,f a))

(* Specification:
   - =p= is set equality (double inclusion)
   - f such that \forall l acc, (f l acc) =p= append (f l []) acc
   - let g = fun x -> f x [] in
   - union_map f l acc =p= append (flatten (map g l)) acc
 *)
let list_union_map f l acc =
  List.fold_left
    (fun x y -> f y x)
    acc
    l

(* A generic cartesian product: for any operator (**), 
   [list_cartesian (**) [x1;x2] [y1;y2] = [x1**y1; x1**y2; x2**y1; x2**y1]], 
   and so on if there are more elements in the lists. *)

let rec list_cartesian op l1 l2 = 
  list_map_append (fun x -> List.map (op x) l2) l1

(* [list_cartesians] is an n-ary cartesian product: it iterates 
   [list_cartesian] over a list of lists.  *)

let list_cartesians op init ll = 
  List.fold_right (list_cartesian op) ll [init]

(* list_combinations [[a;b];[c;d]] gives [[a;c];[a;d];[b;c];[b;d]] *)

let list_combinations l = list_cartesians (fun x l -> x::l) [] l

(* Keep only those products that do not return None *)

let rec list_cartesian_filter op l1 l2 = 
  list_map_append (fun x -> list_map_filter (op x) l2) l1

(* Keep only those products that do not return None *)

let rec list_cartesians_filter op init ll = 
  List.fold_right (list_cartesian_filter op) ll [init]

(* Drop the last element of a list *)

let rec list_drop_last = function [] -> assert false | hd :: [] -> [] | hd :: tl -> hd :: list_drop_last tl

(* Arrays *)

let array_exists f v = 
  let rec exrec = function
    | -1 -> false
    | n -> (f v.(n)) || (exrec (n-1))
  in 
  exrec ((Array.length v)-1) 

let array_for_all f v = 
  let rec allrec = function
    | -1 -> true
    | n -> (f v.(n)) && (allrec (n-1))
  in 
  allrec ((Array.length v)-1) 

let array_for_all2 f v1 v2 =
  let rec allrec = function
    | -1 -> true
    | n -> (f v1.(n) v2.(n)) && (allrec (n-1))
  in 
  let lv1 = Array.length v1 in
  lv1 = Array.length v2 && allrec (pred lv1) 

let array_for_all3 f v1 v2 v3 =
  let rec allrec = function
    | -1 -> true
    | n -> (f v1.(n) v2.(n) v3.(n)) && (allrec (n-1))
  in 
  let lv1 = Array.length v1 in
  lv1 = Array.length v2 && lv1 = Array.length v3 && allrec (pred lv1) 

let array_for_all4 f v1 v2 v3 v4 =
  let rec allrec = function
    | -1 -> true
    | n -> (f v1.(n) v2.(n) v3.(n) v4.(n)) && (allrec (n-1))
  in 
  let lv1 = Array.length v1 in
  lv1 = Array.length v2 &&
  lv1 = Array.length v3 &&
  lv1 = Array.length v4 &&
    allrec (pred lv1) 

let array_for_all_i f i v = 
  let rec allrec i n = n = Array.length v || f i v.(n) && allrec (i+1) (n+1) in 
  allrec i 0

let array_hd v = 
  match Array.length v with
    | 0 -> failwith "array_hd"
    | _ -> v.(0)

let array_tl v = 
  match Array.length v with
    | 0 -> failwith "array_tl"
    | n -> Array.sub v 1 (pred n)

let array_last v =
  match Array.length v with
    | 0 -> failwith "array_last"
    | n -> v.(pred n)

let array_cons e v = Array.append [|e|] v

let array_rev t = 
  let n=Array.length t in
    if n <=0 then () 
    else
      let tmp=ref t.(0) in
      for i=0 to pred (n/2) do 
	tmp:=t.((pred n)-i);
	t.((pred n)-i)<- t.(i);
	t.(i)<- !tmp
      done

let array_fold_right_i f v a =
  let rec fold a n =
    if n=0 then a
    else
      let k = n-1 in
      fold (f k v.(k) a) k in
  fold a (Array.length v)

let array_fold_left_i f v a =
  let n = Array.length a in
  let rec fold i v = if i = n then v else fold (succ i) (f i v a.(i)) in
  fold 0 v

let array_fold_right2 f v1 v2 a =
  let lv1 = Array.length v1 in
  let rec fold a n =
    if n=0 then a
    else
      let k = n-1 in
      fold (f v1.(k) v2.(k) a) k in
  if Array.length v2 <> lv1 then invalid_arg "array_fold_right2";
  fold a lv1

let array_fold_left2 f a v1 v2 =
  let lv1 = Array.length v1 in
  let rec fold a n = 
    if n >= lv1 then a else fold (f a v1.(n) v2.(n)) (succ n)
  in
  if Array.length v2 <> lv1 then invalid_arg "array_fold_left2";
  fold a 0

let array_fold_left2_i f a v1 v2 =
  let lv1 = Array.length v1 in
  let rec fold a n = 
    if n >= lv1 then a else fold (f n a v1.(n) v2.(n)) (succ n)
  in
  if Array.length v2 <> lv1 then invalid_arg "array_fold_left2";
  fold a 0

let array_fold_left_from n f a v = 
  let rec fold a n =
    if n >= Array.length v then a else fold (f a v.(n)) (succ n)
  in 
  fold a n

let array_fold_right_from n f v a = 
  let rec fold n =
    if n >= Array.length v then a else f v.(n) (fold (succ n))
  in 
  fold n

let array_app_tl v l = 
  if Array.length v = 0 then invalid_arg "array_app_tl";
  array_fold_right_from 1 (fun e l -> e::l) v l

let array_list_of_tl v =
  if Array.length v = 0 then invalid_arg "array_list_of_tl";
  array_fold_right_from 1 (fun e l -> e::l) v []

let array_map_to_list f v =
  List.map f (Array.to_list v)

let array_chop n v =
  let vlen = Array.length v in
  if n > vlen then failwith "array_chop";
  (Array.sub v 0 n, Array.sub v n (vlen-n))

exception Local of int

(* If none of the elements is changed by f we return ar itself.
   The for loop looks for the first such an element.
   If found it is temporarily stored in a ref and the new array is produced, 
   but f is not re-applied to elements that are already checked *)
let array_smartmap f ar = 
  let ar_size = Array.length ar in
  let aux = ref None in
  try
    for i = 0 to ar_size-1 do
      let a = ar.(i) in
      let a' = f a in
	if a != a' then (* pointer (in)equality *) begin
	  aux := Some a';
	  raise (Local i)
	end
    done;
    ar
  with
      Local i -> 
	let copy j = 
	  if j<i then ar.(j) 
	  else if j=i then 
	    match !aux with Some a' -> a' | None -> failwith "Error"
	  else f (ar.(j))
	in
	  Array.init ar_size copy

let array_map2 f v1 v2 =
  if Array.length v1 <> Array.length v2 then invalid_arg "array_map2";
  if Array.length v1 == 0 then 
    [| |] 
  else begin
    let res = Array.create (Array.length v1) (f v1.(0) v2.(0)) in
    for i = 1 to pred (Array.length v1) do
      res.(i) <- f v1.(i) v2.(i)
    done;
    res
  end

let array_map2_i f v1 v2 =
  if Array.length v1 <> Array.length v2 then invalid_arg "array_map2";
  if Array.length v1 == 0 then 
    [| |] 
  else begin
    let res = Array.create (Array.length v1) (f 0 v1.(0) v2.(0)) in
    for i = 1 to pred (Array.length v1) do
      res.(i) <- f i v1.(i) v2.(i)
    done;
    res
  end

let array_map3 f v1 v2 v3 =
  if Array.length v1 <> Array.length v2 ||
     Array.length v1 <> Array.length v3 then invalid_arg "array_map3";
  if Array.length v1 == 0 then 
    [| |] 
  else begin
    let res = Array.create (Array.length v1) (f v1.(0) v2.(0) v3.(0)) in
    for i = 1 to pred (Array.length v1) do
      res.(i) <- f v1.(i) v2.(i) v3.(i)
    done;
    res
  end

let array_map_left f a = (* Ocaml does not guarantee Array.map is LR *)
  let l = Array.length a in (* (even if so), then we rewrite it *)
  if l = 0 then [||] else begin
    let r = Array.create l (f a.(0)) in
    for i = 1 to l - 1 do
      r.(i) <- f a.(i)
    done;
    r
  end

let array_map_left_pair f a g b =
  let l = Array.length a in
  if l = 0 then [||],[||] else begin
    let r = Array.create l (f a.(0)) in
    let s = Array.create l (g b.(0)) in
    for i = 1 to l - 1 do
      r.(i) <- f a.(i);
      s.(i) <- g b.(i)
    done;
    r, s
  end

let array_iter2 f v1 v2 =
  let n = Array.length v1 in
  if Array.length v2 <> n then invalid_arg "array_iter2"
  else for i = 0 to n - 1 do f v1.(i) v2.(i) done

let pure_functional = false

let array_fold_map' f v e =
if pure_functional then
  let (l,e) =
    Array.fold_right 
      (fun x (l,e) -> let (y,e) = f x e in (y::l,e))
      v ([],e) in
  (Array.of_list l,e)
else
  let e' = ref e in
  let v' = Array.map (fun x -> let (y,e) = f x !e' in e' := e; y) v in
  (v',!e')

let array_fold_map f e v =
  let e' = ref e in
  let v' = Array.map (fun x -> let (e,y) = f !e' x in e' := e; y) v in
  (!e',v')

let array_fold_map2' f v1 v2 e =
  let e' = ref e in
  let v' = 
    array_map2 (fun x1 x2 -> let (y,e) = f x1 x2 !e' in e' := e; y) v1 v2 
  in
  (v',!e')

let array_distinct v =
  let visited = Hashtbl.create 23 in
  try
    Array.iter
      (fun x ->
        if Hashtbl.mem visited x then raise Exit
        else Hashtbl.add visited x x)
      v;
    true
  with Exit -> false

let array_union_map f a acc =
  Array.fold_left
    (fun x y -> f y x)
    acc
    a

(* Matrices *)

let matrix_transpose mat =
  List.fold_right (List.map2 (fun p c -> p::c)) mat
    (if mat = [] then [] else List.map (fun _ -> []) (List.hd mat))

(* Functions *)

let identity x = x

let compose f g x = f (g x)

let iterate f = 
  let rec iterate_f n x =
    if n <= 0 then x else iterate_f (pred n) (f x)
  in 
  iterate_f

let repeat n f x =
  for i = 1 to n do f x done

let iterate_for a b f x =
  let rec iterate i v = if i > b then v else iterate (succ i) (f i v) in
  iterate a x
 
(* Misc *)

type ('a,'b) union = Inl of 'a | Inr of 'b

module Intset = Set.Make(struct type t = int let compare = compare end)

module Intmap = Map.Make(struct type t = int let compare = compare end)

let intmap_in_dom x m =
  try let _ = Intmap.find x m in true with Not_found -> false

let intmap_to_list m = Intmap.fold (fun n v l -> (n,v)::l) m []

let intmap_inv m b = Intmap.fold (fun n v l -> if v = b then n::l else l) m []

let interval n m = 
  let rec interval_n (l,m) =
    if n > m then l else interval_n (m::l,pred m)
  in 
  interval_n ([],m)


let map_succeed f = 
  let rec map_f = function 
    | [] -> []
    |  h::t -> try (let x = f h in x :: map_f t) with Failure _ -> map_f t
  in 
  map_f 

(* Pretty-printing *)
  
let pr_spc = spc
let pr_fnl = fnl
let pr_int = int
let pr_str = str
let pr_coma () = str "," ++ spc ()
let pr_semicolon () = str ";" ++ spc ()
let pr_bar () = str "|" ++ spc ()
let pr_arg pr x = spc () ++ pr x
let pr_opt pr = function None -> mt () | Some x -> pr_arg pr x
let pr_opt_no_spc pr = function None -> mt () | Some x -> pr x

let nth n = str (ordinal n)

(* [prlist pr [a ; ... ; c]] outputs [pr a ++ ... ++ pr c] *)

let rec prlist elem l = match l with 
  | []   -> mt ()
  | h::t -> Stream.lapp (fun () -> elem h) (prlist elem t)

(* unlike all other functions below, [prlist] works lazily.
   if a strict behavior is needed, use [prlist_strict] instead.
   evaluation is done from left to right. *)

let rec prlist_strict elem l = match l with 
  | []   -> mt ()
  | h::t ->
      let e = elem h in let r = prlist_strict elem t in e++r

(* [prlist_with_sep sep pr [a ; ... ; c]] outputs
   [pr a ++ sep() ++ ... ++ sep() ++ pr c] *)

let rec prlist_with_sep sep elem l = match l with
  | []   -> mt ()
  | [h]  -> elem h
  | h::t ->
      let e = elem h and s = sep() and r = prlist_with_sep sep elem t in
      e ++ s ++ r

(* Print sequence of objects separated by space (unless an element is empty) *)

let rec pr_sequence elem = function
  | []   -> mt ()
  | [h]  -> elem h
  | h::t ->
      let e = elem h and r = pr_sequence elem t in
      if e = mt () then r else e ++ spc () ++ r

(* [pr_enum pr [a ; b ; ... ; c]] outputs 
   [pr a ++ str "," ++ pr b ++ str "," ++ ... ++ str "and" ++ pr c] *)

let pr_enum pr l =
  let c,l' = list_sep_last l in
  prlist_with_sep pr_coma pr l' ++
  (if l'<>[] then str " and" ++ spc () else mt()) ++ pr c

let pr_vertical_list pr = function
  | [] -> str "none" ++ fnl ()
  | l -> fnl () ++ str "  " ++ hov 0 (prlist_with_sep pr_fnl pr l) ++ fnl ()
      
let prvecti elem v =
  let n = Array.length v in
  let rec pr i =
    if i = 0 then 
      elem 0 v.(0)
    else
      let r = pr (i-1) and e = elem i v.(i) in r ++ e
  in
  if n = 0 then mt () else pr (n - 1)

(* [prvect_with_sep sep pr [|a ; ... ; c|]] outputs
   [pr a ++ sep() ++ ... ++ sep() ++ pr c] *)

let prvect_with_sep sep elem v =
  let rec pr n =
    if n = 0 then 
      elem v.(0)
    else 
      let r = pr (n-1) and s = sep() and e = elem v.(n) in 
      r ++ s ++ e
      in
  let n = Array.length v in
  if n = 0 then mt () else pr (n - 1)

(* [prvect pr [|a ; ... ; c|]] outputs [pr a ++ ... ++ pr c] *)

let prvect elem v = prvect_with_sep mt elem v

let pr_located pr (loc,x) =
  if Flags.do_beautify() && loc<>dummy_loc then
    let (b,e) = unloc loc in
    comment b ++ pr x ++ comment e
  else pr x

let surround p = hov 1 (str"(" ++ p ++ str")")

(*s Memoization *)

let memo1_eq eq f =
  let m = ref None in
  fun x ->
    match !m with
        Some(x',y') when eq x x' -> y'
      | _ -> let y = f x in m := Some(x,y); y

let memo1_1 f = memo1_eq (==) f
let memo1_2 f =
  let f' =
    memo1_eq (fun (x,y) (x',y') -> x==x' && y==y') (fun (x,y) -> f x y) in
  (fun x y -> f'(x,y))

(* Memorizes the last n distinct calls to f. Since there is no hash,
   Efficient only for small n. *)
let memon_eq eq n f =
  let cache = ref [] in (* the cache: a stack *)
  let m = ref 0 in      (* usage of the cache *)
  let rec find x = function
    | (x',y')::l when eq x x' -> y', l (* cell is moved to the top *)
    | [] -> (* we assume n>0, so creating one memo cell is OK *)
        incr m; (f x, [])
    | [_] when !m>=n -> f x,[] (* cache is full: dispose of last cell *)
    | p::l (* not(eq x (fst p)) *) -> let (y,l') = find x l in (y, p::l')
  in
  (fun x ->
    let (y,l) = find x !cache in
    cache := (x,y)::l;
    y)


(*s Size of ocaml values. *)

module Size = struct
  
  open Obj

  (*s Pointers already visited are stored in a hash-table, where
      comparisons are done using physical equality. *)

  module H = Hashtbl.Make(
    struct 
      type t = Obj.t 
      let equal = (==) 
      let hash o = Hashtbl.hash (magic o : int)
    end)
	       
  let node_table = (H.create 257 : unit H.t)
		     
  let in_table o = try H.find node_table o; true with Not_found -> false
      
  let add_in_table o = H.add node_table o ()
			 
  let reset_table () = H.clear node_table
			 
  (*s Objects are traversed recursively, as soon as their tags are less than
      [no_scan_tag]. [count] records the numbers of words already visited. *)

  let size_of_double = size (repr 1.0)
			 
  let count = ref 0
		
  let rec traverse t =
    if not (in_table t) then begin
      add_in_table t;
      if is_block t then begin
	let n = size t in
	let tag = tag t in
	if tag < no_scan_tag then begin
	  count := !count + 1 + n;
	  for i = 0 to n - 1 do
      	    let f = field t i in 
	    if is_block f then traverse f
	  done
	end else if tag = string_tag then
	  count := !count + 1 + n 
	else if tag = double_tag then
	  count := !count + size_of_double
	else if tag = double_array_tag then
	  count := !count + 1 + size_of_double * n 
	else
	  incr count
      end
    end
      
  (*s Sizes of objects in words and in bytes. The size in bytes is computed
      system-independently according to [Sys.word_size]. *)

  let size_w o =
    reset_table ();
    count := 0;
    traverse (repr o);
    !count

  let size_b o = (size_w o) * (Sys.word_size / 8)

  let size_kb o = (size_w o) / (8192 / Sys.word_size)

end

let size_w = Size.size_w
let size_b = Size.size_b
let size_kb = Size.size_kb

(*s Total size of the allocated ocaml heap. *)

let heap_size () =
  let stat = Gc.stat ()
  and control = Gc.get () in
  let max_words_total = stat.Gc.heap_words + control.Gc.minor_heap_size in
  (max_words_total * (Sys.word_size / 8))

let heap_size_kb () = (heap_size () + 1023) / 1024

(*s interruption *)

let interrupt = ref false
let check_for_interrupt () = 
  if !interrupt then begin interrupt := false; raise Sys.Break end